14 results about "Methionine synthetase" patented technology

The application provides a method for preparing cross-linking enzyme based on a tyrosinase mutant, the cross-linking enzyme and application thereof. The tyrosinase mutant is mixed with an ultrasonic broken solution of S-adenosylmethionine synthetase containing a tyrosine tag to obtain water-insoluble cross-linking enzyme particles, the cross-linking enzyme is collected by centrifugation or filtration and the like, and enzymatic conversion is carried out. It is found that the cross-linking enzyme of S-adenosylmethionine synthetase can be continuously and stably used for 6 batches, and the activity retention is 85%. The cross-linking enzyme particles prepared by the method have the characteristics of easy recovery, reusability and low cost, and have good industrial application value.

The application discloses a kind of S-methionine synthetase mutant and application, belong to biological enzyme engineering technical field.The wild strain of S-methionine synthesis mutant of the application is derived from Escherichia coli, the 266th position of S-methionine synthetase is subjected to site-directed mutagenesis, and the mutant with improved conversion rate is obtained.The enzyme activity of the mutant is 2.77 times higher than that of the parent WT, and under the conditions that the substrate L-Met is 12mM and the ATP concentration is 12mM, the synthesis yield of S-methionine reaches 4.15g / L, and the conversion rate reaches 86.80%.The enzyme mutant provided in the application has a broad prospect in the production of S-methionine and the construction of S-methionine gene engineering application.

The invention provides application of citrus S-adenosylmethionine synthetase in improving self-incompatibility, and belongs to the technical field of biological genetic engineering, and the gene sequence of the citrus S-adenosylmethionine synthetase is shown as SEQ ID: 1. Experiments prove that citrus S-adenosylmethionine synthetase directly interacts with S-RNase to regulate and control a methionine metabolic pathway so as to influence the growth of a pollen tube; the invention discloses a dual regulation and control effect of the citrus S-adenosylmethionine synthetase in a self-incompatible reaction, and provides a new target for improving the self-compatibility of crops. According to the method, the citrus S-adenosylmethionine synthetase is added into pollen culture or methionine is sprayed onto styles, so that the growth of pollen tubes is improved, the self-incompatibility of the citrus is further improved, a new strategy is provided for improving the self-incompatibility of crops, and the problems of low fruit setting rate, high artificial pollination cost and the like caused by the self-incompatibility are hopefully solved.

The present invention discloses a wheat S-adenosylmethionine synthase, TaSAMS-6B2, and its use in improving wheat resistance to scab. The wheat S-adenosylmethionine synthase gene, TaSAMS-6B2, provided by the present invention, can significantly improve the disease resistance of susceptible wheat, providing an effective technical means for preventing and controlling scab in production. This, in turn, accelerates wheat disease-resistant breeding and improves disease prevention and control measures, thus having broad application prospects.

The invention discloses an Escherichia coli strain capable of efficiently secreting and expressing alpha-lipoic acid and application of the Escherichia coli strain, and belongs to the technical field of biology. Escherichia coli is used as a chassis strain for synthesizing lipoic acid by a microbiological method, and an efficient production strain is constructed by optimizing a metabolic pathway; the related modification comprises the following steps: overexpressing a lipoic amidase coding gene eflpA, a truncated thioesterase mutant 'TesA coding gene, a lipoyl synthase coding gene lipA, an iron-sulfur cluster regeneration gene cluster coding gene iscSUA, an S-adenosylmethionine synthetase coding gene sam2 and a 5'-methyl adenosine thioate / S-adenosylhomocysteine nucleoside enzyme coding gene mtn, and carrying out gene coding. A fatty acid degrading enzyme coding gene fadE, a thioesterase coding gene tesA, a pyruvate formate lyase gene cluster coding gene pflAB and a glucokinase coding gene glk are knocked out. According to the invention, the Escherichia coli realizes efficient de novo synthesis and secretory expression of lipoic acid, and finally the extracellular yield in the shake flask fermentation process reaches 16.96 mg / L.

This invention provides the application of citrus S-adenosylmethionine synthase in improving self-incompatibility, belonging to the field of biogenetic engineering technology. The gene sequence of citrus S-adenosylmethionine synthase is shown in SEQ ID:1. This invention experimentally demonstrates that citrus S-adenosylmethionine synthase affects pollen tube growth by directly interacting with S-RNase and regulating the methionine metabolic pathway. This invention reveals the dual regulatory role of citrus S-adenosylmethionine synthase in self-incompatibility responses, providing a new target for improving crop self-compatibility. This invention improves pollen tube growth by adding citrus S-adenosylmethionine synthase to pollen culture or spraying methionine onto the style, thereby improving citrus self-incompatibility. This provides a new strategy for improving crop self-compatibility and is expected to solve problems such as low fruit set rate and high artificial pollination costs caused by self-incompatibility.

The invention discloses a wheat S-adenosylmethionine synthetase TaSAMS-6B2 and an application of the wheat S-adenosylmethionine synthetase TaSAMS-6B2 in improvement of wheat scab resistance. The wheat S-adenosylmethionine synthetase gene TaSAMS-6B2 provided by the invention can significantly improve the disease resistance of infected wheat, provides an effective technical means for prevention and control of gibberellic disease in production, further accelerates the breeding process of wheat disease resistance, perfects disease prevention and control measures, and has a wide application prospect.

The present invention relates to combination of (i) a methionine-depleting composition, of (ii) one or more methionine synthase inhibitors and of (iii) optionally one or more further agent selected from a chemotherapeutic agent, a radiotherapeutic agent or an immunotherapeutic agent against cancer, for its use for treating a cancer, especially in cancers involving the presence of methionine-independent cancer cells

The application relates to the technical field of feed additives, and particularly discloses a selenium-methionine feed additive and a preparation method thereof. The preparation method of the feed additive is as follows: adding wheat powder, a synthetic precursor, KH2PO4 and MgSO4 into navel orange residues, uniformly mixing, obtaining a fermentation substrate, controlling the moisture content of the fermentation substrate, inoculating a complex strain producing glutathione reductase at pH 4-8, uniformly mixing, controlling the fermentation temperature, fermenting for 10-20 days, inoculating bacillus producing methionine synthetase again, fermenting for 10-15 days, drying, crushing, and obtaining the selenium-methionine feed additive. The prepared feed additive has high organic selenium content, selenium-methionine accounts for more than 50% of the total selenium content, and the highest content reaches 73.11%, which meets the standard of the feed additive, and the preparation method is environment-friendly and has low requirements on production environment conditions.

The invention relates to the technical field of biotechnology and pharmacy, and discloses a preparation method of 1, 4-butanedisulfonic acid adenosine methionine, which comprises the following steps: (1) constructing an adenosine and L-methionine metabolism enhanced genetic engineering strain, and fermenting to generate adenosine and L-methionine; (2) converting adenosine and L-methionine into S-adenosine-L-methionine by using the immobilized multienzyme system; (3) generating 1, 4-butanedisulfonic acid adenosine methionine by reacting S-adenosine-L-methionine with sodium 1, 4-butanedisulfonate, and (4) obtaining the 1, 4-butanedisulfonic acid adenosine methionine crystal by adopting a crystallization and purification process. The escherichia coli is subjected to metabolic engineering transformation, the metabolic path of adenosine and L-methionine is enhanced, especially adenosine synthetase and L-methionine synthetase are over-expressed, and bypass metabolic genes are knocked out, so that the accumulation amount of a substrate is greatly increased.

The present application relates to a kind of recombinant coryneform bacteria and its method for fermenting production of spermidine with glucose as raw material.The present application first knocks out snaA gene in the genome of coryneform bacteria, constructs knockout strain SP-1.Spermidine transporter gene cluster, S-adenosylmethionine synthetase, spermidine synthase, ornithine decarboxylase, S-adenosylmethionine decarboxylase derived from Escherichia coli are expressed in previously constructed knockout strain SP-1 using shuttle plasmid pEC-XK99E and pXMJ19 plasmid between Escherichia coli and coryneform bacteria as expression vector.The recombinant coryneform bacteria of the present application can directly utilize glucose to directly produce spermidine.In the absence of exogenous methionine, 2.61g / L spermidine can be accumulated in 250mL shake flask fermentation for 72h.Spermidine yield can reach 45.2g / L in 5L fermentor by substrate feeding.

The invention discloses a mutant with improved activity of S-adenosylmethionine synthetase and its application, belonging to the field of bioenzyme engineering technology. Site-directed combined mutations were performed on positions 189, 200, 234, 266 and 371 of S-adenosylmethionine synthetase MAT to obtain a series of mutants with improved enzyme activity, among which I189V / N371R had the most obvious improvement, with a specific enzyme activity of 1.092±0.0497U·mg ‑1 , which is 342.82% higher than the parent WT. The enzyme mutant provided in this application has broad application prospects in producing S-adenosylmethionine and constructing genetically engineered microorganisms of S-adenosylmethionine.

The application discloses application of a GmSAMS gene and protein in regulating soybean kernel quality, belongs to the technical field of genetic engineering, and particularly relates to application of the GmSAMS gene in regulating soybean kernel quality, wherein the nucleotide sequence of the GmSAMS gene is shown as SEQ ID NO. 1. The application can reduce the expression of a protein S-adenosylmethionine synthetase of the GmSAMS gene by silencing the GmSAMS gene, improve the protein content of soybean kernels, reduce the oil content of soybean kernels, reduce the total fatty acid content of soybean kernels, and make the soybean kernels smaller, so that the purpose of regulating the quality of soybean kernels is achieved.

A solution containing a boric acid, an S-adenosylmethionine synthase, ATP, methionine, and water.