2107 results about "Mutant" patented technology

The invention discloses a variation test method and device based on an intelligent automation script. The method comprises the following steps: extracting a statement execution sequence and a branch dependency relationship in an original source code by using a context-aware syntax tree, and generating a control flow diagram and a data flow diagram; performing code semantic analysis on the multi-dimensional code features by using a large language model, identifying potential defect types and variation rules, predicting the test efficiency of variants in combination with a deep Q learning model, and generating to-be-processed variants; performing grammar check and equivalence analysis on the to-be-processed variants to obtain effective variants, and testing the effective variants; variation test indexes are calculated, code weak points are positioned, and test blind areas are identified according to survival variants, so that a visual analysis report is generated; and iteratively generating a new test case according to the current survival variant and the visual analysis report, and testing the current survival variant by using the new test case. According to the invention, the variation test efficiency can be improved.

The present invention discloses a Gs12-7 endonuclease variant and a gene editing system mediated thereby. Specifically, by means of a rational mutation strategy, two Gs12-7 mutants were constructed and compared, and it was found that after the 157th amino acid of the Gs12-7 endonuclease was mutated from Glu to Arg, the activity of this gene editing enzyme could be significantly improved, and this variant was designated as Gs12-7MAX. The present invention provides an efficient gene editing technology mediated by the CRISPR-Gs12-7MAX system, which has broad application prospects in the field of genome site-directed modification.

The invention provides an UTR (Untranslated Region) element H2202 P1-G as well as a construction method and application thereof, and relates to the technical field of mRNA (messenger ribonucleic acid). According to the present invention, the ribosome load prediction and the secondary structure optimization are performed on the natural 5 'UTR of the HIV TAT 202 gene through the BaidleHelix platform, and the obtained HTAT 202 P1 sequence avoids the inhibitory hairpin structure so as to significantly improve the luciferase expression quantity compared to the natural UTR; an ncRNA sequence without a secondary structure is introduced on the basis of the HTAT 202 P1, translation inhibition of a 5 'cap region is further relieved, and the protein expression quantity of the constructed H2202 P1-G mutant (the DNA sequence of the H2202 P1-G is as shown in SEQ NO 1, and the RNA sequence is as shown in SEQ NO 2) is further improved.

The invention discloses a bovine I-type alpha interferon-ferritin fusion protein, a mutant thereof, a preparation method and an application of the bovine I-type alpha interferon-ferritin fusion protein. The bovine I-type alpha interferon is fused with a ferritin subunit, and interferon molecules are highly repeatedly and orderly displayed on the surface of a ferritin nanocage by utilizing the self-assembly characteristic of ferritin, so that the expression level, the structural stability and the antiviral activity of the interferon are remarkably improved. The fusion protein is further subjected to single-site or multi-site rational design mutation, and a mutant with significantly improved antiviral activity and stability is obtained. According to the invention, a silkworm or insect cell eukaryotic expression system is adopted to express the fusion protein or the mutant thereof, and the expression system is safe to operate, simple and convenient in procedure, low in cost and extremely beneficial to large-scale industrial production; the prepared fusion protein or mutant nanoparticles have application prospects in preparation of drugs or reagents for preventing or treating bovine viral diseases.

The invention discloses a hydroxysteroid dehydrogenase mutant with improved thermal stability, a screening method and application, key hotspot amino acid residues related to the thermal stability are rapidly identified based on computer-aided design technologies such as hydroxysteroid dehydrogenase structure prediction, PROSS and the like, so that a limited site-directed mutant library is constructed; and further screening to obtain a dominant mutant. The semi-inactivation temperature (T5105) of the obtained mutant is increased by 1.0-7.7 DEG C compared with that before mutation, wherein the semi-inactivation temperatures (T5105) of the mutants A126I and A132H are increased by 7.7 DEG C and 3.7 DEG C respectively. And the relative enzyme activity of the mutant reaches 99.86-136.73% of the relative enzyme activity before mutation. The invention provides a new method for rapidly improving the thermal stability of the enzyme, and lays a foundation for the industrial application of the hydroxysteroid dehydrogenase.

The invention belongs to the technical field of enzyme engineering, and discloses an MHETase-EstD9 mutant and an application of the MHETase-EstD9 mutant. The invention provides an MHETase-EstD9 mutant, the amino acid sequence of the MHETase-EstD9 mutant is shown as SEQ ID No.2, and on the basis of the mutant, the amino acid of the MHETase-EstD9 mutant is further mutated to design five MHETase-EstD9 mutants. At 70 DEG C, compared with wild type MHETase-EstD9, the BHET degradation activity of the MHETase-EstD9 mutant provided by the invention is improved by 15% or more, and the highest BHET degradation activity can be improved by 24 times; meanwhile, the thermal stability of the MHETase-EstD9 mutant is also improved to a certain extent, and the Tm value is maximally improved by 18.0 DEG C. The method can be applied to the fields of degradation of PET, MHET or BHET, preparation of degradation agents of PET and degradation products thereof, TPA recovery and the like, and has important environmental benefits, economic benefits and social benefits.

The embodiment of the invention provides a method for obtaining a tyrosine ammonialyase mutant based on high-throughput screening, the tyrosine ammonialyase mutant and application of the tyrosine ammonialyase mutant. The mutant is subjected to any one of the following amino acid mutations on an amino acid sequence as shown in SEQ ID NO.2: A245G + A247T, and D192V + A245G + A247T. According to the embodiment of the invention, an amino acid sequence as shown in SEQ ID NO.2 is taken as a template (basis), a key active site of the template is subjected to mutation transformation, a mutant library is constructed, and a series of mutants with remarkably improved catalytic activity and / or conversion rate are screened; the tyrosine ammonia lyase mutant provided by the embodiment of the invention can selectively catalyze L-tyrosine to generate p-coumaric acid, and has excellent yield and / or higher yield, which indicates that the mutant has more significant application prospects in catalysis of L-tyrosine to generate p-coumaric acid.

The invention belongs to the technical field of gene engineering, and particularly relates to a mutant of polymyxin efflux transporter and application of the mutant. The mutant is a PmxD transporter mutant, the amino acid sequence of the PmxD transporter mutant is shown as SEQ ID NO: 1, and compared with wild type PmxD, the polymyxin transport capacity of the PmxD transporter mutant (T38W) is improved by 450.46%; and the total discharge amount of polymyxin is increased by 85.72%. Meanwhile, the mutant can significantly improve the growth ability of the strain on a plate containing 250 [mu] g / mL of polymyxin B, namely significantly improve the autoresistance of paenibacillus polymyxa to polymyxin.

The invention discloses an inositol dehydrogenase mutant and a preparation method of D-chiral inositol, and belongs to the technical field of genetic engineering. The inositol dehydrogenase mutant is obtained by mutating an amino acid sequence as shown in SEQ ID NO.2 through the following mutations: the 200th amino acid is mutated into C from V, the 234th amino acid is mutated into Q from V, and the 256th amino acid is mutated into E from R. According to the invention, the amino acid sequence of wild type inositol dehydrogenase is mutated to obtain the inositol dehydrogenase mutant which is a high-activity mutant capable of catalyzing conversion of myo-inositol into 2-keto-myo-inositol; therefore, when the inositol dehydrogenase mutant and keto isomerase act together to prepare D-chiral inositol by taking myo-inositol as a substrate, the yield of the D-chiral inositol is effectively improved.

Glycosyltransferase UGT76G1 and UGT91C1 mutants and a method for catalytic synthesis of rebaudioside A, D, and M by using same, pertaining to the technical field of biocatalytic synthesis. The glycosyltransferase UGT76G1 mutant can effectively synthesize rebaudioside A using stevioside STV as a substrate. The glycosyltransferase UGT91C1 mutant is obtained by mutation screening of wild-type glycosyltransferase UGT91C1, has higher enzyme activity and catalytic rate, and can effectively synthesize rebaudioside D using rebaudioside A as a substrate. The glycosyltransferase UGT76G1 mutant can also be obtained by mutation and subsequent screening of glycosyltransferase UGT76G1, has higher catalytic activity, and can effectively synthesize rebaudioside M using rebaudioside D and UDPG as substrates.

Described herein are programmable DNA proteolytic target chimera complexes that can be used both for the direct treatment of cancer by inhibiting biochemical pathways that are overexpressed in cancer cells, and for the indirect treatment of cancer by recruiting the E3 ligase complex to engage with a protein of interest or a mutant thereof and initiating proteolysis. Also described herein are methods of using the complexes in the treatment of cancer, as well as compositions comprising the complexes.

The invention discloses a Taq DNA polymerase mutant as well as a preparation method and application thereof, and relates to the technical field of biology. The Taq DNA polymerase mutant is mutation on the basis of a wild type Taq DNA polymerase amino acid sequence as shown in SEQ ID NO.1, and comprises at least one of amino acid mutation L345E, L352D and S438M. The Taq DNA polymerase mutant has excellent tolerance to urea, and solves the dual technical problems that complex biological samples containing endogenous inhibitors such as urea can be efficiently amplified, and the Taq DNA polymerase mutant is compatible with difficult PCR reactions which take urea as an additive to optimize a high GC template and the like. Therefore, the mutant is a molecular biology tool enzyme which is wider in applicability and more stable and reliable in performance.

The invention belongs to the field of biosynthesis, and in particular relates to LBD (Levandanenediol Pyrophosphate) synthase and engineered yeast for producing sclareol. In order to solve the problem that in the prior art, the sclareol biosynthesis yield is generally low, LSLPPs mutant containing at least one mutation of D730L, D374L, N674L or G379M is obtained by performing mutation and optimization on LSLPPs pyrophosphate synthase, and the mutant is used for sclareol synthesis. Meanwhile, in order to solve the problem of genetic instability caused by free plasmid expression of part of saccharomyces cerevisiae strains, a sclareol synthesis pathway is constructed in a yeast genome, and meanwhile, an acetyl coenzyme A synthesis pathway, an MVA pathway and a sclareol synthesis pathway are enhanced; chassis bacteria for synthesizing sclareol are modified in a manner of knocking out part of transcription inhibition factors, and the yield of a 5L fermentation tank reaches 26.11 g / L and is greatly improved compared with the prior art.

The invention provides a kit for rapidly detecting MRSA and drug-resistant gene nucleic acid POCT of the MRSA based on a phage lyase mutant. The kit comprises nucleic acid extraction and purification and triple PCR rapid amplification detection reagents. The staphylococcus aureus bacteriophage lyase mutant nucleic acid release liquid containing the amino acid sequence as shown in SEQ ID NO: 1 is adopted, wall breaking can be rapidly conducted on staphylococcus aureus, and nucleic acid is released. The effect of the nucleic acid release liquid acting for 5 minutes is equivalent to or even better than that of the lysozyme acting for 60 minutes; according to the present invention, with the combination of the MRSA and drug-resistant gene triple PCR rapid amplification detection reagent, the total detection time is only 35 min, the time is saved by 55 min or more than 55 min compared with the lysozyme method, and the MRSA and drug-resistant gene nucleic acid POCT rapid detection can be achieved;

The invention relates to the technical field of biomedicine, discloses mutant photo-induced ion channel ChR-2 protein, and further discloses a nucleic acid construct, an expression vector, a cell, related application and a computer model. The light-sensitive channel ChR2 protein mutant obtained by the invention has stronger light current, and the light-sensitive capability of the light-sensitive channel ChR2 protein mutant is at least improved by 100 times; besides, the invention also obtains a nucleotide sequence for coding the light-sensitive channel ChR2 protein mutant, constructs a recombinant expression vector, and obtains the light-sensitive channel ChR2 protein with higher expression quantity and stronger light sensitivity, and the light-sensitive channel ChR2 protein is very suitable for expression in cells of mammals (especially human); according to the invention, the rhodopsin in different channels is systematically studied by modifying the position G224 in the helix 6 of seven transmembrane helix motifs, which proves that the mutation of the position G224 in the helix 6 in WT ChR2 accelerates the photosensitivity of the channels, and the considered position is homologous in the helix 6 of the rhodopsin in different channels.

The invention discloses a p-nitrophenyl ethyl esterase mutant with high enantioselectivity as well as a construction method and application of the p-nitrophenyl ethyl esterase mutant. The p-nitrophenyl ethyl esterase mutant is obtained by mutating an amino acid sequence of wild p-nitrophenyl ethyl esterase pnbA as shown in SEQ ID NO.1 according to one or a combination of more of the following modes: leucine at the 273rd site is mutated into aspartic acid, phenylalanine at the 314th site is mutated into histidine, and leucine at the 362nd site is mutated into arginine. The mutant pnbA-L273D / F314H / L362R provided by the invention shows optimal catalytic performance (E = 47.16) for racemization-acetic acid pinyl hydrate, the enantiomeric excess value of the mutant is 95.13%, the conversion rate of 1S, 5R-acetic acid pinyl hydrate is 90.42%, the enantioselectivity of the mutant is obviously higher than that of a wild type, and the mutant has great application potential in biological catalytic synthesis of monocyclic monoterpenoid chiral alcohols.

The invention belongs to the field of biosynthesis, and particularly relates to sclareol synthase and engineered yeast for producing sclareol. In order to solve the problem that in the prior art, sclareol biosynthesis yield is generally low, sclareol synthase is mutated and optimized, an SsScs mutant containing at least one mutation of Y491F, G307L or N269F is obtained, and the mutant is used for sclareol synthesis. Meanwhile, in order to solve the problem of genetic instability caused by free plasmid expression of part of saccharomyces cerevisiae strains, a sclareol synthesis pathway is constructed in a yeast genome, and meanwhile, an acetyl coenzyme A synthesis pathway, an MVA pathway and a sclareol synthesis pathway are enhanced; chassis bacteria for synthesizing sclareol are modified in a manner of knocking out part of transcription inhibition factors, and the yield of a 5L fermentation tank reaches 21.13 g / L and is greatly improved compared with the prior art.

The invention relates to the field of rice gene engineering, and discloses an application of OsMYB36 protein and a coding gene thereof in regulation and control of rice salt tolerance. The gene of the OsMYB36 protein is edited on the basis of a CRISPR / Cas9 technology, an agrobacterium-mediated method is utilized to introduce a japonica rice variety Zhonghua 11, and a knockout mutant is obtained through screening; tests prove that the survival rate of the rice mutant with the OsMYB36 gene knocked out is remarkably higher than that of a wild-type Zhonghua 11 plant after the rice mutant is subjected to stress treatment for 11 days by 150 mM NaCl and 200 mM NaCl salt and then rehydrated for 7 days after the rice mutant is subjected to two-leaf and one-core stage. And a simple and effective technical means is provided for rapidly creating a new salt-tolerant rice strain. Therefore, the OsMYB36 protein and the coding gene thereof disclosed by the invention can regulate and control the salt tolerance of the rice, and are of great significance to the cultivation of salt-tolerant transgenic rice.

The invention relates to mutant forms of CsgG. The invention also related to analyte detection and characterisation using CsgG.

The invention discloses a chitinase mutant obtained based on random mutation as well as a preparation method and application of the chitinase mutant. On the basis of an error-prone PCR (Polymerase Chain Reaction) technology, the mutant ChiA-7 (T165I / C253Y / A391T / N480S / T508S / K547T / I550V / N607T) of the chitinase ChiA of the bacillus thuringiensis is obtained by the invention. Compared with ChiA, the ChiA-7 has better stability, and the enzyme activity of the ChiA-7 is about 90% of the initial enzyme activity after the ChiA-7 is subjected to heat preservation for 3 hours at 40 DEG C in a phosphate buffer solution with the optimal catalysis condition of 40 DEG C and the pH value of 4.0, while the enzyme activity of the ChiA-7 is attenuated to 75% of the initial enzyme activity. The chiA-7 is connected with a carrier pET20b (+) and is transferred into escherichia coli Escherichia coli BL21 (DE3), and the extracellular enzyme activity of a recombinant bacterium reaches 10.23 U / mL, which is improved by 13.41% compared with the enzyme activity of a control bacterium for expressing chiA. The chitinase mutant obtained by the preparation method disclosed by the invention has good thermal stability and enzymatic activity, and can be applied to hydrolysis of chitin and inhibition of mould.

The invention belongs to the technical field of genetic engineering and enzyme engineering, and particularly relates to a genetically engineered bacterium for stably and efficiently producing L-isoleucine as well as a construction method and application of the genetically engineered bacterium. The genetically engineered bacterium takes E. coliTHRD as a host and contains an RNA (Ribonucleic Acid) polymerase beta-subunit mutant coding gene rpoBM; compared with a parent RNA polymerase beta-subunit, the RNA polymerase beta-subunit mutant has the advantage that the amino acid residue at the 618th site of the amino acid sequence is sequentially replaced with leucine from the N terminal to the C terminal. The genetically engineered bacterium disclosed by the invention can tolerate L-isoleucine and accumulate less alpha-ketobutyric acid, and has a very good industrial application prospect.

The invention discloses a D-pinitol dehydrogenase MtOEPa mutant and application thereof, and belongs to the technical field of gene engineering. The D-pinitol dehydrogenase MtOEPa mutant is obtained by carrying out any one of the following mutations (A)-(F) on an amino acid sequence shown as SEQ ID NO.1: (A) mutating the 87th amino acid from I into A; (B) the 87th amino acid is mutated from I to A, and the 40th amino acid is mutated from N to A; (C) the 87th amino acid is mutated from I to A, and the 160th amino acid is mutated from P to S; (D) the 87th amino acid is mutated from I to A, and the 200th amino acid is mutated from S to A; (E) the 87th amino acid is mutated from I to A, and the 219th amino acid is mutated from F to Y; (F) the 87th amino acid is mutated into A from I, the 160th amino acid is mutated into S from P, and meanwhile, the 219th amino acid is mutated into Y from F. The stability of the D-pinitol dehydrogenase MtOEPa mutant disclosed by the invention is improved, so that the yield of D-chiro-inositol is improved.

The invention discloses application of a gene CsPOD7 in cucumber haploid breeding, and belongs to the technical field of molecular breeding. According to the invention, a parthenogenesis haploid induction gene CsPOD7 is cloned from cucumber, the CsPOD7 is knocked out through a CRISPR-Cas9 gene editing technology, and a cspod7 mutant is used as a male parent to be hybridized with other cucumber materials as a female parent, so that parthenogenesis haploid can be generated. The invention is the first application of the gene CsPOD7 in developing a parthenogenesis haploid induction line in dicotyledon, realizes the application of the haploid induction line based on the gene CsPOD7 in cucumber genetic breeding, accelerates the cucumber breeding process, and has huge potential application value and market prospect.

The invention belongs to the technical field of gene engineering, and particularly relates to a biotin ligase mutant as well as a coding gene, an expression vector, a recombinant cell and application thereof. The amino acid sequence of the biotin ligase mutant is as shown in SEQ ID NO. 2. The biotin ligase (Bar A) mutant provided by the invention can be efficiently expressed in eukaryotes, the expression level of the biotin ligase (Bar A) mutant is obviously improved in mammalian cells compared with a wild type, and the biotin ligase (Bar A) mutant has good catalytic activity after expression, can effectively catalyze biotinylation of protein containing a biotin receptor sequence, and has good application prospects. The method has a wide application prospect in the fields of biotinylated protein preparation, and protein labeling, positioning, immunodetection, affinity purification, function research and the like based on a biotin-avidin system (BAS).

The invention belongs to the technical field of bioengineering, and relates to a transaminase mutant, a recombinant genetically engineered bacterium and application of the transaminase mutant in catalytic synthesis of (R)-1-Boc-3-aminopiperidine.The transaminase mutant is obtained by conducting single-point or combined mutation on the 131 site and / or the 197 site of an amino acid sequence shown in SEQ ID NO.2; the mutation sites comprise that the 131 phenylalanine is mutated into aspartic acid, threonine or tyrosine, and / or the 197 lysine is mutated into arginine or leucine. Experimental results show that compared with wild type transaminase, the catalytic activity, the thermal stability and the organic solvent tolerance of the obtained mutants, especially single-point mutants MyTA1-F131Y and MyTA1-K197R and a combined mutant MyTA1-F131Y-K197R, are all remarkably improved, and compared with the wild type transaminase, the catalytic activity, the thermal stability and the organic solvent tolerance of the obtained mutants are all remarkably improved. The mutant MyTA1-F131Y-K197R can be used for efficiently catalyzing asymmetric amination of N-Boc-3-piperidone to synthesize (R)-1-Boc-3-aminopiperidine, the conversion rate of the (R)-1-Boc-3-aminopiperidine after the (R)-1-Boc-3-aminopiperidine reacts for 24 hours under the condition that the substrate concentration is 100 g / L can reach 90% or above, and the mutant MyTA1-F131Y-K197R has a good industrial application prospect.

The invention discloses an aldehyde reductase mutant and application thereof in synthesis of a dexmethylphenidate hydrochloride intermediate, and belongs to the field of molecular biology and enzyme engineering. The aldehyde reductase mutant, polynucleotide for coding the mutant, and the recombinant expression vector can express the aldehyde reductase mutant and are used for constructing a recombinant cell or a recombinant strain for expressing the aldehyde reductase mutant. The provided aldehyde reductase mutant can catalyze 2-phenyl-2-((R)-piperidine-2)-acetaldehyde into (R)-2-phenyl-2-((R)-piperidine-2)-1-ethanol, especially improves the stereoselectivity of (R)-2-phenyl-2-((R)-piperidine-2)-1-ethanol, solves the problems of strict conditions, complex reaction and high cost in the existing synthesis method, and has a wide application prospect in the field of synthesis of (R)-2-phenyl-2-((R)-piperidine-2)-1-ethanol. Wide application prospects are realized.

The invention discloses application of an OsWRKY28 gene in regulating and controlling the number of regenerated buds of rice callus, and belongs to the technical field of plant genetic engineering. According to the invention, a key regulation factor OsWRKY28 for regulating and controlling the regeneration of the rice callus is found. By constructing the rice OsWRKY28 knockout mutant and the overexpression strain, compared with a wild type, the number of regenerated buds of the callus of the OsWRKY28 knockout mutant is remarkably increased, and the number of regenerated buds of the callus of the OsWRKY28 overexpression strain is remarkably reduced. Therefore, it is determined that the OsWRKY28 gene plays an important role in regulating and controlling the regeneration process of the callus. Therefore, the regeneration capacity of the rice callus can be improved by knocking out the OsWRKY28 gene, so that the transgenosis efficiency is improved.

The invention relates to an application of an arabidopsis gene IDD14, an arabidopsis gene IDD15 and an arabidopsis gene IDD16 in regulating and controlling the flowering time of plants. We find that three mutants with deletion of IDD14, IDD15 and IDD16 bloom in advance, overexpression plants of the three mutants are delayed in blooming, which indicates that a subfamily composed of IDD14, IDD15 and IDD16 participates in blooming regulation and has a negative regulation function which is different from the positive blooming regulation function of other IDD members, so that a new gene resource is provided for the application of IDD in breeding, and the application of IDD14, IDD15 and IDD16 in breeding is promoted. And a support is provided for research on flowering time regulation of grain crops such as corn, rice, wheat and the like and other crops.

The invention belongs to the technical field of gene engineering, and particularly relates to an acid protease mutant as well as a coding gene, a preparation method and application thereof. The amino acid sequence of the acid protease mutant is as shown in SEQ ID NO. 2. The acid protease mutant provided by the invention has the advantages of high enzyme activity, strong pH and temperature adaptability, good high temperature resistance and the like, can react in a wide pH value (pH 2.0-6.0) and temperature range (30-70 DEG C), is beneficial for improving the flexibility of a production process, particularly can adapt to industrial production at a relatively high temperature and can meet a relatively long-time high-temperature catalytic environment, and the acid protease mutant has a wide application prospect. The enzyme prepared by the method is high in enzyme activity, not easy to inactivate in a high-temperature environment, can maintain 70% or more of enzyme activity for 1 h at 50 DEG C, can maintain 55% or more of enzyme activity for 1 h at 55 DEG C, and shows good market prospects and industrial application values in the fields of wine brewing, feed processing, leather softening and the like.

The invention discloses a mint McTTG1 gene as well as an expression protein and application thereof, and belongs to the technical field of plant genetic engineering. The nucleotide sequence of the mint McTTG1 gene disclosed by the invention is shown as SEQ ID NO.1, the amino acid sequence of the expression protein of the mint McTTG1 gene is shown as SEQ ID NO.2, and the mint McTTG1 gene belongs to WD40 family genes participating in regulation and control of epidermal hair development and synthesis of anthocyanin and procyanidine. Transgenic experiments show that after the McTTG1 gene is over-expressed in the arabidopsis thaliana mutant ttg1-13 with epidermal hair loss and significantly reduced accumulation of anthocyanin and procyanidine, the formation of the epidermal hair on the surface of the mutant can be recovered, and the accumulation of anthocyanin and procyanidine can be promoted. Gene resources are provided for plant variety improvement, and cultivation of new mint varieties is facilitated.