441 results about "Methionine biosynthesis" patented technology

The invention relates to the technical field of gene engineering and enzyme engineering, in particular to an esterase mutant for degrading ethyl carbamate and application of the esterase mutant, the esterase mutant has an amino acid sequence as shown in SEQ ID NO.1 which is subjected to site mutation, the site mutation is any one or more site combined mutation of V129S, V161L or I229M, and the amino acid sequence of the esterase mutant is shown in SEQ ID NO.1. The V129S site mutation is that valine at the 129 site is mutated into serine, the V161L site mutation is that valine at the 161 site is mutated into leucine, and the I229M site mutation is that isoleucine at the 229 site is mutated into methionine. Mutation is carried out through a site-directed mutagenesis method, so that the amino acid sequence of the esterase mutant V129S / I229M is changed, the autoplasmic structure and function of eggs are changed, the esterase mutant V129S / I229M with the ethyl carbamate hydrolysis rate increased to 6.55 times in an acid environment is finally obtained, and the esterase mutant V129S / I229M has high industrial application value.

The invention discloses a method for regulating the transport activity of a strain to 1-aminocyclopropane-1-carboxylic acid, and relates to the technical field of bioengineering. The method for regulating and controlling the transport activity of the strain to 1-aminocyclopropane-1-carboxylic acid and / or methionine analogues and the tolerance of the strain to the 1-aminocyclopropane-1-carboxylic acid and / or methionine analogues, disclosed by the invention, comprises the step of transferring a LeuE gene into escherichia coli to obtain an escherichia coli recombinant strain with corresponding functions. The invention discloses the application of the LeuE protein and the LeuE gene in regulating and controlling the transport activity of escherichia coli to the 1-aminocyclopropane-1-carboxylic acid and / or methionine analogue and the tolerance of escherichia coli to the 1-aminocyclopropane-1-carboxylic acid and / or methionine analogue for the first time. The invention discloses that LeuE is an optimal candidate gene for constructing ACC synthetic bacteria for the first time, and the substrate specific transport of the LeuE meets the aim of enhancing the ACC tolerance of cells without influencing precursor supply.

There is provided a fluorinase variant thereof having at least 70% sequence identity to a sequence MSDLGX6TDDSVAQCKGLMLSICPX24VX26IX28DX30CHX33MTPX37DVVEGARYIVDLPR X52FPEGTVFATTTYPATGTX70X71RSVAX76RX78KX80AALGGARGQX90AGSGX95GX97E RAEGX103YIYIAPNNGLLTX116VIEEHGYX124EAYEVSX131TX133VIPX137X138PEPTFYSR EMVAIPSAHLAAGFPLX163X164VGRX168LX170DX172EIVRFEX179X180KX182X183X184VX186G X188X189LX191GX193X194X195X196X197DHPFGNX204WTNX208HRTDLEKAGIX219YX221TX223X 224KX226VX228DGVLX233FX235LPLX239PTFADAX246X247X248GX250PVX253YX255NSRGYLX2 62X263ARNAAX269LAYPYNLX277AGX280SVX283VTX286A (SEQ ID NO: 1), wherein X is a natural amino acid, and wherein the variant comprises one or more mutations at a site selected from the group consisting of an ion-egress site, a S-Adenosyl-L-Methionine (SAM) binding site, an ion-binding site (IBS), and a conserved site. Also disclosed are polynucleotides encoding the variants, vectors comprising the polynucleotides encoding the variants, and host cells comprising the vectors thereof. Also disclosed are Methods for producing the variants, methods of catalyzing the fluorination of a compound, uses of the fluorinase variants, and methods of treatment using the fluorinase variants thereof.

The invention relates to laccase as well as a mutant and application thereof, and belongs to the technical field of biology. The amino acid sequence of the laccase PnLac1 is as shown in SEQ ID NO. 2, and the nucleotide sequence of the laccase PnLac1 is as shown in SEQ ID NO. 1. The mutant is characterized in that aspartic acid at the 166th position of laccase PnLac1 is subjected to site-specific mutagenesis, histidine at the 348th position of laccase PnLac1 is subjected to site-specific mutagenesis, methionine at the 403th position of laccase PnLac1 is subjected to site-specific mutagenesis, or leucine at the 467th position of laccase PnLac1 is subjected to site-specific mutagenesis, amino acid sequences are shown as SEQ ID NO.4, SEQ ID NO.6, SEQ ID NO.8 and SEQ ID NO.10, and nucleotide sequences are shown as SEQ ID NO.3, SEQ ID NO.5, SEQ ID NO.7 and SEQ ID NO.9. The decoloring efficiency of the laccase PnLac1 on crystal violet reaches 5h, and the degradation rate reaches 75%. When the ABTS is used as a substrate, the enzyme activities of the laccase mutants H348F and L467M are respectively improved by 1.89 times and 1.65 times, and the ABTS has the potential of degrading stubborn substances; when guaiacol is used as a substrate, the enzyme activities of the laccase mutants D166A and M403F are respectively improved by 2.07 times and 3.72 times, and the guaiacol has a relatively high application prospect in the field of lignin.

The invention discloses a high-stability carbonyl reductase mutant and application of the high-stability carbonyl reductase mutant in chiral alcohol synthesis. An amino acid sequence as shown in SEQ ID NO.2 is mutated as follows: 20th leucine is replaced by any one of lysine, threonine, aspartic acid or isoleucine, and / or 55th leucine is replaced by any one of methionine, serine, lysine or isoleucine, and / or 55th leucine is replaced by any one of methionine, serine, lysine or isoleucine. Compared with a wild type enzyme, the stability of the obtained mutant is remarkably improved, particularly, single-point mutants Mut-L20I and Mut-L55I and a combined mutant Mut-L20I-L55I show excellent relative enzyme activity, thermal stability and substrate tolerance. The mutant has high catalytic activity and stability to various chiral alcohols, has the advantages of high catalytic efficiency, high thermal stability, strong substrate tolerance, easiness in fermentation production and the like, and is suitable for industrial application of enzymatic synthesis of chiral alcohols.

The invention relates to the field of plant molecular biology and forest genetic engineering, and particularly provides a PagRAP2.3 protein point mutant and application thereof in drought resistance of poplar. The mutant PagRAP2.3 MA is obtained by mutating methionine at the first site and cysteine at the second site of a wild type PagRAP2.3 protein into methionine and alanine. The invention further discloses a preparation method of the mutant PagRAP2.3. An expression vector containing the PagRAP2.3 MA gene is constructed, poplar 84K is transformed through an agrobacterium-mediated method, and a transgenic line with stable expression is obtained. Functional verification results show that overexpression of PagRAP2.3 MA can significantly increase the plant height of the poplar and promote plant growth, but the sensitivity to moisture is enhanced under drought stress. The mutant can be used for regulating and controlling the growth and development of forest trees and evaluating the drought resistance, and has a forestry breeding application prospect.

A pharmaceutical composition comprising a protein arginine methyltransferase 5 (PRMT5) inhibitor and a methionine adenosyltransferase IIα (MAT2A) inhibitor. The pharmaceutical composition can be used for treating various cancers, comprising solid tumors. The combined product can be used for treating any number of diseases associated with PRMT5 and / or MAT2A.

The invention provides a penicillin G acylase AxPGA mutant, an expression plasmid, a genetically engineered bacterium and application, and belongs to the technical field of biocatalysts. The mutant is obtained by mutation of any one or more of the following sites of an amino acid sequence as shown in SEQ ID NO: 1: (1) methionine at the 103rd site is substituted by cysteine, (2) tyrosine at the 424th site is substituted by phenylalanine, (3) tyrosine at the 442nd site is substituted by phenylalanine, and (4) tyrosine at the 451st site is substituted by alanine. The obtained penicillin G acylase AxPGA mutant is relatively high in enzyme activity and can be applied to high-conversion-rate and high-yield synthesis of beta-lactam antibiotics such as benicillin and amoxicillin.

The present application relates to a pyridoxal kinase mutant, a recombinant expression vector and a microbial cell and their applications, and belongs to the technical field of biological catalysis. In order to solve the problem of low product concentration in existing enzyme catalysis, a pyridoxal kinase mutant is provided, the amino acid sequence is selected from the amino acid sequence shown in SEQ ID NO. 1, the lysine at position 229 is mutated to alanine, phenylalanine, methionine, arginine, threonine, histidine, serine, tyrosine, valine, leucine, isoleucine, proline, asparagine, aspartic acid or glutamic acid; the pyridoxal kinase mutant is used for catalyzing pyridoxal to synthesize pyridoxal phosphate, and a recombinant expression vector and a microbial cell can be further formed. The present application has good enzyme activity, high product conversion rate, high concentration of pyridoxal phosphate obtained, and the concentration of the product catalyzed by the wild-type pyridoxal kinase to phosphorylate pyridoxal is obviously improved.

The invention belongs to the technical field of biological detection, and particularly relates to a method for synchronously and quantitatively detecting various folic acid metabolism related substances in trace plasma or serum, which comprises the following steps of: detecting a pretreated trace plasma or serum sample by adopting a liquid chromatography-tandem mass spectrometry method; the following nine folic acid metabolism related substances are synchronously and quantitatively detected: 5-formyl tetrahydrofolic acid, folic acid, 5-methyl tetrahydrofolic acid, S-adenosine-L-methionine, S-adenosine-L-homocysteine, vitamin B12, pyridoxamine, pyridoxine and pyridoxal. The invention further relates to application of the detection method in related detection of child neurodevelopment. According to the detection method, only trace plasma or serum is used, methotrexate is used for replacing an expensive isotope internal standard for more economical detection, and nine folate metabolism related substances can be accurately quantified at the same time. Therefore, the detection method disclosed by the invention has important clinical significance and wide market application prospect.

The invention relates to a blood protein peptide for promoting hair follicle reconstruction and application thereof, and belongs to the technical field of bioactive peptides. The blood protein peptide disclosed by the invention is selected from one or more of an MLL peptide fragment and a WDL peptide fragment; the amino acid sequence of the MLL peptide fragment is as follows: methionine-leucine-leucine; the amino acid sequence of the WDL peptide fragment is as follows: tryptophan-aspartic acid-leucine. The invention also provides a preparation method of the blood protein peptide and application of the blood protein peptide in hair follicle reconstruction. The blood protein peptide prepared by the technical scheme of the invention can obviously improve local blood supply around hair follicles, and has a wide application prospect in the field of treatment of alopecia.

The invention discloses a chitosanase mutant which is derived from bacillus subtilis and has the capacity of hydrolyzing chitosan to produce chitosan disaccharide per unit and belongs to a GH46 family, and application of the chitosanase mutant in hydrolyzing chitosan to produce chitosan oligosaccharide. Compared with wild type chitosanase capable of producing chitodisaccharide and chitotriose, the chitosanase mutant has the advantage that the chitodisaccharide can be produced per unit when the chitodisaccharide is hydrolyzed by the chitosanase mutant. The invention provides eight kinds of chitosanase mutants, and the mutants are obtained by carrying out site-specific mutagenesis on 21st-site glycine on the basis of wild type chitosanase and respectively mutating the 21st-site glycine into lysine, arginine, leucine, histidine, methionine, tyrosine, proline and glutamine. The mutant can hydrolyze chitosan under mild conditions to produce chitosan oligosaccharide with single polymerization degree, and can greatly relieve the difficulty in separation and purification in chitosan oligosaccharide production.

The invention discloses a method for improving the fermentation performance of clostridium aerovorans and application of the clostridium aerovorans, and according to the method, an effective amount of methionine or a derivative thereof is added into a fermentation culture medium of the clostridium aerovorans to completely replace expensive complex organic nitrogen sources such as yeast extracts. The method successfully solves the three technical bottlenecks of slow biomass accumulation, low ethanol yield and dependence on expensive nitrogen sources in the fermentation process of the clostridium aerovorans by utilizing synthesis gas or CO2 / H2 mixed gas. Experiments prove that methionine or a derivative thereof can synergistically promote growth metabolism of thalli and a synthesis path of a product, so that the gas conversion efficiency of a carbon source is remarkably improved and metabolism is guided to flow to ethanol synthesis while the growth rate and the final biomass of the thalli are improved, and thus the production capacity of alcohols is synchronously enhanced. The method is simple in process and remarkable in effect, and an efficient and economical new strategy is provided for reducing the production cost of biofuel and promoting industrial application of a synthesis gas biorefinery technology.

The invention provides an application of synbiotics in preparation of a composition for improving glucagon-like peptide-1 (GLP-1). The composition comprises litchi polyphenol, probiotics and methionine. The probiotics comprise bifidobacterium animalis BCRC910645, bifidobacterium longum BCRC910812, or a combination of the bifidobacterium animalis BCRC910645 and the bifidobacterium longum BCRC910812, so that the content of the glucagon-like peptide-1 is increased.

The invention provides a recombinant O-succinyl-L-homoserine mercaptotransferase mutant, a coding gene thereof, a recombinant vector containing the coding gene of the mutant, a recombinant genetically engineered bacterium obtained by converting the recombinant vector, and application of the recombinant O-succinyl-L-homoserine mercaptotransferase mutant in preparation of L-methionine. The novel recombinant O-succinyl-L-homoserine mercaptotransferase mutant with high activity and high selectivity is used as a catalyst to be applied to catalysis of O-succinyl-L-homoserine for synthesis and preparation of L-methionine, a catalytic reaction system is optimized, the feed ratio and reaction conditions in the reaction are finely regulated and controlled, and the yield of L-methionine is increased. The recombinant O-succinyl-L-homoserine mercaptotransferase mutant has high enzyme activity under the optimal reaction condition, the catalytic efficiency is further improved, the purposes of reducing cost and improving efficiency are achieved, and the method has important significance in promoting industrial application of biological catalysis preparation of L-methionine.

The invention belongs to the technical field of bioengineering, and relates to an ArsL mutant and an application of the ArsL mutant in synthesis of Arsinothricin. The ArsL mutant is a mutant obtained by mutating the 428th cysteine C of the amino acid sequence of wild AST synthetase ArsL into alanine A, and the amino acid sequence of the ArsL mutant is as shown in SEQ ID No.2. The invention also discloses a preparation method of the ArsL mutant. The invention also further provides an application of the ArsL mutant in catalysis of sodium methyl arsenate and S-adenosylmethionine to synthesize Arsinothricin. The invention further provides an application of the ArsL mutant in catalysis of sodium methyl arsenate and S-adenosylmethionine to synthesize Arsinothricin. The ArsL mutant disclosed by the invention has higher catalytic activity and thermal stability, the process of converting high-concentration MMA into AST is realized by utilizing the ArsL mutant, and the catalytic activity of the ArsLC428A mutant is obviously improved compared with that of wild type AST synthetase. In addition, compared with an organic synthesis path, a semi-organic enzyme synthesis path and a natural biological synthesis path, the yield of the synthesis path provided by the invention is obviously improved, and the ArsL mutant can be used as a potential industrial application enzyme and has a wide application prospect.

A bifidobacterium enrichment agent and a use thereof in high-density fermentation. The components of the bifidobacterium enrichment agent include potassium carbonate, arginine, methionine, serine, vitamin C, vitamin B1, vitamin B5, thymine, and calcium pantothenate. The bifidobacterium enrichment agent is added to a basal medium for high-density fermentation, so that the proliferation performance of bifidobacteria can be significantly improved, and the production efficiency can be improved, providing the possibility of preparing a highly active bifidobacterium fermentation liquor, and also providing support for the subsequent preparation and application of bacterial agents.

The invention relates to the technical field of biological medicines, and discloses application of methionine adenosine transferase 2A and related substances thereof in preparation of wound repair products. According to the application disclosed by the invention, a metabolic regulation network in a diabetic wound surface is researched, so that MAT2A expression down-regulated in pericytes is found to be remarkably and negatively correlated with M1 type macrophage infiltration, and the situation that the wound healing is delayed, the wound surface blood perfusion is reduced and the inflammation macrophage infiltration is increased due to MAT2A specific deletion of the pericytes in the wound is observed; and after saMAT2A-loaded pericellular membrane coated lipid nanoparticles (PMCNPs) are further adopted for treatment, the regeneration process of the wound surface can be remarkably enhanced, continuous inflammatory macrophage infiltration in the diabetic wound surface is relieved, microcirculation recovery is promoted, the safety is high, and good application prospects are achieved in the aspect of promoting wound surface repair.

The invention relates to the technical field of agricultural biology, in particular to ALS inhibitor broad-spectrum resistance mutant protein and application. According to the invention, a gene editing technology is utilized to edit rice ALS genes, then resistance screening is carried out to obtain two new rice ALS mutant proteins, and compared with rice wild-type ALS proteins, the ALS mutant proteins have the advantages that the rice ALS mutant proteins have higher rice ALS mutant proteins; the mutation comprises the mutation that the 171st proline is mutated into threonine, the 172nd arginine is mutated into glycine and the 174th methionine is mutated into leucine, or the mutation comprises the mutation that the 169th glutamine is mutated into asparagine and the 170th valine is mutated into glutamine. The two mutant proteins are reported for the first time, so that rice has relatively high resistance to various ALS inhibitor herbicides; meanwhile, the mutant gene can be used as a plant endogenous transgenic selection marker and added with other functional elements for plant gene transformation, and has great value in commercial application of transgenic plants.

The invention relates to the field of biological pharmacy, and discloses a preparation method of an MPL adjuvant, which comprises the following steps: dissolving an MPL raw material in a buffer solution to obtain an MPL solution; adding a freeze-drying protective agent into the MPL solution to form a stable liquid system; carrying out pre-freezing treatment of cooling by stages on the obtained solution; freezing and drying the pre-freezing system under a temperature control condition to obtain freeze-dried powder; and sealing the freeze-dried powder in a treated packaging material to form a final product, the freeze-drying protective agent is prepared from trehalose, a polyethylene glycol-polylactic acid segmented copolymer (PEG-PLA) and L-methionine. A dynamic temperature regulation and control technology is adopted, the temperature of the shelf is adjusted in real time, the sample temperature is kept in a subcritical interval of-42 DEG C to-38 DEG C, the sublimation rate is ensured to be stable, lipid heat stress caused by too high temperature is avoided, and it is also prevented that the drying efficiency is affected by too low temperature.

The invention relates to aspartate kinase for relieving feedback inhibition of L-threonine and application of aspartate kinase, and belongs to the field of enzyme engineering and metabolic engineering. The mutant is obtained by carrying out E253K and / or K507E mutation on the basis of wild type aspartate kinase as shown in SEQ ID NO.1, the enzyme activity of the mutant is not obviously changed under the condition that the concentration of L-threonine is 0-12 mmol / L, and the feedback inhibition effect of L-threonine on the mutant is relieved. The method can be widely applied to synthesis of essential amino acids including L-threonine, L-tryptophan, L-isoleucine, L-lysine, L-leucine, L-valine, L-methionine, L-phenylalanine and the like.

An Fc-binding polypeptide with improved alkaline stability comprising a mutant of the Fc-binding domain of Staphylococcus protein A (SpA), said mutant being defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO 51 or EQ ID NO 52, wherein at least the asparagine or serine residue at a position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

The application discloses application of a combined inhibitor in associated gold-silver-lead-zinc sulfide ore flotation separation, wherein the combined inhibitor is a combination of zinc sulfate and methionine, and the mass ratio of the two combined is 2:1; the combined inhibitor is used to realize associated gold-silver-low-copper-lead-zinc polymetallic sulfide ore flotation separation in a low-alkali environment, has a good separation effect, high concentrate grade, effectively reduces the zinc content of lead concentrate, improves the gold and silver recovery rate in the lead concentrate, and has important significance for improving the quality and efficiency of associated gold-silver-low-copper-lead-zinc polymetallic sulfide ore flotation separation. In addition, the methionine in the combined inhibitor is a small-molecule organic substance, is non-toxic and non-polluting, and is easy to degrade, thereby avoiding the problems of traditional inhibitors, such as toxicity, environmental unfriendliness and human body unfriendliness. The combined inhibitor has small dosage, stable effect, and good process application prospect.

The invention relates to a protein consisting of an amino acid sequence in which at least one modification selected from the group consisting of the following [1] to [7] is introduced in the amino acid sequence represented by SEQ ID NO: 1: [1] a modification in which the amino acid residue at a position 103 is substituted with a lysine residue, [2] a modification in which the amino acid residue at a position 76 is substituted with a cysteine residue, [3] a modification in which the amino acid residue at a position 144 is substituted with a cysteine residue, [4] a modification in which the amino acid residue at a position 134 is substituted with a glycine residue, [5] a modification in which the amino acid residue at a position 222 is substituted with a methionine residue, [6] a modification in which the amino acid residue at a position 73 is substituted with a glutamine residue, and [7] a modification in which the amino acid residue at a position 203 is substituted with a threonine residue.

The invention belongs to the technical field of enzyme gene engineering, and particularly relates to a methionine gamma-lyase mutant with improved enzyme activity and application thereof. The methionine gamma-lyase mutant CqMGLV160I / V265I with high activity is obtained by taking methionine gamma-lyase (CqMGL) which is derived from Calorama quimayensis and of which cysteine residues at 116 sites are replaced by histidine residues as a parent and carrying out site-specific mutagenesis on amino acid residues at key sites through transformation. The methionine gamma-lyase mutant CqMGLV160I / V265I with high activity can be obtained by using the methionine gamma-lyase mutant CqMGLV160I / V265I as the parent. By adopting the CqMGLV160I / V265I mutant disclosed by the invention, the conversion rate of enzyme catalysis can be improved, allicin is efficiently synthesized, and the mutant is successfully applied to the aspects of food, feed, chemical industry, medicine preparation and the like.

Disclosed herein are compounds of Formula (I): or a pharmaceutically acceptable salt thereof, wherein A and A′ are each independently selected from the group consisting of: (a1), (a2), (a3), (4) and (a5) and B, B′, X and Y have the meanings provided herein, that are methionine adenosyltransferase 2A (MAT2A) inhibitors. Also disclosed are pharmaceutical compositions comprising such compounds and methods of treating diseases treatable by inhibition of MAT2A such as cancer.

The application belongs to the technical field of preparation and application of spermidine, and particularly relates to application of fusarium NF01 in preparation of spermidine and catalysis of lignite liquefaction. The fusarium NF01 is fusarium strain Fusarium sp. NF01. The application finds that the fusarium strain Fusarium sp. NF01 can secrete spermidine synthetase, and then catalyze putrescine and decarboxylated S-adenosyl methionine to biosynthesize spermidine through the spermidine synthetase, so that the spermidine acts on lignite, and then the lignite is liquefied, which can promote the technical progress and application expansion in the field of coal development.

The present invention concerns the recovery of methionylmethionine from aqueous alkali ions containing media by intermediate formation of Bis(methionyl)-diketopiperazine.

The invention provides a dipeptide capable of rapidly supplementing methionine and application thereof, and belongs to the field of nutritional and functional food. The problems of quickly supplementing methionine and promoting lactation are solved. The preparation method comprises the step of preparing the dipeptide GM of which the C terminal is methionine through solid-phase synthesis. The dipeptide GM can be used for supplementing methionine, and it is verified that compared with EM, KM and MM, the dipeptide GM has the higher methionine absorption rate in cells based on the PepT1 vector. The dipeptide GM can also be used for promoting lactation, and it is verified that the dipeptide GM has a better lactation promoting effect compared with EM, KM and MM.

The present invention relates to the technical field of genetic engineering. Provided is a method for constructing an efficient zearalenone-degrading enzyme in the gastric environment of a pig. In the zearalenone-degrading enzyme as shown in SEQ ID NO: 1 that is taken as the parent, the amino acid at position 92, the amino acid at position 114, the amino acid at position 117, the amino acid at position 140, the amino acid at position 153, the amino acid at position 157 and the amino acid at position 220 are respectively mutated into lysine, leucine, tryptophan, arginine, methionine, valine and tryptophan to obtain the mutant. The obtained zearalenone-degrading enzyme mutant has high enzymatic activity and thermal stability, and is better adapted to the internal environment of pigs.