140 results about "Random mutation" patented technology

Aspects of the invention relate to the design and synthesis of nucleic acid libraries containing non-random mutations or variants. Aspects of the invention provide methods for assembling libraries containing high densities of predetermined variant sequences. Certain embodiments relate to the design and synthesis of nucleic acid libraries that express a predetermined polypeptide from a library of nucleic acids having silent sequence variants. Certain embodiments relate to the design and synthesis of nucleic acid libraries that express predetermined RNA variants that encode the same polypeptide sequence.

The invention relates to a controlled mutation-based test case generation method for improving fuzzy test coverage, and belongs to the field of loophole mining in information safety. Aiming at the problem that the existing fuzzy test coverage optimization methods are high in time cost, incomplete in test range and low in automation degree, the invention discloses a controlled mutation-based test case generation method. According to the method, feedback is carried out on test case generation processes by utilizing an instrumentation technology, and a random mutation manner and a controlled mutation manner are combined to optimize the test case generation. Experimental results show that when being compared with the un-optimized test methods, the method has the advantages of improving the code coverage by 35-47% and decreasing the number of test cases required under same code coverage by more than 48%. The method is not only capable of improving the test case coverage and decreasing the test case redundancy, but also has the characteristics of being low in time cost, complete in test range and free of manual intervention in test processes.

The invention discloses a CRISPR (clustered regularly interspaced short palindromic repeat)/Cas9 recombinant lentiviral vector containing gRNA sequence specifically targeting CCR5 and application thereof. A lentivirus of the CRISPR/Cas9 recombinant lentiviral vector containing gRNA sequence specifically targeting CCR5 gene Delta 32 region is constructed that the lentivirus can introduce cells into a CRISPR/Cas9 system specific to CCR5, double-chain breakage occurs to a specific site of CCR5 gene, a random mutation is introduced to a breakage site after repairing by means of nonhomogeneous recombinant terminal binding, and the mutation rate reaches 90% and above. As gRNA is a nonhomogeneous region of CCR5 and CCR2, detection shows that the missing efficiency of the two gRNAs is lower than 0.2%. Cells modified via the recombinant lentivirus have significantly decreased efficiency of HIV (human immunodeficiency virus) infection. The system is quick to construct, simple and low in price, and is applicable to gene therapy of acquired immune deficiency syndrome.

The invention belongs to the field of gene engineering, and particularly relates to a chimeric antigen receptor for identifying carcino-embryonic antigens and an application of the chimeric antigen receptor. A single-chain fragment variable (scFV) for identifying the carcino-embryonic antigens, a hinge region, a transmembrane region and an intracellular signal domain are sequentially connected to form the chimeric antigen receptor, and the amino acid sequence of the single-chain fragment variable (scFV) for identifying the carcino-embryonic antigens includes M5A-scFV amino acid sequence or amino acid sequence acquired by performing random mutation on M5A-scFV polypeptide. When the chimeric antigen receptor identifies the carcino-embryonic antigens, T lymphocytes can be more stably expressed, the positive rate of a chimeric antigen receptor of a target CEA (carcino-embryonic antigen) can be maintained in the culture process of patient cells, proliferation capacity and tumor killing capacity of CAR-T (chimeric antigen receptor T lymphocytes) can be improved, the chimeric antigen receptor does not have toxic and side effects on confrontation of original negative cells, can be used for targeted treatment of tumors and high in humanization degree, immunogenicity of the CAR can be effectively reduced, and continuity and safety of the CAR-T in human bodies are improved.

The invention belongs to the field of bioengineering and particularly relates to a flavin monooxygenase mutant and a preparation method thereof. The error-prone PCR technology is used to conduct random mutation on wild type flavin monooxygenase to obtain the flavin monooxygenase mutant. The specific enzyme activity of the flavin monooxygenase mutant is improved by 35% compared with that of the wild type flavin monooxygenase. Meanwhile, a yeast expression system is adopted, when the flavin monooxygenase is displayed on the surface of yeasts, yeast cells can serve as enzyme producers and can also serve as carriers in immobilized enzymes, operation of purification, fixation and the like of the enzymes are omitted, the production link is simplified, and the production cost is reduced.

The invention discloses a pipeline gas pressure measuring device. The pipeline gas pressure measuring device is composed of a shell (1), one or more measuring pipes (2), a line pipe (3), one or more pressure equalizing tanks (4) and a differential pressure transducer (5), and the shell (1) is embedded in a ventilating pipeline. The pipeline gas pressure measuring device is characterized in that the shell (1) is provided with one or more measuring pipes (2) in the radial direction, the measuring pipe (2) extends out of the shell and is provided with a plurality of measuring holes; the shell is provided with one or more pressure equalizing tanks (4), an input pipe (41) of the pressure equalizing tank (4) is communicated with the pressure measuring pipe (21) through the line pipe (3), and an output pipe (42) is communicated with the differential pressure transducer (5) through the line pipe (3). The pipeline gas pressure measuring device disclosed by the utility model has the advantages of high detection precision, good stability, and ability of effectively suppressing server impacts brought about to a measuring value by random mutation pressure generated by high-speed turbulences in an air pipe.

The invention belongs to the technical field of gene engineering and enzyme engineering, specifically to a feruloyl esterase A mutant and the purpose thereof. According to the invention, parent genes of feruloyl esterase A undergo a random mutation by error-prone PCR to construct a random mutation library; 12 heat-resistance enhanced feruloyl esterase A mutant sites are selected by a high-throughput screening system; and a complete sequence synthetic method is adopted to integrate the 12 mutation sites onto a coding sequence so as to obtain a combination mutant. The combination mutant has much more enhanced heat stability than the parents and is of potential application value in industrial fields such as bioenergy, forage, papermaking, health food, medicine and the like.

The present invention discloses one kind of P450BM-3Asp168His variant gene capable of catalyzing indole to generate indigo blue, and the gene is obtained by means of saturated mutation and directional evolution technology mediated random mutation and screening. The P450BM-3Asp168His variant gene has base sequence as shown in SEQ ID No. 1 of the sequence list, and the aspartic acid codon in the 168-th site of the original P450BM-3(F87V/A74G/L188Q) gene mutated into histidine codon. The enzymic kinetic curve measurement shows that the variant enzyme the obtained variant gene expresses has catalysis efficiency obviously higher than that in available technology. The present invention provides new practical enzyme for the biological synthesis of dye indigo blue and wide application foreground for the biological production of dye indigo blue.

The invention relates to a novel high-activity allinase and a preparation method thereof. The preparation method is characterized in that a wild type allinase gene from a garlic bulb is transformed by utilizing a random mutation technology, and a high-activity allinase mutant gene, namely a novel high-activity allinase gene, is obtained; then the novel high-activity allinase gene is expressed in a bacillus subtilis expression system and pichia pastoris expression systems (including a pichia pastoris free expression system and a pichia pastoris cell surface display system) respectively, and recombination strains for producing the high-activity allinase are obtained; detections carried out after fermentation expression show that the specific enzyme activity of the novel high-activity allinase is improved by 50% in comparison with a wild type allinase.

The invention relates to a parameter identification method of an asynchronous motor based on an improved particle swarm optimization algorithm. Based on a standard particle swarm optimization algorithm, the maximum weighting coefficient (as the following formula) and the minimum weighting coefficient (as the following formula) are set in batches respectively; a random mutation operator is added, and the strategy of adding the mutation operator to perform random mutation on gbest improves the ability of the algorithm to jump out of local convergence, improves the problem of premature falling into local optimum of the particle swarm, expands the search scope of particles, improves the global searching ability and convergence speed of the particle swarm optimization algorithm, reduces the risk of falling into the local optimum, and takes both precision and efficiency of an optimization process into account. According to the parameter identification method of the asynchronous motor based on the improved particle swarm optimization algorithm provided by the invention, the measuring value of each working characteristic of the asynchronous motor is obtained by measuring, the improved particle swarm optimization algorithm is used to realize the static parameter identification of the asynchronous motor, and the method still has higher identification accuracy in the presence of noise.

The invention belongs to the technical field of gene engineering of enzyme, and specifically relates to a lipase mutant of which the alkaline resistance is increased, as well as preparation and application thereof. A wild type lipase gene is obtained through a molecular biology technological means, and random mutation is carried out on the wild type lipase gene subjected to escherichia coli codonoptimization by utilizing an error-prone PCR (Polymerase Chain Reaction) technology, so that a lipase mutant N157F and an encoding gene mpc1 thereof can be obtained; a recombinant vector can be reconstructed, efficient expression of the recombinant vector in bacillus subtilis WB600 and pichia pastoris GS115 is realized, and the lipase mutant of which the alkaline resistance is further increased isobtained through technologies of fermentation, extraction and the like.

The invention relates to an assembly line multi-target modeling method, a particle swarm algorithm and an optimization scheduling method, wherein the optimization scheduling method comprises the steps of S1 constructing a assembly line multi-target optimization model; S2 performing multi-target optimization design to the assembly line multi-target optimization model by the particle swarm algorithm and screening the optimization result to reconstruct the assembly line. According to the reconstructible assembly line optimization scheduling method, a crowding distance calculation method and an elite strategy are referred to; diversity maintenance and global optimal value update are conducted on the basis of individual crowding distance ordering; the complex fitness calculating process is avoided; and a small probability random mutation mechanism is introduced, thereby enhancing the global searching optimization capability gratly.

The invention discloses a method for determining the low-loss operation mode of a medium voltage distribution network. The method includes the steps of: 1, firstly establishing a medium voltage distribution network low-loss operation mode customization model which takes the minimal total electric energy loss in a customization period under a plurality of constraint conditions including the reliability constraint as a target; 2, reading basic data of the distribution network; 3, setting reliability index constraint limits; 4, optimally searching different switch vector states of the distribution network by using an evolutionary programming algorithm combined with an improved random mutation strategy; 5, outputting results. According to the method, when customizing the operation mode of the medium voltage distribution network, the minimal total electric energy loss in the customization period is taken as the target, and the power supply reliability constraint is involved, thus being beneficial to improving operation economy and reliability of the distribution network, and being capable of ensuring network structure constraint of the distribution network, namely ensuring the radiation pattern and non-island operation of the distribution network.

The invention discloses an inverse kinematics solving method and device for a service robot in a smart space. The method includes the following steps that: the forward kinematics model of the robot isestablished by using a D-H parameter method; real number coding is performed on the joint variables of the robot; an adaptive function is constructed with difference between a current pose and a target pose adopted as an optimization objective; and a genetic algorithm is used to perform optimization solution on the joint variables, so that the optimal solution of the inverse kinematics problem isobtained. The method of the invention does not need to be limited to robot configurations, and a plurality of populations are introduced, so that parallel optimization search can be realized, and therefore, the method can cope with the increase of the degree of freedom of the robot; the real number coding is adopted for the individuals, and mapping errors occurring during continuous function discretization when binary coding is adopted can be avoided; and on the basis of the real number coding, crossover operation adopts a linear crossover mode, mutation operation adopts a random mutation mode, and adaptive crossover and mutation probabilities are introduced, and therefore, a better solution can be effectively protected in the later stage of evolution, and convergence speed and precisioncan be guaranteed.

The invention provides a method for realizing genome editing and accurate and targeted knock-in of genes in fishes. A technology of producing DNA single-chain gap based on nicking enzyme is utilized,assisted with a set of homologous recombination repair factor RecOFAR, so as to realize high-efficient, accurate and targeted integration of genome editing and gene knock-in in the fishes. The problems that a current existing method is low in efficiency, and random mutation efficiency of target points is higher are overcome.

The invention discloses reorganized corynebacterium glutamicum producing chondroitin and an application of the reorganized corynebacterium glutamicum, and belongs to the technical field of bioengineering. According to the reorganized corynebacterium glutamicum disclosed by the invention, firstly UDP-N-acetylglucosamine C4 isomerase coding genes kfoA and chondroitin synthetase coding genes kfoC aresubjected to heterologous expression in corynebacterium glutamicum, glmU, galU, ugd, glmS and glmM are subjected to overexpression, and a synthesis route of chondroitin is preliminarily constructed;and then random mutation is performed on chondroitin synthetase (KfoC), and the situation that the yield of chondroitin can be increased by 200% through a KfoC (H357G N363S) mutant is found. Through aprotein fusion technique, kfoA, kfoC (mutants) and ugd genes (coding UDP-glucose dehydrogenase) are fused, so that the expressed UDP-N-acetylglucosamine C4 isomerase, the chondroitin synthetase and the UDP-glucose dehydrogenase form an artificial compounds, and the yield of the chondroitin is further increased.

The present invention relates to a gene search vector, a random gene mutation control method and application thereof. Specifically, the present invention relates to a vector for gene search system, a random gene control method, a method for screening high transfer human tumor cell lines, a method for screening a gene for improving human tumor cell line transfer, a whole-genome random mutation library obtained by using the random gene control method, pharmaceutical application of the gene obtained by using the method for screening gene for improving human tumor cell line transfer, pharmaceutical application of an inhibitor of the gene, and pharmaceutical application of an inhibitor of an expression product of the gene. The gene obtained by the method of the invention, the inhibitor of the gene, the expression product of the gene and the inhibitor of the expression product of the gene can be applied to development of specific antitumor drug.

The invention belongs to the field of microorganisms, and discloses a construction method of mutant strains for realizing universal enzyme catalytic functional diversity, which comprises the followingsteps of: constructing a mutant library of a universal enzyme; and screening the mutant strains with catalytic functional diversity through shake flask fermentation. By means of the method, a recombinant saccharomyces cerevisiae mutant strain which generates zeta-carotene by BtCrtI catalytic two-step dehydrogenation reaction and a recombinant saccharomyces cerevisiae mutant strain with the ratioof a lycopene produced by catalytic four-step dehydrogenation and a neurosporene produced by three-step dehydrogenation reaction is 5:1..By means of the method, the recombinant saccharomyces cerevisiae strain is utilized to obtain mutant strains of BtCrtI with different catalytic functions through a random mutation property, key amino acid sites are determined, the controllability of dehydrogenation steps is realized, the functional information of CrtI is enriched, and a foundation is laid for the biosynthesis of important natural products.

This invention relates to a variant gene P450BM-3 to catalytic generation of indigo blue from indole and its use. Due to random mutation caused by PCR process, variant gene P450NM-3 is obtained by screening. ATC of Ile on its 39th digit is mutated into GTC of Val. Its gene sequence is listed in SEQ.ID.No.1 of nucleotide sequence. Its variant protease can catalyze indole to generate indigo blue. Compared with a variant protease with three mutation points, which is obtained by R.D.Schmid' team, its activation increases 1.2-1.4 times in an example.

Compositions and methods are provided for reversibly binding chitin-binding domain (CBD) to a chitin or equivalent substrate under non-denaturing conditions. CBD from either prokaryotes or eukaryotes are modified for example, by random mutation, and screened to identify mutants that achieve this change in properties. Creating a modified CBD with an altered binding affinity for substrate provides new uses for CBD not previously possible with unmodified CBD that binds irreversibly to chitin.

The invention discloses a 1, 3-propanediol oxidation reductase isozyme variant gene Gln202Ala and the use. Mediated random mutation of fallible PCR technology is used for screening and getting 1, 3-propanediol oxidation reductase isozyme variant gene. Codon CAG of glutamine of No. 202 in the gene is mutated into a codon GCG of Alanine, thereby getting 1, 3-propanediol oxidation reductase isozyme variant gene Gln202Ala. The nucleotide sequence of the mutated gene is SEQID No.1, which can encode 1, 3-propanediol oxidation reductase isozyme mutations. The variant gene Gln202Ala is reassembled for expressing 1, 3-propanediol oxidation reductase isozyme mutations through gene engineering technology, which is used for catalyzing hydroxy-propionaldehyde and producing 1, 3-propanediol. The invention has the advantages of improving activity by 1.5 to 2 times and providing wide application prospect for chemical raw material 1, 3-propanediol of biotransformation.