63 results about "Specific activity" patented technology

The present application relates to the field of genetic engineering and PET material degradation, and particularly relates to a PET degrading enzyme mutant and its application in PET material degradation. The present application improves the activity and heat resistance of PET degrading enzyme MuPETase derived from Mumia sp., and screens to obtain mutants Mut1-3, Mut5-8 which show good degradation capacity to PET material under acidic conditions, and the amino acid sequences are shown in SEQ ID NO. 3-5, SEQ ID NO. 7-10 respectively. Compared with the original PET degrading enzyme, the heat stability and / or specific activity of the obtained mutant are significantly improved, and the degradation effect on PET material is greatly improved. The obtained mutant has important application value in the biological degradation treatment of single and mixed PET material waste.

This invention discloses a lipase mutant, an immobilized enzyme, and their applications, belonging to the field of bioengineering. The SpL enzyme mutant K193R / I134V described in this invention exhibits a specific activity of 7-ACA that is 1.6 times higher than before the mutation, and its half-life at 45℃, 50℃, and 55℃ is increased by 1.9 times, 2.6 times, and 3.8 times, respectively. Immobilizing the his-tagged SpL enzyme on a hydrophobically modified nickel-doped SBA-15 mesoporous molecular sieve preserves the enzyme's activity and improves its thermal stability and reusability. Using this immobilized enzyme to catalyze the production of D-7-ACA allows for at least 10 reusable batches, maintaining a conversion rate above 99%.

The invention relates to the field of biochemical engineering, in particular to an alcohol dehydrogenase mutant and application thereof. The mutant is obtained by carrying out mutation on one or more sites selected from 111Y, 258V, 283L, 274L, 107K and 108N aiming at alcohol dehydrogenase, and the mutation is that amino acid at the sites is mutated into one of W, Q, V, G and A. The enzyme activity of the alcohol dehydrogenase mutant is higher than that of a wild type; the enzyme specific activity (36.42) of the mutant A-111-107-274 taking FAL as a substrate is 2.4 times that of a wild type, and the enzyme specific activity (22.16) of the mutant A-111-107-274 taking HMF as a substrate is 9.2 times that of the wild type. Good industrial application performance is shown.

The invention provides an N-deacetylase / N-sulfotransferase and an application of the N-deacetylase / N-sulfotransferase. According to the invention, systematic stability design and surface electrostatic optimization are carried out on the N-deacetylation structural domain of NDST, and multiple engineering strategies such as structural domain fusion and linker peptide optimization are combined to synergistically improve the specific activity, substrate affinity and bifunctional catalytic synergy of enzyme. Experimental results show that the specific enzyme activity of the modified NDST mutant is obviously higher than that of natural enzyme while the difunctional catalytic capability is maintained.

The invention discloses a preparation method of pichia pastoris expression secreting type deglycosylation alkaline phosphatase, and belongs to the technical field of biological engineering. According to the invention, the GS115-BIAP II pichia pastoris genetically engineered bacterium capable of secreting and expressing bovine intestine alkaline phosphatase BIAP II is prepared by using a conventional method. The method comprises the following steps: carrying out site-directed knockout on an ALG3 gene for coding alpha-1, 3-mannosyl transferase and an OCH1 gene for coding alpha-1, 6-mannosyl transferase by using a CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats-associated Protein 9) technology to prepare a glycosylation gene defect type engineering bacterium GS115-delta ALG3-delta OCH1-BIAP II. The secretory expression BIAP II is deglycosylated alkaline phosphatase, and the specific activity of the secretory expression BIAP II is close to that of natural BIAP II. The deglycosylated alkaline phosphatase can improve the antibody coupling efficiency and marking uniformity under specific conditions. The method has remarkable advantages in chemiluminescence diagnosis, high-sensitivity immunodetection and development of multifunctional biological coupling reagents.

The invention relates to the technical field of gene engineering and protein modification, in particular to a high-specific-activity cellulase mutant and application thereof. Compared with the wild type cellulase, the specific activity of the mutants respectively containing single mutation sites of P14A, P19T, S75A, S109N, H118P, M123I, M123L, I130L, I130Q, Y167E, Y167F, Y167W, A176S, A176F, D177S and L192I, provided by the invention, is generally improved by 10.4%-76.1% under a neutral condition. Wherein the specific activity of a single-site mutant containing I130L is the highest, and reaches 183.64 U / mg. The production cost of the cellulase mutant is remarkably reduced, so that wide application of the cellulase mutant is promoted.

The invention relates to the technical field of enzyme engineering, and particularly discloses a phytase mutant and application thereof. The mutant T273K with improved heat resistance is obtained through rational design and site-directed mutagenesis screening on the basis of aspergillus tubingensis phytase. The thermal stability and catalytic ability of the mutant are obviously improved compared with those before mutation; after heat preservation is carried out for 90 min at the temperature of 60 DEG C, the relative enzyme activity is 69.4%, and compared with WT, the relative enzyme activity is improved by 20.4%; the specific activity is improved by about 77.78% compared with that of WT, and the catalytic efficiency kcat / Km is improved by 50.56% compared with that of WT; and the enzyme activity retention rate reaches 33.8% under the condition of 10% salinity. The phytase mutant T273K has the comprehensive characteristics of salt resistance, heat resistance and the like, the phytase mutant T273K can better exert the phytic acid enzymolysis effect in the food processing process, turbidity generated by phytic acid in liquid food such as soy sauce, vinegar, cooking wine and the like can be remarkably reduced, so that the product quality is improved, and the phytase mutant T273K has a wide application prospect.

The invention discloses pseudomonas aeruginosa 24F6 and application thereof, and belongs to the technical field of microorganisms. The invention discloses a pseudomonas aeruginosa strain 24F6 with the preservation number of CGMCC No.35032. The chicken feather degradation rate is 86%, and the wool degradation rate is 40%. The specific activity of the strain cultured for 24 hours under the conditions that the pH value is 7.0 and the temperature is 40 DEG C is 119.67 U / mg. The invention also relates to application of the keratin degrading agent in preparation of keratin degrading products. The pseudomonas aeruginosa 24F6 has the following advantages that a plurality of bacteria are separated from the excrement of the larva of the costustomoth, strains with different keratin degradation capacities are screened out through a keratin selective culture medium, and the pseudomonas aeruginosa 24F6 is a strain which is reported for the first time and has unique keratin degradation characteristics; the specific activity of the strain under the optimal fermentation condition is obviously higher than that of reported similar strains, the degradation rate of natural chicken feathers is as high as 86%, and the strain shows good industrial application potential.

The invention belongs to the technical field of genetic engineering and protein engineering modification, and particularly relates to a high-specific-activity cellulase mutant and application thereof. Compared with wild cellulase, the specific activity of the mutant is improved by 51.9% and reaches 319 U / mg, and an unexpected technical effect is achieved. The mutant can be widely applied to the field of textile industry, is uniform in flower formation, small in flower point and strong in stereoscopic impression, most importantly, the strength loss of the fabric is very small, the strength retention rate is improved by 10-15% compared with that of the fabric treated by wild type cellulase, the use amount of the cellulase can be greatly reduced, the cost is reduced, and the application prospect is wide.

Provided are high-specific-activity cellulase mutants and use thereof. Compared to the wild-type cellulase, the specific activity of the provided mutants that comprise single mutation sites P14A, P19T, S75A, S109N, H118P, M123I, M123L, I130L, I130Q, Y167E, Y167F, Y167W, A176S, A176F, D177S, and L192I, respectively, under neutral conditions is generally increased by 10.4% to 76.1%. The single-point mutant comprising I130L has the highest specific activity, which reaches 183.64 U / mg. The production costs of the cellulase mutants are significantly lower, which facilitates the wide use thereof.

This invention relates to a glutathione S-transferase derived from Antarctic krill, its encoding gene, and its applications, belonging to the field of enzymology. The amino acid sequence of the glutathione S-transferase is shown in SEQ ID NO.1, and the amino acid sequence of the gene encoding the glutathione S-transferase is shown in SEQ ID NO.2. The specific activity of the glutathione S-transferase of this invention can reach up to 6.01 μmol / min / mg. The optimal temperature and optimal pH are 20 °C and 8, respectively. The Antarctic krill-derived glutathione S-transferase of this invention exhibits good catalytic activity and substrate affinity at relatively low temperatures.

This invention provides a method for purifying high-purity recombinant follicle-stimulating hormone (FSH). Specifically, it includes the following steps: (a) providing a raw material solution containing recombinant FSH; (b) sequentially subjecting the raw material solution to: (b1) ammonium sulfate precipitation; (b2) hydrophobic interaction chromatography (HIC); (b3) low pH incubation to inactivate the virus; and (b4) reversed-phase chromatography (RPC); wherein steps (b1), (b2), (b3), and (b4) cannot be performed in any arbitrary order. Compared with existing preparation methods, the recombinant FSH obtained by the method of this invention is simpler and easier to operate, and the purity of the recombinant FSH obtained by the method of this invention can reach up to 99.5% w / w, with a specific activity as high as 16000 IU / mg.

The application discloses a method for detecting specific activity of recombinant Pseudomonas aeruginosa vaccine rPO stock solution, and comprises the following steps: (1) using OprI-B052 as a capture antibody to coat an enzyme-labeled plate; (2) adding a sample to be detected into the coated enzyme-labeled plate; (3) diluting an enzyme-labeled antibody PcrV-A039 and then performing a color reaction to measure an OD 450 / 630 nm value; and (4) preparing a standard curve by using a rPO reference product, and calculating the specific activity of the rPO antigen in the sample according to the standard curve. In the application, OprI-B052 is used as a coating antibody, and PcrV-A039 is used as a detection antibody. The specific activity of the recombinant Pseudomonas aeruginosa vaccine rPO stock solution can be quantitatively detected, and the application has good stability and repeatability.

The invention relates to the technical field of nuclear material analysis, in particular to a plutonium solution specific activity determination method and application, and the plutonium solution specific activity determination method comprises the following steps: taking a plutonium solution with known specific activity A1 as a standard solution, determining the liquid flash counting rate of the standard solution, and recording the liquid flash counting rate as C1; obtaining a second-order conductance spectrum of the standard solution by using an ultraviolet-visible absorption spectrum method, determining the peak area of a characteristic absorption peak of tetravalent plutonium in the second-order conductance spectrum of the standard solution, and recording the peak area as S1; measuring the liquid flash counting rate of the to-be-measured solution, and recording the liquid flash counting rate as C2; obtaining a second-order conductance spectrum of the to-be-detected solution by using an ultraviolet-visible absorption spectrometry, determining the peak area of a characteristic absorption peak of tetravalent plutonium in the second-order conductance spectrum of the to-be-detected solution, and recording the peak area as S2; and calculating the specific activity A2 of the solution to be detected according to the following formula. According to the method, liquid scintillation counting and ultraviolet-visible spectrophotometry are combined, so that combination of activity response and concentration response is realized, and acquisition of isotope composition of a plutonium solution to be detected and complex sample pretreatment are not needed.

An anti-fibroblast activation protein alpha (FAP) polypeptide comprising at least one single-domain antibody directed against FAP. A pharmaceutical composition comprising an anti-FAP single-domain antibody conjugated to a radioisotope at a ratio that maximizes specific activity but does not compromise affinity. A method of reducing a tumor is a subject in need thereof, comprising administering the pharmaceutical composition to a subject.

The application discloses a novel radionuclide therapeutic drug targeting nucleolus DDX24 helicase and a preparation method and application thereof. 64 The Cu-DOTA-TDP-2 has good tumor targeting uptake specificity, and is expected to provide a precise molecular imaging method for esophageal squamous cell carcinoma and other DDX24 high-expression malignant tumors; the novel radionuclide targeted drug 177 The Lu-DOTA-TDP-2 has high radiochemical yield and specific activity, good chemical stability, high affinity for DDX24 helicase, and a simple and easy-to-operate preparation method, and can be used for the treatment of DDX24 high-expression malignant tumors; the novel radionuclide targeted drug 177 The Lu-DOTA-TDP-2 has excellent biological safety performance and good tumor inhibition effect in esophageal squamous cell carcinoma and other DDX24 high-expression malignant tumors.

The invention discloses a bacillus subtilis alcohol dehydrogenase mutant with improved catalytic activity, and belongs to the field of gene engineering and protein expression. The mutant BsBDHAH42A / V266C / G292A is obtained by performing single mutation and combined mutation on 42,266 and 292 amino acids of (2, 3)-butanediol dehydrogenase (BsBDHA) of bacillus subtilis, the specific activity and catalytic efficiency of the mutant BsBDHAH42A / V266C / G292A are remarkably improved compared with those of wild type BsBDHA for catalyzing (R)-PED, the specific activity reaches 11.6 U / mg, and the catalytic efficiency reaches 2.52 mM <-1 > s <-1 > or above; compared with BsBDHAI49L / V266L in the prior art, the specific activity of the BsBDHAH42A / V266C / G292A mutant disclosed by the invention is improved by 21 times; compared with the mutant BsBDHAI49L / V266L in the prior art, the catalytic efficiency of the mutant BsBDHAI49L / V266L is improved by 31 times; and the conversion rate of catalyzing 2-hydroxyacetophenone in 6 hours reaches 92.1%.

The invention belongs to the field of source item control during shutdown of a nuclear power plant, and discloses a method for evaluating the oxidation purification effect of a primary loop of the nuclear power plant. According to the method, a specific activity model of nuclide changing along with time after a loop oxidation peak appears is established, and then a theoretical lower limit purification curve and an expected upper limit purification curve of the nuclide specific activity are obtained according to the expected upper limit and the theoretical lower limit of the continuous specific activity release rate after the peak value appears after the nuclide is oxidized. And whether deposition or additional release occurs in the process is judged by comparing the actually measured nuclide specific activity value with the relative position of the curve. And the duration of oxidation purification is decided through the nuclide specific activity expectation upper limit purification curve. And by comparing the relative position relationship between the actually measured nuclide specific activity value before the oxidation purification is finished and the calculated value of the deposition-free purification model curve at the moment, the overall purification effect evaluation of the oxidation purification is given.

A C-terminal truncated alginate lyase and its application. This invention belongs to the fields of bioengineering, genetic engineering, and enzyme engineering, and relates to a C-terminal truncated alginate lyase TY2 designed with molecular docking assistance, its encoding gene, recombinant vector, strain, and its application in the preparation of low-polymerization degree alginate oligosaccharides. Using wild-type MhAly6 as the parent, the truncation boundary was determined through structural prediction and molecular docking. A portion of the linker peptide was retained, and the C-terminal GH28 family domain was deleted to obtain the truncated form TY2. TY2 has approximately twice the specific activity of the wild-type enzyme, and even higher residual activity after incubation at 45°C for 1 hour, achieving a synergistic improvement in catalytic activity and thermal stability. + The relative enzyme activity reached 4.3 times that of the control group, which can degrade pretreated Sargassum powder. The product is mainly ΔDP2–ΔDP4 low-polymerization brown algae oligosaccharides, which are suitable for related enzymatic degradation and oligosaccharide preparation.

The invention provides a reactor fission product escape rate coefficient determination method and system, and the method comprises the steps: obtaining the specific activity of an indication nuclide and the specific activity of a target nuclide in a fission product of a reactor coolant when a reactor is in a stable operation condition; the specific activity recoil share of the indication nuclide is determined, wherein the specific activity recoil share refers to the proportion of the specific activity of the indication nuclide released through a recoil mechanism in the total specific activity; determining the target specific activity of the target nuclide in the fission product according to the specific activity of the indication nuclide, the specific activity of the target nuclide and the specific activity recoil share of the indication nuclide; and determining the value range of the escape rate coefficient of the target nuclide according to the specific activity recoil share of the indication nuclide and the target specific activity of the target nuclide in the fission product. According to the method, the recoil and diffusion release mechanisms of the fission products are distinguished, and the recoil share is introduced to calculate the value range of the escape rate coefficient, so that the accuracy and operation safety of nuclear reactor fuel rod damage assessment are remarkably improved.

The present application relates to the technical field of medical isotopes, and particularly relates to a thorium phosphonate framework material, a preparation method thereof and application of the thorium phosphonate framework material in a thorium-radium generator. The thorium phosphonate framework material has a chemical formula of Th2(TppmH4)2(H2O)4·8H2O, a monoclinic crystal structure, a space group of P21 / c, a unit cell parameter of a=14.4222-14.4242 Å, b=22.5950-22.5982 Å, c=22.1265-22.1301 Å, β=108.993-108.997°, and a unit cell volume of 6819.239 ų. The thorium phosphonate framework material is a solid particle for imprisoning thorium ions in a framework material, and when applied in a thorium-radium generator, the volume of the generator can be reduced, and the specific activity of a radium product can be improved; when thorium is decayed into radium, the radium can be released from the restraint of the framework material, and the radium can be directly eluted out of the framework material.

The application discloses a preparation method of deuterium or tritium labeled oligonucleotide, which adopts a combination of solid-phase synthesis and liquid-phase synthesis for the first time, and successfully prepares 5' end deuterium or tritium labeled oligonucleotide. The application can not only precisely control the labeling site of deuterium or tritium, avoid non-specific labeling, but also significantly improve the specific activity of tritium labeled oligonucleotide, and provides a new technology for the synthesis of labeled oligonucleotide.

The present application relates to the field of genetic engineering and PET plastic degradation, and particularly relates to a PET degrading enzyme mutant based on hot spring metagenome and application thereof. Based on the sequence of TsmPETase from hot spring metagenome, multiple mutants Mut1-4 with excellent performance under high temperature conditions are obtained through random mutation, and the amino acid sequences are shown as SEQ ID No. 3-6 in sequence. The mutants are significantly superior to the original enzyme in terms of thermal stability and / or specific activity, and show good degradation effect on single and mixed PET plastic waste, thereby providing more efficient and stable enzyme preparation selection for biodegradation of PET.

The present application relates to the technical field of genetic engineering and protein modification, and particularly relates to a high specific activity cellulase mutant and application thereof. The mutant provided by the present application comprises substitution of amino acids at at least one position selected from the group consisting of 44, 84, 109, 123, 178, 183, 194, 225 and 234. The specific activity of the mutant at 50 DEG C is generally increased by 7.1% to 38%; wherein the specific activity of the S44N single-point mutant, the I123L single-point mutant and the L194I single-point mutant is respectively increased by 26.8%, 25.7% and 38%, thereby facilitating the wide application of the cellulase in the textile field.

Providing radiolabeling and formulations for the scale-up of 64Cu-DOTATATE. [Solution] This specification provides the following: 64 Cu-DOTATATE preparation, final formulation parameters and 64 Design of Experiments (DOE) to monitor the effect of Cu-DOTATATE on stability, 500mCi~2000mCi 64 Scaled-up experiments for preparing Cu-DOTATATE, and its final formulation 64 The stability of Cu-DOTATATE, optimization of the amount of DOTATATE used relative to the total activity used for radiolabeling, and 64 Cu-DOTATATE purity 64 The effect of the specific activity of copper chloride solution.

The present application relates to the technical field of genetic engineering and protein modification, and particularly relates to a high specific activity cellulase mutant and application thereof. The mutant provided by the present application comprises substitution of amino acids at at least one position selected from the group consisting of 44, 84, 109, 123, 178, 183, 194, 225 and 234. The specific activity of the mutant at 50 DEG C is generally increased by 7.1% to 38%; wherein the specific activity of the S44N single-point mutant, the I123L single-point mutant and the L194I single-point mutant is respectively increased by 26.8%, 25.7% and 38%, thereby facilitating the wide application of the cellulase in the textile field.

The application provides a rational design method for improving thermal stability of lipase, and belongs to the field of enzyme engineering. A flexible region of the lipase to be reformed is determined through molecular dynamics simulation, a reforming region is determined through structure analysis, a reforming site is determined through comprehensive measurement of multiple calculation tools, a mutant library is established through site-directed saturation mutation using NNK degenerate codon, and an excellent mutant with improved thermal stability is screened through a microplate screening method based on spectrophotometry. The half-life of the Candida antarctica lipase B mutant of the application at 50 DEG C is 9 times that of the wild type, and the specific activity is also 6.32% higher than that of the wild type. The application breaks the trade-off between stability and activity, and realizes the improvement of the thermal stability of the lipase, which is conducive to the important role of the lipase mutant in the industrial application in the fields of food, medicine or biodiesel.

The application belongs to the technical field of biological medicine. More specifically, it relates to a preparation and application of in-situ imaging DNA-PROTAC based on strand displacement activation. The novel DNA-PROTAC provided by the application is designed by three modules, which are respectively recruitment module A (E3 ligase ligand-linker-clicking group), locking module B (aptamer-shielded chain double-stranded complex) and activation module C (DNA single strand), three physically separated components, so that the degradation activity is completely silent in the delivery stage. Only after the drug reaches the target area, the in-situ assembly of recruitment module A and locking module B can be triggered by adding activation module C to trigger the strand displacement reaction, thereby effectively avoiding the non-specific activity of traditional degrading agents in the whole body circulation, and significantly reducing the off-target toxicity. In addition, the application converts the large conjugate into multiple independent components with medium and small molecular weights by physical splitting, overcoming the macromolecular delivery barrier.

The present application relates to the technical field of genetic engineering and protein modification, and particularly relates to a high specific activity cellulase mutant and application thereof. The mutant provided by the present application comprises substitution of amino acids at at least one position selected from the group consisting of 44, 84, 109, 123, 178, 183, 194, 225 and 234. The specific activity of the mutant at 50 DEG C is generally increased by 7.1% to 38%; wherein the specific activity of the S44N single-point mutant, the I123L single-point mutant and the L194I single-point mutant is respectively increased by 26.8%, 25.7% and 38%, thereby facilitating the wide application of the cellulase in the textile field.