48 results about "Substrate specificity" patented technology

The invention discloses a glycosyl transferase mutant and an application of the glycosyl transferase mutant in synthesis of rebaudioside. According to the invention, single-point mutation and multi-point mutation are carried out on the basis of a glycosyl transferase amino acid sequence as shown in SEQ ID NO: 1, and a mutant with improved catalytic activity is obtained. The catalytic activity, the substrate specificity and / or the substrate specificity of the glycosyl transferase mutant are / is changed, and the catalytic activity of enzyme to a specific substrate can be remarkably improved by mutation at a specific site. And carrying out induced expression and protein purification on the obtained mutation sequence to obtain the mutant enzyme. The mutant enzyme is used as a catalyst, and UDPG is used as a glycosyl donor, so that the catalytic reaction efficiency of substrates such as stevioside ST, rebaudioside A (RebA) and rebaudioside D (RebD) can be obviously improved. According to the glycosyl transferase UGT76G1 mutant constructed by the research, the catalytic activity of the glycosyl transferase UGT76G1 mutant is improved, and efficient production of rebaudioside M is realized by optimizing a reaction system.

The invention relates to a UGT enzyme subtype substrate specificity prediction method and model. On the basis of a directional message passing neural network, graph structure characterization of a small molecule compound and features of specific protein binding sites of UGT enzyme are deeply fused, a bimodal prediction normal form of'molecule + protein binding sites' is designed, a deep learning model is constructed, conversion from compound center prediction to molecule-enzyme binding site comprehensive prediction is achieved, and the prediction accuracy is improved. And accurate classification prediction can be carried out on UGT enzyme substrates and non-substrates.

The invention discloses polyethylene glycol terephthalate hydrolase PmPETase and application thereof.The hydrolase PmPETase is protein with the amino acid sequence shown in SEQ ID NO.1. An expression system suitable for the PmPETase is constructed, recombinase protein with catalytic activity is obtained, and the polyethylene glycol terephthalate hydrolase PmPETase can be used for preparing the polyethylene glycol terephthalate hydrolase PmPETase. The substrate specificity, the catalytic property and the potential plastic degradation capacity of the PET degrading enzyme are comprehensively analyzed, and a new theoretical basis and application reference are provided for development and utilization of the PET degrading enzyme and a high polymer material green treatment technology.

The invention discloses a method for detecting F26G enzyme activity based on an HPLC (High Performance Liquid Chromatography) technology, and belongs to the technical field of biological enzyme activity detection. According to the method, on the basis of the characteristic that furostanol saponin 26-O-beta-D-glucosidase (F26G) hydrolyzes furostanol saponin C-26 glucosyl, a detection system which takes furostanol saponin as a substrate and quantifies substrate consumption through an HPLC technology to calculate enzyme activity is established, the method has high substrate specificity, and compared with a pNPG method, the method has the advantages that the detection efficiency is high, and the detection cost is low. The method has the advantages of high sensitivity and high accuracy, can accurately eliminate the interference of other glucosidase in the system, overcomes the defects of poor specificity, low sensitivity and difficulty in accurate determination of the enzyme activity of the traditional pNPG method, provides a new method for accurate detection of the activity of the F26G enzyme in the medicinal materials, and provides technical support for quality monitoring of the medicinal materials and decoction pieces.

This invention discloses the application of arginine-depleted engineered bacteria for the treatment of soft tissue sarcomas, including preliminary validation, obtaining qualified engineered bacteria SGR1, obtaining drug compositions and regimens, experimental conclusions, and clinical application promotion. During use, clinical soft tissue sarcoma samples are collected, including undifferentiated pleomorphic sarcoma, synovial sarcoma, and liposarcoma. Immunohistochemistry (IHC) is used to detect ASS1 protein expression, qPCR is used to detect ASS1 gene transcription levels, and the proportion of ASS1 deletion / low expression is statistically analyzed. Arginine auxotrophic sarcoma subpopulations are confirmed based on literature. Cells are cultured in arginine-containing or arginine-free media, and cell viability, colony formation, cell cycle, and apoptosis are detected. The sensitivity of ASS1-deficient cells to arginine deprivation is verified, and therapeutic targets are identified. The enzyme activity, substrate specificity, and immunogenicity of human ARG I / II, mycoplasma ADI, and Pseudomonas ADI are compared. High-activity, low-immunogenic enzymes or enzyme combinations (such as human ARG I + microbial ADI) are selected, and site-directed mutagenesis or codon optimization is performed on microbial ADI to increase expression levels.

The purpose of the present invention is to provide: a plant having an increased yield of storage tissue; and a method for producing the plant. It was discovered that the yield of storage tissue in a plant can be increased by expressing, in the storage tissue of the plant, a sucrose synthase having a substrate specificity to adenosine diphosphate.

The present invention relates to variants of TEV protease that have—compared to the wildtype enzyme—increased stability and catalytic activity as well as altered substrate specificity. The invention further relates to compositions comprising these variants as well as uses thereof and methods in which these variants are employed.

The invention discloses an ingenol ABC transport protein ElABCG39 as well as a coding gene and application thereof. The protein is positioned in a cytoplasmic membrane, and expression of the protein in yeast proves that the protein has ingenol transmembrane efflux transport function, improves the ingenol tolerance of the yeast, and proves that the ElABCG39 has certain substrate specificity in the yeast. The ingenol ABC transporter ElABCG39 can be used for producing ingenol by fermentation of microorganisms or plant tissues.

The application provides a hot liquid source quorum quenching strain Shiquan Haeyuan bacteria and application thereof, the strain screened can inhibit pathogenic bacteria and is used for preparing bacteriostatic drugs; the preservation number of the Shiquan Haeyuan bacteria screened is CCTCC NO: M 20251224.The application also provides an AHL degradation enzyme Aii937 protein separated from the YESM3 strain, characterized in that the amino acid sequence of the protein is SEQ ID NO: 2.The YESM3 strain of the application can block the QS path of pathogenic bacteria through AHL lactonase Aii937, reduce the secretion of virulence factors of pathogenic bacteria; the strain YESM3 has no pathogenicity.AHL lactonase does not have broad spectrum, has strong substrate specificity, and only degrades C6-HSL and 3OC-C 14 -HSL.

The current invention relates to a computer-implemented method for ranking and / or identifying substrate-enzyme combinations according to the likelihood that a substrate undergoes catalytic conversion by an enzyme or inhibits the enzyme; to a computer system; and a computer program product. The invention also relates to uses of the method for predicting the substrate range of an enzyme X, for screening enzyme variants with altered substrate specificity and / or catalytic activity in relation to a substrate of interest, and for predicting biological phenotypes associated with an enzyme X.

This invention discloses a glycosyltransferase mutant and its application in the synthesis of rebaudioside. Based on the amino acid sequence of the glycosyltransferase shown in SEQ ID NO:1, this invention performs single-point and multi-point mutations to obtain mutants with enhanced catalytic activity. The catalytic activity, substrate specificity, and / or substrate specificity of the glycosyltransferase mutant are altered; mutations at specific sites can significantly improve the enzyme's catalytic activity for specific substrates. The mutant enzyme is obtained by inducing expression and purifying the protein from the obtained mutant sequence. Using the mutant enzyme as a catalyst and UDPG as a glycosyl donor, the catalytic reaction efficiency for the substrates steviol glycoside ST, rebaudioside A (RebA), and rebaudioside D (RebD) can be significantly improved. The glycosyltransferase UGT76G1 mutant constructed in this study improves its catalytic activity, and the efficient production of rebaudioside M is achieved through optimization of the reaction system.

This invention discloses a polyethylene terephthalate (PET) hydrolase, PmPETase, and its applications. The hydrolase PmPETase is a protein with the amino acid sequence shown in SEQ ID NO:1. This invention constructs an expression system suitable for PmPETase, obtains a recombinant enzyme protein with catalytic activity, and comprehensively analyzes its substrate specificity, catalytic properties, and potential plastic degradation ability. This provides a new theoretical basis and application reference for the development and utilization of PET degrading enzymes and green treatment technology for polymer materials.

The invention relates to the technical field of catecholamine detection, in particular to a copper-doped carbon dot with similar catechol oxidase activity as well as a preparation method and application of the copper-doped carbon dot. The copper-doped carbon dot provided by the invention can be used as a nano-enzyme for specific catalytic oxidation of catecholamine, so that catecholamine is detected by a colorimetric method. Copper atoms in the copper-doped carbon dots are dispersed in a monatomic form, and a local coordination structure is Cu-N3O which is similar to metal active sites in natural enzyme; according to the structure, the electron transfer capability and the redox activity of a Cu center are remarkably enhanced, so that the structure shows efficient catalytic activity and substrate specificity in a catecholamine oxidation reaction.

This invention provides libraries of Botulinum neurotoxin A (BoNT / A) protease variants for stepwise evolution of the enzyme to generate BoNT / A variants that can specifically cleave a desired cleavage site in a target protein. Related methods for performing stepwise evolution of BoNT / A with the BoNT / A variant libraries and simultaneous stepwise evolution of a desired substrate sequence in a target protein are also provided by the disclosure. Additionally provided in the disclosure are specifically evolved BoNT / A variant enzymes and conjugate proteins that specifically degrade intrinsically disordered proteins (IDPs) that are involved in human deceases, e.g., a-Synuclein. Polynucleotide sequences encoding the engineered BoNT / A proteases, expression vectors and related pharmaceutical compositions are also provided in this disclosure. Further encompassed by the invention are therapeutic methods that utilize the engineered BoNT / A enzymes in the treatment of various synucleinopathies.

The invention belongs to the technical field of biology, and particularly relates to recombinant glucoside hydrolase and application thereof in preparation of rare ginsenoside F2. The recombinant glucoside hydrolase provided by the invention is a further modified product on the basis of specific fusion protein. The recombinant glucoside hydrolase provided by the invention can efficiently catalyze a reaction under a relatively mild condition, and has the characteristics of strong substrate specificity and high conversion rate. In the aspect of reaction efficiency, the enzyme shows excellent catalytic performance: a large amount of ginsenoside Rb1 substrate can be converted into the rare ginsenoside F2 in a short time, the performance is excellent, and the efficient and high-purity preparation of the rare ginsenoside F2 is facilitated.

The present application belongs to the technical field of biotechnology and enzyme engineering, and relates to a molecular modification method for improving substrate specificity of aldehyde ketone reductase, which is achieved by constructing a substrate library of aldehyde ketone reductase AKR13B3 and analyzing kinetic parameters, determining a mutation site by performing loop structure analysis and amino acid sequence alignment on a complex structure of aldehyde ketone reductase AKR13B3, coenzyme NADPH and substrate 3-keto-DON, and screening a mutant with increased substrate specificity, the present application designs the geometric shape of the entrance loop region of the substrate binding pocket of AKR13B3 to change substrate preference and realize the increase of catalytic activity of the enzyme on specific substrates, in addition, the present application provides a feasible scheme for designing aldehyde ketone reductase with good substrate specificity, and provides great hope for developing high-efficiency enzyme preparations.

Provided is a technique that can further improve substrate specificity to an L-form during L-menthol and / or L-menthol ester production. A polypeptide that: has A120G, Q88A, Q88G, Q88D, Q88M, Q88L variants of a polypeptide comprising the amino acid sequence represented by sequence no. 1, and in said variants, has a random different moiety other than an amino-acid residue into which a substitution has been introduced; has esterification activity for L-menthol and / or hydrolyzing activity for L-menthol ester, and improves substrate specificity to L-menthol and / or L-menthol ester compared to a polypeptide comprising the amino acid sequence represented by sequence no. 1. During L-menthol and / or L-menthol ester production, the polypeptide can further improve the optical purity of the product.

The present invention provides an enzyme useful for establishing an excellent N-acyl-amino group-containing compound production system, and the like. More specifically, the present invention provides a modified enzyme comprising: (A) a modified amino acid sequence consisting of an amino acid sequence comprising mutations of one or more certain amino acid residues in an amino acid sequence of a wild type enzyme having an N-acylation activity; (B) an amino acid sequence comprising substitution, deletion, insertion, or addition of one or several additional amino acid residues in the modified amino acid sequence; or (C) an amino acid sequence comprising additional mutations of one or more amino acid residues in the modified amino acid sequence and having 90% or more identity to the modified amino acid sequence, having an N-acylation activity, and having an improved N-acylation activity to L-glutamic acid or L-aspartic acid or an improved substrate specificity to L-glutamic acid as compared with the wild type enzyme, and the like.

The present invention provides variants of a beta-1, 3-N-acetylglucosamino transferase polypeptide, which variants have a higher substrate specificity for lactose than for milk-N-neotetraose as compared to Neisseria meningitidis LgtA, and also provides microbial cells having such variants of a beta-1, 3-N-acetylglucosamino transferase polypeptide, which variants have a higher substrate specificity for lactose than for milk-N-neotetraose as compared to Neisseria meningitidis LgtA, in particular to a mutant of a beta-1, 3-N-acetylglucosamino transferase polypeptide, in particular to a mutant of a beta-1, 3-N-acetylglucosamino transferase polypeptide, and a mutant of a beta-1, 3-N-acetylglucosamino transferase polypeptide. And their use in the production of oligosaccharides of interest containing N-acetylglucosamine moieties.

The invention discloses an antifungal protein and application thereof. The invention provides any one of the following applications (i) to (ii) of a biological material: (i) an application in preparation of an antifungal reagent; (ii) a use in the preparation of soluble beta-glucan oligosaccharides. More specifically, the invention provides an antifungal protein which is derived from Vitis vinifera and has incision beta-1, 3-glucanase activity, a recombinant expression preparation method of the antifungal protein, and an application of the antifungal protein in the aspect of fungus inhibition. The antifungal protein has remarkable substrate specificity on a natural beta-1, 3-glucan substrate, and can be used for efficiently hydrolyzing beta-1, 3-glucan. In addition, the compound has inhibitory activity on various typical plant pathogenic fungi, and shows good biological control potential. The method is suitable for the fields of functional oligosaccharide preparation, fungus prevention and control, fruit and vegetable preservation, green prevention and control of agricultural diseases and the like, and has a wide application prospect.

The invention discloses a PROTAC compound for degrading TRIM15 protein. The PROTAC compound has a structure as shown in a formula (I). The molecule can effectively inhibit the RIG-1 signal channel, and has application prospects in preparation of anti-inflammatory or autoimmune disease drugs. Meanwhile, the invention further provides a chemical probe molecule with the structure shown in the formula (III). One end of the molecule is combined with TRIM15, and the other end of the molecule can be combined with tag protein (such as Halog-tag) or other target protein, so that TRIM15 is recruited as E3 ubiquitin ligase to carry out ubiquitination modification on the tag protein (or the target protein). The molecule can be used as an innovative research tool and is used for exploring the biological function of the E3 ligase of TRIM15, the substrate specificity and non-K48 type ubiquitination modification.

The present disclosure provides proteolytic enzymes, i.e., S53 family proteases, having increased thermostability, increased enzymatic activity, and / or increased substrate specificity and which can digest a variety of food proteins, thereby enhancing a food's protein bioavailability. The S53 family proteases have amino acid sequences that are at least 80% identical to SEQ ID NO: 1 and comprises at least one mutation in the amino acid sequence's 513-loop which corresponds to amino acids 513 to 517 of SEQ ID NO: 1, wherein the at least one mutation is located at position 513, 514, 515, and / or 517.

The invention relates to the technical field of functional lipid preparation, in particular to high-purity microalgae glyceroglycolipid enriched by an enzymic method and a preparation method of the high-purity microalgae glyceroglycolipid. The invention provides high-purity microalgae glyceroglycolipid enriched by an enzymic method and a preparation method of the high-purity microalgae glyceroglycolipid, triglyceride and phospholipid are selectively hydrolyzed by using substrate specificity of candida antarctica lipase B, but glyceroglycolipid components which cannot be hydrolyzed are retained and enriched, the glyceroglycolipid is retained to the maximum extent, and the yield of the microalgae is increased. The invention provides a method which is mild in reaction condition, environment-friendly, simple in step and high in purity for efficient enrichment of the microalgae glyceroglycolipid.

The invention relates to the technical field of biology, in particular to multi-substrate specific carrageenase and application thereof. The invention provides a multi-substrate specific carrageenase, the amino acid sequence of which is SEQ ID NO.1. The multi-substrate specific carrageenase can degrade iota-carrageenan, kappa-carrageenan and beta / kappa carrageenan in a random type incision action mode, and is beneficial to simply and conveniently degrading hybrid carrageenan and preparing oligosaccharides with different polymerization degrees and specific composition units; and polysaccharide composition analysis is facilitated, quantification of different oligosaccharide components is achieved, and the method can be applied to the fields of food industry, chemical analysis and the like.

To provide a plant with increased yield of storage tissue and a method for producing the same. [Solution] In the storage tissue of a plant, a sucrose synthase that has substrate specificity for adenosine diphosphate is expressed, thereby increasing the yield of the storage tissue of the plant.

The invention discloses an aminopeptidase APs8-A297V, an aminopeptidase APs8-A599V, and an application of the aminopeptidase APs8-A297V and the aminopeptidase APs8-A599V in degradation of bitter peptides. The amino acid sequence of the aminopeptidase APs8-A297V is as shown in SEQ ID NO.5, and the amino acid sequence of the aminopeptidase APs8-A599V is as shown in SEQ ID NO.6. The invention further discloses a preparation method of the aminopeptidase. The aminopeptidase APs8-A297V and the aminopeptidase APs8-A599V are obtained through site-specific mutagenesis of the aminopeptidase APs8, optimization of substrate specificity and remarkable improvement of catalytic activity are achieved, good temperature stability, pH stability and excellent high-salt tolerance are shown, accurate hydrolysis can be achieved according to bitter peptide characteristics of different food source proteins, and the application prospect is wide. The bitter taste of the food is reduced to the maximum extent, the quality of the food is improved, and theoretical and practical support is provided for diversified application of the aminopeptidase in the food industry.

The invention discloses a phenylalanine ammonialyase mutant and application thereof, and belongs to the technical field of bioengineering. The technical problems that existing natural phenylalanine ammonialyase is poor in thermal stability and limited in catalytic efficiency and has cross catalytic activity are solved. According to the mutant provided by the invention, 73rd-site serine of an amino acid sequence as shown in SEQ ID NO: 1 is substituted into asparagine, 84th-site phenylalanine is substituted into tyrosine, 90th-site valine is substituted into arginine or 95th-site glutamic acid is substituted into valine, or conservative substitution derivation is carried out on the basis, so that the mutant is obtained. Therefore, the phenylalanine ammonialyase mutant with significantly improved catalytic efficiency and thermal stability and strict substrate specificity is obtained. The mutant is mainly used for efficiently removing phenylalanine in protein raw materials, and has important application value in preparation of low-phenylalanine formula food for special medical purposes and related health care products suitable for phenylketonuria patients.

The invention discloses a directional transformation method and application of a flavonoids compound of pericarpium citri reticulatae, and the directional transformation method of the flavonoids compound of pericarpium citri reticulatae comprises the following steps: inoculating bacillus velezensis into a fermentation system containing the flavonoids compound of pericarpium citri reticulatae, and fermenting to obtain the transformed flavonoids compound, the tangerine peel flavonoid compound comprises at least one of hesperidin, nobiletin and tangeretin. By screening an exclusive bacillus velezensis strain and an established oriented biotransformation system, the core technical bottlenecks of heavy pollution and severe conditions of a traditional chemical method and poor substrate specificity, low transformation efficiency and the like of a conventional microbiological method are fundamentally overcome, and efficient, green and oriented transformation of hesperidin, nobiletin and tangeretin is realized; the method is successfully applied to a solid-state fermentation process of the Xinhui pericarpium citri reticulatae, the content of high-activity flavone components is remarkably increased, and an innovative solution with remarkable industrial advantages is provided for high-value development of traditional Chinese medicinal materials.

The invention discloses a caulis sinomenii methyltransferase and an application of the caulis sinomenii methyltransferase in synthesis of sinomenine. The amino acid sequence of the caulis sinomenii methyltransferase is as shown in SEQ ID NO: 2. According to the invention, a new methyltransferase SaOMT3 is identified from a medicinal plant caulis sinomenii for the first time, and it is found that the methyltransferase participates in biosynthesis of sinomenine. Functional identification on SaOMT3 can greatly promote the research on the biosynthesis path of sinomenine, provide sufficient raw material guarantee for the creation of new sinomenine drugs, and also provide reference for the research of other medicinal plants. Meanwhile, the caulis sinomenii methyltransferase SaOMT3 disclosed by the invention is good in substrate specificity, high in catalytic efficiency and very high in application value.

Provided are variants of a β-1,3-N-acetylglucosaminyltransferase polypeptide which possess a higher substrate specificity for lactose than for lacto-N-neotetraose as compared to Neisseria meningitidis LgtA, microbial cells possessing such a variant β-1,3-N-acetylglucosaminyltransferase polypeptide, and their use in producing oligosaccharides of interest which contain an N-acetylglucosamine moiety.