161 results about "Molecular modification" patented technology

This invention provides an in vitro cell-free protein synthesis system, its reagent kit, and its applications, belonging to the field of protein synthesis technology. This invention improves an in vitro cell-free protein synthesis system based on Kluyveromyces lactis by adding exogenous L-arabinose, significantly enhancing the system's protein synthesis capacity. Furthermore, it provides a more efficient and higher-throughput in vitro protein synthesis reagent kit and a method for synthesizing exogenous proteins. The improvements provided by this invention can be achieved without molecular modification, are simple and convenient to operate, and save costs.

The invention discloses a 3-sterone-delta1-dehydrogenase mutant and application of the 3-sterone-delta1-dehydrogenase mutant in preparation of a steroid drug intermediate. The mutant is obtained by performing single mutation or multiple mutation on 551, 468, 48 and 157 sites of an amino acid sequence of 3-sterone-delta1-dehydrogenase as shown in SEQ ID NO: 1. The 3-ketosterone-delta1-dehydrogenase is subjected to molecular modification through directed evolution and semi-rational design, the mutant with improved enzyme activity is screened in a high-throughput mode, the mutant can effectively improve the conversion rate of a substrate 11alpha, 17alpha-dihydroxyprogesterone, and the substrate conversion rate of the mutant ISM-2 is improved to 92.4% compared with 36.7% before mutation.

The invention provides a molecular modification method for glycosyltransferase based on artificial intelligence. The method comprises the following steps: acquiring description information of enzyme mutants to form a basic data set; performing physicochemical property analysis on the basic data set to obtain an analysis result set; calculating the quantized value of the conservative degree of the mutation site and the quantized value of the influence degree of different mutations on the sequence so as to construct a position specificity scoring matrix; extracting a position specificity scoring value and a frequency from the scoring matrix, determining a functional section, and performing weighting processing; performing three-dimensional structure prediction and energy calculation based on the three-dimensional structure reconstruction model of the mutant to obtain an energy value; calculating an energy change value between the mutant and the wild type; performing molecular docking and dynamic simulation analysis on the mutant protein to obtain quantitative description of an interaction mode and strength and dynamic simulation characteristic data; and constructing a model training set to train a machine learning model for predicting the change of the enzyme activity of the mutant.

The invention provides a modified nucleic acid aptamer and application thereof. On the first aspect, the invention provides a modified nucleic acid aptamer, the nucleic acid aptamer is a nucleic acid aptamer Sgc8, and the nucleotide sequence of the nucleic acid aptamer Sgc8 is SEQ ID NO: 1; one end of the nucleic acid aptamer is extended through a polynucleotide fragment, and fluorescent molecular modification is carried out on the extended tail end of the polynucleotide fragment; the nucleotide sequence of the polynucleotide fragment is TTTTT. According to the invention, the base sequence with a certain length is added between the fluorescent molecule and the aptamer, so that the interference of the fluorescent molecule on an aptamer recognition structural domain can be effectively avoided, and the recognition and imaging efficiency is improved.

The invention discloses a molecular modification design method for improving the catalytic activity and the thermal stability of citrobacter vinegaticus-derived hyaluronidase and expression application of the citrobacter vinegaticus-derived hyaluronidase. The interaction of citrobacter vinegaticus hyaluronidase active pocket amino acid residues and hyaluronate tetrasaccharide molecules is visually explored through Pymol, conservative analysis of pocket amino acid evolution is carried out through Consurf, and rational design is carried out through policies of FoldX for calculating enzyme-substrate binding free energy, so that the hyaluronidase catalytic activity is improved. A mutant with significantly improved enzyme activity is obtained through screening, and the thermal stability of the enzyme is further improved through PROSS design and an analysis strategy of mutation site amino acid evolution conservative property and position. According to the invention, the sequence, structure and function of hyaluronidase are deeply studied, and hyaluronidase is mutated from two aspects of stabilizing a catalytic structure and promoting a catalytic reaction, so that a high-activity enzyme with higher application value in industrial production is obtained.

The invention belongs to the technical field of bioengineering, and particularly relates to an alkaline protease mutant which is obtained through molecular modification and has improved enzyme activity and thermal stability and application of the alkaline protease mutant. An ALK wild type is mutated by utilizing a site-directed mutagenesis technology to obtain a mutant T56C / A90C of which the enzyme activity is improved relative to that of the wild type at 40 DEG C, and the mutant T56C / A90C is subjected to heat preservation at 60 DEG C for 4 hours to determine the protease activity and residual enzyme activity and has certain activity in a high-temperature environment, so that the heat stability of alkaline protease is improved, and the alkaline protease can play a role in a relatively high alkaline environment; therefore, the method can be widely applied to a plurality of industries such as washing, leather, medicine, feed, silk, food and the like.

The invention belongs to the field of enzyme engineering, and relates to a glycosyl transferase mutant and application thereof in synthesis of salidroside. On the basis of a glycosyl transferase amino acid sequence as shown in SEQ ID NO: 1, iterative saturated mutation is carried out through a molecular modification technology, and the enzymatic activity and catalytic efficiency of the modified glycosyl transferase mutant are greatly improved. The mutation at a specific site can significantly promote the glycosylation activity of a tyrosol substrate. The mutant enzyme is obtained by carrying out induced expression and protein purification on the obtained mutant strain. The substrate conversion rate of the transformed glycosyl transferase mutant for catalyzing the tyrosol glycosylation reaction can reach 95% or above, the yield reaches 55.0 g / L, and an efficient and green new way is provided for salidroside production.

The invention relates to the technical field of pharmaceutical preparations, in particular to a multiple nano emulsion adjuvant and a preparation method thereof. The multiple nano emulsion adjuvant is prepared from 2.73 to 6.37 g of an oil phase matrix based on 100 g of a raw material system, 0.10 to 0.25 g of a sterol compound; 0.212 to 0.424 g of a nonionic surfactant; 0.00050 to 0.00200 g of a triterpenoid saponin type active adjuvant; 0.010 to 0.020 g of an anionic polymer modifier; 0.005 to 0.015 g of a cationic polymer modifier; 70-90 g of a buffer solution; the total mass of the raw materials is 100 g. The nano emulsion adjuvant prepared by the invention can be stored for 6 months at 2-8 DEG C under a low sterol condition, the particle size change does not exceed + 5%, no crystallization or layering is generated, and the stability of the active adjuvant is remarkably improved.

The invention belongs to the technical field of bioengineering, and particularly relates to a polyphosphate kinase mutant and application thereof in synthesis of beta-nicotinamide mononucleotide, and the polyphosphate kinase mutant is obtained by single-point or multi-point mutation of 99th, 186th, 190th and 204th amino acids of polyphosphatase with an amino acid sequence shown as SEQ ID NO.1. The invention also relates to a preparation method of the polyphosphate kinase mutant, and the application of the polyphosphate kinase mutant in synthesis of beta-nicotinamide mononucleotide in synthesis of beta-nicotinamide mononucleotide in synthesis of beta-nicotinamide mononucleotide in synthesis of beta-nicotinamide mononucleotide. Polyphosphokinase derived from Lampropedia Hyalina DSM 16112 is subjected to molecular modification to obtain multiple mutants, the enzyme activity of the mutants is improved by 1.5-14 times compared with that of wild type polyphosphokinase, the preference of the mutants to AMP is improved by 1.08-4.88 times compared with that of the wild type polyphosphokinase, and an ATP regeneration system constructed by the mutants can remarkably reduce the use amount of enzyme and reduce the fermentation capacity and cost; the reaction time can be greatly shortened, the influence of AMP on the enzyme activity is reduced, the requirements of large-scale industrial production of NMN prepared by adopting a biological enzyme method can be met, and the method has a wide application prospect.

The present invention belongs to the field of enzyme engineering technology, and specifically relates to a plastic hydrolase ThPETase mutant and its application, wherein the plastic hydrolase ThPETase mutant is obtained by multiple mutations in the 48th, 204th, 213th, 214th and 253rd positions of the amino acid sequence shown in SEQ ID NO.1. The present invention performs molecular modification on the basis of the wild-type ThPETase. While the wild-type ThPETase has almost no hydrolysis activity for PBAT, the mutant obtained by the present invention has obvious hydrolysis ability for PBAT, and can hydrolyze a plastic film made of PBAT into powder in 2 weeks at 37°C. Moreover, the mutant obtained by the present invention has a significant improvement in thermal stability compared with the wild-type, and has great industrial application prospects.

The present invention discloses a Nitrospira The invention relates to nitrite oxidizing bacteria and their applications, belonging to the field of microbial and environmental protection technology. The strain is named Nitrospira sp. Z02, with a deposit number of GDMCC No: 66050, and was deposited in Guangdong Provincial Microbial Culture Collection Center on March 25, 2025. The strain is a new species, belongs to chemoautotrophic type, and expands Nitrospira The strains are diverse and can oxidize nitrite under different oxygen concentrations, have good adaptability to oxygen concentrations, retain oxidation activity within the pH range of 5.5 to 8.5, and can tolerate weakly acidic conditions. They can grow on solid plates and have the potential for molecular modification. Therefore, this strain has good application value in the treatment of nitrite-containing wastewater.

The invention discloses a mutant with improved enzyme activity of sucrose isomerase and application of the mutant, and belongs to the technical field of genetic engineering and enzyme engineering in molecular biology. A known sucrose isomerase parent is subjected to molecular modification by utilizing a site-directed mutagenesis technology to obtain mutant enzymes T522S / K340D, D222H / K340D, G467N / K340D, T522S, K340D, D222H and G467N, and the catalytic activity of the series of mutants provided by the invention is increased by 10%-25% compared with that of original bacteria; the isomaltulose conversion rates of the combined mutants T522S / K340D, D222H / K340D and G467N / K340D are respectively increased by 2.3%, 1.5% and 1.3% compared with those of original bacteria, and the strain has good stability, can be used for biological preparation of isomaltulose and has potential application prospects.

The invention provides a high-activity chitinase mutant and application thereof in degradation of crustacean waste, and belongs to the technical field of enzyme engineering and agricultural waste conversion. According to the invention, chitinase PbChi from Paenibacillus barengltzii is subjected to molecular modification, and a plurality of chitinase mutants with high activity are successfully constructed by increasing the flexibility of a connexin, changing steric hindrance at a substrate catalytic crack inlet and changing catalytic residues in a beta sheet layer in a catalytic structural domain through calculation design and experimental verification; the chitinase mutant can effectively degrade shrimp shell meal, so that carapace waste is effectively utilized, and the chitinase mutant has a wide application prospect in the biological feed industry.

The invention provides an Akkermann Amuc1100 protein mutant as well as a preparation method and application thereof, wild Akkermann Amuc1100 protein is subjected to mutation modification through a molecular biological technical means, and the bioactivity of the Amuc1100 protein mutant subjected to molecular modification is obviously improved compared with that of the wild protein; compared with a wild type Amuc1100 protein, the wild type Amuc1100 protein has a better effect when being applied to the aspects of regulating intestinal immunity, relieving acute pancreatitis, promoting browning of white adipose cells, inhibiting obesity, relieving ulcerative colitis and the like, and a very good application prospect is provided for developing bioactive medicines with higher efficiency.

The invention discloses a preparation method of a nuclear magnetic resonance imaging contrast agent based on surface hepatocyte targeting molecule modification ferroferric oxide nanoparticles, which comprises the following steps: synthesizing ferroferric oxide nanoparticles (Fe3O4 NPs) by a thermal decomposition method, and connecting the Fe3O4 NPs with a ligand dopamine-PEG2000-EOB carrying hepatocyte targeting molecules by a ligand exchange method to obtain the nuclear magnetic resonance imaging contrast agent. The nanoparticles Fe3O4-EOB-PEG capable of carrying out selective T2 nuclear magnetic resonance imaging on the hepatocytes are formed. The method is simple and easy to operate, the controllability of the preparation process is high, the biocompatibility of the obtained product is good, T2 signals of hepatocytes can be remarkably improved, the good early diagnosis effect on liver tumors is achieved, and wide application prospects are achieved.

The invention belongs to the technical field of genetic engineering, and particularly relates to a saccharomyces cerevisiae esterifying enzyme mutant for catalyzing production of ethyl hexanoate as well as a preparation method and application of the saccharomyces cerevisiae esterifying enzyme mutant. In order to improve the yield of ethyl hexanoate produced by the existing esterifying enzyme, the 28th site, the 69th site, the 125th site, the 180th site and the 214th site of the amino acid sequence of the esterifying enzyme derived from saccharomyces cerevisiae are subjected to substitution and / or deletion and / or insertion of at least one amino acid through a genetic engineering technology to obtain various esterifying enzyme mutants, so that the molecular modification is realized, and the yield of ethyl hexanoate produced by the esterifying enzyme is improved. Therefore, the reaction activity of catalyzing the esterification enzyme to produce ethyl hexanoate is improved. According to the method, the biosynthesis efficiency of ethyl hexanoate is improved through enzyme molecule modification, new power is injected for transformation and upgrading of the modern brewing industry, and the traditional brewing industry is promoted to develop towards the intelligent and precise direction.

The invention provides a molecular modification design method for improving esterification activity of lipase. The method comprises the following steps: calculating a channel structure of lipase to be modified through CAVER ANALYST 2.0, determining a modification site through comprehensive measurement of other calculation tools, establishing a mutant library by adopting NNK degenerate codons for site-saturated mutation, and screening out excellent mutants with improved esterification performance by adopting a microwell plate screening method based on a copper soap complexing method. According to the candida antarctica lipase B mutant M5 disclosed by the invention, in various different types of esterification reactions, the catalytic efficiency of the mutant M5 is improved by 4.5 times or more than that of a wild type. The molecular modification design method disclosed by the invention can be used for improving the esterification performance of the lipase and has relatively wide esterification reaction application applicability, so that the lipase mutant can play an important role in industrial application in the fields of foods, medicines or biodiesel and the like.

The invention discloses a high-temperature-resistant cellobiose epimerase mutant and application thereof. The mutant is obtained by performing single mutation on the 242nd site of an amino acid sequence as shown in SEQ ID No.1. The invention also discloses a preparation method of the high-temperature-resistant cellobiose epimerase mutant. According to the invention, molecular modification is carried out on cellobiose epimerase (DiCE) from Dictyoglomus thermophilum, a mutant with improved thermal stability is screened out, the lactulose conversion efficiency of the obtained mutant is obviously improved, the mutant A242L can tolerate the temperature of 80 DEG C, the lactulose conversion rate is 64.41%, and the industrial application prospect is good.

The invention discloses a method for covalently modifying magnetic nanoparticles by metal ion-induced DNA (Deoxyribose Nucleic Acid) and application of the magnetic nanoparticles in quantitative detection of ochratoxin A, and belongs to the technical field of fluorescent biosensing analysis. The method for covalently modifying the magnetic nanoparticles by metal ion-induced DNA provided by the invention comprises the following steps: adsorbing DNA molecules on the surfaces of polydopamine-coated magnetic nanoparticles under the induction of metal ions, and carrying out covalent linkage to obtain the DNA molecule-modified magnetic nanoparticles. In the method provided by the invention, the electrostatic repulsion between the DNA molecules and the surface of the polydopamine is overcome through the induction effect of the metal ions, and the modification amount of the DNA molecules on the surfaces of the magnetic nanoparticles is greatly increased. The method is simple in steps, and the obtained DNA molecule modified magnetic nanoparticles have very high sequence selectivity and capture capability on uncombined OTA aptamers, and are beneficial to improving the sensitivity and accuracy of OTA detection.

The invention discloses an incision beta-1, 3-glucanase mutant with improved enzyme activity and thermal stability, and belongs to the technical field of gene engineering and enzyme engineering. According to the invention, a site-directed mutagenesis technology is utilized to carry out molecular modification on wild type beta-1, 3-glucanase, and a series of mutants S22F, N226D and N187S are obtained. Compared with a wild enzyme, the beta-1, 3-glucanase mutant constructed by the invention has the advantages that the enzyme activity is improved by 1.04-1.81 times, the Tm value is improved by 0.97-1.19 DEG C, and the half-life period at 70 DEG C is prolonged to 1.08-1.28 times. According to the invention, the enzyme activity and the thermal stability of the wild beta-1, 3-glucanase are improved at the same time, and better use conditions are created for the enzyme in practical application.

The invention provides a mutant of xylose reductase and application of the mutant in synthesis of D-tagatose. According to the present invention, the xylose reductase (XR) derived from Saccharomyces cerevisiae is subjected to molecular modification on the basis of the sequence and structure-oriented semi-rational modification strategy so as to obtain the high activity xylose reductase mutant, and the xylose reductase mutant has the following characteristics that: the xylose reductase (XR) derived from Saccharomyces cerevisiae is subjected to molecular modification so as to obtain the xylose reductase mutant, according to the invention, the mutant of the xylose reductase is integrated into a redox pathway for synthesizing the D-tagatose by virtue of a genetic engineering means, and is expressed in bacillus subtilis 168, so that a recombinant engineering bacterium for synthesizing the D-tagatose by fermenting D-galactose is successfully constructed, the efficient synthesis of the D-tagatose is realized, and the yield of the D-tagatose is improved. And the method has obvious practical application value and economic benefit.

The invention relates to the technical field of environmental pollution treatment and particularly provides a dust suppressant as well as a preparation method and application thereof. In order to achieve the purpose, the dust suppressant provided by the invention is prepared from the following raw material components: sodium lignin sulfonate extracted based on lotus stems, deionized water, a first cross-linking agent, a second cross-linking agent, an aqueous solution of organic acid, a first initiator and a second initiator. Wherein the sodium lignin sulfonate is extracted from lotus stems. Through a specific molecular modification technology, sodium lignin sulfonate is extracted and prepared from lotus stems, and the novel dust suppressant applied to roads is prepared through graft copolymerization. The dust suppressant has multiple properties, the structure of the dust suppressant is beneficial to suppression of a dust resuspension phenomenon, and the dust suppressant has adsorption and adhesion effects on dust and is particularly suitable for road dust suppression.

The application discloses a carbonyl reductase mutant and application thereof in preparation of (R)-8-chloro-6-hydroxyoctanoate compounds. The application relates to a mutant of carbonyl reductase with improved catalytic performance and stereoselectivity after rational molecular modification, a recombinant expression plasmid containing the mutant gene of the enzyme, a recombinant expression transformant, a preparation method of the recombinant enzyme, and application of the recombinant enzyme or the recombinant cell as a catalyst in asymmetric reduction of 8-chloro-6-carbonyloctanoate compounds (I) to prepare (R)-8-chloro-6-hydroxyoctanoate compounds (II), in particular, in an intermediate (R)-8-chloro-6-hydroxyoctanoate methyl ester of thioctic acid. The disclosed carbonyl reductase SsCR mutant has the advantages of high reaction efficiency and high catalytic activity, and exhibits the advantages of high substrate concentration, low catalyst consumption and short reaction time in the process of catalytic preparation of the compound (II).

The application belongs to the technical field of cosmetic and pharmaceutical chemistry, and discloses a 2,4-dihydroxyphenyl thiazole derivative and application thereof. The 2,4-dihydroxyphenyl thiazole derivative has the structure shown in the following formula: wherein n1 and n2 are each independently 1, 2, 3 or 4; and R is methyl or ethyl. Compared with existing peptide amido compounds, the 2,4-dihydroxyphenyl thiazole derivative of the application, while maintaining the active structure of the parent nucleus, significantly improves the solubility and physicochemical stability through molecular modification, and optimizes the pharmacokinetic characteristics. The derivative can effectively inhibit the activity of tyrosinase, and can be used as an active ingredient to prepare a novel tyrosinase inhibitor, related whitening and freckle-removing cosmetics and a drug for tyrosinase-related diseases.

The invention provides a biological target magnetic separation method based on a carbon-based sheet-shaped magnetic label, and relates to the technical field of microbiological detection. The method comprises the following steps: respectively obtaining a biological target solution to be separated and a carbon-based sheet-shaped magnetic aggregate, wherein the carbon-based sheet-shaped magnetic aggregate is a two-dimensional flexible magnetic aggregate containing a carbon-based two-dimensional sheet-shaped material and magnetic nanoparticles; the surface of the carbon-based sheet-shaped magnetic aggregate is modified with biological targeting molecules, the carbon-based sheet-shaped magnetic label is obtained, and the biological targeting molecules correspond to biological targets in the biological target homogeneous solution; capturing a biological target in the biological target solution to be separated by using a carbon-substrate-shaped magnetic label to obtain a captured solution; and separating to obtain the biological target in the captured solution. According to the separation method, the conversion rate of the biological target to the magnetic information can be effectively improved, and the problems of low sensitivity and high difficulty in biological target detection can be effectively solved.

The application discloses a kind of polypeptide modified long afterglow nano-complex and its preparation method and application, nano-complex, for core-shell structure, core-shell structure is composed of the core body in inside and the shell that surrounds core body, core body is long afterglow nanomaterial, shell is by polypeptide modification and modified molecule modification, and drug loaded dendritic polymer;The nano-complex of the application can realize multiscale imaging to osteoclast, through in vivo afterglow imaging and in vivo two-photon microscopic imaging, the morphology, migration and distribution of osteoclast can be more accurately analyzed, avoid photo toxicity and background interference, improve imaging sensitivity;The nano-complex of the application is loaded with osteoporosis treatment drug alendronate ALN, and treatment drug can be replaced according to actual demand, and treatment scheme is adjusted, so that the drug loading system has universality.

The invention discloses a surface-enhanced Raman probe as well as a preparation method and application thereof, and belongs to the technical field of biomedical imaging and stem cell therapy. The preparation method comprises the following steps: coating an ultrathin silver shell layer on the surface of gold nanoparticles to obtain Au-coated Ag particles; 4-sulfydryl phenylboronic acid pinacol ester molecules are modified on the surface of Au (at) Ag to form a Raman report layer, then sulfydryl-polyethylene glycol is introduced to realize biological orthogonal coupling, and the modified SERS probe is obtained through bovine serum albumin modification; jointly incubating the modified SERS probe and the azidation-labeled mouse bone marrow mesenchymal stem cells, so as to form an mmol / LSC-SERS composite probe; the obtained probe has good biocompatibility, stability and anti-interference capability and is suitable for a complex physiological environment, and the preparation method is simple and good in repeatability, is completely carried out in a water phase and does not need an organic solvent.

A method for producing a food product with gluten molecule modification, comprising the steps of: a) mixing at least gluten-containing flour with at least one liquid until a homogeneous mixture is obtained; b) containing the mixture in a gas-tight container and extracting air from the gas-tight container within 15 minutes after obtaining the mixture according to step a) in order to obtain a vacuum of at least equal to 70% inside the gas-tight container and maintaining the homogeneous mixture inside the container at a vacuum for a period of at least equal to 3 hours, thereby obtaining a mixture; c) obtaining a food product using the mixture obtained at the end of step b).

The application belongs to the field of bioengineering. The application provides a molecular modification design method for improving the hydrophobicity of the catalytic center of bacillus subtilis protease, which comprises the following steps: searching for a resolved bacillus subtilis protease crystal structure in a protein database PDB, generating an enzyme-substrate complex by docking a hexapeptide substrate through a Glide mode of software, calculating the polar charge of each amino acid residue of polar atoms N and O and H combined thereof within a 10 angstrom range of the catalytic center amino acid of the bacillus subtilis protease by using a PPC force field, calculating the absolute value sum of the polar charge, selecting a potential mutation site of the bacillus subtilis protease, virtually mutating the potential mutation site into a large steric hindrance nonpolar amino acid, calculating the absolute value sum of the polar charge of polar atoms N, O and H within a 10 angstrom range of the catalytic center amino acid of the single-point mutant by using the PPC force field, selecting a virtual bacillus subtilis protease single-point mutant, expressing the mutant and iteratively mutating, re-expressing, obtaining a modified bacillus subtilis protease mutant, and verifying the hydrophobicity. The molecular modification design method can quickly and effectively reduce water molecules in the catalytic center of the bacillus subtilis protease and improve the hydrophobicity thereof. It has been verified that the enzyme modification method is effective and reliable.