53results about How to "High specific vitality" patented technology

The invention discloses a new nitrilase and gene thereof, a recombinant expression vector and a recombinant expression transformant containing the gene, a method for preparing the recombinant nitrilase or microbial cell containing the recombinant nitrilase by use of the recombinant expression transformant, and application of the microbial cell in dehydrating ortho-chlorine mandelonitrile or other analogues and producing chiral ortho-chlorine mandelonitrile or other analogues. The recombinant nitrilase disclosed by the invention comes from Labrenzia aggregate and can be used as a catalyst for dehydrating and splitting ortho-chlorine mandelonitrile or other analogues; and the recombinant nitrilase has the advantages of high catalysis efficiency, strong enantioselectivity, mild reaction conditions, environmental friendliness and the like.

The present invention is Agkistrodon acutus venon 36KD single-stranded hemocoagulase and its preparation process, and aims at providing single-stranded Agkistrodon acutus venon hemocoagulase with high potency and low toxicity. SDS-PAGE electrophoresis shows that the hemocoagulase has molecular weight of 36KD+/-2KD, single color zone, and at least 90 % homogeneity with the N end sequence of the single-stranded amino acid shown in SEQ ID No. 1. The preparation process includes dissolving Agkistrodon acutus venon in Tris-HCl buffering solution (pH8.0) and dialysis; adding the supernatant to Metal Sepharose F.F affinity chromatographic column and collecting the penetrating peak component; adding the penetrating peak component to DEAE-Sepharose F.F ion exchange column and collecting active peak component; separating in Superdex 75 column and Sephacryl S-100 column; desalting in Sephadex G-25 column; sterilizing and freeze drying.

The invention belongs to the technical field of enzyme engineering, and relates to a S-adenosyl-L-methionine synzyme mutant and a preparation method using the same. The mutant is mutated into a plurality of amino acid sites in wild S-adenosyl-L-methionine synzyme of which the amino acid sequence is shown as SEQID NO.1, and the mutated amino acid sites comprise C9R and K224R. According to the S-adenosyl-L-methionine synzyme mutant and the preparation method using the same, compared with the wild S-adenosyl-L-methionine synzyme, the mutant has higher specific activity and has higher product yield and lower enzyme activity reduction when catalyzing is performed for preparing the S-adenosyl-L-methionine synzyme.

This invention discloses a method for extracting linoleic acid isomerase from bacteria generating linoleic acid isomerase. The method comprises: (1) pulverizing and homogenizing the bacteria generating linoleic acid isomerase, centrifuging and collecting the supernatant containing crude enzyme liquid; (2) fractionally precipitating with (NH4)2SO4 with a saturation degree of 40-90%, collecting the precipitate, and suspending with K3PO4 buffer to obtain crude enzyme liquid; (3) loading crude enzyme liquid on an ion exchange column, eluting with 0.1-0.7 mol/L NaCl solution, and collecting the eluate with linoleic acid isomerase activity; (4) dialyzing with 0.08-0.15 mol/L K3PO4 buffer (pH = 5.5-7.0) to remove salts; (5) loading on a gel filtration column, and eluting with 0.08-0.15 mol/L K3PO4 buffer (pH = 5.5-7.0) to obtain linoleic acid isomerase.

The invention discloses fermentation preparation and application of Chaetomium globosum dextranase and belongs to the technical fields of fermentation technology, enzymic preparations and sugar engineering. A high-yield Chaetomium globosum dextranase fermentation method is determined by optimizing medium components and fermentation conditions through orthogonal test, thereby improving the yield ofChaetomium globosum dextranase up to 698.22 U/mL; when applied to hydrolyzing high-molecular-weight glucan and at a final concentration of 2 U/ml, the Chaetomium globosum dextranase can achieve a high-molecular-weight glucan (T2000) hydrolyzing rate up to 97.9% within 15 minutes; the rate of inhibition of the Chaetomium globosum dextranase on biological membranes formed by streptococcus mutans can reach 97.9%, and the clearance rate of the biological membranes reaches up to 49.07%. The prepared Chaetomium globosum dextranase has a good application prospect in food and sugar industries and thefield of medicine.

The invention discloses externally tangent type algin lyase VsAly7D and a recombinant strain and application thereof. The amino acid sequence of the externally tangent type algin lyase disclosed by the invention is as shown in SEQ ID No.6, and the nucleotide sequence of the coding amino acid sequence is as shown in SEQ ID No.5. The suitable reaction temperature of the externally tangent type alginlyase is 20-35 DEG C, and the externally tangent type algin lyase has high stability at 0-30 DEG C, so that the enzyme can effectively degrade substrate at low temperature and belongs to cold-adaptedalgin lyase; the externally tangent type algin lyase has degradation capacity on algin, polyG and polyM, a degradation manner is an externally tangent type, and a final degraded product is unsaturated monose and has NaCl dependence. The invention further constructs a recombinant carrier and recombinant strain containing externally tangent type algin lyase VsAly7D coded genes, and a favorable basecan be provided for industrialized application and production of biologic ethanol.

The invention discloses a method for extracting superoxide dismutase from the blood of a mammal, belonging to the technical field of food processing. The method is used to solve the problems of high cost, low benefit and low purity in extracting superoxide dismutase from the blood of the mammal. The method for extracting superoxide dismutase from the blood of the mammal comprises the following steps of: (a) collection of the blood of the mammal; (b) hemolysis; (c) thermal denaturation in the presence of copper salt; (d)ultrafiltration; (e) precipitation of acetone and recovery of acetone with a rotary evaporator; (f)column chromatography; and (g)freeze-drying. The method for extracting superoxide dismutase from the blood of the mammal can be widely used in extracting superoxide dismutase from the blood of any mammal.

The invention relates to a low-temperature beta-xylosidase mutant with improved thermal stability and specific activity. The mutant is a low-temperature beta-xylosidase mutant G110S, and an amino acidsequence of the mutant is SEQ ID NO.1; alternatively, the mutant is a low-temperature beta-xylosidase mutant Q201R, and an amino acid sequence of the mutant is SEQ ID NO.2; and alternatively, the mutant is a low-temperature beta-xylosidase mutant loop2, and an amino acid sequence of the mutant is SEQ ID NO.3. The low-temperature beta-xylosidase mutant with improved thermal stability and specificactivity is more suitable for industrial applications, and has wider application prospects in the fields of food, feed, papermaking and the like, so that the application potential of low-temperature beta-xylosidase is expanded in food, pharmaceutical, papermaking, feed and other fields.

The invention discloses low-immunogenicity lumbrukinase, a preparation method and application thereof, and belongs to the field of biological pharmacy. The method provided by the invention comprises the following steps of: first, extracting to obtain a lumbrukinase crude product from an earthworm, and then, passing the crude product through an ion exchange column to elute, purifying, colleting a component with fibrinolytic activity, freezing, drying, concentrating, separating a concentrated lumbrukinase solution by using a gel filtration chromatographic column, detecting the fibrinolytic activity by using an agarose-hemaleucin flat band method, collecting a second eluting peak with the fibrinolytic activity, wherein detected by SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electropheresis), the molecular weight of the second eluting peak is 23500-27500 Da; and after the eluting peak is dialyzed, desalted and subjected to low-temperature freeze drying, carrying out molecular modification on the eluting peak by utilizing activated monomethoxy polyethyleneglycol and dextran to obtain the low-immunogenicity lumbrukinase. The lumbrukinase prepared by the invention has the characteristics of low immunogenicity, high enzyme activity and the like, and can be used for the research and the preparation of an antithrombotic drug and a drug for treating or preventing cardiovascular and cerebrovascular diseases.

The invention belongs to the technical field of enzyme engineering, and relates to a tyrosinase mutant and application thereof. According to the tyrosinase mutant, a plurality of amino acid sites are mutated in wild type tyrosinase with an amino acid sequence as shown in SEQ ID NO.1. According to the tyrosinase mutant and the method for preparing theaflavin by using the tyrosinase mutant, the mutant has higher specific activity than wild type tyrosinase, and has higher yield during catalytic preparation of theaflavin.

The invention relates to an autotomy-resistant high-specific-activity trypsin mutant, particularly relates to the autotomy-resistant high-specific-activity trypsin mutant obtained through molecular modification and screening, a coding gene thereof and application of the autotomy-resistant high-specific-activity trypsin mutant and belongs to the technical fields of proteins and genetic engineering.The trypsin mutant provided by the invention is obtained through mutating at least one of the following loci: R107H, R107L, R115S, R115T, K133A, K133A, K147D, K157E, K208P and K210A on the basis of an amino acid sequence shown in SEQ ID No. 2. Compared with a protoenzyme, the trypsin mutant has better autotomy resistance and higher specific activity; and compared with wild type trypsin, the autotomy resistance is improved by 0.67 to 2.88 times, the specific enzyme activity is improved by 0.07 to 2.98 times, and thus, the problem that the trypsin is prone to activity lowering due to autotomy during storage and use is solved.

The invention discloses a polyethylene glycol-modified aprotinin and a preparation method thereof. The polyethylene glycol-modified aprotinin is characterized in that an amino group of aprotinin is connected with a chain of polyethylene glycol or a derivative thereof. The polyethylene glycol-modified aprotinin can improve the specific activity of the aprotinin, dramatically lowers the immunogenicity of the aprotinin and improves the stability of the aprotinin, thereby improving pharmacokinetic properties of the aprotinin and the tolerance, and reducing drug delivery times.

The invention provides a biological enzymolysis production method for controllable narrow molecular weight functional chitosan oligosaccharide. The biological enzymolysis production method includes the step of preparing a culture medium. The method further comprises the step of preparing a chitosan culture medium. The chitosan culture medium is prepared from, by weight, 15-18 parts of chitosan, 300-380 parts of acetic acid solution of 1.3-1.5%, 3-5 parts of (NH4)2SO4 powder, 20-22 parts of dried skim milk and 500-800 parts of sterile water. The effective content of chitosan oligosaccharide prepared through the method is 92.21-98.45%, and the deacetylation degree of the chitosan oligosaccharide prepared through the method is 95.6-98.2%; chitosan oligosaccharide is mainly used for preventing and controlling diseases in high-end agriculture and improving human immunity and used for preventing and controlling tumors and immunologic derangement diseases.

The invention discloses a 1, 4-alpha-glucan branching enzyme, a gene thereof, and engineering bacteria containing the gene and an application of the engineering bacteria. The invention provides the gene of the 1, 4-alpha-glucan branching enzyme. The overall length of the gene is 1881bp, G+C content is 68.4%, 626 amino acids are coded, the nucleotide sequence of the gene is as shown in SEQ ID NO.1,and the amino acid sequence of coded protein is as shown in SEQID NO.2. A recombinant 1, 4-alpha-glucan branching enzyme obtained through an engineering bacterium strain constructed through the geneuses potato starch as an activity measuring substrate, and through iodine liquid detection, the specific activity is 2784U/mg. The 1, 4-alpha-glucan branching enzyme produced from the gene can be usedfor starch modification, including preparation of slowly digestible starch or resistant starch, preparation of high-branching-degree modified starch having gel characteristic optimization or aging resistant characteristic, preparation of cold water soluble starch and the like.

The invention discloses efficient xyloglucanase and application thereof, and the efficient xyloglucanase is derived from Coniella vitis and is selected from one of the following: (a) a protein with the 19-390 amino acid sequence in SEQ ID NO: 3, (b) a protein with an amino acid complete sequence as shown in SEQ ID NO: 3; and (c) a protein which has the complete sequence as shown in SEQ ID NO: 3 or the 19-390th amino acid sequence which is subjected to conservative substitution, deletion or insertion by one or more amino acids and has the same function as the complete sequence as shown in SEQ ID NO: 3. The invention also provides a coding gene of the high-efficiency xyloglucanase, a recombinant expression vector containing the gene, an engineering bacterium and application thereof. The efficient xyloglucanase has excellent endo-xyloglucanase activity, the enzyme activity is kept stable under a strong acid condition, the characteristic completely meets the condition requirements of a synchronous saccharification and fermentation process, and the efficient xyloglucanase has a very high application prospect in many fields as the endo-xyloglucanase.

The invention discloses a novel neutral phytase gene obtained from Citrobacter braakii, which has a nucleotide sequence shown as SEQ ID NO:1. The gene can be utilized to industrially produce neutral phytase with high enzymatic activity.

The invention specifically provides a GDP-mannose-4,6-dehydratase-encoding gene in Sacchrina japonica, and a protein and application thereof, belonging to the field of genetic engineering technology. The gene is derived from Sacchrina japonica and is named gene SjaGM46D1. The nucleotide sequence of the gene is a sequence shown as SEQ ID NO. 1. An amino acid sequence of the gene encoding the protein is a sequence as shown in SEQ ID NO. 2, and the protein is GDP-mannose-4,6-dehydratase. According to the invention, the gene sequence is cloned by using gene cloning technology, and a prokaryotic expression vector is constructed. The results of enzyme activity assay of the recombinant protein show that the recombinant protein is capable of catalyzing the conversion of GDP-mannose into GDP-4-keto-6-deoxymanose, can be applied to the synthesis of GDP fucose, and has significantly higher activity compared with other GDP-mannose-4,6-dehydratases disclosed in the prior art.

The invention relates to the technical field of protein engineering modification, and particularly provides a high-specific-activity mannase mutant. Compared with a wild type, the mannase mutant provided by the invention has the advantages that the specific activity of the mannase mutant is generally improved by 4.4%-38.97%. The specific activity of the mannase mutant is improved, the production cost of mannase is reduced favorably, wide application of the mannase in the field of feed is accelerated, and the market prospect is wide.

The invention provides a prolyl endopeptidase mutant with increased catalytic activity and enzyme specific activity, and belongs to the field of enzyme engineering. The invention replaces hydrophobic amino acids Thr370 and/or Thr516 on a loop near a catalytic center of a parent Aspergillus oryzae prolyl endopeptidase with other small molecular weight amino acids or hydrophobic amino acids, or mutates Cys508 and/or Gln512 near catalytic key site group histidine His507 into His508 and/or Arg512 to obtain a series of mutants.