CN109321541B - Mutant of L-amino acid oxidase - Google Patents
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- CN109321541B CN109321541B CN201811350819.5A CN201811350819A CN109321541B CN 109321541 B CN109321541 B CN 109321541B CN 201811350819 A CN201811350819 A CN 201811350819A CN 109321541 B CN109321541 B CN 109321541B
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Abstract
The invention discloses a mutant of L-amino acid oxidase, a preparation method and application thereof, belonging to the technical field of genetic engineering. The mutant Q183A is obtained by carrying out site-directed mutagenesis on L-amino acid oxidase derived from corynebacterium glutamicum, and the mutant Q183A is subjected to heterologous expression in escherichia coli, so that the catalytic efficiency of the obtained recombinant bacterium on L-valine is improved by 18.7%, the yield of alpha-ketoisocaproic acid reaches 54.6g/L, and the molar conversion rate of a substrate is 84.6%. Compared with a chemical method, the whole-cell transformation method provided by the invention has the advantages of mild reaction conditions, single target product, easiness in separation, environmental friendliness and the like, and is simple in process, convenient to control and easy to popularize and apply.
Description
Technical Field
The invention relates to a mutant of L-amino acid oxidase, a preparation method and application thereof, belonging to the technical field of genetic engineering.
Background
L-amino acid oxidase is an oxidoreductase which catalyzes the production of an alpha-keto acid from an L-amino acid. Researchers have conducted extensive studies on the spatial structure, substrate specificity, and catalytic ability of an L-amino acid oxidase to a non-natural substrate, and in recent years, the application of the enzyme to the bioconversion production of an alpha-keto acid has attracted attention.
The alpha-keto acid is an important intermediate, and is mainly applied to the fields of food, medicine, cosmetics and the like, so that the enzymatic conversion of the alpha-keto acid has wide application in industrial production. L-amino acid oxidase is a flavoproteinase, and the oxidative deamination of L-amino acids can be divided into two steps: firstly amino acid CαThe hydrogen is transferred to FAD, the amino acid is changed into imino acid, and the imino acid is unstably decomposed into alpha-keto acid and water. Then FADH2Oxidized by oxygen molecules to become reduced FAD. The L-amino acid oxidase has wide substrate spectrum and high catalytic efficiency, which provides possibility for transforming L-valine to produce alpha-ketoisovalerate by heterologously expressed amino acid oxidase.
However, the existing method for improving L-amino acid improves the yield and conversion rate of alpha-ketoisovalerate to a certain extent, but the yield is still very low, so that in order to improve the yield and conversion rate of alpha-ketoisovalerate and enhance the industrial application value of alpha-ketoisovalerate, the improvement of the catalytic efficiency of L-amino acid oxidase on L-valine is urgently needed.
Disclosure of Invention
The first object to be solved by the present invention is to provide a mutant of an L-amino acid oxidase, which comprises an amino acid sequence shown in SEQ ID NO.1 in the amino acid sequence of the mutant, or which is shown in SEQ ID NO. 1.
It is a second object of the invention to provide a gene encoding a mutant of said L-amino acid oxidase.
In one embodiment of the invention, the mutant L-amino acid oxidase is Q183A, and the nucleotide sequence of the gene encoding it is shown in SEQ ID NO. 2.
It is a third object of the present invention to provide a method for constructing the mutant, which comprises:
(1) cloning L-amino acid oxidase encoding gene derived from Corynebacterium glutamicum;
(2) connecting the L-amino acid oxidase coding gene of the corynebacterium glutamicum obtained in the step (1) with pET series vectors to obtain pET series vectors carrying L-amino acid oxidase genes derived from the corynebacterium glutamicum;
(3) determining mutation sites by structural analysis on the basis of L-amino acid oxidase homologous modeling of corynebacterium glutamicum sources; and (3) designing a site-directed mutagenesis primer by taking the ligation product in the step (2) as a template, carrying out site-directed mutagenesis PCR to obtain a mutagenesis plasmid Q183A-pET series vector, and transforming the mutagenesis plasmid into escherichia coli for expression.
It is a fourth object of the present invention to provide a method for improving the catalytic efficiency of L-valine by an L-amino acid oxidase, which comprises mutating the amino acid glutamine Gln at position 183 of an L-amino acid oxidase derived from Corynebacterium glutamicum to alanine Ala.
In one embodiment of the invention, the L-amino acid deaminase derived from Corynebacterium glutamicum has Genbank accession number AJE67504 and contains 380 amino acids.
The fifth purpose of the invention is to provide a method for improving the yield of alpha-ketoisovalerate, which is to convert a substrate containing L-valine to obtain the alpha-ketoisovalerate by using the L-amino acid oxidase mutant strain as a whole-cell catalyst.
In one embodiment of the present invention, a transformation system comprising whole cells at a final concentration of 25 to 35g/L, L-valine at a final concentration of 60 to 70g/L, and Tris buffer (pH 8.0) at a final concentration of 20mM is allowed to react at 20 to 37 ℃ for 20 to 24 hours.
In one embodiment of the present invention, the genetically engineered bacteria are cultured, and the culture medium is collected and centrifuged to obtain a cell body.
In one embodiment of the invention, the genetically engineered bacteria are cultured in LB medium at 37 ℃ for 12-16h, the culture solution is inoculated into the fermentation medium according to the inoculation amount of 2%, and the culture solution is cultured to OD at 35-37 DEG C6000.6-0.8, adding IPTG with final concentration of 0.4-0.6mM into the fermentation medium, inducing at 25-30 deg.C for 10-12h, collecting the fermentation liquor, and centrifuging to obtain thallus.
In one embodiment of the invention, the LB medium used for culturing the strain contains per liter: 10g of peptone, 5g of yeast powder, 10g of sodium chloride and distilled water to a constant volume of 1L.
In one embodiment of the invention, the fermentation medium used for the fermentation contains per liter: peptone 12g, yeast extract 24g, glycerin 4mL, potassium dihydrogen phosphate 2.31g, dipotassium hydrogen phosphate 16.42 g.
The invention also claims the application of the mutant in the fields of food, medicine and chemical industry, such as improving the yield of the alpha-keto acid applied in the fields of food, medicine, cosmetics and the like.
Has the advantages that: the invention provides an L-amino acid oxidase mutant and a preparation method and application thereof, wherein the L-amino acid oxidase mutant Q183A is transformed into escherichia coli for expression, the obtained recombinant bacteria can efficiently catalyze L-valine to generate alpha-ketoisocaproic acid, the yield of the alpha-ketoisocaproic acid reaches 54.6g/L, and the molar conversion rate of a substrate reaches 84.6%. Compared with the recombinant bacteria expressing the original L-amino acid oxidase, the recombinant bacteria expressing the L-amino acid oxidase mutant Q183A have the catalytic efficiency on L-valine improved by 18.7 percent. Compared with a chemical method, the whole-cell transformation method provided by the invention has the advantages of mild reaction conditions, single target product, easiness in separation, environmental friendliness and the like, and is simple in process, convenient to control and easy to popularize and apply.
Drawings
FIG. 1 shows the mass spectrum of recombinant bacterium expressing L-amino acid oxidase mutant Q183A, wherein the mass spectrum of recombinant bacterium catalyzing L-valine to generate ketovaline A: STANDARD, a ketovaline sodium STANDARD; SAMPLE, namely a reaction product.
FIG. 2 shows the yield of alpha-ketoisovalerate produced by recombinant bacteria expressing L-amino acid oxidase mutants, WT is recombinant bacteria expressing wild-type L-amino acid oxidase; q183: recombinant bacteria expressing the mutant L-amino acid oxidase.
Detailed Description
LB culture medium: 10g of peptone, 5g of yeast powder, 10g of sodium chloride and distilled water to a constant volume of 1L.
Fermentation medium: (TB Medium): peptone 12g, yeast extract 24g, glycerin 4mL, potassium dihydrogen phosphate 2.31g, dipotassium hydrogen phosphate 16.42g, distilled water to constant volume of 1L.
Sample preparation: 1mL of the transformed transformation solution was centrifuged at 12000rpm for 5min, the supernatant was diluted and filtered through a 0.45 μm filter, and the filtrate was subjected to liquid chromatography.
Content determination of alpha-ketoisovalerate: a waters high performance liquid chromatograph (equipped with an ultraviolet visible detector) adopts a BerleAminex HPX-87H (300 multiplied by 7.8mm, 9 mu m) chromatographic column, the mobile phase is dilute sulfuric acid with the concentration of 2.5mmol/L, the mobile phase is filtered by a 0.22 mu m filter membrane, ultrasonic degassing is carried out, the flow rate is 0.6mL/min, the column temperature is 35 ℃, and the detection is carried out at the ultraviolet detection wavelength of 210 nm.
EXAMPLE 1 preparation of L-amino acid oxidase mutant
Using the genome of corynebacterium glutamicum as a template, designing primers to perform PCR, and cloning L-amino acid oxidase coding genes derived from corynebacterium glutamicum, wherein the primers are as follows: to be provided with
As a forward primer, to
Obtaining target genes (the bold parts are respectively Xho I and hind III enzyme cutting sites) for reverse primer amplification; PCR procedure: pre-denaturation at 95 ℃ for 3min, denaturation at 95 ℃ for 3min and then entering the following cycle: denaturation at 98 deg.C for 10s, annealing at 55 deg.C for 30s, and extension at 72 deg.C for 1min for 40 s; 34 cycles of treatment; extending for 10min at 72 ℃, and keeping the temperature at 4 ℃.
The target gene and the expression vector pET28a 37 are cut by restriction enzymes XhoI and hind III for 2h at 37 ℃, and then the cut and glue-recovered target gene and the plasmid pET28a 16 are respectively connected by T4 ligase for 10h at 16 DEG C
A pET28a plasmid (abbreviated as cg-pET28a) connected with a Corynebacterium glutamicum L-amino acid oxidase coding gene is used as a template, a PCR product with the size of about 1143bp is obtained by one-time PCR by using a mutation primer of Q183A, the PCR product is treated by Dpn I and transformed into escherichia coli JM109 competent cells, and a transformant is selected for sequencing verification.
The mutation primers are shown below (underlined parts are mutation sites): Q183A mutant primer pair:
upstream of P1-Q183A, 5' -agtcatccaagcaggcg-3’；
Downstream of P2-Q183A, 5' -cgcctgcttggatgact-3’。
The PCR systems are all as follows:
the PCR conditions were all as follows:
pre-denaturation at 95 ℃ for 3min, denaturation at 95 ℃ for 3min and then entering the following cycle: denaturation at 98 deg.C for 10s, annealing at 55 deg.C for 30s, and extension at 72 deg.C for 1min for 40 s; 34 cycles of treatment; extending for 10min at 72 ℃, and keeping the temperature at 4 ℃.
Sequencing results show that random mutation does not occur except the required mutation sites, so that the mutant plasmid Q183A-pET28a is successfully constructed.
Example 2 inducible expression of L-amino acid oxidase mutant Q183A
The mutation Q183A-pET28a was transformed into E.coli BL21(DE3) cells, and transformants were selected for sequencing verification. The positive transformants after the verification were cultured overnight at 37 ℃ in LB medium, then inoculated into TB medium at an inoculum size of 2%, and cultured to OD600When the concentration is about 0.6-0.8, IPTG is added to the mixture to a final concentration of 0.04mM, and the mixture is induced at 25 ℃ for 12 h.
Collecting fermentation liquor, centrifuging at 8000rpm for 8min at 4 deg.C, and collecting thallus.
Example 3: catalytic efficiency of recombinant bacteria on L-valine
The catalyzed reaction system was 20mL, including recombinant E.coli whole cells at a final concentration of 30g/L, substrate 70 g/L-valine, and 20mM Tris buffer (pH 8.0), and samples were taken after 24 hours of reaction at 200rpm and 25 ℃ and analyzed by HPLC. The catalytic efficiency is calculated by the amount of product formed.
The mass spectrum of the reaction product obtained by catalyzing L-valine by the recombinant bacteria expressing the L-amino acid oxidase mutant Q183A is shown in FIG. 1, and the comparison of the mass spectrum of the ketovaline standard product and the reaction solution proves that the reaction product is ketovaline. The catalysis result is shown in figure 2, the yield of the recombinant bacterium expressing the L-amino acid oxidase mutant Q183A after being catalyzed for 24 hours can reach 54.6g/L, the conversion rate reaches 84.6%, while the yield of the recombinant bacterium expressing the wild-type L-amino acid oxidase after being catalyzed for 24 hours is 46g/L, and the conversion rate is 70.1%.
Comparative example
(1) Construction of L-amino acid oxidase mutant F33A (the construction method is the same as in example 1)
The mutation primers are shown below (bold is the mutation site): F33A mutant primer pair
P1-F33A upstream:
downstream of P2-F33A:
(2) inducible expression of L-amino acid oxidase mutant F33A
The expression of the L-amino acid oxidase mutant F33A was carried out in the same manner as in example 1.
(3) Catalytic efficiency of recombinant bacteria on L-valine
The yield can reach 26g/L after the recombinant bacteria expressing the L-amino acid oxidase mutant F33A are catalyzed for 24 hours, the conversion rate is only 40 percent, while the yield is 46g/L after the recombinant bacteria expressing the wild type L-amino acid oxidase are catalyzed for 24 hours, and the conversion rate is 70.1 percent. Thus, the catalytic efficiency of F33A was much lower than the wild type.
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
SEQUENCE LISTING
<110> university of south of the Yangtze river
WUXI CHENMING BIOTECHNOLOGY Co.,Ltd.
<120> a mutant of L-amino acid oxidase
<160> 2
<170> PatentIn version 3.3
<210> 1
<211> 380
<212> PRT
<213> Artificial Synthesis
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Met Lys Ile Ala Val Ile Gly Leu Gly Ser Thr Gly Ser Met Ala Leu
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Pro Phe Gln Arg Leu Val Glu Ser Val Glu Arg Tyr Glu Leu Pro His
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<213> Artificial Synthesis
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gcattcacag gggagtcccg actgtttcgc atggcctacc acgaaggcag cacctacgtt 180
ccgttgctca aacgcgcacg agcactatgg tcatcactga gcgagatttc cggacgcgaa 240
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gtcatcgcag caggcgaaga aaccacaatc gtggaccgcg ttatcgtcac caccggcagt 600
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acctggttcc tgcccaacaa cccagtggac ttccagccgg aaaacctgcc atgcttcatc 720
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ag 1142
Claims (10)
1. A mutant of L-amino acid oxidase, characterized in that the amino acid sequence of the mutant of L-amino acid oxidase is shown in SEQ ID NO. 1.
2. A gene encoding a mutant of the L-amino acid oxidase of claim 1.
3. A vector comprising the gene of claim 2.
4. A method for constructing a mutant of an L-amino acid oxidase of claim 1,
(1) cloning L-amino acid oxidase encoding gene derived from Corynebacterium glutamicum;
(2) connecting the L-amino acid oxidase coding gene of the corynebacterium glutamicum obtained in the step (1) with pET series vectors to obtain pET series vectors carrying L-amino acid oxidase genes derived from the corynebacterium glutamicum;
(3) and (3) designing a site-directed mutagenesis primer by taking the ligation product in the step (2) as a template, carrying out site-directed mutagenesis PCR to obtain a mutagenesis plasmid Q183A-pET series vector, and transforming the mutagenesis plasmid into escherichia coli for expression.
5. A method for improving the catalytic efficiency of L-valine by an L-amino acid oxidase, which comprises mutating the amino acid glutamine Gln at position 183 of an L-amino acid oxidase derived from Corynebacterium glutamicum (Corynebacterium glutamicum) to alanine Ala; the amino acid sequence after mutation is shown as SEQ ID NO. 1.
6. A genetically engineered bacterium which expresses the mutant L-amino acid oxidase of claim 1.
7. A method for improving the yield of alpha-ketoisovalerate, characterized by using the genetically engineered bacterium of claim 6 as a whole-cell catalyst to convert a substrate containing L-valine to obtain alpha-ketoisovalerate.
8. The method according to claim 7, wherein the transformation system containing the whole cells at a final concentration of 25 to 35g/L and the L-valine at a final concentration of 60 to 70g/L is allowed to react at 20 to 37 ℃ for 20 to 24 hours.
9. The method according to claim 8, wherein the genetically engineered bacterium according to claim 6 is cultured, and the culture medium is collected and centrifuged to obtain a cell body.
10. The mutant of claim 1 or the recombinant bacterium of claim 6, which is used in the fields of food, medicine, and chemical industry.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105316257A (en) * | 2015-10-23 | 2016-02-10 | 重庆邮电大学 | lysinibacillus xylanilyticus and method for preparing alpha-ketoacid with same |
| CN107988131A (en) * | 2018-01-15 | 2018-05-04 | 江南大学 | A kind of method of high yield α -one-γ-methylmercapto butyric acid |
-
2018
- 2018-11-14 CN CN201811350819.5A patent/CN109321541B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105316257A (en) * | 2015-10-23 | 2016-02-10 | 重庆邮电大学 | lysinibacillus xylanilyticus and method for preparing alpha-ketoacid with same |
| CN107988131A (en) * | 2018-01-15 | 2018-05-04 | 江南大学 | A kind of method of high yield α -one-γ-methylmercapto butyric acid |
Non-Patent Citations (7)
| Title |
|---|
| A role for glutamine 183 in the folate oxidative half-reaction of methylenetetrahydrofolate reductase from Escherichia coli;Chong Zuo等;《Archives of Biochemistry and Biophysics》;20180515;第642卷;第63-74页 * |
| amino acid oxidase [Corynebacterium glutamicum];Genbank;《Genbank》;20150826;第1-2页 * |
| Ligand complex structures of l-amino acid oxidase/monooxygenase from Pseudomonas sp. AIU 813 and its conformational change;Im D.,等;《FEBS Open Bio》;20180208;第8卷(第3期);第314-324页 * |
| N-methyl-L-tryptophan oxidase [Corynebacterium glutamicum];Genbank;《Genbank》;20170805;第1页 * |
| Rational molecular engineering of L-amino acid from L-valine by Escherichia coli;Ruoxi Li等;《RSC Advances》;20171231;第7卷;第6615-6621页 * |
| The X-ray structure of N-methyltryptophan oxidase reveals the structural determinants of substrate specificity;Ilari A.,等;《Proteins》;20080630;第71卷(第4期);第2065-2075页 * |
| 酶法转化生产α-酮酸的研究进展;张权等;《生物工程学报》;20190725;第35卷(第7期);第1193-1205页 * |
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