U.S. patent application number 10/920239 was filed with the patent office on 2005-01-27 for process for producing optically active-4-halo-3-hydroxybutanoate.
This patent application is currently assigned to Sumitomo Chemical Company, Limited. Invention is credited to Asako, Hiroyuki, Itoh, Nobuya, Matsumura, Kenji, Shimizu, Masatoshi, Wakita, Ryuhei.
Application Number | 20050019816 10/920239 |
Document ID | / |
Family ID | 27481854 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050019816 |
Kind Code |
A1 |
Asako, Hiroyuki ; et
al. |
January 27, 2005 |
Process for producing optically
active-4-halo-3-hydroxybutanoate
Abstract
There are provided a polynucleotide sequence coding for an amino
acid sequence capable of preferentially producing
(S)-4-bromo-3-hydroxybutanoa- te by asymmetrically reducing
4-bromo-3-oxobutanoate, A DNA construct having a promoter in
operative linkage with the polynucleotide sequence, a recombinant
vector containing the polynucleotide sequence, a transformant, a
recombinant vector and the like.
Inventors: |
Asako, Hiroyuki; (Osaka,
JP) ; Matsumura, Kenji; (Osaka, JP) ; Shimizu,
Masatoshi; (Osaka, JP) ; Itoh, Nobuya;
(Toyama-shi, JP) ; Wakita, Ryuhei; (Osaka,
JP) |
Correspondence
Address: |
FITCH, EVEN, TABIN & FLANNERY
P. O. BOX 65973
WASHINGTON
DC
20035
US
|
Assignee: |
Sumitomo Chemical Company,
Limited
Osaka
JP
|
Family ID: |
27481854 |
Appl. No.: |
10/920239 |
Filed: |
August 18, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10920239 |
Aug 18, 2004 |
|
|
|
10004115 |
Dec 6, 2001 |
|
|
|
Current U.S.
Class: |
435/6.12 ;
435/135; 435/197; 435/252.3; 435/320.1; 435/488; 435/69.1;
536/23.2 |
Current CPC
Class: |
C12P 7/62 20130101; C12P
13/002 20130101; C12N 9/0006 20130101; C12P 7/42 20130101 |
Class at
Publication: |
435/006 ;
435/135; 435/069.1; 435/197; 435/252.3; 435/320.1; 435/488;
536/023.2 |
International
Class: |
C12Q 001/68; C07H
021/04; C12P 007/62; C12N 009/18; C12N 015/74 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 7, 2000 |
JP |
2000-372704 |
Jan 15, 2001 |
JP |
2001-006144 |
Feb 2, 2001 |
JP |
2001-026594 |
Jun 11, 2001 |
JP |
2001-175175 |
Claims
1. An isolated polynucleotide sequence having: a) a polynucleotide
sequence coding for an amino acid sequence represented by SEQ ID
NO: 1; b) a polynucleotide sequence that hybridizes with a
polynucleotide sequence coding for an amino acid sequence
represented by SEQ ID NO: 1 to form a hybrid, under stringent
conditions, the amino acid sequence being an amino acid sequence of
an enzyme capable of preferentially producing
(S)-4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanotate; c) a polynucleotide sequence represented
by SEQ ID NO: 2, d) a polynucleotide coding for an amino acid
sequence of SEQ ID NO: 1 having additional 6 amino acids of
Trp-Ile-Ser-Thr-Lys-Leu (SEQ ID NO:37) at the C-terminal of the
amino acid sequence; e) a polynucleotide sequence having 80% or
more sequence identity with the polynucleotide sequence coding for
an amino acid sequence of SEQ ID NO: 1, or f) a polynucleotide
sequence that hybridizes with a polynucleotide sequence coding for
an amino acid sequence represented by SEQ ID NO: 1 to form a hybrid
under high ion concentrations of 450 to 900 mM sodium chloride and
45 to 90 mM sodium citrate at 65.degree. C. and the hybride formed
is maintained as a hybrid after being kept at 65.degree. C. for 30
minutes under a low ion concentration of 15 to 300 mM sodium
chloride and 1.5 to 30 mM sodium citrate and 0.1 to 1.0 wt % of
SDS, the amino acid sequence being an amino acid sequence of an
enzyme capable of preferentially producing
(S)-4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate.
2. canceled
3. canceled
4. canceled
5. canceled
6. canceled
7. canceled
8. canceled
9. A recombinant vector containing A) a polynucleotide construct as
defined in claim 1, and B) a polynucleotide coding for an enzyme
capable of converting oxidized .beta.-nicotinamide-adenine
dinucleotide phosphate into a reduced form, wherein the enzyme is
glucose dehydrogenase.
10. (canceled).
11. A transformant having the vector according to claim 9.
12. A transformant according to claim 11, wherein the host is a
microorganism.
13. A transformant according to claim 12, wherein the microorganism
is E. coli.
14. canceled
15. A protein having: i) an amino acid sequence of SEQ ID NO: 1;
ii) an amino acid sequence encoded by a polynucleotide sequence
that hybridizes under stringent conditions with a polynucleotide
sequence of SEQ ID NO: 2 coding for an amino acid sequence of a
protein capable of preferentally producing
(S)-4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate; or iii) an amino acid sequence of SEQ ID
NO: 1, wherein one or more amino acids are deleted, replaced or
added, said amino acid sequence being an amino acid sequence of a
protein capable of preferentially producing
(S)-4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate.
16. A process for producing (S)-4-halo-3-hydroxybutanoate, which
comprises reacting 4-halo-3-oxobutanoic acid ester with the protein
as defined in claim 15, a transformant, which produces said protein
or a treated product thereof.
17. A process according to claim 16, which comprises allowing the
coexistence of an enzyme capable of converting the oxdized
.beta.-nicotinamide-adenine dinucleotide phosphate into a reduced
form.
18. A process according to claim 17, wherein the enzyme capable of
converting an oxidized .beta.-nicotinamide-adenine dinucleotide
phosphate into a reduced form is a glucose dehydrogenase.
19. A process according to claim 17, wherein the
4-halo-3-oxobutanoic acid ester is contacted with the transformant
as defined in any one of claims 11 to 14 or a treated product
thereof.
20. A process according to claim 16, 17, 18 or 19, wherein the
4-halo-3-oxobutanoic acid ester is represented by a formula (1):
7wherein R.sub.1 represents an alkyl group, and R.sub.2 represents
a methyl group which is substituted with a halogen atom, which
process comprises reacting 4-halo-3-oxobutanoic acid ester of
formula (2): 8wherein R.sub.1 and R.sub.2 represent the same as
defined above.
21. A process for producing an optically active 3-hydroxybutanoic
acid ester of formula (1a): 9wherein R.sub.1 represents an alkyl
group, and R.sub.20 represents a methyl group which may be
substituted with a halogen atom, which process comprises reacting
3-oxobutanoic acid ester of formula (2a): 10wherein R.sub.1 and
R.sub.20 represent the same as defined above, with whole cells of a
microorganism or a treated product thereof, which microorganism
belongs to Penicillium citrinum, Cryptcoccus humicolus, or Bacillus
alvei and is capable of asymmetrically reducing the oxo group at
3-position of the compound of formula (2a) to corresponding
3-hydroxy group.
22. A process according to claim 21, wherein R.sub.2 represents a
halomethyl group.
23. A process according to claim 21 or 22, wherein the
microorganism is a strain selected from the group of Penicillium
citrinum (IFO4631), Cryptcoccus humicolus (IFO1527), and Bacillus
alvei (IFO3343t).
24. A process for producing an optically active
4-bromo-3-hydroxybutanoate of formula (1b): 11wherein R.sub.1
represents a (C2-C8) alkyl group, which process comprises reacting
4-bromo-3-oxobutanoate of formula (2b): 12wherein R.sub.1
represents the same as defined above, with an enzyme having: iv) an
amino acid sequence of SEQ ID NO: 34; v) an amino acid sequence
encoded by a polynucleotide sequence that hybridizes, under
stringent conditions, with a polynucleotide sequence of SEQ ID NO:
34, wherein said amino acid sequence is an amino acid sequence of a
protein capable of preferentially producing optically active
4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate; and vi) an amino acid sequence of SEQ ID
NO: 3, wherein one or more amino acids are deleted, replaced or
added, said amino acid sequence being an amino acid sequence of a
protein capable of preferentially producing optically active
4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxbutanoate.
25. A process for producing 4-cyano-3-hydroxybutanoic acid, which
comprises reacting 4-bromo-3-hydroxybtanoic acid ester with a metal
cyanide in the presence of an alkaline earth metal hydroxide and an
alkaline earth metal halogenide.
26. A process according to claim 25, which further comprises the
step of reacting the 4-cyano-3-hydroxybutanoic acid with dialkyl
sulfate to produce 4-cyano-3-hydroxybutanoic acid alkyl ester.
27. A process according to claim 25 or 26, wherein the alkaline
earth metal hydroxide is calcium hydroxide, and the alkaline earth
metal halogenide is calcium chloride.
28. A process according to claim 25, wherein the
4-bromo-3-hydroxybutanoic acid ester is (C1-C8) alkyl
4-bromo-3-hydroxybutanoate, and the dialkyl sulfate is dimethyl or
diethyl sulfate.
29. A process according to claim 25 or 26, wherein the
4-bromo-3-hydroxybutanoic acid and hydroxybutanoic acid are
optically active compounds.
30. A process according to claim 25 or 26, wherein
4-bromo-3-hydroxybutano- ic acid is (S)-4-bromo-3-hydroxybutanoic
acid ester and 4-cyano-3-hydroxybutanoic acid is
(R)-4-cyano-3-hydroxybutanoic acid.
31. A process for producing (R)-4-cyano-3-hydroxybutanoic acid,
which comrpises producing (S)-4-bromo-3-hydroxybutanoic acid ester
by asymmetrically reducing the 4-bromo-3-oxobutanoic acid ester,
and reacting (S)-4-bromo-3-hydroxybutanoic acid ester with a metal
cyanide in the presence of an alkaline earth metal hydroxide and an
alkaline earth metal halogenide.
32. A process according to claim 31, wherein the asymmetrical
reduction is conducted by a microorganism or treated product
thereof capable of asymmetrically reducing the
4-bromo-3-oxobutanoic acid ester to (S)-4-bromo-3-hydroxybutanoic
acid ester.
33. A process according to claim 32, wherein the microorganism is a
microorganism belong to Penicillium citrinum.
34. A process according to claim 31, 32 or 33, wherein
(S)-4-bromo-3-hydroxybutanoic acid ester and 4-bromo-3-oxobutanoic
acid ester are (C1-C8) alkyl ester.
35. A process according to claim 33, wherein the microorganism is a
strain Penicillium citrinum (IFO 4631).
36. A process according to any one of claims 31 to 35, wherein the
alkaline earth metal hydroxide is calcium hydroxide and the
alkaline earth halogenide is calcium chloride.
37. A process according to claim 31, which further comprises the
step of reacting (R)-4-cyano-3-hydroxybutanoic acid with dialkyl
sulfate to produce (R)-4-cyano-3-hydroxybutanoic acid alkyl
ester.
38. A process according to claim 32, wherein the alkyl group of the
dialkyl sulfate is a methyl or ethyl group.
Description
BACKGROUND OF THE INVENTION
[0001] Optically active 4-halo-3-hydroxy butanoate and related
compounds are known as a useful intermediate compounds for the
production of pharmaceuticals and agrochemicals.
[0002] Various methods for optically active
4-halo-3-hydroxybutanoate and compounds derivatized therefrom have
been known so far, however, these methods are not always
satisfactory in yield or industrial applicability.
SUMMARY OF THE INVENTION
[0003] According to the present invention, optically active
4-halo-3-hydroxy butanoate and related compounds can be readily
obtained in an industrially desirable manner.
[0004] The present invention provides:
[0005] 1. a polynucleotide sequence having:
[0006] a) a polynucleotide sequence coding for an amino acid
sequence of SEQ ID NO: 1;
[0007] b) a polynucleotide sequence that hybridizes, under
stringent conditions, with a polynucleotide sequence coding for an
amino acid sequence of SEQ ID NO: 1, the amino acid sequence being
an amino acid sequence of a protein capable of preferentially
producing (S)-4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate; or
[0008] c) a polynucleotide sequence of SEQ ID NO: 2 (hereinafter
referred to as "the present gene or the present
polynucleotide";
[0009] 2. a protein having:
[0010] i) an amino acid sequence of SEQ ID NO: 1;
[0011] ii) an amino acid sequence encoded by a polynucleotide
sequence that hybridizes under stringent conditions with a
polynucleotide sequence of SEQ ID NO: 2 coding for an amino acid
sequence of a protein capable of preferentially producing
(S)-4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate; or
[0012] iii) an amino acid sequence of SEQ ID NO: 1, wherein one or
more amino acids are deleted, replaced or added, said amino acid
sequence being an amino acid sequence of a protein capable of
preferentially producing (S)-4-bromo-3-hydroxybutanoate by
asymmetrically reducing 4-bromo-3-oxobutanoate (hereinafter
referred to as "the present protein or enzyme");
[0013] 3. a process for producing (S)-4-halo-3-hydroxybutanoate,
which comprises reacting 4-halo-3-oxobutanoic acid ester with the
protein as defined above, a transformant, which produces the
protein or a treated product thereof;
[0014] 4. a process for producing an optically active
3-hydroxybutanoate of formula (1a): 1
[0015] wherein R.sub.1 represents an alkyl group, and R.sub.20
represents a methyl group which may be substituted with a halogen
atom, which process comprises reacting 3-oxobutanoate of formula
(2a): 2
[0016] wherein R.sub.1 and R.sub.20 represent the same as defined
above, with a whole cells of a microorganism or a treated product
thereof, which microorganism belongs to Penicillium citrinum,
Cryptcoccus humicolus, or Bacillus alvei and is capable of
asymmetrically reducing the oxo group at 3-position of the compound
of formula (2a) to corresponding 3-hydroxy group;
[0017] 5. a process for producing an optically active
4-bromo-3-hydroxybutanoate of formula (1b): 3
[0018] wherein R.sub.1 represents a (C2-C8)alkyl group, which
process comprises reacting 4-bromo-3-oxobutanoate of formula (2b):
4
[0019] wherein R.sub.1 represents the same as defined above, with
an enzyme having:
[0020] iv) an amino acid sequence of SEQ ID NO: 34;
[0021] v) an amino acid sequence encoded by a polynucleotide
sequence that hybridizes, under stringent conditions, with a
polynucleotide sequence of SEQ ID NO: 35, wherein the amino acid
sequence is an amino acid sequence of a protein capable of
preferentially producing optically active
4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate; and
[0022] vi) an amino acid sequence of SEQ ID NO: 34, wherein one or
more amino acids are deleted, replaced or added, said amino acid
sequence being an amino acid sequence of a protein capable of
preferentially producing optically active
4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate (hereinafter referred to as "the instant
enzyme"); and
[0023] 6. A process for producing 4-cyano-3-hydroxybutanoic acid,
which comprises reacting 4-bromo-3-hydroxybutanoic acid ester with
a metal cyanide in the presence of an alkaline earth metal
-hydroxide and an alkaline earth metal halogenide.
DETAILED DESCRIPTION OF THE INVENTION
[0024] First, a description will be made to the first aspect of the
present invention drawn to the present gene. The present gene may
be a wild-type gene or an artificially produced gene by introducing
a mutation through site-specific mutation introduction method
and/or a mutagenic treatment as described below into the wild
type-gene. The wild-type gene can be found out and obtained among
microorganisms capable of preferentially producing
(S)-4-bromo-3-hydroxybutanoate ester by asymmetrically reducing
4-bromo-3-oxo-butanoate ester. Examples of the miroorganism
include, for example, microorganisms belonging to the genus
Penicillium such as Penicillium citrinum.
[0025] Examples of the present gene include, for example,
polynucleotides shown above in a) to c) and the like.
[0026] The stringent conditions in b) above include conditions that
are referred to in a Southern hybridization method as described,
for example, in the "Cloning and Sequence" (supervised by K.
Watanabe, edited by M. Sugiura and published from Noson Bunkasha
Co., Ltd. in 1989). More specifically, examples of the
polynucleotide include, for example, a polynucleotide that is
defined by the following conditions: (1) the polynucleotide
hybridizes with a polynucleotide coding for the amino acid sequence
of SEQ ID NO: 1 to form a hybrid with the polynucleotide coding for
the amino acid sequence of SEQ ID NO: 1 under high ion
concentration conditions (e.g., 6.times.SSC (900 mM sodium
chloride, 90 mM sodium citrate) at 65.degree. C., and (2) the
polynucleotide hybrid formed is maintained as a hybrid after being
kept at 65.degree. C. for 30 minutes under a low ion concentration
(e. g. 6.times.SSC (15 mM sodium chloride and 1.5 mM of sodium
citrate).
[0027] Examples of the present gene also includes, for example,
[0028] (d) a polynucleotide coding for an amino acid sequence of
SEQ ID NO: 1 in which a part of the nucleotides is deleted,
substituted or added; and
[0029] (e) a polynucleotide sequence having 80% or more sequence
identity with the polynucleotide sequence coding for an amino acid
sequence of SEQ ID NO: 1; and the like.
[0030] These polynucleotide sequences may be a polynucleotide
obtained by cloning from the wild-type gene or may be a
polynucleotide obtained from the cloned gene or a recombinant gene
therefrom by artificially introducing partial deletion,
substitution or addition of nucleotide(s) in the polynucleotide
sequence coding for the amino acid sequence of SEQ ID NO: 1.
Specific examples thereof include, for example, a polynucleotide
sequence of SEQ ID NO: 2, and a polynucleotide sequence of SEQ ID
NO: 28, and the like.
[0031] The polynucleotides a) to d) as defined above of the present
invention can be prepared, for example, by preparing a cDNA library
and conducting PCR (polymerase chain reaction) using the cDNA as a
template and a suitable primer. The cDNA library can be prepared,
for example, from microorganisms belonging to the genus Penicillium
such as Penicillium citrinum according to genetic engineering
methods (e.g. "A new cell engineering experiment protocol" (edited
by the Cancer Research Unit, Medical Science Research Laboratory,
the University of Tokyo, Shujinsha, Co., Ltd., 1993).
[0032] The polynucleotide sequence of SEQ ID NO: 28 can be
amplified by carrying out PCR using the aforementioned cDNA library
as a template and using an oligonucleotide sequence of SEQ ID NO:
23 and an oligonucleotide sequence of SEQ ID NO: 24 as primers.
[0033] Examples of the PCR conditions include, for example, a
reaction condition in which a reaction mixture containing four
types of dNTP, each of which are added so that the final
concentration thereof in the mixture is 20 .mu.M, 15 pmol of two
types of oligonucleotide as primers, 1.3 U of Taqpolymerase and the
cDNA library as a template is heated at 97.degree. C. (for 2
minutes), 10 times of a cycle of reacting at 97.degree. C. (for
0.25 minutes), 50.degree. C. (for 0.5 minutes) and 72.degree. C.
(for 1.5 minutes), 20 times of a cycle of reacting at 97.degree. C.
(for 0.25 minutes), 55.degree. C. (for 0.5 minutes) and 72.degree.
C. (for 2.5 minutes), and at 72.degree. C. for 7 minutes.
[0034] A recognition sequence for a restriction enzyme may be added
to the 5' terminal of the primer used for the PCR.
[0035] The present gene can also be prepared by PCR using the cDNA
described above as a template and using, as primers, an
oligonucleotide selected from a partial sequence of the
polynucleotide sequence coding for the amino acid sequence of SEQ
ID NO: 1 (e.g. an oligonucleotide comprising about 14 or more
nucleotides at the 5' terminal of the polynucleotide sequence
coding for the amino acid sequence of SEQ ID NO:1) and an
oligonucleotide comprising about 14 or more nucleotides complement
to a nucleotide sequence at the vicinity of DNA inserting site of
the vector used for constructing the cDNA.
[0036] Cloning of the amplified polynucelotide into a vector can
provide a recombinant vector suitably used for the present
invention according to methods as disclosed in "Molecular Cloning:
A Laboratory Manual 2nd edition" (1989), Cold Spring Harbor
Laboratory Press, "Current Protocols in Molecular Biology" (1987),
John Wiley & Sons, Inc. ISBN 0-471-50338-X, etc. Examples of
the vector that may be used include, for example, pUC119 (Takara
Shuzo Co., Ltd.), pTV118N (Takara Shuzo Co., Ltd.), pBluescriptII
(Toyobo Co., Ltd.), pCR2.1-TOPO.TM. (Invitrogen Co., Ltd.), pTrc99A
(Pharmacia) and pKK223-3 (Pharmacia).
[0037] Alternatively, the present gene can be obtained by
hybdridizing a nucleotide sequence comprising about 15 or more
nucleotides selected from the nucleotide sequence coding for the
amino acid sequence of SEQ ID NO:1, as a probe, with the cDNA
inserted into a vector derived from a microorganism or a phage,
thereby detecting the desired DNA which specifically binds to the
probe, under a hybridization conditions described below.
[0038] Colony hybridization or plaque hybridization can be employed
as a method for hybridizing a probe with a chromosomal DNA or cDNA
library, and can be selected in accordance with the type of the
vector used for preparation of the library.
[0039] Colony hybridization is preferably used together with the
library prepared from a plasmid vector. For example, the library
DNA is introduced into a host microorganism to produce a
transformant, and the transformant is diluted, the diluted product
is inoculated on an agar plate, and incubated until a colony
appears.
[0040] Plaque hybridization is preferably used together with the
library DNA prepared from a phage vector. For example, a host
microorganism is mixed with the phage having the library, the
resulting mixture is mixed with a soft cultivation agar medium
under suitable conditions for infection, the mixture is then placed
on an agar plate and incubated until formation of a plaque is
confirmed.
[0041] A membrane is placed on the surfaces of the cultivation agar
medium obtained by the hybridization methods as described above,
thereby the transformant or the phage is adsorbed onto the membrane
to give a transcribed membrane. After this membrane is subjected to
alkaline treatment, it is neutralized and the DNA is then
immobilized on the membrane. More specifically, in the case of
plaque hybridization, nitro cellulose membrane or nylon membrane
(e.g. Hybond-N.sup.+ (registered trademark of Amasham Inc.)) is
placed on the aforementioned cultivation agar medium and is left
standing for about one minute so that the phage particle is
adsorbed by the membrane. Then, the membrane is immersed in alkali
solution (e.g. 1.5 M sodium chloride and 0.5M sodium hydroxide) for
about three minutes until the phage particle is dissolved. After
the phage DNA is eluted onto the membrane, it is immersed in a
neutralization solution (e.g. 1.5 M sodium chloride and 0.5 M
tris-hydrochloric acid buffer solution at pH 7.5) for about five
minutes. Then, the membrane is washed with a solution (e.g. 0.3 M
sodium chloride, 30 mM citric acid, 0.2 M tris-hydrochloric acid
buffer solution at pH 7.5) for five minutes. Thereafter, it is
heated at about 80.degree. C. for about 90 minutes until the phage
DNA is immobilized on the membrane.
[0042] Using the membrane prepared in the aforementioned steps,
hybridization is performed with the DNA as a probe. Hybridization
can be carried out according to the method disclosed, for example,
in "Molecular Cloning: A Laboratory Manual 2nd edition (1989)" by
J. Sambrook, E. F Frisch and T. Maniatis, Cold Spring Harbor
Laboratory Press.
[0043] The DNA used as a probe can be labeled with either
radioactive isotope or fluorophore. The probe DNA may be labeled,
for example, by conducting PCR in which the dCTP in PCR reaction
solution is replaced with (.alpha.-32P) dCTP using the Random
Primer Labeling Kit (Takara Shuzo Co., Ltd.) and the probe DNA is
used as a template. The labeling of the probe DNA with the
fluorophore can be accomplished, for example, by ECL Direct Nucleic
Acid Labeling and Detection System produced by Amasham, and the
like.
[0044] For example, hybridization can be carried out as
follows:
[0045] The membrane prepared in the aforementioned step is immersed
in a pre-hybridization solution containing sodium chloride at a
concentration of 450 to 900 mM and sodium citrate at a
concentration of 45 to 90 mM, sodium dodecyl sulfate (SDS) at a
concentration of 0.1 to 1.0 wt %, denatured nonspecific DNA at a
concentration of 0 to 200 .mu.l/ml, (a preferred pre-hybridization
solution contains 900 mM sodium chloride, 90 mM sodium citrate,
1.0% SDS and 100 .mu.l/ml of modified calf-thymus DNA), and
optionally albumin, Ficoll and polyvinyl pyrrolidone each at a
concentration of 0 to 0.2 wt %, wherein the amount of the solution
is 50 to 200 .mu.l per 1 cm.sup.2 of the membrane, and maintained
at 42 to 65.degree. C. for one to four hours.
[0046] Then the membrane is immersed in a solution obtained by
mixing the pre-hybridization solution as used above with the probe
prepared in the aforementioned step in such an amount equivalent to
1.0.times.10.sup.4 to 2.0.times.10.sup.6 cpm per 1 cm.sup.2 of
membrane) and maintained at 42 to 65.degree. C. for 12 to 20 hours,
wherein the amount of the solution is 50 to 200 .mu.l per 1
cm.sup.2 of the membrane.
[0047] After the hybridization, the membrane is taken out and is
washed at 42 to 65.degree. C. with a washing solution containing 15
to 300 mM sodium chloride, 1.5 to 30 mM sodium citrate and 0.1 to
1.0 wt % of SDS (a preferred, washing solution contains 15 mM
sodium chloride and 1.5 mM sodium citrate and 1.0% of SDS). The
washed membrane is slightly rinsed with 2.times.SSC (300 mM sodium
chloride 30 mM sodium citrate), and is then dried. This membrane is
applied to the autoradiography, for example, to detect the position
of the probe on the membrane, whereby position of the clone of the
DNA hybrid is located on the original cultivating agar medium, and
the clone containing the desired DNA can be picked up and isolated.
The present gene can be obtained by cultivating the clone thus
obtained.
[0048] The recombinant vector according to the present invention
can be obtained by cloning of the DNA prepared in the
aforementioned step into the vector according to the method
disclosed in "Molecular Cloning: A Laboratory Manual 2nd edition
(1989)", Cold Spring Harbor Laboratory Press, "Current Protocols in
Molecular Biology" (1987), John Wiley & Sons, Inc.
ISBNO-471-50338-X, etc. Examples of the vector include, for
example, pUC119 (Takara Shuzo Co., Ltd.), pTV118N (Takara Shuzo
Co., Ltd.), pBluescriptII (Toyobo Co., Ltd.), pCR2.1-TOPO.TM.
(Invitrogen Co., Ltd.), pTrc99A (Pharmacia) and pKK223-3
(Pharmacia) and the like.
[0049] The aforementioned DNA sequence can be analyzed by the
Dideoxy method described in the Proceeding of Natural Academy of
Science, by F. Sanger, S. Nicklen and A. R. Coulson, U.S.A. (1977)
74: PP. 5463-5467. In order to prepare samples for analysis of the
DNA sequence, it is possible to use the commercially available
reagent such as ABI PRISM Dye Terminator Cycle Sequencing Ready
Reaction Kit of Parkin Elmer Inc. or the like.
[0050] The activity of the enzyme protein, encoded by the obtained
DNA, produced by the transformant can be confirmed by introducing a
vector having a promoter in operative linkage with the obtained DNA
which locates downstream of the promoter as described below to a
microorganism, and allowing the cultivated product of the
transformant to react with 4-bromo-3-oxobutanoate to analyze the
amount of (S)-4-bromo-3-hydroxybuta- noate in the reaction.
[0051] The phrase "a promoter in operative linkage with the DNA"
above means that the linkage with the promoter is made in such a
way that the gene of the present invention will be expressed under
the control of the promoter in a host cell introduced with the gene
to transform the host cell. Examples of the promoter include, for
example, the lactose operon promoter of Escherichia coli,
tryptophan operon promoter of Escherichia coli and synthetic
promoter such as tac promoter or trc promoter which can function in
Escherichia coli. It is also possible to use the promoter
controlling the expression of the present in Penicillium citrinum
per se.
[0052] Generally, the present gene is introduced into the host cell
in a form of a recombinat vector having a promoter in operative
linkage with the DNA. A vector having a selective marker gene (e.
g. antibiotic-resistance conferring gene such as kanamycin
resistant gene and neomycin resistant gene), can also be used,
whereby the transformant having the vector can be selected using
the phenotype of the relevant selective marker gene as an
indicator.
[0053] Examples of the host cell into which the vector as described
above or a DNA construct having a promoter in operative linkage
with the present gene can be introduced include, for example, a
microorganism belonging to Escherichia, Bacillus, Corynebacterium,
Staphylococcus, Streptomyces, Saccharomyces, Kluyveromyces or
Aspergillus.
[0054] A suitable method is selected to produce the transformant in
accordance with the kind of cells used as the host. Examples of
such methods include the calcium chloride method disclosed in
"Molecular Cloning: A Laboratory Manual 2nd edition" (1989), Cold
Spring Harbor Laboratory Press, and "Current Protocols in Molecular
Biology" (1987), John Wiley & Sons, Inc. ISBNO-471-50338-X,
etc., and the electroporation method described in "Method in
Electroporation: Gene Pulser/E. coli Pulser System", Bio-Rad
Laboratories, (1993), etc.
[0055] The present gene contained in the transformant can be
confirmed by verifying the site of the restriction enzyme, analysis
of the polynucleotide sequence, Southern hybridization, Western
hybridization, etc., with respect to the DNA prepared subsequent to
preparation of the vector DNA from the transformant, according to
the normal method given in "Molecular Cloning: A Laboratory Manual
2nd edition" (1989), Cold Spring Harbor Laboratory Press.
[0056] The present protein will be explained below.
[0057] Examples of the amino acid sequence wherein one or more
amino acids are deleted, substituted or added in the amino acid
sequence of SEQ ID No: 1 include, for example, an amino acid
sequence having additional 6-amino acid of Trp-Ile-Ser-Thr-Lys-Leu
at the C-terminal of the amino acid sequence of SEQ ID NO: 1 in
addition to those defined in i) to iii) above.
[0058] The present protein can be produced by cultivating the
transformant containing the present gene.
[0059] Examples of the medium that may be used for cultivating the
transfected host microorganisms include, for example, various
mediums that contains a carbon source or a nitrogen source, an
organic salt, an inorganic salt or the like in suitable
amounts.
[0060] Examples of the carbon source include, for example,
saccharides such as glucose, dextrin and sucrose, sugar alcohol
such as glycerol, organic acid such as fumaric acid, citric acid
and pyruvic acid, animal oil, plant oil and molasses. The amount of
these carbon sources to be applied to the media is normally in the
range of about 0.1 to 30% (w/v) with respect to culture
solution.
[0061] Examples of the nitrogen source include, for example, a
naturally occurring organic nitrogen sources such as meat extract,
peptone, yeast extract, malt extract, pulverized soy bean, Corn
Steep Liquor, cottonseed, dried yeast and casamino acid; ammonium
salt of inorganic acid such as amino acids and sodium nitrate,
ammonium salt of inorganic acid such as ammonium chloride, ammonium
sulfate and ammonium phosphate; ammonium salt of organic acid such
as ammonium fumarate and ammonium citrate; and urea. Of these
substances, an ammonium salt of organic acid, naturally occurring
nitrogen source and amino acid can also be used as carbon sources
in many cases. The amount of these nitrogen sources that may be
applied to the media is normally in the range of about 0.1 to 30%
(w/v) with respect to culture medium.
[0062] Examples of the organic and inorganic salt include, for
example, chloride, sulfate, acetate, carbonate and phosphate of
calcium, sodium, magnesium, iron, manganese, cobalt and zinc.
Specific examples thereof include, for example, sodium chloride,
potassium chloride, magnesium sulfide, ferrous sulfide, manganese
sulfide, cobalt chloride, zinc sulfate, copper sulfate, sodium
acetate, calcium carbonate, monopotassium hydrogenphosphate,
potassium dihydrogenphosphate and the like. The amount of these
organic and/or inorganic salts that may be applied to the media is
normally in the range of about 0.0001 to 5% (w/v) with respect to
culture medium.
[0063] A small amount of isopropyl thio-.beta.-D-galactoside (IPTG)
can be added, as an inducer of the production of the present
protein, to the medium for cultivating the transformant having a
promoter (e.g. tac promoter, trc promoter and lac promoter which
are induced by allolactose) in operative linkage with the gene.
[0064] Cultivation of the transform ant having the present gene can
be conducted by a conventional method used for cultivating a host
cell such as microorganism. For example, it can be done in the
following method: liquid cultivation such as test tube shake
cultivation, reciprocative shaking cultivation, jar fermenter
cultivation and tank cultivation, and solid cultivation.
[0065] Cultivation temperature can be varied within the range where
the microorganism can grow. It is normally within the range of 15
to 40.degree. C. Preferably, the pH value of the medium is set
within the range from about 6 to 8. Cultivation time varies
according to the cultivation conditions, and normally from about
one to five days are preferred.
[0066] The present protein can be purified by a suitable
purification method that may be usually applied to purify a
protein. Examples thereof include following methods. Cells are
collected by subjecting cultivated products of the transformant to
centrifugation of the cultivation and collected cells are disrupted
by physical disrupting such as ultrasonic treatment and French
pressing, or chemical disrupting method using such a lytic enzyme
as lysozyme. Impurities are removed from the obtained disrupted
solution by centrifugation and membrane filter whereby cell-free
extract is prepared. The extract is fractionated by a suitable
separation and refining method such as cation exchange column
chromatography, anion ion exchange column chromatography,
hydrophobic column chromatography and gel column chromatography,
whereby the present protein can be purified.
[0067] Examples of the support that may be used for the
chromatography include, for example, a cellulose introduced with a
carboxy methyl (CM) group, a diethyl amino ethyl (DEAE) group, a
phenyl group or a butyl group, and a insoluble polymer support such
as dextrin, agarose or the like. A commercially available columns
charged with support can be used. Examples of the column available
on the market include, for example, Q-Sepharose FF,
Phenyl-Sepharose HP (trade names by Amasham Pharmacia Biotech) and
TSK-gel G3000SW (trade name by Toso Co., Ltd.).
[0068] The fraction including the present protein can be selected,
for example, by testing the capability of preferentially producing
(S)-4-bromo-3-hydroxybutanoate by asymmetrically reducing
4-bromo-3-oxobutanoate.
[0069] Next, a description will be made to the method for producing
(S)-4-halo-3-hydroxybutanoate of formula (1): 5
[0070] wherein R.sub.1 represents an alkyl group, and R.sub.2
represents a methyl group which is substituted with a halogen atom,
which process comprises reacting 4-halo-3-oxobutanoate of formula
(2): 6
[0071] wherein R.sub.1 and R.sub.2 represent the same as defined
above with the present enzyme, a transformant which produces the
enzyme, or a treated product thereof.
[0072] In the formula (1) and (2), R.sub.1 denotes C1-C8 alkyl
groups, and R.sub.2 denotes methyl group substituted with a halogen
atom or atoms.
[0073] Examples of the C1-C8 alkyl group represented by R.sub.1
include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl,
pentyl, hexyl, heptyl, and octyl groups.
[0074] Examples of a methyl group which is substituted with a
halogen atom or atoms (e.g, fluorine, chroline, bromine, or iodine)
represented by R.sub.2 include, for example, monofluoromethyl,
monochloromethyl, monobromomethyl, difluoromethyl, dichloromethyl,
dibromomethyl, trifluoromethyl, and trichloromethyl groups.
[0075] Specific examples thereof include, for example,
4-halo-3-oxobutanoate ester include methyl 4-chloro-3-oxobutanoate,
ethyl 4-chloro-3-oxobutanoate, propyl 4-chloro-3-oxobutanoate,
methyl 4-bromo-3-oxobutanoate, ethyl 4-bromo-3-oxobutanoate, propyl
4-bromo-3-oxobutanoate, and octyl 4-bromo-3-oxobutanoate.
[0076] The production is usually carried out in the presence of
water and reduced form nicotine amide adenine dinucleotide
phosphate (hereinafter referred to as "NADPH"). Water used in this
case may be an aqueous buffer solution. Examples of buffer agent
that may be used for this aqueous buffer solution include, for
example, an alkali phosphate metal salt such as sodium phosphate
and potassium phosphate, alkali acetate metal salt such as sodium
acetate aqueous solution and potassium acetate, and mixtures
thereof.
[0077] The reaction may be conducted in the co-presence of an
organic solvent. Examples of the organic solvent include, for
example, an ether such as t-butyl methyl ether, diisopropyl ether,
tetrahydrofuran or the like; an ester such as ethyl formate, ethyl
acetate, propyl acetate, butyl acetate, ethyl propionate, butyl
propionate or the like; a hydrocarbon such as toluene, hexane,
cyclohexane, heptane, isooctane or the like; an alcohol such as
methanol, ethanol, 2-propanol, butanol, t-butyl alcohol or the
like; an organic sulfur compound such as dimethylsulfoxide or the
like; a ketone such as acetone or the like; a nitrile such as
acetonitrile or the like; and mixtures thereof.
[0078] The reacting of 4-halo-3-oxobutanoic acid ester of formula
(2) with the present enzyme, a transformant which produces the
enzyme, or a treated product thereof is usually conducted by
stirring, shaking or mixing water, NADPH and 4-halo-3-oxobutanoate
ester together with transformant or the treated substance,
optionally in the presence of the organic solvent.
[0079] The pH of the reaction can be suitably set, normally within
a range of 3 to 10. Reaction temperature is normally within the
range of 0 to 60.degree. C. in view of the stability of the
4-halo-3-oxobutanoate ester and a product thereof and reaction
velocity.
[0080] Progress of the reaction can be monitered by, for example,
tracing 4-halo-3-oxobutanoate ester in the reaction solution by
means of high performance liquid chromatography or the like. The
reaction time is usually in the range of 05 hour to 10 days.
[0081] After completion of the reaction,
(S)-4-halo-3-hydroxybutanoate can be separated and recovered from
the reaction mixture by a suitable methods. For example, the
reaction mixture is subjected to post-treatment such as extraction,
concentration of organic solvent, or a optional combination
thereof, and the product may be further purified by column
chromatography and distillation, if necessary.
[0082] The present protein, the transformant which produces the
same or the treated product thereof can be used in various forms in
the reaction. Examples of the applicable form thereof include, for
example, the cultivated product of the transformant containing the
present gene, the transformant cell containing the present gene;
the treated product of thereof cell-free extract; a crude purified
protein; a purified protein; and the immobilized product
thereof.
[0083] Examples of the treated product of the transformant include,
for example, a freeze dried trnasformant, an organic solvent
treated transformant, a dried transformant, a transformant ground
by friction, a self-digested transformant, an ultrasonically
treated transformant, an extract of the transformant and an
alkali-treated transformant. Immobilized products can be obtained,
for example, by the carrier bonding method (wherein the present
protein is adsorbed onto an inorganic support such as silica gel,
ceramic or the like, cellulose and ion exchange resin), and
inclusion method (wherein the present protein is entrapped in the
network structure of polymers such as polyacrylamide, a sulfur
containing polysaccharide gel (e.g. carageenan gel), alginic acid
gel and agar gel).
[0084] Sterilized transformants, as a treated product, is
preferably used for an industrial production rather than the
transformant containing the present gene per se, in view of less
restriction imposed on production facilities.
[0085] Examples of the method for sterilizing the transformant for
such a purpose include, for example, physical sterilization
(heating, drying, freezing, light beams, ultrasound, filtration and
application of electric current) and chemical sterilization
(alkali, acid, halogen, oxidizing agents, sulfur, boron, arsenic,
metal, alcohol, phenol, amine, sulfide, ether, aldehyde, ketone,
cyan and antibiotics). Preferably selected is a method which
accompanies lesser pollution or contamination in the reaction
system and lesser loss of the enzymatic activity of the present
protein.
[0086] The reaction is preferably conducted in the presence of
NADPH. The NADPH is converted to the oxidized form .beta.-nicotine
amide adenine dinucleotide phosphate (hereinafter referred to as
"NADP.sup.+") with the progress of the reaction. Since the
NADP.sup.+ can be converted back to the original NADPH by an enzyme
capable of converting the NADP.sup.+ into NADPH, such an enzyme
capable of converting the NADP.sup.+ into the NADPH may also be
added to the reaction.
[0087] Examples of the enzyme capable of converting the NADP.sup.+
into the NADPH include, for example, a glucose dehydrogenase, an
alcohol dehydrogenase, an aldehyde dehydrogenase, an amino acid
dehydrogenase, an organic dehydrogenase (malic acid dehydrogenase)
and the like.
[0088] The activity of the glucose dehydrogenase in the reaction
system can be enhanced by adding glucose thereto.
[0089] The protein capable of converting the NADP.sup.+ into the
NADPH can be applied or added to the reaction system in any form,
for example, of the enzyme, a microorganism having the enzymatic
activity or treated product thereof.
[0090] Alternatively, the microorganism having the activity
described above may be a transformant having a gene coding for an
enzyme capable of converting the NADP.sup.+ into the NADPH, or a
treated product of the transformant. The treated product herein
includes an equivalent thereof.
[0091] The transformant having gene of the enzyme capable of
converting the NADP.sup.+ into the NADPH as described above and the
present gene can be employed in this reaction.
[0092] Both of the genes may be introduced into a host cell by
transfecting the same with a single vector having both of the
genes, or with a plurality of recombinant vectors introduced with
the respective gene. A further method of introducing the gene
comprises introducing the present gene or both of the genes into
chromosome of a host cell.
[0093] Examples of the method for introducing both of the genes
into a single vector include, for example, a method for
constructing a vector by linking expression control regions such as
promoters and terminators to respective genes and a method of
constructing a recombinat vector for expressing an operon
containing multiple cistrons such as lactose operon.
[0094] Next a description will be made to the second aspect of the
present invention relating to a process for producing an optically
active 3-hydroxybutanoic acid ester of formula (la) as defined
above, which process comprises reacting 3-oxobutanoic acid ester of
formula (2a) as defined above, with a whole cells of a
microorganism or a treated product thereof, which microorganism
belongs to Penicillium citrinum, Cryptcoccus huumicolus, or
Bacillus alvei and is capable of asymmetrically reducing the oxo
group at 3-position of the compound of formula (2a) to
corresponding 3-hydroxy group.
[0095] According to the second aspect of the present invention, the
desired optically active ester compound can be readily produced in
an industrially desirable manner.
[0096] Examples of a C1-C8 alkyl group represented by R.sub.1 in
the general formula (1) and (2) include methyl, ethyl, propyl,
isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, and
octyl groups.
[0097] Examples of a methyl group which may be substituted with a
halogen atom or atoms represented by R.sub.20 include methyl group
and methyl groups substituted with a halogen atom or atoms.
Specifically, examples of the methyl group substituted with a
halogen atom or atoms include, for example, monofluoromethyl,
monochloromethyl, monobromomethyl, difluoromethyl, dichloromethyl,
dibromomethyl, trifluoromethyl, and trichloromethyl groups.
[0098] In the instant production method, the reaction of converting
a 3-oxobutanoate of formula (1a) to an optically active
3-hydroxybutanoate of formula (2a) is achieved by employing cells
or cell products of one or more microorganisms selected from the
group consisting of Penicillium citrinum, Cryptococcus humicolus,
and Bacillus alvei.
[0099] Specific examples of cells or cell products of
microorganisms which can be used in the reaction include those of
Penicillium citrinum IFO 4631, Cryptococcus humicolus IFO 1527, and
Bacillus alvei IFO 3343t.
[0100] The cultivation of microorganisms that can be used in this
aspect of the invention can be conducted, for example, as described
for the production of the transformant using the same cultivation
medium and conditions in the first aspect of the present
invention.
[0101] Microorganisms that may be used in the instant production
method can be cultivated using media for various microorganisms
comprising carbon and nitrogen sources, organic and inorganic
salts, and others as appropriate.
[0102] Examples of carbon sources contained in the media include
glucose, sucrose, glycerol, starch, organic acids, and molasses.
Examples of nitrogen sources include yeast extract, meat extract,
peptone, casamino acid, malt extract, soybean flour, corn steep
liquor, cottonseed flour, dried yeast, ammonium sulfate, and sodium
nitrate. Examples of organic and inorganic salts include sodium
chloride, potassium chloride, sodium carbonate, monopotassium
phosphate, dipotassium phosphate, calcium carbonate, ammonium
acetate, manganese sulfate, copper sulfate, zinc sulfate, ferrous
sulfate, and cobalt chloride.
[0103] Examples of methods for culturing include solid culture and
liquid culture (such as tube culture, flask culture, and jar
fermenter culture).
[0104] The temperature for cultivation and the pH of the medium are
not limited to any specific values as long as they are within the
range allowing the microorganisms to grow. The temperature for
culturing, for example, can be in the range of 15 to 45.degree. C.
and the pH of the medium in the range of 4 to 8.
[0105] The cultivation period can be suitable set, depending on the
cultivation conditions, and is usually one to seven days.
[0106] Microorganism cells obtained by cultivation can be used in
the reaction according to the instant production methods without
any treatment. For example, the cultivation liquid is utilized as
it is, a method in which cells are harvested by centrifuging the
cultivated liquid or the like, and wet cells obtained by washing
the harvested cells with a buffer solution or water can be
utilized.
[0107] Examples of products of microorganism cells which can be
used in the present reaction include, for example, products made by
subjecting cells obtained by cultivation to treatments with an
organic solvent (acetone, ethanol, and the like), freeze-dried
cells, alkali-treated cells, and products made by disrupting the
cells physically or enzymatically. Furthermore, Examples of the
cell products include those obtained by carrying out immobilization
according to well-known procedures after the above-described
treatments.
[0108] The reaction is usually carried out in the presence of
water, and the water may be used in the form of buffer solutions.
Examples of buffering agents that may be used in the buffer
solutions include, for example, alkali metal salts of phosphoric
acid such as sodium phosphates and potassium phosphates, and alkali
metal salts of acetic acid such as sodium acetate and potassium
acetate. In such cases, the pH of the aqueous layer during the
reaction can be varied, if necessary, in the range where the
reaction proceeds, and is usually in the range of 3 to 10.
[0109] The reaction can further utilize a hydrophobic organic
solvent, such that the reaction can be carried out in the bilayer
system of water and such a hydrophobic organic solvent. Examples of
hydrophobic organic solvents that may be used in this case include,
for example, an ester such as ethyl formate, ethyl acetate, propyl
acetate, butyl acetate, ethyl propionate, butyl propionate or the
like, an alcohol such as n-butyl alcohol, n-amyl alcohol, n-octyl
alcohol or the like; an aromatic hydrocarbon such as benzene,
toluene, xylene or the like, an ether such as diethyl ether,
diisopropyl ether, methyl-t-butyl ether or the like, a halogenated
hydrocarbon such as chloroform, 1,2-dichloroethane or the like, and
a mixture thereof.
[0110] The concentration of the starting compound in the reaction,
the 3-oxobutanoate of formula (1a), is usually 50% (w/v) or less.
In order that the concentration of the 3-oxobutanoate of formula
(1a) in the reaction system be maintained at an almost constant
level, the 3-oxobutanoate of formula (1a) may be added to the
reaction system in a continuous or successive manner.
[0111] The reaction temperature is usually in the range of 0 to
60.degree. C.
[0112] In the reaction, saccharides such as glucose, sucrose, and
fructose, alcohols such as ethanol, surfactants can optionally be
added.
[0113] The reaction time is usually in the range of 0.5 hour to 10
days. The progress of the reaction can be monitored, for example,
by determining the amount of the starting compound in the reaction
solution with high performance liquid chromatography, gas
chromatography, or the like, after the addition of a 3-oxobutanoate
of formula (1a).
[0114] After completion of the reaction, an optically active
3-hydroxybutanoate of formula (2a) can be isolated by subjecting
the reaction solution to usual post-treatments such as extraction
with an organic solvent, concentration, etc. The isolated compound
can be further purified with column chromatography, distillation,
or the like, if necessary.
[0115] Next a description will be made to the third aspect of the
present invention relating to a process for producing an optically
active 4-bromo-3-hydroxybutanoate of formula (1b) as defined above,
which process comprises reacting 4-bromo-3-oxobutanoate of formula
(2b) as defined above with an enzyme having an amino acid sequence
as defined in iv) to vi) above, which enzyme will be referred to as
"the instant enzyme".
[0116] Examples of the C2-C8 alkyl group represented by R.sub.1 in
the 4-bromo-3-oxobutanoate of formula (1a) include, for example,
ethyl, propyl, isopropyl, butyl, pentyl, hexyl, and octyl
groups.
[0117] The polynucleotide sequence coding for an enzyme having the
amino acid sequence shown in SEQ ID NO: 34 which can be employed in
the instant production method is shown in SEQ ID NO: 35 (Appl.
Microbiol. Biotechnol. (1999) 52, 386-392). The present
polynucleotide may be naturally occurring or produced by a suitable
mutation of the naturally occurring sequence such as point
mutations, mutagenic treatments, or the like.
[0118] pUAR containing the DNA shown in SEQ ID NO: 35 is deposited
undr the Butapest Treaty with the Deposition No. FERM BP-7752,
which had been originally deposited under FERM P-18127 with an
International Patent Organism Depositary, National Institute of
Advanced Industrial Science and Technology.
[0119] The instant enzyme can be produced, for example, by
cultivating microorganisms containing the instant polynucloetide of
SEQ ID NO: 34.
[0120] The microorganism containing the instant polynulceotide of
SEQ ID NO: 35 can be obtained by cultivating a transformed
microorganism host cell transfected with a vector having the
polynulceotide of SEQ ID NO: 35.
[0121] Examples of host cells include, for example, microorganisms
belonging to Escherichia, Bacillus, Corynebacterium,
Staphylococcus, Streptomyces, Saccharomyces, Kluyveromyces, and
Aspergillus.
[0122] Introduction of the polynucleotide into the host cell can be
accomplished by a suitable conventional method, depending on the
kind of cells used as the host. Examples of the methods include
calcium chloride methods described in "Molecular Cloning: A
Laboratory Manual, 2nd edition" (1989), Cold Spring Harbor
Laboratory Press, "Current Protocols in Molecular Biology" (1987),
John Wiley & Sons, Inc., ISBNO-471-50338-X, etc., and
electroporation methods described in "Methods in Electroporation:
Gene Pulser/E. coli Pulser System", Bio-Rad Laboratories, (1993),
etc.
[0123] Transformed microorganisms having the desired polynucleotide
can be selected using, as an index, the phenotype or the like of a
selectable marker gene contained in a vector, which include those
described above in the first aspect of the present invention. It
can be confirmed as to whether the transformed microorganisms carry
the gene by preparing the vector DNA from the transformed
microorganisms, and then subjecting the prepared vector DNA, for
example, to a usual method (identification of restriction enzyme
sites, analysis of the polynucleotide sequence, southern
hybridization, or the like) as described in "Molecular Cloning" (J.
Sambrook et al., Cold Spring Harbor, 1989) and others.
[0124] Cultivation of the transformed cells to express the desired
enzyme can be conducted by using, as a medium for culturing the
above-described microorganisms, various kinds of medium including
those comprising carbon and nitrogen sources commonly used in
culturing microorganisms, and organic and inorganic salts, and
others as appropriate.
[0125] Examples of carbon sources include: saccharides such as
glucose, dextrin and sucrose; sugar alcohols such as glycerol;
organic acids such as fumaric, citric and pyruvic acids; animal and
vegetable oils; and molasses. The amount of these carbon sources to
be added into the medium may be usually in the range of 0.1 to 20%
(w/v) with respect to the entire medium volume.
[0126] Examples of nitrogen sources are organic or inorganic
nitrogen sources, including: natural organic nitrogen sources or
amino acids such as meat extract, peptone, yeast extract, malt
extract, soybean flour, corn steep liquor, cottonseed flour, dried
yeast and casamino acid; inorganic acid ammonium salts and nitrates
such as sodium nitrate, ammonium chloride, ammonium sulfate and
ammonium phosphate; organic acid ammonium salts such as ammonium
fumarate and ammonium citrate; and urea. Among these, organic acid
ammonium salts, natural organic nitrogen sources, amino acids, and
the like can also be used as carbon sources in many cases. The
amount of nitrogen sources to be added may be usually in the range
of 0.1 to 30% (w/v) with respect to the entire medium volume.
[0127] Examples of organic and inorganic salts may include
chlorides, sulfates, acetates, carbonates and phosphates of
potassium, sodium, magnesium, iron, manganese, cobalt, zinc, and
others. Specifically, examples of such salts include sodium
chloride, potassium chloride, magnesium sulfate, ferrous sulfate,
manganese sulfate, cobalt chloride, zinc sulfate, copper sulfate,
sodium acetate, calcium carbonate, sodium carbonate, monobasic
potassium phosphate, dibasic potassium phosphate, and others. The
amount of an organic or inorganic salt to be added may se usually
in the range of 0.0001 to 5% (w/v) with respect to the entire
medium volume.
[0128] A small amount of isopropyl thio-.beta.-D-galactoside (IPTG)
can be added, as an inducer of the production of the instant
protein, to the medium for cultivating the transformant having a
promoter (e.g. tac promoter, trc promoter and lac promoter which
are induced by allolactose) in operable linkage with the gene of
the instant protein.
[0129] Cultivation can be carried out according to procedures
commonly used for cultivating microorganisms. Examples of the
procedures include, for example, liquid culture such as
tube-shaking culture, reciprocally shaking culture, jar fermenter
culture, and tank culture; and solid culture. When a jar fermenter
is used, it is necessary to introduce sterile air into the jar
fermenter, and an aeration rate of about 0.1 to about 2 times the
volume of the cultivating medium per minute is usually chosen. The
temperature for cultivation can be varied within the range where
microorganisms stay viable, and usually, cultivation temperatures
in the range of about 15.degree. C. to about 40.degree. C. are
preferred. The pH of the medium is preferably in the range of about
6 to about 8. The period for culturing is varied depending on
culturing conditions, and a period from about one day to about five
days is desirable in usual cases.
[0130] Cells containing the instant enzyme thus produced, cell
products, or purified materials of the instant enzyme can be used
in this aspect of the invention.
[0131] Examples of cell products include, for example, freeze-dried
cells, organic solvent treated cells, dried cells, triturated
cells, cell autolysates, sonicated cells, cell extracts,
alkali-treated cells, and in addition, products obtained by
immobilizing these by commonly employed methods.
[0132] Purified enzyme can be produced, for example, by purifying
the instant enzyme from cultures of microorganisms carrying the
instant enzyme.
[0133] The instant enzyme isolated from cultures of the
microorganisms, may be further purified a conventional method as
used for the purification of ordinary proteins.
[0134] For example, cells are harvested from the cultivated
microorganism by centrifugation or the like, and these cells are
homogenized by physical disrupting procedures such as an ultrasonic
treatment, Dynomill treatment and French press treatment, or by
chemical disrupting procedures using surfactants or cell-lytic
enzymes such as lysozyme. Insoluble materials are usually removed
from the resultant homogenate by centrifugation, membrane
filtration, or the like to prepare a cell-free extract, which will
be then fractionated through separation and purification procedures
such as cation exchange column chromatography, anion exchange
column chromatography, hydrophobic column chromatography, gel
column chromatography, and the like to purify the instant enzyme.
Examples of the support that may be used for the chromatography
include, for example, resin support such as cellulose, dextran and
agarose, having an carboxymethyl (CM), DEAE, phenyl, butyl group,
or the like. Commercially available carrier-packed columns may also
be used, such as Q-Sepharose FF, Phenyl-Sepharose HP (trade name,
both manufactured by Amersham Pharmacia Biotech), TSK-gel G3000SW
(trade name, manufactured by Toso Co., Ltd.), and others.
[0135] Next, the instant production method will be described.
[0136] 4-bromo-3-oxobutanoate of formula (1b) is converted to an
optically active 4-bromo-3-hydroxybutanoate of formula (2b) by
subjecting a 4-bromoacetoacetic acid ester compound of formula (1b)
to the reaction with the instant enzyme.
[0137] The reaction is usually carried out in the presence of
water, and the water can be in the form of buffer solutions.
Examples of buffering agents that may be used include, for example,
alkali metal phosphates such as sodium phosphates and potassium
phosphates; alkali metal salts of acetic acid such as sodium
acetate and potassium acetate.
[0138] The pH in this case can be varied within the range where the
reaction proceeds. The pH is usually optionally set within the
range of pH 4 to 10.
[0139] The amount of the buffer that may be used is usually 100
parts by weight or less per one part by weight of a
4-bromo-3-oxobutanoate of formula (1b).
[0140] The reaction temperature for the above-described reaction is
between 0 and 70.degree. C. in view of stability and reaction rate
of the instant enzyme, and preferably between 10 and 40.degree.
C.
[0141] The reaction can also be carried out in the co-presence of
an organic solvent. Examples of the organic solvent include, for
example, an ether such as tetrahydrofuran, t-butyl methyl ether,
isopropyl ether or the like, a hydrocarbon such as toluene, hexane,
cyclohexane, heptane, isooctane, decane or the like, an alcohol
such as t-butanol, methanol, ethanol, isopropanol, n-butanol or the
like, a sulfoxide such as dimethylsulfoxide or the like; a ketone
such as acetone or the like; a nitrile such as acetonitrile or the
like, and a mixture thereof.
[0142] The amount of an organic solvent that may be used in the
reaction is usually 100 parts by weight or less, and preferably 50
parts by weight or less, per one part by weight of 4-bromoacetoate
of formula (1b).
[0143] A coenzyme (e.g., NADH, NADPH) may also be added for the
above-described reaction. The amount of the coenzyme that may be
used in the reaction is usually 0.5 part or less, and preferably
0.1 part or less, per one part by weight of 4-bromo-3-oxobutanoate
of formula (1b), by weight.
[0144] Additional substances described below is preferably added
together with the coenzyme in order to enhance the coenzyme
efficiency:
[0145] 1) compound(s) such as formic acid, glucose, isopropanol,
2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, and the
like, wherein the amount of these compounds the may be used is 100
parts or less by weight, and preferably 10 parts or less by weight,
per one part by weight of 4-bromo-3-oxobutanoate of formula (1b);
and
[0146] 2) dehydrogenase such as formate dehydrogenase, glucose
dehydrogenase, and the like,
[0147] wherein the amount of dehydrogenase to be used is 0.1 part
or less by weight, and preferably 0.05 part or less by weight, per
one part by weight of 4-bromo-3-oxobutanoate of formula (1b).
[0148] The reaction can be carried out, for example, by stirring
and shaking a mixture of water, a 4-bromo-3-oxobutanoate of formula
(1b), the instant enzyme, a coenzyme, if necessary, an organic
solvent, and others.
[0149] The progress of the reaction can be monitored, for example,
by checking the amount of the starting compound in the reaction
solution with high performance liquid chromatography, gas
chromatography, or the like. The range of the reaction time is
usually a period varying from five minutes to four days.
[0150] After completion of the reaction, for example, the reaction
solution can be extracted with an organic solvent such as hexane,
heptane, tert-butyl methyl ether, ethyl acetate, toluene, or the
like, and the organic layer can be dried and concentrated, thereby
obtaining the desired product. The product can be further purified
by column chromatography or the like, if necessary.
[0151] The instant production method can also be performed, for
example, by using a polynucleotide constructed by subjecting the
polynucleotide of SEQ ID NO: 35, for example, to well-known
techniques for causing a point mutation or mutations in the
polynucleotide such as the site-specific mutation, a recombinant
method by cleaving the polynucleotide selectively or deleting,
substituting or adding a suitably selected nucleotide or
nucleotides, and ligating the resulting polynucleotide sequences to
obtain a desirably modified polynucleotide, or an oligonucleotide
mutation method, thereby producing a polynucleotide that codes for
an enzyme capable of reducing a 4-bromo-3-oxobutanoate of formula
(1b) to an optically active 4-bromo-3-hydroxybutanoate of formula
(2b); and carrying out the preparation of transformants,
cultivation and reaction in the above described method.
[0152] Next a description will be made to the fourth aspect of the
present invention relating to a process for producing
4-cyano-3-hydroxybutanoic acid, which comprises reacting
4-bromo-3-hydroxybtanoic acid ester with a metal cyanide in the
presence of an alkaline earth metal hydroxide and an alkaline earth
metal halogenide.
[0153] According to this aspect of the present invention,
4-cyano-3-hydroxybutanoic acid or ester thereof can be obtained in
a good yield.
[0154] A racemic or optically active 4-bromo-3-hydroxybutanoic acid
ester can be used in this process. Examples of the ester include,
for example, a lower alkyl ester of 4-bromo-3-hydroxybutanoic acid
and optically active isomer thereof. Specific examples of the lower
alkyl ester include, for example, C1-C5 alkyl esters such as a
methyl, ethyl, propyl, isopropyl, or butyl ester.
[0155] Examples of the metal cyanide to be used include, for
example, sodium cyanide and potassium cyanide.
[0156] Examples of the alkaline earth metal hydroxide used include,
for example, magnesium hydroxide, calcium hydroxide, and barium
hydroxide.
[0157] Examples of the alkaline earth metal halide used include,
for example, alkaline earth metal chloride and alkaline earth metal
bromide, and preferred is calcium chloride.
[0158] The reaction of the 4-bromo-3-hydroxybutanoic ester and
metal cyanide in the presence of an alkaline earth metal hydroxide
and an alkaline earth metal halide is prefereably carried out in
the presence of water. An organic solvent can also be added, if
necessary.
[0159] The reaction temperature is normally from -10 to 100.degree.
C., or preferably, from -10 to 40.degree. C.
[0160] An amount of the metal cyanide that may be used in the
reaction is normally from 0.8 to 2 moles per mol of
4-bromo-3-hydroxybutanoic acid ester.
[0161] An amount of the alkaline earth metal hydroxide and alkaline
earth metal halide to be used in the reaction is preferably from
0.8 to 5 moles per mol of 4-bromo-3-hydroxybutanoic acid ester.
[0162] The progress of the reaction can be monitored by checking
the amount of 4-bromo-3-hydroxybutanoic acid using such an analysis
means as the gas chromatography, the high-performance liquid
chromatography, the thin layer chromatography or the like.
[0163] After completion of the reaction, for example, an inorganic
acid such as hydrochloric acid is usually added to the reaction
solution, thereafter the resulting mixture may be extracted with an
organic solvent and the obtained organic layer is typically
concentrated to obtain the 4-cyano-3-hydroxybutanoic acid.
[0164] The 4-Bromo-3-hydroxybutanoic ester and metal cyanide are
made to react in the presence of an alkaline earth metal hydroxide
and an alkaline earth metal halide, and the resulting mixture is
then allowed to react with dialkyl sulfuric acid to produce the
4-cyano-3-hydroxybutanoic acid ester.
[0165] The reaction of the 4-cyano-3-hydroxybutanoic acid obtained
as above with a dialkyl sulfuric acid is usually carried out in the
presence of a base, preferably in a solvent.
[0166] Examples of the solvent that may be used in the reaction
include, for example, an ester such as ethyl acetate, butyl acetate
or the like, an ether such as tetrahydrofuran, 1,4-dioxyane or the
like, water and a mixture thereof. Examples of the base include,
for example, tertiary amines such as pyridine, 4-dimethylamino
pyridine, triethylamine and diisopropylethylamine.
[0167] The reaction is conducted normally from 0 to 100.degree.
C.
[0168] The dialkyl sulfuric acid is usually used in an amount of
from 1 to 2 moles and the base is usually used in an amount of from
1 to 3 moles per mol of the 4-cyano-3-hydroxybutanoic acid.
[0169] The progress of the reaction can be monitored by checking
the amount of the 4-bromo-3-hydroxybutanoic acid using analytical
means such as gas chromatography, the high-performance liquid
chromatography, thin layer chromatography or the like.
[0170] After completion of the reaction, for example, saturated
sodium bicarbonate solution is added to the reaction mixture,
thereafter, the mixture is usually extracted with an organic
solvent and the obtained organic layer is concentrated to give the
4-cyano-3-hydroxybutanoic acid ester.
[0171] The reaction of the dialkyl sulfate with the resulting
4-cyano-3-hydroxybutanoic acid is usually carried out after
isolating the acid or the reaction can be conducted by reacting the
dialkyl sulfate with the reaction mixture containing
4-cyano-3-hydroxybutanoic acid produced, wherein dialkyl sulfuric
acid is preferably added to the reaction mixture.
[0172] The following describes the present invention in detail with
reference to embodiments, which by no means limit the scope of the
present invention.
REFERENCE EXAMPLE 1
[0173] 100 ml of medium (potato dextrose broth (by Vecton
Dickinson) dissolved to water at a ratio of 24 g/L) was put into a
500 ml flask, and was sterilized at 121.degree. C. for 15 minutes.
Then 0.5 ml of one strain of Penicillium citrinum IF04631
cultivated in the medium of the same composition (cultured by
shaking at 30.degree. C. for 48 hours) was added to it, and was
shaken and cultured at 30.degree. C. for 72 hours. Then the
obtained cultivation solution was centrifuged (8000 xg for ten
minutes), and the resulted precipitation was collected. This
precipitation was washed in 50 ml of 20 mM potassium phosphate
buffer (pH7) three times to obtain about 1.0 g of wet bacterial
cell.
[0174] 10 g of said wet bacterial cell was used to prepare total
RNA according to the guanidine phenol chloroform thiocyanate
method, and about 1.5 mg of total RNA was obtained. Further, about
9.3 .mu.g of RNA containing poly(A) was obtained from 0.5 mg of
total RNA using oligotex(dT)30-Super (Takara Shuzo Co., Ltd.).
[0175] cDNA library was prepared according to the Gubler and
Hoffman method as follows. A single-stranded cDNA was prepared
using the RNA (3.0 .mu.g) containing the above poly (A),
Oligo(dT)18-linker primer ((including XhoI site) Takara Shuzo Co.,
Ltd.) and RAV-2 Rtase and SuperScriptII Rtase. E. coli DNA
polymerase, E. coli Rnase/E. coli DNA ligase mixture and T4 DNA
polymerase was added to this reaction solution to carry out double
stranded cDNA synthesis and smooth terminalization. This was
followed by ligation between this double stranded cDNA and
EcoRI-NotI-BamHI adaptor (Takara Shuzo Co., Ltd.). The DNA was
ligated, phosphorylated and was digested by XhoI. The low molecular
weight DNA was removed by the spin column (Takara Shuzo Co., Ltd.),
and .lambda. ZapII (EcoRI-XholI digest) and ligation were
performed. After that, packaging was made using the in vitro
packaging kit (Stratagene Inc.), whereby a cDNA library
(hereinafter referred to as "cDNA library" (A)) was obtained.
EXAMPLE 1
[0176] (1) 23 g of wet bacterial cells of the Penicillium citrinum
IF04631 strain which were prepared under the same conditions as
those of the Reference Example 1 were suspended in 50 mM potassium
phosphate buffer (pH 7.0) and were disrupted by Dynomill
(manufactured by Symal Enterprise Inc., a glass bead 0.1 to 0.2 mm
in diameter, at 3000 rpm for 30 minutes). The disrupted solution
obtained in this step was subjected to centrifugal separation
(10,000 xg for 10 minutes). The supernatant was further subjected
to ultracentrifugation (100,000 xg for 120 minutes) to give 160 ml
of untracentrifuged supernatant.
[0177] Ammonium sulfate was gradually added to 160 ml of the
ultracentrifuged supernatant obtained in the aforementioned step
until the concentration reached 1.5M. Then the solution is spread
over hydrophobic interaction chromatography column [Hi-LoadPhenyl
(26/10) (manufactured by Amasham Pharmacia Biotech), which was
equibrated with BIS-TRIS-PROPANE buffer (20 mM, pH 7.0) containing
1.5M ammonium sulfate], and eluted, as a mobile phase, with a
BIS-TRIS-PROPANE buffer (concentration gradient of ammonium
sulfate: 1.5M.fwdarw.0.6M) containing ammonium sulfate. Thus, 20 ml
of eluted fraction with an ammonium sulfate concentration of 1.1 to
0.9M was obtained as a fraction having a reducing enzyme
activity.
[0178] The eluted fraction was subjected to desalination and was
replaced by Tris-HCl buffer solution (20mM, pH 7.7), and then
spread over the ion exchange chromatography column [Hi-Load Q
Sepharose (16/10) (manufactured by Amasham Pharmacia Biotech),
which is buffered by Tris-HCl buffer solution (20 mM, pH7.7)].
Tris-HCl buffer solution (concentration gradient of sodium
chloride: 0.fwdarw.0.5M) containing sodium chloride was used as a
mobile phase to elute. Thus, 3 ml of a fraction containing a sodium
chloride at a concentration of 0.02 to 0.08M was obtained as a
fraction having reducing enzyme activity. The fraction was
concentrated and the concentrated solution was subjected to gel
filtration (column: Superdex 200 (10/30) (manufactured by Amasham
Pharmacia Biotech)) [mobile phase: BIS-TRIS-PROPANE buffer (20 mM,
pH7.0)]. Thus, 1 ml of a fraction corresponding to a molecular
weight of about 33000 Dalton (hereinafter referred to as "active
fraction (A)") was obtained as a fraction having a reducing enzyme
activity.
[0179] The reducing enzyme activity of the fraction obtained by
chromatography or the like was measured according to the following
steps.
[0180] The eluted fraction obtained by the chromatography was added
to 0.9 ml of phosphoric acid buffer solution (20 mM, pH7.0)
containing methyl 4-bromo-3-oxobutanoate (1.56 mg/ml) and NADPH
(0.226 mg/ml) to make a total volume of 1 ml. After it was
maintained at 37.degree. C. for 20 seconds, the absorbance of 340
nm was measured. The NADPH consumption was calculated from the
absorbance of 340 nm, thereby recovering the reducing enzyme
activity of the fraction.
[0181] (2) The active fraction (A) obtained in the aforementioned
step was subjected to SDS polyacryl amide gel electrophoresis
according to the method described in "Laemmli, U.K., Nature, (1970)
227, 680". The gel after the electrophoresis was stained with a
stain solution, Coomassie brilliant blue G250 (manufactured by
Bio-Rad Inc.), and the gel on the stained portion was cut off. This
gel was subjected to reductive alkylation by dithiothreitol and
acetoamide iodide. After trypsin-treatment, a peptide was extracted
from the gel. The extracted peptide was fractionated by HPLC
(column: TSK gel ODS-80=Ts, 2.0 mm.times.250 mm (Toso Co., Ltd.),
mobile phase: concentration gradient of 0.1% aqueous
trifluoroacetate/acetonitrile=100/0.fwdarw.20/80). A protein
sequencer (494cLC) was used to determine the amino acid sequences
using the five fractions, which were found to be highly pure
according to the TOS-MS. The amino acid sequences determined are
shown in SEQ ID NOs: 3, 4, 5, 6 and 7.
[0182] (3) The oligonucleotide primers of SEQ ID NOs: 8, 9, 10, 11,
12, 13 and 14 was synthesized based on the amino acid sequence of
SEQ ID NO: 3.
[0183] PCR was conducted by using any one of the oligonucleotide
primers of SEQ ID NOs. 8, 9, 10, 11, 12, 13 and 14, and a SK
oligonucleotide primer (by Stratagene) as a primer, and the
aforementioned cDNA (A) as a template in the reaction solution
having the following composition under the following reaction
conditions. (Expand High Fidelity PCR System manufactured by Rosche
Diagnostic was used.)
1 Composition of reaction solution: cDNA library stock solution 1
.mu.l dNTP (each 2.5 mM-mix) 0.4 .mu.l Primer (20 pmol/.mu.l) 0.75
.mu.l each 10 .times. buffer (with MgCl) 5 .mu.l enz. expandHiFi
(3.5 .times. 10.sup.3 U/ml) 0.375 .mu.l Deionized water 41.725
.mu.l
[0184] Reaction Conditions:
[0185] The reaction vessel containing the reaction solution of the
aforementioned composition was set to the PERKIN ELMER-GeneAmp PCR
System 2400, and was heated at 97.degree. C. (for 2 minutes). Then
a cycle of 97.degree. C. (0.25 min.).fwdarw.50.degree. C. (0.5
min.).fwdarw.72.degree. C. (1.5 min.) was repeated ten times,
followed by a cycle of 97.degree. C. (0.25 min.).fwdarw.55.degree.
C. (0.5 min.).fwdarw.72.degree. C. (2.5 min.) repeated twenty
times, and maintained at 72.degree. C. (7 min.).
[0186] Thereafter, a portion of the PCR reaction solution was
subjected to agarose gel electrophoresis, and a band of a DNA
fragment of about 740 bp was detected for the following cases: the
oligonucleotide primer containing the polynucleotide sequence of
SEQ ID NO: 10 and the SK oligonucleotide primer were used as a
primer; the oligonucleotide primer containing the polynucleotide
sequence of SEQ ID NO: 12 and the SK oligonucleotide primer were
used as a primer; and the oligonucleotide primer containing the
polynucleotide sequence of SEQ ID NO: 14 and the SK oligonucleotide
primer were used as a primer.
[0187] Using each of the PCR reaction solutions where the band of a
DNA fragment of about 740 bp was detected, each of the
aforementioned DNA fragments of about 740 bp was ligated to the
existing "PCR product insertion site" of the p CR2.1-TOPO vector
(where TOPO.TM. TA cloning kit manufactured by Invitrogen was
used). E. coli DH5.alpha. was transformed with the obtained
ligation solution. 30 .mu.l of 4% aqueous solution of
5-bromo-4-chloro-3-indolyl-.beta.-D-galactocide (hereinafter
referred to as "X-gal") and 30 .mu.l of 0.1M IPTG were applied onto
the LB (1% bactotrypton, 0.5% bacto yeast-extract and 1% sodium
chloride) agar medium containing 50 .mu.g/ml of ampicillin. The
transformant obtained was inoculated onto it, and was incubated. Of
the colonies formed, each of the white ones was picked up and was,
inoculated into a sterilized LB medium (2 ml) containing 50
.mu.g/ml of ampicillin. It was incubated in a test tube under
shaking (at 30.degree. C. for 24 hours). Plasmid was prepared from
each cultivated bacterial cells using the QIAprep Spin Miniprep Kit
(manufactured by Qiagen).
[0188] Hereinafter, the plasmid derived from the DNA fragment
obtained by PCR using the oligonucleotide primer of SEQ ID NO: 10
and SK oligonucleotide primer as a primer, will be described as
"p27-1"; the plasmid derived from the DNA fragment obtained by PCR
using the oligonucleotide primer of SEQ ID NO: 12 and SK
oligonucleotide primer as a primer, will be described as "p27-2";
and the plasmid derived from the DNA fragment obtained by PCR using
the oligonucleotide primer of SEQ ID NO: 14 and SK oligonucleotide
primer will be described as "p27-3";
[0189] The polynucleotide sequence of the DNA fragment inserted
into each of plasmids p27-1, p27-2 and p27-3 was analyzed, and it
was found that the polynucleotide sequences of the inserted DNA
fragments were identical except for the primer sequence
portions.
[0190] The polynucleotide sequence of the DNA fragment inserted
into plasmid p27-1 is shown in SEQ ID NO: 15.
[0191] Analysis of the polynucleotide sequence of the DNA fragment
inserted into the plasmid was made as follows: Sequence reaction
was carried out according to the Dye Terminator Cycle Sequence FS
Ready Reaction Kit (by Perkin Elmer) with each plasmid used as a
template, and the polynucleotide sequence of the obtained DNA was
analyzed by the DNA sequencer 373A (by Perkin Elmer).
[0192] (4) Oligonucleotide primers containing the polynucleotide
sequence of SEQ ID NO. 16 or 17 was synthesized based on the
polynucleotide sequence of SEQ ID NO: 15.
[0193] PCR was conducted by using the reaction solution of the
following composition and reaction conditions, wherein the
oligonucleotide primers containing of SEQ ID NO: 16 and SK
oligonucleotide primers (by Stratagene), or the oligonucleotide
primer of SEQ ID NO: 17 and T7 oligonucleotide primer (by
Stratagene) were used as a primer, and the aforementioned cDNA (A)
was employed as a template. (Expand High Fidelity PCR System by
Rosche Diagnostic was used.)
2 Composition of reaction solution: cDNA library stock solution 1
.mu.l dNTP (each 2.5 mM-mix) 0.4 .mu.l Primer (20 pmol/.mu.l) 0.75
.mu.l each 10 .times. buffer (with MgCl) 5 .mu.l enz. expandHiFi
(3.5 .times. 10.sup.3 U/ml) 0.375 .mu.l Deionized water 41.725
.mu.l
[0194] Reaction Conditions:
[0195] The reaction vessel containing reaction solution of the
aforementioned composition was set to the PERKIN ELMER-GeneAmp PCR
System 2400, and was heated at 97.degree. C. (for 2 minutes). Then
a cycle of 97.degree. C. (0.25 min.).fwdarw.55.degree. C. (0.5
min.).fwdarw.72.degree. C. (1.5 min.) was repeated ten times,
followed by twenty times a cycle of 97.degree. C. (0.25
min.).fwdarw.55.degree. C. (0.5 min.).fwdarw.72.degree. C. (2.5
min.). Further, it was maintained at 72.degree. C. for 7
minutes.
[0196] Thereafter, a portion of the PCR reaction solution was
subjected to agarose gel electrophoresis. A band of DNA fragment of
about 350 bp was detected when the oligonucleotide primer
containing the polynucleotide sequence of SEQ ID NO: 16 and the SK
oligonucleotide primer were used as a primer. A band of a DNA
fragment of about 650 bp was detected when the oligonucleotide
primer containing the polynucleotide sequence of SEQ ID NO: 17 and
T7 oligonucleotide primer were used as a primer.
[0197] Using the PCR reaction solution containing the DNA fragment
of about 350 bp obtained in the aforementioned PCR or the PCR
reaction solution containing the DNA fragment of about 650 bp, the
aforementioned DNA fragment of about 350 bp and the DNA fragment of
about 650 bp were ligated respectively to the existing "PCR product
insertion site" of the p CR2.1-TOPO vector (where TOPO.TM. TA
cloning kit by Invitrogen was used). E. coli DH5.alpha. was
transformed with the obtained ligation solution. 30 .mu.l of 4%
aqueous solution of X-gal and 30 .mu.l of 0.1M IPTG were applied to
the LB agar medium containing 50 .mu.g/ml of ampicillin. The
transformant obtained was inoculated thereon, and was incubated. Of
the colonies formed, each of the white ones was picked up and was
inoculated into a sterilized LB medium (2 ml) containing 50
.mu.g/ml of ampicillin. It was incubated under shaking in a test
tube (at 30.degree. C. for 24 hours). Plasmid was prepared from
each cultivated bacterial cells using the QIAprep Spin Miniprep Kit
(by Qiagen).
[0198] Hereinafter, the plasmid derived from the DNA fragment
obtained by PCR using the oligonucleotide primer of SEQ ID NO: 16
and SK oligonucleotide primer as a primer, will be denoted by
plasmid pBR-1; and the plasmid derived from the DNA fragment
obtained by PCR using the oligonucleotide primer of SEQ ID NO: 17
and T7 oligonucleotide primer as primers, will be denoted by
pBR-2.
[0199] The polynucleotide sequence of the DNA fragment inserted
into each of plasmids pBR-1 and pBR-2 was analyzed. The
polynucleotide sequence of the DNA fragment inserted into plasmid
pBR-1 is shown in SEQ ID NO: 18. The polynucleotide sequence of the
DNA fragment inserted into plasmid pBR-2 is shown in SEQ ID NO:
19.
[0200] Analysis of the polynucleotide sequence of the DNA fragment
inserted into the plasmid was made as follows: Sequence reaction
was carried out according to the Dye Terminator Cycle Sequence FS
Ready Reaction Kit (by Perkin Elmer) with each plasmid used as a
template, and the polynucleotide sequence of the obtained DNA was
analyzed by the DNA sequencer 373A (by Perkin Elmer).
[0201] (5) An oligonucleotide primer of SEQ ID NO: 20 was
synthesized based on the polynucleotide sequence of SEQ ID NO: 15.
An oligonucleotide primer of SEQ ID NO: 21 was synthesized based on
the polynucleotide sequence of SEQ ID NO: 19.
[0202] PCR was conducted using the following composition of
reaction solution and reaction conditions, wherein the
oligonucleotide primer of SEQ ID No: 20 and the oligonucleotide
primer of SEQ ID NO: 21 were used as a primer, and the
aforementioned cDNA library (A) was employed as a template. (Expand
High Fidelity PCR System by Rosche Diagnostic was used.)
3 Composition of reaction solution: cDNA library stock solution 1
.mu.l dNTP (each 2.5 mM-mix) 0.4 .mu.l Primer (20 pmol/.mu.l) 0.75
.mu.l each 10 .times. buffer (with MgCl) 5 .mu.l enz. expandHiFi
(3.5 .times. 10.sup.3 U/ml) 0.375 .mu.l Deionized water 41.725
.mu.l
[0203] Reaction Conditions:
[0204] The reaction vessel containing reaction solution of the
aforementioned composition was set to the PERKIN ELMER-GeneAmp PCR
System 2400, and was heated at 97.degree. C. (for 2 minutes). Then
a cycle of 97.degree. C. (0.25 min.).fwdarw.55.degree. C. (0.5
min.).fwdarw.72.degree. C. (1.5 min.) was repeated ten times,
followed by twenty times a cycle of 97.degree. C. (0.25
min.).fwdarw.55.degree. C. (0.5 min.).fwdarw.72.degree. C. (2.5
min.). Further, it was maintained at 72.degree. C. for 7
minutes.
[0205] Thereafter, a portion of the PCR reaction solution was
subjected to agarose gel electrophoresis. A band of a DNA fragment
of about 400 bp was detected.
[0206] Using the PCR reaction solutions containing the DNA fragment
of about 400 bp obtained in the aforementioned PCR was ligated to
the existing "PCR product insertion site" of the pCR2.1-TOPO vector
(TOPO.TM. TA cloning kit by Invitrogen was used). The obtained
ligation solution was utilized to transform E. coli DH5.alpha..
[0207] 30 .mu.l of 4% aqueous solution of X-gal and 30 .mu.l of
0.1M IPTG were applied to the LB agar medium containing 50 .mu.g/ml
of ampicillin. The transformant obtained was inoculated thereto,
and was incubated. Of the colonies formed, each of the white ones
was picked up and was inoculated into a sterilized LB medium (2 ml)
containing 50 .mu.g/ml of ampicillin. It was incubated under
shaking in a test tube (at 30.degree. C. for 24 hours). Plasmid was
prepared by using the QIAprep Spin Miniprep Kit (by Qiagen) from
each cultivated bacterial cells. (Hereinafter, this will be
described as plasmid plasmid pBR-3).
[0208] The polynucleotide sequence of the DNA fragment inserted
into each of plasmid pBR-3 was analyzed. The polynucleotide
sequence of the DNA fragment inserted into plasmid pBR-3 is shown
in SEQ ID NO: 22.
[0209] Analysis of the polynucleotide sequence of the DNA fragment
inserted into the plasmid was made as follows: Sequence reaction
was carried out by using the Dye Terminator Cycle Sequence FS Ready
Reaction Kit (by Perkin Elmer) and plasmid pBR-3 as a template, and
the polynucleotide sequence of the obtained DNA was analyzed by the
DNA sequencer 373A (by Perkin Elmer).
[0210] ORF search was conducted based on the SEQ ID NOs. 18, 19 and
22 to determine the polynucleotide sequence (SEQ ID NO: 28) of the
gene coding for the protein capable of preferentially producing
methyl (S)-4-bromo-3-hydroxybutanoate by asymmetrically reducing
methyl 4-bromo-3-oxobutanoate contained in the Penicillium citrinum
IF04631 strain. Further, amino acid sequence of SEQ ID NO: 1 of the
protein was determined based on the polynucleotide sequence of SEQ
ID NO: 28. Comparison between SEQ ID NO: 1 and SEQ ID NOs. 3, 4, 5,
6, and 7 showed that the amino acid sequence of SEQ ID NOs. 3, 4,
5, 6, and 7 almost coincide with a part of the amino acid sequence
of SEQ NO: 1.
EXAMPLE 2
[0211] (1) The oligonucleotide primer of SEQ ID NO: 23 was
synthesized based on the polynucleotide sequence of SEQ ID NO: 18,
and that of SEQ ID NO: 24 was synthesized based on the
polynucleotide sequence of SEQ ID NO: 19.
[0212] PCR was conducted according to the following composition of
reaction solution and reaction conditions, wherein the
oligonucleotide primers containing the polynucleotide sequences of
SEQ ID NOs. 23 and 24 were used as primers, and the aforementioned
cDNA (A) was employed as a template. (Expand High Fidelity PCR
System by Rosche Diagnostic was used.)
4 Composition of reaction solution: cDNA library stock solution 1
.mu.l dNTP (each 2.5 mM-mix) 0.4 .mu.l Primer (20 pmol/.mu.l) 0.75
.mu.l each 10 .times. buffer (with MgCl) 5 .mu.l enz. expandHiFi
(3.5 .times. 10.sup.3 U/ml) 0.375 .mu.l Deionized water 41.725
.mu.l
[0213] Reaction Conditions:
[0214] The vessel containing reaction solution of the
aforementioned composition was set to the PERKIN ELMER-GeneAmp PCR
System 2400, and was heated at 97.degree. C. (for 2 minutes). Then
the cycle of 97.degree. C. (0.25 min.).fwdarw.55.degree. C. (0.5
min.).fwdarw.72.degree. C. (1.5 min.) was repeated ten times,
followed by the cycle of 97.degree. C. (0.25
min.).fwdarw.55.degree. C. (0.5 min.).fwdarw.72.degree. C. (2.5
min.) repeated twenty times. Further, it was maintained at
72.degree. C. for 7 minutes.
[0215] Thereafter, a part of the PCR reaction solution was
subjected to agarose gel electrophoresis. A band of a DNA fragment
of about 1000 bp was detected.
[0216] Two types of restriction enzymes (NcoI and BamHI) were added
to the remaining PCR reaction solution, and the DNA fragment of
about 1000 bp was subjected to double digestion, followed by
purification of the enzyme digested DNA fragment.
[0217] The plasmid vector pTV118N (Takara Shuzo Co., Ltd.) was
digested by two types of restriction enzymes (NcoI and BamHI), and
the digested DNA fragments were then purified.
[0218] The DNA fragments subjected to enzyme digestion were mixed
and were ligated by T4 DNA ligase. E. coli DH5.alpha. was
transformed by ligation solution obtained in the above step.
[0219] The obtained transformant was cultured in a LB agar medium
containing 50 .mu.g/ml of ampicillin. Six out of the grown colonies
were selected at random. These selected colonies were inoculated
into the sterilized LB medium (2 ml) containing 50 .mu.g/ml of
ampicillin. It was incubated under shaking in a test tube (at
30.degree. C. for 24 hours). A plasmid was prepared from each
cultured bacterial cell using the QIAprep Spin Miniprep Kit (by
Qiagen). A portion of the plasmid obtained in the above step was
subjected to double digestion by means of two types of restriction
enzymes. Then electrophoresis was carried out and all the plasmids
were verified to have about 1000 bp of the aforementioned DNA
fragments inserted therein. (This plasmid will be described as
plasmid pTRPc hereinafter).
[0220] (2) E. coli HB101 was transformed by plasmid pTRPc. The
transformant obtained was inoculated in a sterilized LB medium (100
ml) containing 0.1 mM of 1PTG and 50 .mu.l g/ml of ampicillin, and
cultivated under shaking (at 30.degree. C. for 12 hours). The
obtained cultivation solution was subjected to centrifugal
separation to obtain 0.4 g of wet bacterial cells. 300 mg of methyl
4-bromo-3-oxobutanoate, 0.4 g of the aforementioned wet bacterial
cells, 9 mg of NADP.sup.+, 750 mg of glucose, 1.2 mg of glucose
dehydrogenase (by Amano Pharmaceutical Co., Ltd.), 15 ml of 100 mM
phosphoric acid buffer solution (pH 6.5) and 15 ml of butyl acetate
were mixed and stirred at 30.degree. C. for 7 hours. During
stirring, 2M aqueous solution of sodium carbonate was gradually
added so that the pH value of the reaction solution is maintained
within a range of 6.5.+-.0.2. Then the reaction solution was
subjected to centrifugal separation to give an organic layer. This
organic layer was subjected to content analysis by gas
chromatography under the conditions given below. It was found that
methyl 4-bromo-3-hydroxybutanoate was obtained in a yield of 98.5%
in terms of the methyl 4-bromo-3-oxobutanoate used for reaction.
The optical purity of methyl (S)-4-bromo-3-hydroxybutanoate in the
organic layer was measured under the conditions given below and
found to be 96.1% e. e. This organic layer was concentrated to
obtain crude methyl (S)-4-bromo-3-hydroxybutanoate.
[0221] Content Analysis Conditions:
[0222] Column: HR-20M (0.53 mm.times.30 m, 1 .mu.m) (by Shinwa Kako
Co., Ltd.)
[0223] Column temperature: 120.degree. C. (5 min).fwdarw.3.degree.
C..fwdarw.150.degree. C. (5 min.).fwdarw.10.degree.
C./min.fwdarw.200.degree. C. (5 min.)
[0224] Carrier gas: Helium (flow rate: 20 ml/min.)
[0225] Detector: FID
[0226] Optical Purity Measuring Conditions:
[0227] Column: G-TA (0.25 cm.times.30 m, 0.125 .mu.m) (by Astech,
Ltd.)
[0228] Column Temperature: 110.degree. C. (20 min).fwdarw.5.degree.
C./min.fwdarw.180.degree. C. (1 min).
[0229] Carrier Gas: Helium (Flow rate: 1 ml/min).
[0230] Detector: FID
[0231] Split ratio: 1/50
[0232] The absolute configuration of the product was determined by
comparison with an authentic sample of methyl
(S)-4-bromo-3-hydroxybutano- ate.
EXAMPLE 3
[0233] (1) Plasmid pTRPc was subjected to double digestion by means
of two types of restriction enzymes (NcoI and BamHI), and the
resulting DNA fragments were purified. Plasmid pTrc99A (by
Pharmacia) was subjected to double digestion by means of two types
of restriction enzymes (NcoI and BamHI), and the resulting DNA
fragments were purified.
[0234] The digested DNA fragments were mixed and were ligated by T4
DNA ligase. E. coli DH5.alpha. was transformed by the ligation
solution obtained in the above step.
[0235] The transformant obtained was cultivated on a LB medium
containing 50 .mu.g/ml of ampicillin. Six out of the grown colonies
were selected at random. These selected colonies were inoculated
into the sterilized LB medium (2 ml) containing 50 .mu.g/ml of
ampicillin. It was incubated under shaking in a test tube (at
30.degree. C. for 24 hours).
[0236] Plasmids were prepared from each cultivated bacterial cell
using the QIAprep Spin Miniprep Kit (by Qiagen). A portion of the
plasmid picked up in the above step was subjected to double
digestion by means of two types of restriction enzymes (NcoI and
BamHI). Then electrophoresis was carried out and all the plasmids
were verified to have the aforementioned DNA fragments of about
1000 bp inserted therein. (This plasmid will be described as
plasmid pTrcRPc hereinafter).
[0237] (2) E. coli HB101 was transformed by plasmid pTrcRPc.
[0238] The transformant obtained was cultivated in a sterilized LB
medium (100 ml) containing 0.1 mM of IPTG and 50 .mu.g/ml of
ampicillin. It was incubated under shaking (at 30.degree. C. for 12
hours). The obtained cultivation solution was subjected to
centrifugal separation to give 0.4 g of wet bacterial cells.
[0239] 1500 mg of methyl 4-bromo-3-oxobutanoate, 0.4 g of the
aforementioned wet bacterial cells, 18 mg of NADP.sup.+, 3000 mg of
glucose, 3 mg of glucose dehydrogenase (by Amano Pharmaceutical
Co., Ltd.), 15 ml of 100 mM phosphoric acid buffer solution (pH
6.5) and 15 ml of butyl acetate were mixed and stirred at
30.degree. C. for 7 hours. While stirring, 2M aqueous solution of
sodium carbonate was gradually added thereto so that the pH of the
reaction solution is maintained with in a range of 6.5.+-.0.2. Then
the reaction solution was subjected to centrifugal separation to
obtain an organic layer. This organic layer was subjected to
content analysis under the conditions given in Example 2. It was
found that methyl 4-bromo-3-hydroxybutanoate was obtained in a
yield of 99.2% based on the consumed methyl 4-bromo-3-oxobutanoate.
The optical purity of methyl (S)-4-bromo-3-hydroxybutanoate in the
organic layer was measured under the conditions given in Example 2
and found to be 95.7% e. e.
[0240] This organic layer was further concentrated to give crude
methyl (S) 4-bromo-3-hydroxybutanoate.
EXAMPLE 4
[0241] (1) Bacillus megaterium IF012108 strain was cultivated in a
sterilized LB medium, thereby obtaining 0.4 g of bacterial cells.
From these bacterial cells, chromosomal DNA (hereinafter referred
to as "chromosome DNA (B)") was purified using the Qiagen Genomic
Tip (by Qiagen) according to the method described in the Manual
attached thereto.
[0242] (2) The oligonucleotide primers of SEQ ID NOs: 25 and 26
were synthesized based on the polynucleotide sequence of the
glucose dehydrogenase derived from Bacillus megaterium IWG3
described in the Journal of Biological Chemistry Vol. 264, NO:11,
6381-6385(1989).
[0243] PCR was conducted using the primers of SEQ ID NOs. 25 and 26
as primers and the aforementioned DNA (B) as a template in the
reaction solution of the following composition under the following
reaction conditions. (Expand High Fidelity PCR System by Rosche
Diagnostic was used.)
5 Composition of reaction solution: Chromosome DNA stock solution 1
.mu.l dNTP (each 2.5 mM-mix) 0.4 .mu.l Primer (20 pmol/.mu.l) 0.75
.mu.l each 10 .times. buffer (with MgCl) 5 .mu.l enz. expandHiFi
(3.5 .times. 10.sup.3 U/ml) 0.375 .mu.l Deionized water 41.725
.mu.l
[0244] Reaction Conditions:
[0245] The reaction vessel containing reaction solution of the
aforementioned composition was set to the PERKIN ELMER-GeneAmp PCR
System 2400, and was heated at 97.degree. C. (for 2 minutes). Then
the cycle of 97.degree. C. (0.25 min.).fwdarw.55.degree. C. (0.5
min.).fwdarw.72.degree. C. (1.5 min.) was repeated ten times,
followed by twenty times of a cycle of 97.degree. C. (0.25
min.).fwdarw.55.degree. C (0.5 min.).fwdarw.72.degree. C. (2.5
min.). Further, it was maintained at 72.degree. C. for 7
minutes.
[0246] Thereafter, a portion of the PCR reaction solution was
subjected to agarose gel electrophoresis. A band of a DNA fragment
of about 950 bp was detected.
[0247] Using the PCR reaction solutions obtained in the above step
and TOPO.TM. TA cloning kit by Invitrogen, the DNA fragment of
about 950 bp obtained in the aforementioned PCR were ligated to the
existing "PCR product insertion site" of the pCR2.1-TOPO vector.
The obtained ligation solution was utilized to transform E. coli
DH5.alpha..
[0248] 30 .mu.l of 4% aqueous solution of X-gal and 30 .mu.l of
0.1M IPTG were applied onto the LB agar medium containing 50
.mu.g/ml of ampicillin. The transformant obtained was inoculated
thereto, and was incubated. Of the colonies formed, one white
colony was picked up and was inoculated into a sterilized LB medium
(2 ml) containing 50 .mu.g/ml of ampicillin. It was incubated under
shaking in a test tube (at 30.degree. C. for 24 hours). A plasmid
was prepared by using the QIAprep Spin Miniprep Kit (by Qiagen)
from the cultivated bacterial cells. A portion of the plasmid
prepared in the above step was digested with a restriction enzyme
(EcoRI). Then electrophoresis was carried out and it was shown that
the plasmid has the aforementioned DNA fragment of about 950 bp
inserted therein. (This plasmid will be described as plasmid
pSDGDH12 hereinafter).
[0249] The polynucleotide sequence of the DNA fragment inserted
into plasmid pSDGDH12 was analyzed. The result is shown in SEQ ID
NO: 27.
[0250] Analysis of the polynucleotide sequence of the DNA fragment
inserted into the plasmid was made as follows: Sequence reaction
was carried out according to the Dye Terminator Cycle Sequence FS
Ready Reaction Kit (by Perkin Elmer) with plasmid pSDGDH12 as a
template, and the polynucleotide sequence of the obtained DNA was
analyzed by the DNA sequencer 373A (by Perkin Elmer).
[0251] (3) Plasmid pSDGDH12 was subjected to double digestion by
means of two types of restriction enzymes (BamHI and XbaI), and the
resulting DNA fragments were purified.
[0252] Plasmid pTrcRPc was subjected to double digestion by means
of two types of restriction enzymes (BamHI and XbaI), and the
resulting DNA fragments were purified.
[0253] Each of the digested DNA fragments was ligated by T4 DNA
ligase. E. coli DH5.alpha. was transformed by ligation solution
obtained in the above step. The transformant obtained was
cultivated on a LB medium containing 50 .mu.g/ml of ampicillin. Six
out of the grown colonies were selected at random. These selected
colonies were inoculated into the sterilized LB medium (2 ml)
containing 50 .mu.g/ml of ampicillin. It was incubated under
shaking in a test tube (at 30.degree. C. for 24 hours). Plasmid was
prepared from each cultivated bacterial cells using the QIAprep
Spin Miniprep Kit (by Qiagen). A portion of the plasmid prepared in
the above step was subjected to double digestion by means of two
types of restriction enzymes (BamHI and XbaI). Then electrophoresis
was carried out and all the plasmids were shown to have the
inserted DNA fragments of about 1000 bp. (This plasmid will be
described as plasmid pTrcRSbG12 hereinafter).
[0254] (4) Plasmid pTrcRSbG12 was used to transform E. coli HB101.
The transformant obtained was inoculated into a sterilized LB
medium (100 ml) containing 0.1 mM IPTG and 50 .mu.g/ml of
ampicillin. It was incubated under shaking (at 30.degree. C. for 12
hours). The incubated solution was subjected to centrifugal
separation, thereby obtaining 0.3 g of wet bacterial cells.
[0255] 0.3 g of methyl 4-bromo-3-oxobutanoate, 0.3 g of the
aforementioned wet bacterial cells, 9 mg of NADP.sup.+, 750 mg of
glucose, 15 ml of 100 mM phosphate buffer solution (pH 6.5) and 15
ml of butyl acetate were mixed and stirred at 30.degree. C. for 7
hours. While stirring, 2M aqueous solution of sodium carbonate was
gradually added so that the pH of the reaction solution is
maintained within a range of 6.5.+-.0.2. Then the reaction solution
was subjected to centrifugal separation to give an organic layer.
This organic layer was subjected to content analysis under the
conditions given in the Example 2. Methyl
4-bromo-3-hydroxybutanoate was found to have been produced in a
yield of 99% in terms of methyl 4-bromo-3-oxobutanoate used. The
optical purity of methyl (S)-4-bromo-3-hydroxybutanoate in the
organic layer was measured under the conditions given in Example 2
and was found to be 96% e. e.
[0256] This organic layer was further concentrated to give crude
methyl (S)-4-bromo-3-hydroxybutanoate.
EXAMPLE 5
[0257] (1) The oligonucleotide primer of SEQ ID NO: 29 was
synthesized based on the polynucleotide sequence of SEQ ID NO:
19.
[0258] PCR was conducted by using the oligonucleotide primers
containing the polynucleotide sequences of SEQ ID NOs. 23 and 29 as
primers, and the aforementioned plasmid pTRPc as a template in
thereaction solution of the following composition under the
following reaction conditions (Expand High Fidelity PCR System by
Rosche Diagnostic was used.).
6 Composition of reaction solution: Plasmid pTRPc solution 1 .mu.l
dNTP (each 2.5 mM-mix) 0.4 .mu.l Primer (20 pmol/.mu.l) 0.75 .mu.l
each 10 .times. buffer (with MgCl) 5 .mu.l enz. expandHiFi (3.5
.times. 10.sup.3 U/ml) 0.375 .mu.l Deionized water 41.725 .mu.l
[0259] Reaction Conditions:
[0260] The reaction vessel containing reaction solution of the
aforementioned composition was set to the PERKIN ELMER-GeneAmp PCR
System 2400, and was heated at 97.degree. C. (for 2 minutes). Then
a cycle of 97.degree. C. (0.25 min.).fwdarw.55.degree. C. (0.5
min.).fwdarw.72.degree. C. (1.5 min.) was repeated ten times,
followed by twenty cycles of 97.degree. C. (0.25
min.).fwdarw.55.degree. C. (0.5 min.).fwdarw.72.degree. C. (2.5
min.). Further, it was maintained at 72.degree. C. for 7
minutes.
[0261] Thereafter, a part of the PCR reaction solution was
subjected to agarose gel electrophoresis. A band of a DNA fragment
of about 1000 bp was detected. The remaining PCR reaction solution
was purified and digested with two types of restriction enzymes
(NcoI and BamHI), and the DNA fragment of about 1000 bp was
subjected to double digestion, followed by purification of the
enzyme digested DNA fragments.
[0262] The plasmid vector pTV118N (Takara Shuzo Co., Ltd.) was
digested by two types of restriction enzymes (NcoI and BamHI), and
the digested DNA fragments were then purified.
[0263] The DNA fragments digestion above were mixed and ligated by
T4 DNA ligase. E. coli DH5.alpha. was transformed by ligation
solution obtained in the above step.
[0264] The obtained transformant was cultivated on a LB agar medium
containing 50 .mu.g/ml of ampicillin. Six out of the grown colonies
were selected at random. These selected colonies were inoculated
into the sterilized LB medium (2 ml) containing 50 .mu.g/ml of
ampicillin. It was incubated under shaking in a test tube (at
30.degree. C. for 24 hours). A plasmid was prepared from each
cultured bacterial cell using the QIAprep Spin Miniprep Kit (by
Qiagen). A portion of the plasmid prepared in the above step was
subjected to double digestion by means of two types of restriction
enzymes (NcoI and BamHI). Then electrophoresis was carried out and
all the plasmids were shown to have the aforementioned inserted DNA
fragments of about 1000 bp. (This plasmid will be described as
plasmid pTRPcS hereinafter). The sequence of the DNA fragment
inserted into the plasmid pTRPcS was analyzed, and is shown in SEQ
ID NO: 30. Sequence analysis of the DNA fragment was conducted by a
sequence reaction using Dye Terminator Cycle sequenceing FS ready
Reaction Kit (Perkin Elmer) and plasmid pTRPcS as a template, and
obtained polynucleotide sequence of the DNA was analyzed by DNA
Sequencer 373A (Perkin Elmer).
[0265] (2) E. coli HB101 was transformed by plasmid pTRPcS. The
transformant obtained was inoculated in a sterilized LB medium (100
ml) containing 0.1 mM of 1PTG and 50 .mu.g/ml of ampicillin, and
cultivated under shaking (at 30.degree. C. for 12 hours). The
obtained cultivation solution was subjected to centrifugal
separation to obtain 0.4 g of wet bacterial cells. 300 mg of methyl
4-bromo-3-oxobutanoate, 0.4 g of the aforementioned wet bacterial
cells, 9 mg of NADP.sup.+, 750 mg of glucose, 1.2 mg of glucose
dehydrogenase (by Amano Pharmaceutical Co., Ltd.), 15 ml of 100 mM
phosphoric acid buffer solution (pH 6.5) and 15 ml of butyl acetate
were mixed and stirred at 30.degree. C. for 19 hours. While
stirring, 2M aqueous solution of sodium carbonate was gradually
added thereto so that the pH value of the reaction solution is
maintained within a range of 6.5.+-.0.2. Then the reaction solution
was subjected to centrifugal separation to give an organic layer.
This organic layer was subjected to content analysis by gas
chromatography as in Example 2. It was found that methyl
4-bromo-3-hydroxybutanoate was obtained in a yield of 97.3% in
terms of the methyl 4-bromo-3-oxobutanoate used for reaction. The
optical purity of methyl (S)-4-bromo-3-hydroxybutanoate in the
organic layer was measured under the conditions given below and
found to be 96.5% e. e. This organic layer is concentrated to give
crude methyl (S)-4-bromo-3-hydroxybutanoate.
EXAMPLE 6
[0266] (1) The oligonucleotide primers of SEQ ID NOs: 31 and 32
were synthesized based on the polynucleotide sequence of SEQ ID NO:
27.
[0267] PCR was conducted by using the oligonucleotide primers of
SEQ ID NOs. 31 and 32 as primers, and the aforementioned DNA (B) as
a template in the reaction solution of the following composition
under the following reaction conditions (Expand High Fidelity PCR
System by Rosche Diagnostic was used.).
7 Composition of reaction solution: Chromosome DNA stock solution 1
.mu.l dNTP (each 2.5 mM-mix) 0.4 .mu.l Primer (20 pmol/.mu.l) 0.75
.mu.l each 10 .times. buffer (with MgCl) 5 .mu.l enz. expandHiFi
(3.5 .times. 10.sup.3 U/ml) 0.375 .mu.l Deionized water 41.725
.mu.l
[0268] Reaction Conditions:
[0269] The reaction vessel containing reaction solution of the
aforementioned composition was set to the PERKIN ELMER-GeneAmp PCR
System 2400, and was heated at 97.degree. C. (for 2 minutes). Then
a cycle of 97.degree. C. (0.25 min.).fwdarw.55.degree. C. (0.5
min.).fwdarw.72.degree. C. (1.5 min.) was repeated ten times,
followed by twenty cycles of 97.degree. C. (0.25
min.).fwdarw.55.degree. C. (0.5 min.).fwdarw.72.degree. C. (2.5
min.). Further, it was maintained at 72.degree. C. for 7
minutes.
[0270] Thereafter, a part of the PCR reaction solution was
subjected to agarose gel electrophoresis. A band of a DNA fragment
of about 850 bp was detected. The remaining PCR reaction solution
was purified and digested with two types of restriction enzymes
(NcoI and BamHI), and the DNA fragment of about 850 bp was
subjected to double digestion, followed by purification.
[0271] The plasmid vector pTV118N (Takara Shuzo Co., Ltd.) was
digested by two types of restriction enzymes (NcoI and BamHI), and
the digested DNA fragments were then purified.
[0272] The digested DNA fragments above were mixed and ligated by
T4 DNA ligase. E. coli DH5.alpha. was transformed by ligation
solution obtained in the above step.
[0273] The obtained transformant was cultivated in a LB agar medium
containing 50 .mu.g/ml of ampicillin. Six out of the grown colonies
were selected at random. These selected colonies were inoculated
into the sterilized LB medium (2 ml) containing 50 .mu.g/ml of
ampicillin. It was incubated under shaking in a test tube (at
30.degree. C. for 24 hours). A plasmid was obtained from each
cultured bacterial cell using the QIAprep Spin Miniprep Kit (by
Qiagen). A portion of the plasmid obtained in the above step was
subjected to double digestion by means of two types of restriction
enzymes (NcoI and BamHI). Then electrophoresis was carried out and
all the plasmids were shown to have the aforementioned inserted DNA
fragments of about 850 bp. (This plasmid will be described as
plasmid pTGDH 12 hereinafter).
[0274] (2) The oligonulceotide primers of SEQ ID NO: 33 was
synthesized based on the polynucleotide sequence of plasmid vector
pTV118N (by Takara Shuzo, Co., Ltd). PCR reaction was conducted by
using the oligonucleotide primers of SEQ ID NO: 32 and NO: 33 as
primers and plasmid pTGH12 as a template in the reaction solution
of the following composition under the following reaction
conditions.
8 Composition of reaction solution: Plasmid pTGDH12 solution 1
.mu.l dNTP (each 2.5 mM-mix) 0.4 .mu.l Primer (20 pmol/.mu.l) 0.75
.mu.l each 10 .times. buffer (with MgCl) 5 .mu.l enz. expandHiFi
(3.5 .times. 10.sup.3 U/ml) 0.375 .mu.l Deionized water 41.725
.mu.l
[0275] Reaction Conditions:
[0276] The reaction vessel containing reaction solution of the
aforementioned composition was set to the PERKIN ELMER-GeneAmp PCR
System 2400, and was heated at 97.degree. C. (for 2 minutes). Then
a cycle of 97.degree. C. (0.25 min.).fwdarw.55.degree. C. (0.5
min.).fwdarw.72.degree. C. (1.5 min.) was repeated ten times,
followed by twenty cycles of 97.degree. C. (0.25
min.).fwdarw.55.degree. C. (0.5 min.).fwdarw.72.degree. C. (2.5
min.). Further, it was maintained at 72.degree. C. for 7
minutes.
[0277] Thereafter, a portion of the PCR reaction solution was
subjected to agarose gel electrophoresis. A band of a DNA fragment
of about 1000 bp was detected. The obtained DNA fragment of about
1000 bp was ligated to an existing PCR Product insertion site of
pCR2.1-TOPO vector using the PCR solution obtained above and
TOPO.TM. TA cloning kit VER. Eby Invitrongen Co., Ltd, and E. coli
DH5.alpha. was transformed with the ligation solution.
[0278] 30 .mu.l of 4% aqueous solution of X-gal and 30 .mu.l of
0.1M IPTG were applied onto the LB agar medium containing 50
.mu.g/ml of ampicillin. The transformant obtained was inoculated
thereto, and was incubated. Of the colonies formed, one white
colony was picked up and was inoculated into a sterilized LB medium
(2 ml) containing 50 .mu.g/ml of ampicillin. It was incubated under
shaking in a test tube (at 30.degree. C. for 24 hours). A plasmid
was prepared from using the QIAprep Spin Miniprep Kit (by Qiagen)
from the cultivated bacterial cells. A portion of the plasmid
prepared in the above step was digested with a restriction enzyme
(BamHI). Then electrophoresis was carried out and it was shown that
the plasmid has the aforementioned inserted DNA fragment of about
1000 bp. (This plasmid will be described as plasmid pCGDH12
hereinafter).
[0279] (3) Plasmid pCGDH12 was subjected to digestion by means of
restriction enzymes (BamHI), and the resulting DNA fragment of
about 1000 bp was purified.
[0280] Plasmid vector pACYC184 (Nippon Gene Co., Ltd.) was
subjected to digestion of a restriction enzyme (BamHI), and the
resulting DNA fragments were purified, and further dephosphorylated
with Alkaline Phosphatase (Takara Shuzo Co., Ltd) to prevent
self-ligation.
[0281] The digested DNA fragments above were mixed and ligated by
T4 DNA ligase. E. coli DH5.alpha. was transformed by ligation
solution obtained in the above step. The transformant obtained was
cultivated on LB agar medium containing 20 .mu.g/ml of
chloramphenicol. Four out of the grown colonies were selected at
random. These selected colonies were inoculated into the sterilized
LB medium (2 ml) containing 20 .mu.g/ml of chloramphenicol. It was
incubated under shaking in a test tube (at 30.degree. C. for 24
hours). Plasmid was prepared from each cultivated bacterial cells
using the QIAprep Spin Miniprep Kit (by Qiagen). A portion of the
plasmid prepared in the above step was subjected to digestion by a
restriction enzyme (BamHI). Then electrophoresis was carried out
and all the plasmids were shown to have the inserted DNA fragments
of about 1000 bp. (This plasmid will be described as plasmid
pAGDH12 hereinafter).
[0282] (4) Plasmids pTRPc and pAGDH12 were used to transform E.
coli HB101. The transformant obtained was inoculated into a
sterilized LB medium (100 ml) containing 0.1 mM IPTG and 50
.mu.g/ml of ampicillin and 20 .mu.g/ml of chloramphenicol. It was
incubated under shaking (at 30.degree. C. for 18 hours). The
incubated solution was subjected to centrifugal separation, thereby
obtaining 0.4 g of wet bacterial cells.
[0283] 0.3 g of methyl 4-bromo-3-oxobutanoate, 0.4 g of the
aforementioned wet bacterial cells, 9 mg of NADP.sup.+, 750 mg of
glucose, 15 ml of 100 mM phosphate buffer solution (pH 6.5) and 15
ml of butyl acetate were mixed and stirred at 30.degree. C. for 19
hours. While stirring, 2M aqueous solution of sodium carbonate was
gradually added so that the pH of the reaction solution is
maintained within a range of 6.5.+-.0.2. Then the reaction solution
was subjected to centrifugal separation to give an organic layer.
This organic layer was subjected to content analysis under the
conditions given in the Example 2. Methyl
4-bromo-3-hydroxybutanoate was found to have been produced in a
yield of 98.6% in terms of methyl 4-bromo-3-oxobutanoate used. The
optical purity of methyl (S)-4-bromo-3-hydroxybutanoate in the
organic layer was measured under the conditions given in Example 2
and was found to be 96.2% e. e.
[0284] This organic layer is further concentrated to give crude
methyl (S) -4-bromo-3-hydroxybutanoate.
EXAMPLE 7
[0285] Into a 500 ml Sakaguchi flask was placed 100 ml of a
sterilized medium (prepared by dissolving 200 g of potato extract
and 20 g of dextrose in 1 L of water) and inoculated with cells of
Penicillum citrinum IFO 4631. Culturing was carried out under
aerobic conditions at 30.degree. C. with shaking. The culture was
then centrifuged to harvest cells, and the harvested cells were
suspended in 5 ml of saline. To this cell suspension was added 300
ml of cold acetone, and the cells were filtered. The resulting
cells were dried under vacuum to obtain acetone-dried cells of
Penicillium citrinum IFO 4631.
[0286] To 15 mg of the acetone-dried cells of Penicillium citrinum
IFO 4631 described above were added 1.5 ml of butyl acetate in
which 15 mg of methyl 4-bromo-3-oxobutuanoate was dissolved and 1.5
ml of 100 mM phosphate buffer, pH 6.5, in which 75 mg of glucose, 9
mg of NADP.sup.+, and 15 U of glucose dehydrogenase were dissolved,
and the mixture was shaked at 30.degree. C. for 18 hours. The
reaction mixture was then centrifuged to separate the organic
layer. The organic layer was analyzed for the content with gas
chromatography, and it was confirmed that 5.5 mg of methyl
4-bromo-3-hydroxybutanoate was formed.
[0287] Analysis Conditions for Content:
[0288] Column: HR-20M (0.53 mm.times.30 m, 1 .mu.m) (manufactured
by Shinwa Kako, Ltd.).
[0289] Column Temperature: 120.degree. C. (5 min.).fwdarw.3.degree.
C/min..fwdarw.150.degree. C. (5 min.).fwdarw.10.degree.
C./min..fwdarw.200.degree. C. (5 min.).
[0290] Carrier Gas: helium (flow rate: 20 ml/min.).
[0291] Detector: FID.
[0292] Then, the methyl 4-bromo-3-hydroxybutanoate isolated by
concentrating the organic layer under vacuum was dissolved in
dichloromethane, and trifluoroacetic anhydride was added. The
mixture was allowed to stand at room temperature for one hour. This
solution was analyzed under the optical isomer analysis conditions
described below, and it was determined that the resulting methyl
(S)-4-bromo-3-hydroxybuta- noate was 98% e.e.
[0293] Analysis Conditions for Optical Isomers:
[0294] Column: Chirasil-DEX CB (0.32 mm.times.25 m, 0.25 .mu.m)
(manufactured by CHROMPACK, Ltd.).
[0295] Column Temperature: 80.degree. C. (20 min.).fwdarw.7.degree.
C./min..fwdarw.150.degree. C. (5 min.).
[0296] Carrier Gas: Helium (flow rate: 1.25 ml/min.).
[0297] Detector: FID.
[0298] In this case, the absolute configuration of the product was
determined by comparison with the authentic sample of methyl
(S)-4-bromo-3-hydroxybutanoate.
EXAMPLE 8
[0299] Into a 500 ml Sakaguchi flask was placed 100 ml of a
sterilized medium (prepared by dissolving 200 g of potato extract
and 20 g of dextrose in 1 L of water) and inoculated with cells of
Cryptococcus humicolus IFO 1527. Cultivation was carried out under
aerobic conditions at 30.degree. C. under shaking. The cultivate
was then centrifuged to harvest cells, and the harvested cells were
suspended in 5 ml of saline. To this cell suspension was added 300
ml of cold acetone, and the cells were filtered. The resulting
cells were dried under vacuum to obtain acetone-dried cells of
Cryptococcus humicolus IFO 1527.
[0300] To 15 mg of the acetone-dried cells of Cryptococcus
humicolus IFO 1527 were added 1.5 ml of butyl acetate in which 15
mg of methyl 4-bromo-3-oxobutanoate was dissolved and 1.5 ml of 100
mM phosphate buffer, pH 6.5, in which 75 mg of glucose, 9 mg of
NADP.sup.+, and 15 U of glucose dehydrogenase were dissolved, and
the mixture was shaked at 30.degree. C. for 18 hours. The reaction
mixture was then centrifuged to separate the organic layer. The
organic layer was analyzed for the content with gas chromatography,
and it was confirmed that 2.0 mg of methyl
4-bromo-3-hydroxybutanoate was formed.
[0301] Next, the methyl 4-bromo-3-hydroxybutanoate isolated by
concentrating the organic layer under vacuum was dissolved in
dichloromethane, and trifluoroacetic anhydride was added. The
mixture was allowed to stand at room temperature for one hour. This
solution was analyzed under the same optical isomer analysis
conditions as in Example 7, and it was determined that the
resulting methyl (S)-4-bromo-3-hydroxybutanoate was 88% e.e.
EXAMPLE 9
[0302] Into a 500 ml Sakaguchi flask was placed 100 ml of a
sterilized medium (prepared by dissolving 20 g of glucose, 5 g of
polypeptone, 3 g of yeast extract, 3 g of meat extract, 1 g of
potassium dihydrogen phosphate, 0.5 g of magnesium sulfate
heptahydrate, and 2 g of ammonium sulfate in 1 L of water) and
inoculated with 0.3 ml cultivated product of Bacillus alvei IFO
3343t which had been pre-cultivated in a medium having the same
composition. Cultivation was carried out at 30.degree. C. for two
days under shaking. The cultivated product was then centrifuged to
harvest cells, and the harvested cells were washed with saline and
then suspended in 5 ml of saline. To this cell suspension was added
300 ml of cold acetone, and the cells were filtered. The resulting
cells were dried under vacuum to obtain acetone-dried cells of
Bacillus alvei IFO 3343t.
[0303] To 15 mg of the acetone-dried cells of Bacillus alvei IFO
3343t described above were added 1.5 ml of butyl acetate in which
15 mg of methyl 4-bromo-3-oxobutanoate was dissolved and 1.5 ml of
100 mM phosphate buffer, pH 6.5, in which 75 mg of glucose, 9 mg of
NAD.sup.+, and 15 U of glucose dehydrogenase were dissolved, and
the mixture was shaked at 30.degree. C. for 18 hours. The reaction
mixture was then centrifuged to separate the organic layer.
[0304] The content of the product in the organic layer was analyzed
with gas chromatography, and it was found that 4.5 mg of methyl
4-bromo-3-hydroxybutanoate was formed.
[0305] Next, the methyl 4-bromo-3-hydroxybutanoate isolated by
concentrating the organic layer under reduced pressure was
dissolved in dichloromethane, and trifluoroacetic anhydride was
added thereto. The mixture was allowed to stand at room temperature
for one hour. This solution was analyzed under the same analysis
conditions as in Example 7, and it was determined that the purity
of the resulting methyl (R)-4-bromo-3-hydroxybutanoate was 96%
e.e.
EXAMPLE 10
[0306] Into a 30 l jar fermenter was placed 18 l of a sterilized
medium (prepared by dissolving 20 g of glucose, 5 g of polypeptone,
3 g of yeast extract, 3 g of meat extract, 1 g of potassium
dihydrogen phosphate, 0.5 g of magnesium sulfate heptahydrate, and
2 g of ammonium sulfate in 1 L of water) and added 180 ml culture
of Bacillus alvei IFO 3343t which had been pre-cultivated in a
medium having the same composition. Cultivation was carried out at
30.degree. C. for two days under shaking. The cultivated product
was then centrifuged to harvest cells. The harvested cells were
washed with saline and then suspended in saline. To this cell
suspension was added cold acetone, and the cells were filtered. The
resulting cells were dried under vacuum to obtain acetone-dried
cells of Bacillus alvei IFO 3343t.
[0307] To 750 mg of the acetone-dried cells of Bacillus alvei IFO
3343t described above were added 150 mg of ethyl
4,4,4-trifluoro-3-oxobutanoate and 30 ml of 100 mM phosphate
buffer, pH 6.5, in which 750 mg of glucose, 9 mg of NAD+, and 2.25
mg (70 U/mg) of glucose dehydrogenase were dissolved, and the
mixture was shaken at 30.degree. C. for 27 hours. Later, ethyl
acetate was added, and then centrifuged.
[0308] The organic layer was analyzed with gas chromatography, and
it was found that 114 mg of ethyl
4,4,4-trifluoro-3-hydroxybutanoate was formed.
[0309] (Analysis Conditions for Content)
[0310] Column: DB-1 (0.53 mm.times.30 m, 1.5 .mu.m).
[0311] Column Temperature: 40.degree. C. (5 min.).fwdarw.4.degree.
C./min..fwdarw.60.degree. C. (0 min.).fwdarw.30.degree.
C./min..fwdarw.290.degree. C. (2 min.).
[0312] Carrier Gas: Helium (flow rate: 20 ml/min.).
[0313] Detector: FID.
[0314] Next, the ethyl 4,4,4-trifluoro-3-hydroxybutanoate isolated
by concentrating the organic layer under reduced pressure was
dissolved in dichloromethane, and trifluoroacetic anhydride was
added thereto. The mixture was allowed to stand at room temperature
for one hour. This solution was analyzed under the same analysis
conditions described below, and it was determined that the purity
of the resulting ethyl (R)-4,4,4-trifluoro-3-hydroxybutanoate was
99% e.e.
[0315] (Analysis Conditions for Optical Isomers)
[0316] Column: GAMMMA-DEX 120 (0.25 mm.times.30 m, 0.25 .mu.m)
(manufactured by SUPELCO, Ltd.).
[0317] Column Temperature: 80.degree. C. (5 min.).fwdarw.5.degree.
C./min..fwdarw.130.degree. C..fwdarw.20.degree.
C./min..fwdarw.200.degree- . C. (5 min.)
[0318] Carrier Gas: Helium (flow rate: 1.25 ml/min.).
[0319] Detector: FID.
EXAMPLE 11
[0320] Into a flask was placed 900 ml of liquid medium (prepared by
dissolving 10 g of tryptone, 5 g of yeast extract, and 5 g of
sodium chloride in 1000 ml of water, and adding dropwise 1 N
aqueous sodium hydroxide solution to adjust the pH to 7.0) and
sterilized, and then ampicilin and isopropyl
thio-.beta.-galactoside (IPTG) were added to make a concentration
of 100 .mu.g/ml and 0.4 mM, respectively. This medium was
inoculated with 1 ml of the cultivated liquid resulting from
cultivation, in the liquid medium having the above-mentioned
composition, a transformed E. coli strain JM109/pUAR obtained by
transforming an E. coli strain JM109 by a conventional method using
plasmid pUAR containing the DNA shown in SEQ ID NO: 35 (Deposition
No. FERM BP-7752 undr the Butapest Treaty), and cultivated at
37.degree. C. for 14 hours with shaking. The culture was
centrifuged (15000 xg, 15 minutes, 4.degree. C.) to harvest cells,
which were suspended in 30 ml of 50 mM monopotassium
phosphate-dipotassium phosphate buffer (pH 7.0), followed by
centrifugation (15000 xg, 15 minutes, 4.degree. C.) to obtain
washed cells.
[0321] To 50 ml of 50 mM monopotassium phosphate-dipotassium
phosphate buffer (pH 7.0) containing 5% of 2-propanol were added
0.1 mmol of NAD.sup.+ and 6 g of the washed cells described above.
To this mixture was added 50 ml of decane containing 70 mg (0.31
mmol) of isopropyl 4-bromo-3-oxobutanoate, and the mixture was
stirred at room temperature for a night and day. Celite was then
put into the reaction solution, and stirred for a while and
filtered off to separate the resultant solution. The aqueous layer
was further extracted three times with ethyl acetate, and combined
organic layers were concentrated to give 50 mg of isopropyl
4-bromo-3-hydroxybutanoate.
[0322] .sup.1H-NMR (CDCl.sub.3) .delta.(ppm): 1.26 (6H), 2.60 (2H),
3.21 (1H), 3.50 (2H), 4.19-4.28 (1H), 5.02-5.11 (1H).
[0323] Chemical purity: 99% (GC).
[0324] Optical purity: 77% e.e. (HPLC, a Daicel chiralcel OD
column.
[0325] Mobile phase: hexane/isopropanol=98/2 plus 0.1%
trifluoroacetic acid, 0.5 ml/min., UV 220 nm).
[0326] Retention time: 21 minutes.
[0327] The following describes Reference Example for producing the
authentic sample for determining the optical purity of isopropyl
4-bromo-3-hydroxybutanoate.
REFERENCE EXAMPLE 2
[0328] Twenty-three grams of isopropyl 3-oxobutanoate was dissolved
in methylene chloride, and 26 g of bromine was added dropwise while
cooling it on ice. The mixture was heated to room temperature and
stirred for 8 hours, after which the reaction solution was
concentrated to 35 g of isopropyl 4-bromo-3-hydroxybutanoate.
[0329] Four grams of isopropyl 4-bromo-3-hydroxybutanoate was
dissolved in 50 ml of ethanol, and while cooling it on ice, a
suspension of 4.04 g of sodium boron hydride in 10 ml of ethanol
was slowly added dropwise. After adding was completed, acetic acid
was added to the reaction solution, water layer and ethyl acetate
layer were separated. The organic layer was dried over anhydrous
sodium sulfate, and concentrated. The resulting residue was
subjected to a column chromatography on silica gel (developing
solvent: hexane/ether) to give 1.3 g of isopropyl
4-bromo-3-hydroxybutanoate.
[0330] .sup.1H-NMR (CDCl.sub.3) .delta.(ppm): 1.26 (6H), 2.60 (2H),
3.21 (1H), 3.50 (2H), 4.19-4.28 (1H), 5.02-5.11 (1H).
[0331] The resulting isopropyl 4-bromo-3-hydroxybutanoate was
analyzed by HPLC using a Daicel chiralcel OD column (mobile phase:
hexane/2-propanol=98/2 plus 0.1% trifluoroacetic acid, 0.5 ml/min.,
a UV detector at 220 nm), giving an almost equal area ratio of two
peaks at a retention time of 19 and 21 minutes.
EXAMPLE 12
[0332] 1.6 g of calcium chloride (15 mmol) and 0.6 g (8.1 mmol) of
calcium hydroxide were dissolved in 3.7 ml of water and stirred at
room temperature for 20 minutes. At the same temperature, 2.00 g
(10 mmol) of methyl 4-bromo-3-hydroxybutanoate was added dropwise
over 5 minutes. After stirring for further ten minutes, the mixture
was cooled by ice, and 0.6 g (12 mmol) of sodium cyanide was added
thereto. Then, the mixture was stirred at an internal temperature
of 25 to 33.degree. C. for 4.5 hours. Then, concentrated
hydrochloric acid was added dropwise in the reaction solution, and
ethyl acetate was used for extraction five times. The organic layer
was concentrated under reduced pressure to get 1.2 g of
4-cyano-3-hydroxybutanoic acid. The purity of the obtained
4-cyano-3-hydroxybutanoic acid was 91% (high-performance liquid
chromatography in area percentage).
EXAMPLE 13
[0333] 35 g of 4-cyano-3-hydroxybutanoic acid was dissolved in 250
g of ethyl acetate, and 41 g of triethylamine and 54 g of diethyl
sulfate were added thereto at room temperature. Then, the mixture
was stirred at an internal temperature of 55 to 60.degree. C. for
30 minutes. After the reaction solution was left cooled down to
room temperature, it was added to a saturated sodium bicarbonate
solution, and ethyl acetate was used for extraction. The organic
layer was washed with saturated saline solution, and the residue
obtained by concentrating under reduced pressure was subjected to
distillation under reduced pressure, whereby 24.5 g of ethyl
4-cyano-3-hydroxybutanoate was obtained. The purity of the obtained
ethyl 4-cyano-3-hydroxybutanoate was 99% (gas chromatography in
area percentage).
EXAMPLE 14
[0334] 22.8 g (205 mmol) of calcium chloride and 8.4 g (114 mmol)
of calcium hydroxide were dissolved in 50 g of water and stirred
for 20 minutes. Then, 28.0 g (142 mmol) of methyl
4-bromo-3-hydroxybutanoate was added dropwise at room temperature
over 5 minutes. The mixture was stirred at room temperature for 10
minutes and then cooled by ice, and 8.7 g (178 mmol) of sodium
cyanide was added thereto. Then, the mixture was further stirred at
an internal temperature of 25 to 33.degree. C. for 4.5 hours. Then,
concentrated hydrochloric acid was added dropwise, and ethyl
acetate was used for extraction five times. The residue that was
obtained by concentrating the organic layer under reduced pressure
was dissolved in ethyl acetate and dried over anhydrous magnesium
sulfate. The solution from which magnesium sulfate was removed
through filtration was cooled with ice, and 20.0 g (198 mmol) of
triethylamine and 26.5 g (172 mmol) of diethyl sulfate were added
thereto. It was stirred for about 30 minutes while gradually
heating to room temperature. It was further stirred at an internal
temperature of 55 to 63.degree. C. for 40 minutes. Then, the
reaction solution was cooled by ice and 50 ml of saturated sodium
hydrogen carbonate was added thereto, which was then stirred. This
solution was separated, and solution layer was subjected again to
extraction with ethyl acetate. Combined organic layers were washed
with saturated saline solution dried over anhydrous magnesium
sulfate, and concentrated. The residue was subjected to the
distillation under reduced pressure and 15.7 g of ethyl
4-cyano-3-hydroxybutanoate was obtained. The purity of the obtained
ethyl 4-cyano-3-hydroxybutanoate was 95% (gas chromatography in
area percentage).
EXAMPLE 15
[0335] Into a 500 ml Sakaguchi flask was placed 100 ml of a
sterilized medium (prepared by dissolving 200 g of potate extract
and 20 g of dextrose in 1 L of water) and inoculated with 0.3 ml
cultivated product of Penicillium citrinum IFO 4631. Cultivation
was aerobically carried out at 30.degree. C. under shaking. The
cultivated product was then centrifuged to harvest cells, and the
harvested cells were washed with saline. To this cell suspension
was added 300 ml of cold acetone, and the cells were collected by
filtration. The collected cells were dried at room temperature
under vacuum to obtain acetone-treated cells of Penicillium
citrinum IFO 4631. The same procedure was repeated 15 times to give
150 g of the acetone-treated cells of Penicililum citrinum IFO
4631
[0336] A solution was prepared by dissolving 75 g of glucose, 0.85
g of oxidized form of nicotine adenine dinucleotide phosphate, 0.11
g of glucose dehydrogenase (glucose amino 2; by Amano enzyme) in
1500 g of a phosphate buffer solution (pH 6.5) and 1300 g of butyl
acetate and 37 g of methyl 4-bromo-3-oxobutanoate were added
thereto, and then 150 g of the acetone-treated cells of Penicillium
citrinum IFO 4631described above were added to thereto under
stirring. 15% aqueous sodium carbonate solution was dropwise added
thereto so that the pH of the reaction solution is maintained
within a range of from 6.5.+-.0.5. After stirring for 24 hours, 90
g of celite were added thereto and filtered under reduced pressure.
The organic layer separated from the filtrate was concentrated
under reduced pressure to give 28 g of methyl
(S)-4-bromo-3-hydroxybutanoate.
[0337] Chemical Purity: 88%, Optical purity: 97% e.e.
[0338] Analysis of Chemical Purity:
[0339] Column: HR-20M (0.53 mm.times.30 m, 1 .mu.m) (manufactured
by Shinwa Kako, Ltd.).
[0340] Column Temperature: 120.degree. C. (5 min.).fwdarw.3.degree.
C./min..fwdarw.150.degree. C. (5 min.).fwdarw.10.degree.
C./min..fwdarw.200.degree. C. (5 min.).
[0341] Carrier Gas: helium (flow rate: 20 ml/min.).
[0342] Detector: FID.
[0343] Analysis of Optical Purity:
[0344] High performance Liquid chromatography
[0345] Column: Daicel chiralcel OD column (4.6 mm.phi..times.25 cm,
10 .mu.m)
[0346] Mobile phase: hexane/2-propanol, 0.5 ml/min.,
[0347] Column Temperature: 40.degree. C.,
[0348] Detector: UV (220 nm)
[0349] 23 g of calcium chloride and 8.4 g of calcium hydroxide were
dissolved in 50 g of water and stirred for 20 minutes. Then, 28.0 g
of methyl (S)-4-bromo-3-hydroxybutanoate obtained above was added
dropwise at room temperature over 5 minutes. The mixture was
stirred at room temperature for 10 minutes and then cooled by ice,
and 8.7 g of sodium cyanide was added thereto. Then, the mixture
was further stirred at an internal temperature of 25 to 33.degree.
C. for 4.5 hours. Then, concentrated hydrochloric acid was added
dropwise to the reaction solution to make the pH thereof less than
1, and extracted with ethyl acetate five times. The combined
organic layers were concentrated under reduced pressure to give a
residue, which was dissolved in ethyl acetate and dried over
anhydrous magnesium sulfate. Magnesium sulfate was removed by
filtration to give a solution of (R)-4-cyano-3-hydroxybutanoic
acid.
[0350] The solution was cooled with ice, and 20.0 g (198 mmol) of
triethylamine and 27 g of diethyl sulfate were added thereto. It
was stirred for about 30 minutes while gradually heating to room
temperature. It was further stirred at an internal temperature of
55 to 63.degree. C. for 40 minutes. Then, the reaction solution was
cooled by ice and 50 ml of saturated sodium hydrogen carbonate was
added thereto, and separated. Aqueous layer was again extracted
with ethyl acetate. Combined organic layers were washed with
saturated saline solution dried over anhydrous magnesium sulfate,
and concentrated. The residue was concentrated under reduced
pressure to give 14 g of ethyl (R)-4-cyano-3-hydroxybutanoate.
(Purity: 95%, Optical purity: 97% e.e.)
[0351] MS (EI, m/z): 157(M.sup.+),
[0352] .sup.1H-NMR (CDCl.sub.3) .delta.(ppm): 1.29 (t, 6H),
2.57-2.71(m, 4H), 3.57(d, 1H), 4.20(q, 2H), 4.30-4.39(m, 1H).
[0353] [.alpha.].sub.D.sup.25 -28.degree. (c: 1.02, CHCl.sub.3)
[0354] "Free Text for Sequence Table"
[0355] SEQ ID NO: 8
[0356] Oligonucleotide primer designed for PCR
[0357] SEQ ID NO: 9
[0358] Oligonucleotide primer designed for PCR
[0359] SEQ ID NO: 10
[0360] Oligonucleotide primer designed for PCR
[0361] SEQ ID NO: 11
[0362] Oligonucleotide primer designed for PCR
[0363] SEQ ID NO: 12
[0364] Oligonucleotide primer designed for PCR
[0365] SEQ ID NO: 13
[0366] Oligonucleotide primer designed for PCR
[0367] SEQ ID NO: 14
[0368] Oligonucleotide primer designed for PCR
[0369] SEQ ID NO: 16
[0370] Oligonucleotide primer designed for PCR
[0371] SEQ ID NO: 17
[0372] Oligonucleotide primer designed for PCR
[0373] SEQ ID NO: 20
[0374] Oligonucleotide primer designed for PCR
[0375] SEQ ID NO: 21
[0376] Oligonucleotide primer designed for PCR
[0377] SEQ ID NO: 23
[0378] Oligonucleotide primer designed for PCR
[0379] SEQ ID NO: 24
[0380] Oligonucleotide primer designed for PCR
[0381] SEQ ID NO: 25
[0382] Oligonucleotide primer designed for PCR
[0383] SEQ ID NO: 26
[0384] Oligonucleotide primer designed for PCR
[0385] SEQ ID NO: 27
[0386] Oligonucleotide primer designed for PCR
[0387] SEQ ID NO: 28
[0388] Oligonucleotide primer designed for PCR
[0389] SEQ ID NO: 29
[0390] Oligonucleotide primer designed for PCR
[0391] SEQ ID NO: 30
[0392] Oligonucleotide primer designed for PCR
[0393] SEQ ID NO: 31
[0394] Oligonucleotide primer designed for PCR
[0395] SEQ ID NO: 32
[0396] Oligonucleotide primer designed for PCR
[0397] SEQ ID NO: 33
Sequence CWU 0
0
* * * * *