408 results about "Amino acid mutation" patented technology

A mutant bispecific antibody that includes (a) a human hinge constant region from IgG having one or more amino acid mutations in the C_H2 domain, (b) two scFvs; and (c) two Fvs has been constructed. This type of antibody displays enhanced clearance, which has been found to be particularly useful in the context of pre-targeting methods.

Provided herein are isolated heteromultimers comprising: at least one single domain antigen-binding construct attached to at least one monomer of a heterodimer Fc region; wherein the heterodimer Fc region comprises a variant CH3 domain comprising amino acid mutations that promote the formation of said heterodimer with stability comparable to that of a native Fc homodimer; and wherein said isolated heteromultimer is devoid of immunoglobulin light chains and optionally devoid of immunoglobulin CH1 region. These novel molecules comprise complexes of heterogeneous components designed to alter the natural way antibodies behave and that find use in therapeutics.

PQQGDH having an improved substrate specificity or having an improved specific activity in an assay system using ferricyanide ion as a mediator is provided. Modified PQQGDH having the enhanced substrate specificity by introducing an amino acid mutation in a particular region of PQQGDH, and a method of enhancing the specific activity compared with a wild type in the assay system using the ferricyanide ion as the mediator by deleting, substituting, or adding one or more amino acids in an amino acid sequence of the wild type pyrroloquinoline quinone dependent glucose dehydrogenase.

The invention describes a PS4 variant polypeptide derivable from a parent polypeptide having amylase activity selected from the group consisting of: (a) a polypeptide comprising an amino acid mutation at each of positions 33, 34, 121, 134, 141, 146, 157, 161, 178, 179, 223, 229, 272, 303, 307, 309 and 334; (b) a polypeptide comprising an amino acid mutation at each of positions 33, 34, 121, 134, 141, 145, 146, 157, 178, 179, 223, 229, 272, 303, 307 and 334; (c) a polypeptide comprising an amino acid mutation at each of positions 33, 34, 121, 134, 141, 146, 157, 178, 179, 223, 229, 272, 303, 307, 309 and 334; and (d) a polypeptide comprising an amino acid mutation at each of positions 3, 33, 34, 70, 121, 134, 141, 146, 157, 178, 179, 223, 229, 272, 303, 307, 309 and 334; with reference to the position numbering of a Pseudomonas saccharophilia exoamylase sequence shown as SEQ ID NO: 1, uses of such a polypeptide as a food or feed additive, and nucleic acids encoding such.

Chimeric flaviviruses that are avirulent and immunogenic are provided. The chimeric viruses are constructed to contain amino acid mutations in the nonstructural proteins of a flavivirus. Chimeric viruses containing the attenuation-mutated nonstructural genes of the virus are used as a backbone into which the structural protein genes of a second flavivirus strain are inserted. These chimeric viruses elicit pronounced immunogenicity yet lack the accompanying clinical symptoms of viral disease. The attenuated chimeric viruses are effective as immunogens or vaccines and may be combined in a pharmaceutical composition to confer simultaneous immunity against several strains of pathogenic flaviviruses.

The invention relates to lipase mutants with enhanced thermal stability, which belongs to the technical field of enzyme gene engineering. Rhizopus chinensis CCTCC No.M201021 lipase used as the parent is processed by molecular biotechnology to obtain the lipase mutants with enhanced thermal stability. In the amino acid sequences of the mutants, the related amino acid mutation(s) is(are) one or a plurality of Met101Thr, Glu107Gly, Ala129Ser, Ser151Asn, Cys160Leu, Lys161Arg, Pro168Leu, Pro168His, Leu180His, Asp182Tyr, Thr183Ala, Thr218Ser, Lys219Asp, Ala230Phe, Ser234Phe, Val261Gly, His317Pro, Val329Ala, Glu363Arg, Asn366Asp and Ser373Cys. The mutants are expressed by half-life period t50 at 65 DEG C. The thermal stability of the mutants is enhanced as compared with the parent Rhizopus chinensis lipase. The invention also discloses a DNA sequence, an expression carrier and a host cell for coding the lipase mutants.

The invention relates to pre-fusion RSV F protein and polypeptides that contain one or more amino acid mutations that stabilize the pre-fusion conformation or destabilize the post-fusion conformation. The invention also relates to methods for inducing an immune response to pre-fusion RSV F.

Disclosed is an antibody having an enhanced ADCC activity. Also disclosed is a method for producing the antibody. It was attempted to advance the technique of the amino acid mutation in an Fc region established by researchers of Genentech Inc. or the like, and a study was made on whether or not the ADCC activity can be enhanced by the mutation of an amino acid residue in an Fc region into cysteine (Cys) which may cause a drastic structural change that cannot be drawn by a computational search. As a consequence, a chemeric antibody is provided which has the mutation of an amino acid residue at least one position selected from the group consisting of 286th, 287th, 288th, 289th, 290th, 291st, 292nd, 294th, 298th, 301st, 302nd, 303rd, 305th, 306th, 307th, 308th and 309th positions into a Cys residue in an H-chain constant region.

The invention relates to the technical field of biological information, and discloses a method and system for predicting amino acid mutation. The method and system for predicting amino acid mutation aim at improving the accuracy and the effect of prediction and effectively solving the problems that bioexperiment is blind, the cost of the bioexperiment is high and the like. The method for predicting amino acid mutation comprises the steps of establishing a protein sample set; determining characteristics of prefiltering, and integrating characteristics of the same sample into one characteristic sequence to combinedly establish an initial characteristic set of the sample; screening out relatively important characters through a stable character selection algorithm to combinedly establish a first screening out characteristic set of the sample; screening out important characters through a sequence forward selection algorithm to combinedly establish the final screening out characteristic set of the sample; selecting a positive sample and a negative sample to establish a training set and an independent test set, substituting the final screening out characteristic set of samples in the training set into a gradient promoting tree algorithm to be subjected to training so as to obtain a final disaggregated model, and conducting assessment on a prediction result of the disaggregated model by combining the final screening out characteristic set of the independent test set.

The present invention relates to recombinant blood coagulation factor IX (rFIX) mutants having improved FIX clotting activity. Three full length FIX proteins with combinations of mutations of amino acids important for functional activity of FIX and FIX wild type were cloned and expressed in HEK 293 cells. The proteins were tested by an activated partial thromboplastin time (aPTT) assays in FIX-depleted plasma. Two mutant proteins had increased specific FIX activity. Furthermore, a pre-activated FIX protein had an increased activity in FIX-depleted plasma. Therefore these FIX mutants can be used for the treatment of FIX associated bleeding disorders.

Recombinant microbial cells are disclosed herein that produce an oil comprising at least 28 percent eicosapentaenoic acid (EPA) measured as a weight percent of dry cell weight. These cells may comprise a polynucleotide sequence encoding an active acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT) comprising at least one amino acid mutation in a membrane-bound O-acyltransferase motif. In addition, the cells may comprise a down-regulation of an endogenous polynucleotide sequence encoding Sou2 sorbitol utilization protein, and/or one or more polynucleotides encoding phospholipid:diacylglycerol acyltransferase (PDAT), delta-12 desaturase, a dihomo-gamma-linolenic acid (DGLA) synthase multizyme, delta-8 desaturase, malonyl-CoA synthetase (MCS), or acyl-CoA:lysophosphatidic acid acyltransferase (LPAAT). Also disclosed are methods of using the recombinant microbial cells to produce oil containing omega-3 polyunsaturated fatty acids such as EPA.

Disclosed is a modified glucose dehydrogenases that has dramatically increased productivity in Escherichia coli and dramatically increased thermal stability, which is obtained by introducing specific amino acid mutations to glucose dehydrogenase derived from Botryotinia fuckeliana. Also disclosed is a modified glucose dehydrogenases that has dramatically increased productivity in E. coli and dramatically increased thermal stability, which is obtained by replacing two amino acid residues in glucose dehydrogenase of fungal origin with cysteine residues. The novel glucose dehydrogenase has a low reactivity to xylose.

A modified polypeptide having carbohydrate processing enzymatic activity is provided, said polypeptide comprising an amino acid sequence selected from: (a) the amino acid sequence of SEQ ID NO:2 comprising a mutation in at least one of W433, E432 and M439; (b) the amino acid sequence of an enzyme of glycosyl hydrolase family 1, comprising at least one mutation at an amino acid residue equivalent to W433, E432 or M439 of SEQ ID NO:2; and (c) a variant of (a) or (b) having carbohydrate processing enzymatic activity and comprising at least one amino acid mutation at a position equivalent to W433, E432 or M439 of SEQ ID NO:2.

The invention relates to a thermal stability improved lipase mutant constructed through orthogenesis, belonging to the technical field of enzymatic genetic engineering. The invention discloses a thermal stability improved lipase mutant obtained through a molecular biological technology by using a Rhizopuschinensis CCTCC M201021 lipase as a parent. In amino acid sequences of each mutant, the related amino acid mutant is one or more of Met101Thr, Glu107Gly, Ala129Ser, Ser151Asn, Cys160Leu, Lys161Arg, Pro168Leu, Pro168His, Leu180His, Asp182Tyr, Thr183Ala, Thr218Ser, Lys219Asp, Ala230Phe, Ser234Phe, Val261Gly, His317Pro, Val329Ala, Glu363Arg, Asn366Asp and Ser373Cys. The mutants are represented by a half-life period of t50 at 65 DEG C, and the thermal stability of the mutants are improved compared with the parent of Rhizopuschinensis lipase. The invention also discloses a DNA (Deoxyribonucleic Acid) sequence, an expression vector and a host cell for encoding the lipase mutant.

The invention discloses a neoantigen prediction method and device based on next-generation sequencing and a storage medium. The method comprises the following steps: obtaining genome sequencing data of a tumor sample and a normal sample, and tumor transcriptome sequencing data; carrying out mutation detection on the genome sequencing data to obtain point mutation and insertion and deletion mutation, and carrying out fusion gene mutation detection on the tumor transcriptome sequencing data to obtain fusion gene mutation; detecting the type of an HLA molecule to obtain an HLA molecule type result, matched with the normal sample, of the HLA molecule of the tumor sample; carrying out annotation from gene mutation to amino acid mutation on the point mutation, the insertion and deletion mutationand the fusion gene mutation; predicting peptide fragments subjected to point mutation, insertion and deletion mutation and fusion gene mutation to obtain corresponding mutation prediction peptide fragments; and inputting the mutation prediction peptide fragments and the HLA molecule type result into a neoantigen prediction model, and performing scoring and sorting through the neoantigen prediction model to obtain a neoantigen prediction result. High-quality neoantigen can be accurately obtained from the sequencing data.

The invention discloses a preparation method of a pseudotype virus for nucleic acid detection of 2019-nCoV, and relates to the technical field of biology. The preparation method comprises a method forpreparing standard quality control products which contain but are not limited to a 2019-nCoV nucleotide sequence and are used for nucleic acid detection through a non-integrated slow virus vector system, a method which is used for preparing the standard quality control products for nucleic acid detection, and a method for constructing a non-integrated slow virus through mutating 64-locus amino acid Asp of integrase of slow virus auxiliary plasmid into Asn, and amino acids Arg, Arg and Lys at 262-264 loci into Ala, Ala and His. In the manner of removing elements of promoters and the like of slow viruses, the load quantity of virus vectors can be promoted, a pseudotype virus which can be used for nucleic acid detection and complete flow quality control is constructed, and the preparation method can be used for constructing a pseudotype virus for corona viruses and can also be used for constructing a pseudotype virus for SARS-COV, MERS-COV, influenza viruses and the like.