485 results about "Valine" patented technology

The invention discloses a formate dehydrogenase mutant and application thereof in catalytic synthesis of D-mannitol, and belongs to the technical field of bioengineering. According to the formate dehydrogenase mutant provided by the invention, the 18th-site glutamic acid of wild-type formate dehydrogenase with an amino acid sequence shown as SEQ ID NO.2 is mutated into proline, the 57th-site asparagine is mutated into glutamic acid, the 70th-site histidine is mutated into tryptophan, the 235th-site serine is mutated into threonine, and the 316th-site valine is mutated into threonine, so that the formate dehydrogenase mutant is high in enzyme activity and catalytic activity; the coenzyme circulation efficiency during the production of D-mannitol can be obviously improved, so that the yield of D-mannitol can be effectively improved. When the genetically engineered bacterium co-expressed by the formate dehydrogenase mutant and the mannitol dehydrogenase mutant is used for catalyzing 150 g / L fructose to produce D-mannitol, the yield of D-mannitol within 15 h can reach 140 g / L or above.

The invention discloses a cyclic nonapeptide with repairing and anti-oxidation effects and application of the cyclic nonapeptide, the amino acid sequence of the cyclic nonapeptide is cyclic (arginine-glycine-aspartic acid-serine-arginine-lysine-valine-lysine-serine), the prepared cyclic nonapeptide has the repairing and anti-oxidation effects, and the cyclic nonapeptide has the repairing and anti-oxidation effects. The composition can be applied to preparation of cosmetics with repairing and / or anti-oxidation effects.

The invention discloses a hydrogel patch for gastric perforation repair and a preparation method thereof, and belongs to the technical field of biomedical materials. The preparation method comprises the following steps: dissolving acryloyl valine, acrylic acid, methylene bisacrylamide, a compound A and a photoinitiator in an alcohol solvent, and defoaming to obtain a precursor solution; and placing the precursor solution in a mold, carrying out ultraviolet-induced curing, soaking the obtained hydrogel in a hydrochloric acid solution, and replacing the alcohol solvent to obtain the hydrogel patch for gastric perforation repair. The hydrogel patch provided by the invention has the advantages of strong acid corrosion resistance, good biocompatibility, low swelling ratio, stable adhesion performance in a fluctuating pH environment and the like. The tough and stable adhesion performance ensures that the hydrogel can be permanently and reliably adhered to a gastric perforation part in a dynamic gastric acid environment, and a stable platform is provided for drug delivery, so that the surgical operation time is expected to be shortened, and wound healing is promoted.

The invention relates to an L-valine production strain as well as a construction method and application thereof, the strain is obtained by transformation through a metabolic synthesis path of L-valine, and the construction method comprises the following steps: by taking Cornebacterium glutamicum ATCC 13032 (C.glutamicum) as an original strain, carrying out editing transformation such as gene knockout, gene overexpression, gene heterologous expression, gene double-copy expression and the like on a genome of the original strain by utilizing a metabolic engineering means. The L-valine production strain disclosed by the invention can be used for synthesizing L-valine from the beginning by taking glucose as a carbon source, has the advantages of high production rate, short fermentation period, high strain stability and low cost, and lays a foundation for realizing large-scale production of L-valine. According to the fermentation tank fermentation method, the L-valine is produced in a mechanical stirring type fermentation tank by using the L-valine production strain Va1-09, 86.4 g / L of L-valine is produced by fermenting for 36 hours, and the method has a good industrial prospect.

The invention relates to the technical field of biological catalysis, and discloses an M88V mutant enzyme for preparing rebaudioside I. The M88V mutant enzyme is obtained by the following mutations generated by UGT76G1: M88V: methionine of the 88th amino acid sequence of UGT76G1 is mutated into valine. Aiming at the technical bottlenecks of low RI yield and poor selectivity in the existing RA biotransformation process, an efficient solution is provided for the UGT76G1 mutant developed by the invention. The mutant can specifically catalyze conversion from RA to RI, and the conversion rate of a target product is remarkably increased to 65% or above from general less than 7%. The excellent catalytic performance of the catalyst is verified in milliliter-level to upgraded reaction systems, the key problems of conversion efficiency and process amplification are solved, and a foundation is laid for large-scale green manufacturing of a high-added-value product RI.

The invention provides a nicotinamide nucleotide transhydrogenase mutant and application thereof, valine at the 169th site of the nicotinamide nucleotide transhydrogenase mutant is designed to be mutated into isoleucine, the isoleucine is used for constructing a lysine production strain, and the new strain does not contain plasmids, does not have growth defects, does not need induction, and has the advantages of good genetic stability, high fermentation yield and the like. The lysine can be efficiently and stably produced from the beginning by taking glucose as a substrate.

The invention provides a valine production strain and a construction method and application thereof, a designed acetohydroxy acid synthase mutant is that the 88th basic group of an ilvB gene is changed from a to c, the 382nd basic group is changed from a to g, the 413th basic group is changed from c to t, the gene sequence of a designed artificial operon comprises a promoter, an ilvB (A138V) gene or ilvB (Q30K, S128G, A138V) gene of coding mutated acetohydroxy acid synthase, and an ilvN (G20D, I21D, I21D, I21D, I21D, I21D, I21D, I21D) gene. I22F) gene, a pyk gene for coding pyruvate kinase, and a terminator; by designing a specific acetohydroxyacid synthase mutant and related biological materials and artificial operon, the strain constructed by directional modification of the strain by using a pK18mobsacB system gene editing technology based on allele exchange has the advantages of good genetic stability, high fermentation yield and the like, and valine can be stably produced.

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 provides a valine production strain as well as a construction method and application thereof, the strain is constructed by utilizing a CRIPSR / Cas9 system gene editing technology based on allele exchange, an artificial operon is designed and constructed, the artificial operon is constructed at a ygaY site, a strong promoter Ptrc is used for controlling ilvIH (G14N S17F)-pykF to carry out synchronous multi-copy expression, and the valine production strain can be used for producing valine. On the basis of the strain, an artificial operon is constructed at an ycgH site, a strong promoter Ptrc is used for controlling ilvC-ilvD to carry out synchronous multi-copy expression, meanwhile, feedback inhibition of valine on ilvIH is relieved, and an ilvIH natural promoter is replaced by the strong promoter Ptrc, so that more pyruvic acid flows to valine; the constructed strain does not contain plasmids, has no defects, does not need induction, has the advantages of good genetic stability, high fermentation yield and the like, and can be used for efficiently synthesizing valine from the beginning by taking glucose as a substrate.

The present disclosure is directed to HLA class II molecules having a higher affinity for CD4 than naturally occurring HLA class II molecules. In certain aspects, the HLA class II molecule comprises a DQ beta chain having (i) an amino acid other than leucine at a position corresponding to amino acid residue 114 of SEQ ID NO: 1, (ii) an amino acid other than valine at a position corresponding to amino acid residue 143 of SEQ ID NO: 1, (iii) or both (i) and (ii). Certain aspects of the present disclosure are directed to nucleic acid molecules encoding the HLA class II molecules, vectors comprising the nucleic acid molecule, cells comprising the same, and methods of use thereof.

The invention discloses a salicylic acid decarboxylase mutant and application of the salicylic acid decarboxylase mutant in degradation of salicylic acid. The mutant is obtained by carrying out site-specific modification on salicylic acid decarboxylase NahG, and specifically, valine at the 46th site, tyrosine at the 380th site and leucine at the 382nd site of an amino acid sequence shown in SEQ ID NO.2 are mutated into cysteine, phenylalanine and phenylalanine at the same time. The mutant shows remarkably improved catalytic efficiency, and salicylic acid can be efficiently and thoroughly decarboxylated and converted into catechol under mild conditions. The invention also provides a coding gene, a recombinant vector and an engineering bacterium of the mutant. The mutant not only can be used for efficient bioremediation of salicylic acid pollution, but also can effectively break through and accelerate a naphthalene catabolism pathway due to the characteristic of directionally generating catechol, and has important application value in the fields of environmental pollution abatement and biological catalysis.

The present invention relates to the fields of agriculture, plant biotechnology, and molecular biology. Specifically, the present invention relates to a wheat EPSPS mutant protein and use thereof in improving the tolerance of wheat to glyphosate. The mutant protein comprises an amino acid sequence having the following mutations compared to the EPSPS amino acid sequence of any genome of wild-type wheat: in the amino acid sequence set forth in SEQ ID NO: 2, the amino acid at position 168 is mutated from threonine to isoleucine, the amino acid at position 169 is mutated from alanine to valine, and the amino acid at position 172 is mutated from proline to serine. The mutant protein enables the production of stable glyphosate-resistant wheat, showing important significance for wheat breeding.

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 invention provides a preparation method of L-valine. The method comprises the following steps: (1) immobilizing thalli in a seed culture solution by adopting a hollow cellulose membrane reactor in a fermentation system to obtain thalli immobilized on a hollow cellulose membrane; wherein the hollow cellulose membrane reactor comprises a hollow cellulose membrane; (2) circularly flushing the thalli fixed on the hollow cellulose membrane by adopting a fermentation culture medium to ferment the thalli fixed on the hollow cellulose membrane, and performing temperature control on the fermentation process by utilizing a plate heat exchanger to obtain fermentation liquor; and (3) carrying out anaerobic catalysis on the fermentation liquor by utilizing a catalytic culture medium. The method has obvious energy-saving and consumption-reducing effects, does not need to filter again to remove bacteria and impurities, and reduces the cost.

The present specification relates to a composition including a new amide-based compound derived from an amino acid structure such as valine, leucine, phenylalanine, proline, pipecolic acid, or the like, wherein the composition exhibits a skin anti-aging or skin reverse-aging effect by restoring the size and number of dendrites of aged melanin-producing cells to those of young cells. As a result, the composition may exhibit a skin brightening effect by inhibiting the amount of melanin produced in the melanin-producing cells.

The present invention addresses the problem of providing a composition for lyophilizing extracellular vesicles or artificial cell vesicles, which makes it possible to prevent the extracellular vesicles or the artificial cell vesicles from being deteriorated in shape preserving properties or functions thereof or from being reduced in particle diameters when the extracellular vesicles or the artificial cell vesicles are recovered by hydration after lyophilization. The composition for lyophilizing extracellular vesicles or artificial cell vesicles is prepared, the composition being characterized by being intended to be added to extracellular vesicles or artificial cell vesicles upon use and also being characterized by containing the following hydrophobic substances: (a) phenylalanine or a methyl ester thereof; (b) a dipeptide which is composed of one or two kinds of hydrophobic amino acids selected from the group consisting of phenylalanine, leucine, glycine, valine, isoleucine, tryptophan, and alanine and contains at least one phenylalanine molecule as a constituent amino acid; and the like.

The application relates to the technical field of beef cattle breeding, and particularly discloses a compound preparation for promoting the feed intake, daily weight gain and improving the meat quality of beef cattle and application thereof, which is prepared from the following components in percentage by volume: 40% of micro-ecological preparation, 30% of hawthorn, 10% of medicated leaven, 10% of malt, 5% of areca nut and 5% of dried tangerine or orange peel; the compound preparation is prepared from microorganisms and multiple natural Chinese herbal medicines in a specific and scientific matching ratio; experiments prove that the compound preparation can increase the feed intake of beef cattle by 11.33%, increase the daily weight gain by 16.16%, and significantly shorten the breeding cycle; meanwhile, the contents of aspartic acid, threonine, glutamic acid, alanine, valine, isoleucine, leucine, tyrosine, phenylalanine, lysine, arginine and proline in the muscle are significantly increased, the nutritional quality and flavor taste of beef are effectively improved, the preparation is natural, residue-free and side-effect-free, the preparation method is simple, the cost is low, and the preparation has extremely high practical value and popularization prospect.

This invention provides a ketolic acid reductase mutant and its application in constructing genetically engineered bacteria that produce high levels of D-pantothenic acid. To address the technical problem of low D-pantothenic acid yield in existing microbial fermentation, this invention utilizes semi-rational enzyme design to obtain a substrate-specific ketolic acid reductase mutant, which is then applied to construct genetically engineered bacteria that produce high levels of D-pantothenic acid. Furthermore, this invention employs CRISPR-Cas9 gene editing technology to construct genetically engineered bacteria that produce high levels of D-pantothenic acid using the aforementioned ketolic acid reductase mutant, increasing D-pantothenic acid production by approximately 12.04%. Compared to the starting strain, the accumulation of valine in the fermentation broth remained almost unchanged compared to the control, but the accumulation of the branched-chain amino acid isoleucine was lower, achieving substrate-specific modification of the ketolic acid reductase.

The invention discloses a phytase mutant AppA as well as a coding gene, a preparation method and application thereof. The phytase mutant AppA is obtained by mutating amino acids at the 137th site, the 185th site and the 255th site of wild type phytase AppA from asparagine, aspartic acid and tyrosine into valine, asparagine and aspartic acid respectively; the amino acid sequence and the nucleotide sequence of the gene are SEQ ID NO.1 and SEQ ID NO.2 respectively. The catalytic efficiency of the mutant enzyme AppA provided by the invention on sodium phytate is improved by 2.5 times compared with that of a wild enzyme AppA; under the condition of 70 DEG C, the half-life period of the mutant enzyme AppA is 3.4 times that of the wild enzyme AppA. The mutant enzyme AppA has the characteristic of high enzyme activity under a high-temperature condition, which indicates that the mutant enzyme AppA has an important application prospect in industrial production of a feed in which phytic acid needs to be degraded under the high-temperature condition.

The invention relates to the technical field of biomedical materials, in particular to a sodium hyaluronate composite solution for relieving skin aging and a preparation method thereof, the sodium hyaluronate composite solution comprises sodium hyaluronate, taurine, proline, glutamic acid, glycine and valine; sodium hyaluronate has a specific molecular weight, the composite solution has a specific pH value and osmotic pressure, and all the components have a synergistic effect, so that a moist environment is provided for skin, free radicals are removed, collagen synthesis is promoted, and aging phenomena such as skin laxity and wrinkles are improved. The composition can maintain skin moisture for a long time, scavenge free radicals, resist oxidation and promote collagen synthesis to improve skin aging, the preparation process guarantees stable components, the solution is matched with the physiological environment of the skin, and the composition is non-irritant, safe to use and good in anti-aging effect.

The application belongs to the technical field of protein extraction, and provides a method for improving water holding property and oil holding property of peony seed protein, the core of the method is that before the extraction of the peony seed protein, the peony seed is pretreated by the following method: the peony seed meal is subjected to steam explosion treatment under the condition of 0.4-1.2 Mpa and 60-150 s, preferably 0.8 Mpa and 100 s, to obtain the steam exploded peony seed, and the sample after the steam explosion is subjected to drying treatment; preferably heat pump drying. The peony seed protein prepared by the method has obviously improved water holding property, oil holding property, foaming property, foam stability, emulsifying property and emulsion stability; the valine is increased by 8.58%, the leucine is increased by 6.63%, and the tyrosine is increased by 10.65%; the extraction rate of the seed protein is 76.82%, and the extraction effect is excellent.

The present disclosure can improve the degree of soy protein proteolysis and the ability to produce valine, isoleucine, and leucine, which are branched-chain amino acids, as well as other amino acids, such as threonine, glycine, tyrosine, and lysine. Accordingly, the present disclosure can prevent sarcopenia and has antioxidant activity. Also, the present disclosure can maintain protein metabolic balance and relieve sarcopenia by muscle synthesis.The self-aggregation, hydrophobicity, and intestinal adhesion of a mixed strain is improved compared to a case where a single strain used for the mixed strain is used. Therefore, when the mixed strain of the present disclosure is ingested, the strain can remain for a long time in the intestine.

The present invention relates to an antibody or binding fragment thereof that binds to a protein, preferably a T cell receptor, comprising an epitope comprising or consisting of an amino acid sequence having at least 80 %, such as 83 %, preferably at least 90 %, for instance 100 % sequence identity to the amino acid sequence set forth in SEQ ID NO: 62 (EVPKXiR), wherein Xi is selected from Alanine (A), Arginine (R), Asparagine (N), Aspartic acid (D), Cysteine (C), Glutamine (Q), Glutamic acid (E), Glycine (G), Histidine (H), Isoleucine (I), Leucine (L), Lysine (K), Methionine (M), Phenylalanine (F), Proline (P), Serine (S), Threonine (T), Tryptophan (W), Tyrosine (Y), Valine (V). Further, the invention relates to pharmaceutical compositions comprising such an antibody or binding fragment thereof and to the use of such an antibody or binding fragment thereof for use as a medicament or for use as a screening agent.

The present invention discloses a β-folded self-assembly antimicrobial peptide regulated by hydrogen bonds, a preparation method and an application thereof, and its amino acid sequence is shown in SEQ ID NO.1. The antimicrobial peptide KVL-1 is designed using a "++ABBBCCCD++" template, wherein "+" is lysine, "A" and "D" are serine and tryptophan with side chains capable of forming hydrogen bonds, and "B" and "C" are valine and leucine that are easy to form a β-folded structure. The overall structure is a Bola structure with hydrophilic ends and a hydrophobic core. The antimicrobial peptide KVL-1 exhibits β-folded characteristics in PBS / SDS solution, and has a critical aggregation concentration of 12.66 μM in PBS. At high concentrations, it can form a nanochain assembly composed of spherical units arranged in a nanostructured structure, has a strong inhibitory effect on a variety of common pathogens, has no obvious hemolytic activity and cytotoxicity, and has a simple preparation process and low cost, and has the potential to be used as an antibiotic substitute.

A collagen-boosting supplement that contains at least 4, optionally at least 10, collagen building block amino acids and is substantially free of histidine. The building block amino acids may be selected from: Glycine, L-Proline, L-Hydroxyproline, L-Glutamic Acid, L-Alanine, L-Arginine, L-Aspartic Acid, L-Serine, L-Leucine, L-Lysine, L-Hydroxylysine, L-Valine, L-Phenylalanine, L-Threonine, L-Isoleucine, L-Methionine, and L-Tyrosine. The supplement may further comprise: vitamin C; one or more mast cell stabilisers which may be selected from: quercetin, molybdenum, bromelain, DAO (diamine oxidase), Urtica Dioica (stinging nettle), Nigella Sativa (black cumin), Zingiber (ginger), Scutellaria baicalensis (Chinese skullcap), Sambucus (Elderberry), Aloe Vera, Syzygium aromaticum (clove), and matcha; one or more collagen-strengthening herbs which may be selected from: Bilberry, Centella, and Astragulus; one or more Glucosaminoglycans (GAGs) which may be selected from: Hyaluronic acid, glucosamine, and chondroitin; one or more antioxidants which may be selected from: astaxanthin and resveratrol; and / or one or more cofactors which may be selected from: zinc, biotin, silicon, manganese, magnesium, Vitamin D, Vitamin A, Vitamin E, and iron. The supplement may be a foodstuff, medicament, nutraceutical, or cosmetic. The supplement may be used to treat hypermobile Ehlers-Danlos syndrome (hEDS) while reducing the likelihood of mast cell degranulation through histamine activation.

This invention discloses a cyclic lipopeptide delivery system, comprising a cyclic lipopeptide carrier and nucleic acid; the head of the cyclic lipopeptide carrier is composed of heptapeptides R1R2R2R3R4R2R2 linked together by amide bonds to form a ring, and the hydrophobic tail of the cyclic lipopeptide carrier is composed of a fatty acid with a carbon chain length of 6-44 forming an ester bond with the hydroxyl group on the head amino acid R3, with the following general structural formula: where R1 is a basic amino acid, including one of histidine (His), lysine (Lys), or arginine (Arg); R2 is a hydrophobic amino acid, including one of leucine (Leu), isoleucine (Ile), or valine (Val); R3 is a hydrophilic amino acid, including one of tyrosine (Tyr), serine (Ser), or threonine (Thr); R4 is one of glutamate (Glu) or glutamine (Gln); n is an integer from 5 to 43; the cyclic lipopeptide carrier encapsulates the nucleic acid drug to form cyclic lipopeptide-nucleic acid nanoparticles.

The application discloses a 17beta-hydroxysteroid dehydrogenase mutant, an engineering bacterium and application, and uses the 17beta-hydroxysteroid dehydrogenase mutant to biotransform methyl diketone as a substrate to prepare nandrolone. The 17beta-hydroxysteroid dehydrogenase is 17beta-hydroxysteroid dehydrogenase (17beta-HSDcl) from a fungus Cochliobolus lunatus, and the mutant is a single mutant in which histidine His at the 164th position is mutated into valine Val, a single mutant in which threonine Thr at the 151st position is mutated into alanine Ala, or a double mutant in which the 164th position and the 151st position are jointly mutated. The application uses pET28a as an expression plasmid, realizes heterologous expression of the 17beta-HSDcl mutant in E.coli BL21 (DE3), and through 24h whole cell transformation of the engineering bacterium, the nandrolone yield of the single mutant H164V, the single mutant T151A and the double mutant H164V / T151A is 1.27 times, 1.30 times and 1.34 times that of before mutation, respectively. The application provides a basis for industrialized production of nandrolone by microorganisms.

The application provides a promoter, an expression vector, a valine production strain and application thereof. The nucleotide sequence of the promoter is shown in any one of SEQ ID NO: 2-6. The valine production strain constructed by using the promoter does not contain plasmid, has no growth defect, does not need induction, has the advantages of good genetic stability, high fermentation yield and the like, is an excellent strain capable of stably producing valine, and the strain efficiently synthesizes valine from scratch by using glucose as a substrate, and the yield of valine is significantly improved.

The application discloses a kind of genetic engineering escherichia coli plasmid expression culture medium and fermentation process, including basic medium and feed medium;The basic medium includes glycerol, yeast hydrolysate, yeast peptone, L-glutamic acid, L-valine, L-isoleucine, arginine, tyrosine, lysine, proline, glycine, ammonium sulfate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, citric acid, magnesium sulfate, ferrous sulfate, zinc sulfate, calcium chloride, manganese chloride, cobalt chloride, copper chloride, sodium ethylenediaminetetraacetate;Feed medium includes glycerol, citric acid, magnesium sulfate, ferrous sulfate, zinc sulfate, calcium chloride, manganese chloride, cobalt chloride, copper chloride, sodium ethylenediaminetetraacetate.The application inhibits the accumulation of harmful metabolites, and creates the optimal intracellular environment for stable replication of plasmid.In industrial fermentation scale, the amount of plasmid harvested per liter of fermentation broth is more than 1 gram, and the supercoiling ratio of plasmid DNA is stably maintained at more than 90%, with minimal batch-to-batch variation.