64 results about "Isoleucine" patented technology

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.

The present application relates to a microorganism capable of producing L-isoleucine, into which a gene encoding an exogenous glutamate dehydrogenase has been introduced, a method for producing L-isoleucine using the microorganism, and a composition for producing L-isoleucine containing the microorganism.

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.

The application discloses a novel Rdl gene mutant with V332I mutation, and a method for detecting insect resistance to broflanilide. The gene mutant is characterized in that the base of the amino acid at the 332th position is mutated from GTT, GTC or GTA to ATT, ATC or ATA, and the encoded amino acid sequence is mutated from valine (V) in the wild type to isoleucine (I). The V332I mutation site can be used for molecular detection of insect resistance to broflanilide, and also provides an important reference for research and application of insecticides targeting the gamma-aminobutyric acid receptor encoded by the Rdl gene.

This invention relates to the field of bioengineering technology, specifically to a cis-epoxysuccinate hydrolase mutant and its applications. The cis-epoxysuccinate hydrolase mutant is obtained by single-point or multi-point mutations at positions 127 and 141 of the amino acid sequence of the wild-type cis-epoxysuccinate hydrolase shown in SEQ ID NO. 1. The single-point mutation involves replacing valine at position 127 with isoleucine, or replacing aspartic acid at position 141 with threonine. The cis-epoxysuccinate hydrolase mutant obtained by this invention exhibits high thermal stability, significantly improving the service life of the cis-epoxysuccinate hydrolase in the industrial production of D(-)-tartaric acid.

This invention discloses the application of a branched-chain amino acid (BCAA) restricted diet in the preparation of drugs for treating liver metastases of tumors. Through mouse model experiments, this invention found that restricting the intake of BCAAs (valine, isoleucine, and leucine) in the diet, or using the SCD1 inhibitor A939572, can significantly inhibit liver metastases of tumors, especially pancreatic cancer liver metastases. Experimental results show that a BCAA restricted diet or SCD1 inhibitor can reduce the number and volume of liver metastases and inhibit their growth. This invention also reveals its mechanism of action: BCAA restriction reduces the propionylation modification of SREBP1, downregulates the transcriptional expression of its target gene SCD1, and thus reduces lipid synthesis, thereby exerting an anti-tumor liver metastasis effect. This invention provides a novel dietary intervention strategy and drug target for the treatment of liver metastases of tumors.

This invention discloses a mutant, gene, and recombinant bacteria of a highly thermostable single-chain sweet protein. The mutant is characterized by the following amino acid sequences shown in SEQ ID NO.1: isoleucine (I) at position 5 is mutated to glutamic acid (E), glutamic acid (E) at position 23 is mutated to alanine (A), isoleucine (I) at position 26 is mutated to arginine (R), cysteine ​​(C) at position 41 is mutated to alanine (A), tyrosine (Y) at position 65 is mutated to isoleucine (I), glycine (G) at position 83 is mutated to arginine (R), and asparagine (N) at position 90 is mutated to glutamic acid (E). Based on structural analysis and computationally assisted design for protein stability, this invention achieves site-directed mutagenesis of the single-chain sweet protein, resulting in a highly thermostable mutant. Compared to the original single-chain sweet protein, the thermostable mutant of this invention exhibits higher T... m It was heated by more than 20.4°C while maintaining its sweetness.

Method of feeding young pigs involves feeding young pigs with complete mixed feed. Wherein, isoleucine levels in the composition of mixed feed are specifically regulated by introducing synthetic isoleucine. The ratio of standardized ideal digestible (SID) isoleucine to lysine in the diet is 0.55. The specified ratio is maintained in the diets of young pigs during the nursery after weaning, from 24 to 70 days of age.

The application discloses a mutant and gene of single-chain sweet protein with high thermal stability, wherein the mutant is obtained by mutating isoleucine (I) at the 5th position, glutamic acid (E) at the 23rd position, isoleucine (I) at the 26th position, tyrosine (Y) at the 65th position, glycine (G) at the 83rd position and asparagine (N) at the 90th position in the amino acid sequence shown in SEQ ID NO. 1 to alanine (A), arginine (R), isoleucine (I), glutamic acid (E) and aspartic acid (D) respectively; the application is based on structural analysis and protein stability calculation aided design, and the single-chain sweet protein is subjected to site-directed mutagenesis, so that the mutant of single-chain sweet protein with high thermal stability is obtained; compared with the single-chain sweet protein, the mutant of single-chain sweet protein with high thermal stability has a T m increase of 18.4 DEG C or more and maintains sweetness.

This invention relates to the fields of transcription factor engineering and metabolic engineering, and discloses an engineered strain that produces L-isoleucine, its construction method, and its applications. This strain... E. coli K12, MG1655 ( E. coli A1) serves as the host, integrating the subunit of the host factor IHF. ihfβ, ihfα Natural promoter replaced with P trc Strong promoters enable IHF overexpression, resulting in engineered bacteria. E. coli IHF4. This invention also discloses the construction steps of this strain, as well as its application method for L-isoleucine production by inoculating it into a fermentation medium, culturing it at 36-38℃ and 200 r / min for 40-60 h, and adjusting the pH and supplementing sugar. This engineered strain increases the yield of L-isoleucine by 42.11% compared to the starting strain. The construction method is simple and suitable for industrial microbial fermentation production of L-isoleucine.

A method for selecting camelid nanobodies from an array library collected from B cells of a camelid animal immunized with an antigen is provided. The method comprises (a) (i)phenylalanine (F) at position 42 (IMGT number), and (ii)a short hinge, and (iii)two or more cysteines in the nanobody sequence, and (iv)glutamine (Q) at position 123 (IMGT number), and (v)a low immunogenicity index, and (vi)a non-conventional VHH derived from germline IGHV3, or valine (V) included at position 42 (IMGT number), and (vii)a non-conventional VHH derived from germline IGHV4, or isoleucine (I) included at position 42 (IMGT number), and (viii)histidine (H), aspartic acid (D), or glutamic acid (E) in the CDR region, and (ix)histidine (H), aspartic acid (D), or glutamic acid (E) in the top 3 amino acid residues of the nanobody sequence, the FR2 region, or the top 16 amino acid residues of the FR3 region, and (x)tyrosine (Y) at position 42 (IMGT number), and a nanobody having a cyclic concave paratope structure arrangement, or (xi)phenylalanine (F) at position 42 (IMGT number), and a nanobody having a convex paratope structure arrangement, identifying a camelid nanobody having at least one of the features, and (b)measuring one or more biological activities of the nanobody identified in step (a).

The application provides a pyroglutamic acid transaminase mutant and application thereof, the mutant is obtained by mutation on the basis of wild-type pyroglutamic acid transaminase, and specific mutation includes at least one of the following sites: (1) the 13th isoleucine is mutated into arginine; (2) the 35th valine is mutated into arginine; (3) the 183rd asparagine is mutated into aspartic acid; and the mutant is suitable for industrial enzymatic production of L-aspartic acid and the process of amino acids taking L-aspartic acid as a precursor; especially, the I13R / V35R / N183D mutant obtained by modification has high positive catalytic activity and strict direction selectivity, and completely loses the reverse reaction activity of decomposing L-aspartic acid; the mutant is overexpressed with phosphoenolpyruvate carboxylase in L-threonine production strain THRS-6, and a high-efficiency L-threonine synthesis metabolic pathway is constructed, and the yield of L-threonine is significantly improved when glucose is used as a substrate.

This invention provides a leucine dehydrogenase mutant, a valine-producing strain comprising this leucine dehydrogenase mutant, and its applications. The invention designs a leucine dehydrogenase mutant with the following mutations: tyrosine (Tyr) at position 48 is mutated to serine (Ser), histidine (His) at position 127 is mutated to arginine (Arg), tyrosine (Tyr) at position 186 is mutated to phenylalanine (Phe), isoleucine (Ile) at position 256 is mutated to valine (Val), and lysine (Lys) at position 308 is mutated to arginine (Arg). These mutations are used to construct a valine-producing strain. The new strain is plasmid-free, has no growth defects, requires no induction, and exhibits advantages such as good genetic stability and high fermentation yield. It is an excellent strain capable of stably producing valine. This strain efficiently synthesizes valine de novo using glucose as a substrate, significantly increasing valine yield.

This application belongs to the field of biology, and specifically relates to a polypeptide and its applications. This application provides a polypeptide comprising an Alphabody and BDNF linked by a linker. The Alphabody has a structure shown in the general formula HRS1-L1-HRS2-L2-HRS3, wherein each of HRS1, HRS2, and HRS3 is independently an α-helix structure containing 2 to 4 consecutive heptapeptide repeating units, said heptapeptide repeating units being polypeptide fragments represented as "abcdefg" or "defgabc", wherein at least 50% of all a and d positions are occupied by isoleucine residues, and wherein each HRS begins with an aliphatic or aromatic amino acid residue located at the a or d position; L1 and L2 are each independently a linker fragment. The polypeptide of this application can increase the exposure of BDNF in plasma and prolong its half-life.

The application relates to the technical field of genetic engineering, in particular to a sucrose phosphorylase mutant and application thereof in synthesis of alpha-maronia. Streptococcus parasanguinis The application is characterized in that the histidine at the 152th position of the wild-type sucrose phosphorylase from Streptococcus sanguis is mutated into threonine, and the isoleucine at the 336th position is mutated into proline, so that the sucrose phosphorylase mutant is obtained, the catalytic activity and stability of the sucrose phosphorylase are significantly improved. When sucrose and hydroquinone are used as substrates, the yield of alpha-maronia is increased by more than 40% compared with the wild type, and the catalytic reaction time can be greatly shortened.

The present disclosure provides: an L-isoleucine-producing microorganism expressing threonine export protein RhtC; a method for producing L-isoleucine, comprising a step of culturing the microorganism; a method for increasing L-isoleucine productivity of the microorganism, comprising a step of introducing a threonine export protein RhtC gene into a cell; and a use thereof for producing L-isoleucine.

The application discloses an alcohol dehydrogenase mutant and application thereof in preparation of cis-4-propylcyclohexanol. The mutant is obtained by substituting at least one amino acid in three positions of an amino acid sequence shown in SEQ ID No. 1, i.e. the 43th, 271th and 282th positions. The 43th phenylalanine (F) is substituted into valine (V) or serine (S), the 271th isoleucine (I) is substituted into valine (V) or phenylalanine (F), and the 282th phenylalanine (F) is substituted into valine (V). The wild-type alcohol dehydrogenase gene is subjected to directional evolution modification, and the alcohol dehydrogenase mutant has higher catalytic activity and higher stereoselectivity than the wild-type alcohol dehydrogenase, so that the cis-4-propylcyclohexanol is efficiently and highly stereoselectively generated.

The application discloses a protein mutant coded by NCgl0216 and application of biological material of the protein mutant in production of L-isoleucine, and belongs to the technical field of biotechnology.The application solves the technical problem of how to improve the yield of L-isoleucine.The sequence of the disclosed protein is SEQ ID No.4 or SEQ ID No.2.The coding gene of the protein shown in SEQ ID No.2 in the original biological cell is replaced by the coding gene of the protein shown in SEQ ID No.4, or the content or activity of the protein shown in SEQ ID No.2 or SEQ ID No.4 in the original biological cell is improved, so that the yield of L-isoleucine can be improved.

The application discloses a trehalose-6-phosphate phosphatase and a mutant and application thereof, and belongs to the technical field of biology. The amino acid sequence of the wild-type LcTre6PPase is shown as SEQ ID NO:1, and the encoding nucleotide sequence is shown as SEQ ID NO:2. The mutant is obtained by mutating the isoleucine at the 571th position of the wild-type enzyme into leucine (I571L), the amino acid sequence is shown as SEQ ID NO:3, and the corresponding encoding nucleotide sequence is shown as SEQ ID NO:4. Bidirectional enzyme activity analysis shows that, compared with the wild type, the I571L mutant is improved by about 1.2 times in the direction of catalyzing glucose-6-phosphate and beta-D-glucose-1-phosphate to synthesize trehalose-6-phosphate, and the activity in the direction of catalyzing trehalose-6-phosphate to phosphorolyze is reduced to 0.8 times of the wild type. The mutant shows good application potential in the efficient synthesis of trehalose-6-phosphate, and provides a new enzyme tool for preparing trehalose-6-phosphate.

The application belongs to the technical field of enzyme engineering and genetic engineering, and discloses a ketoreductase mutant, method and application. The mutant comprises the following point mutations: the isoleucine at the 91th position of the amino acid sequence shown in SEQ ID No. 1 is mutated into glycine (I91G), and the alanine at the 139th position is mutated into methionine (A139M). The ketoreductase mutant obtained by the application can produce N-BOC-cis-3-hydroxy-L-proline methyl ester in high selectivity and high yield. Under the conditions of OD 600 =10, 300mM glucose, 2mM NADP + / NAD + , 50mg / ml ls GDH, and a substrate concentration of 200mM, the yield is 96.5% and de>99% after 18h of reaction.

A pyridoxal kinase mutant is provided. To solve the problem of low concentration of existing enzyme catalyzed products, provided is a pyridoxal kinase mutant having an amino acid sequence selected from an amino acid sequence as shown in SEQ ID NO: 1 in which lysine at position 229 is mutated to alanine, phenylalanine, arginine, threonine, histidine, serine, tyrosine, valine, leucine, isoleucine, proline, aspartic acid, or glutamic acid; and the pyridoxal kinase mutant is used to catalyze the synthesis of pyridoxal phosphate from pyridoxal.

Provided is a method of selecting a camelid nanobody from a library of camelid nanobody sequences collected from B cells from a camelid immunized with an antigen. The method comprises: (a) identifying a camelid nanobody that has at least one of the following features (i) a phenylalanine (F) at position 42 (IMGT numbering); (ii) a short hinge; (iii) two or more cysteines in the nanobody sequence; (iv) a glutamine (Q) at position 123 (IMGT numbering); (v) low immunogenicity metric; (vi) non-classic VHH derived from germline IGHV3 or a valine (V) at position 42 (IMGT numbering); (vii) non-classic VHH derived from germline IGHV4 or an isoleucine (I) at position 42 (IMGT numbering); (viii) a histidine (H), aspartic acid (D) or glutamic acid (E) in the CDR region; (ix) a histidine (H), aspartic acid (D) or glutamic acid (E) in the first three amino acid residues, the FR2 region, or the first sixteen amino acid residues of the FR3 region of the nanobody sequence; (x) a tyrosine (Y) at position 42 (IMGT numbering), and the nanobody having a loop, concave paratope structure configuration; or (xi) a phenylalanine (F) at position 42 (IMGT numbering), and the nanobody having a convex paratope structure configuration; and (b) measuring one or more biological activities of the nanobody identified in step (a).

This article provides derivatives of sea hare proline-sea hare isoleucine peptide. It also provides peptide analogs, pharmaceutical compositions comprising these compounds, and methods for treating cancer with these compounds.

This invention provides a flexible multi-gate single-channel OECT molecularly imprinted sensor and its fabrication method, belonging to the field of flexible chemical sensor technology. This sensor employs a unique multi-gate single-channel integrated structure with gates symmetrically arranged at equal intervals around the source and drain electrodes and synergistically controlled within the same channel. Combined with MIP and OECT technologies, it possesses both high-sensitivity amplification capability and highly specific recognition of three non-electroactive BCAAs (leucine, isoleucine, and valine), enabling the detection of multiple substances with a single device.

Methods, systems, apparatuses, and computer program products are described herein for printing artificial constructs or tissue models from a bioink using digital light processing (DLP). Bioinks can include polyethylene glycol diacrylate (PEGDA), gelatin methacrylate (GelMA), hyaluronic acid methacrylate (HAMA), lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), tartrazine, arginine-glycerine-aspartic acid (RGD), isoleucine-lysine-valine-alanine-valine (IKVAV), and Dulbecco's Phosphate-Buffered Saline (dPBS) pH buffered with calcium and magnesium. Such bioinks can result in printed constructs that exhibit improved vascularity / perfusability and improved stem cell growth and regulation. Bioink can be formed by vortexing a solution of PEGDA, GelMA, HAMA, LAP, tartrazine, RGD, IKVAV, and / or dPBS at a temperature of, e.g., about 60°C or greater. DLP bioprinting can be carried out layer-by-layer with an average thickness of each layer being between about 25 µm and about 100 µm. Average light intensity emitted during DLP bioprinting can be between about 10 mW / cm2 and about 30 mW / cm2.

Disclosed herein are leukocyte-targeting molecules, pharmaceutical compositions comprising leukocyte-targeting molecules and an optional pharmaceutical agent, and methods of using same. In some embodiments, a leukocyte-targeting molecule is a peptide having the formula: X1X2AAX3AX4X5X17AX6X7X8AX9X10A(P)nX11x12(X13)n, or a pharmaceutically acceptable salt thereof: wherein X1, X2, X11, and X12 are each, independently, lysine, arginine, or ornithine; X3, X4, X5, X6, X7, X8, X9, and X10 are each, independently, valine, leucine, isoleucine, or norleucine; X13 is tyrosine; X17 is praline or alanine; and n is 0 or 1.

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 present application relates to the field of bioengineering technology, in particular to mutants of enzymes used in branched-chain amino acid biosynthesis and a construction method and application thereof. The mutants provided by the present application include: the 25th amino acid of wild-type acetohydroxy acid synthase encoded by ilvN gene is mutated from valine V to isoleucine I; and / or the 90th amino acid of wild-type acetohydroxy acid isomerase encoded by ilvC gene is mutated from isoleucine I to serine S. The mutant ilvN of acetohydroxy acid synthase V25I and / or the mutant ilvC of acetohydroxy acid isomerase I90S , and a mutant strain thereof has a significant positive effect on the yield of main product valine and a significant negative effect on the yield of by-product isoleucine, and provides a reference for the construction of a production strain of valine, leucine, isoleucine and other three branched-chain amino acids and derivatives taking them as precursors.