40results about How to "Maintain native conformation" patented technology

The invention relates to a magnetic composite microsphere immobilized laccase and a preparation method thereof, and belongs to the field of environmental microbiology. In the immobilized laccase, metal-chelated magnetic composite microspheres are taken as a carrier, and laccase is immobilized on the carrier through coordination bonding action. The preparation method comprises two steps of: preparing the carrier, namely synthesizing magnetic ferroferric oxide nanoparticles by using a chemical precipitation process, preparing core-shell magnetic silica by taking the nanoparticles as cores through a sol-gel method, grafting polymer containing carbonyl or amino on the surface of the magnetic silica by taking gamma-chloropropyltrimethoxysilane as a medium, and preparing a functional carrier capable of immobilizing the laccase by chelating transition metal ions (such as Cu2+. Zn2+, Ni2+ or Co2+); and immobilizing the laccase, namely performing coordination adsorption of the laccase on the surface of the carrier, washing, and drying to obtain the finished product of immobilized laccase. The immobilized laccase prepared by the method has high stability and activity and quick magnetic response, is easily recovered from a reaction system and can be repeatedly used; and the preparation process is simple and the cost is low.

The invention discloses a method for preparing an enzyme electrode with an MWCNTs-TiO2/Nafion composite medium. In the method, MWCNTs-TiO2 core-shell nanocomposite materials are scattered into Nafion to prepare an organic-inorganic composite membrane as a fixed matrix for biological molecules for structuring a hemoglobin electrode, and a hemoglobin biosensor with fast response, high sensitivity and strong catalytic capacity is prepared by using the properties of large specific surface area, high surface reactivity, strong adsorption capacity, large electrical conductivity and the like of the MWCNTs-TiO2 core-shell nanocomposite materials and the properties of membrane forming, high chemical stability, high anti-interference capacity and the like of the Nafion. The biosensor has good biocompatibility, stability and repeatability, and has potential application in structuring biosensors. The sensor can be used for detecting the substances of hydrogen peroxide, trichloroacetic acid and the like, and has the advantages of low sensitivity, low detection limit and the like.

The invention relates to a method for preparing a biological polysaccharide self-assembly modificatory chitosan antibacterial biological material, which is characterized by comprising the following steps: (1) preparing a lentinan derivant, i.e. lentinan sulfate; (2) preparing a chitosan membrane base material; (3) preparing a lentinan sulfate solution and a chitosan solution; and (4) carrying outlayer-by-layer self-assembly of the lentinan sulfate and the chitosan on the surface of the base material: respectively carrying out alternative self-assembly on the chitosan membrane base material in the lentinan sulfate solution and the chitosan solution for 5 times to obtain a surface layer-by-layer self-assembly modificatory chitosan mebrane containing 5 bilayers with the outermost layer of the lentinan sulfate, washing and drying to obtain the biological polysaccharide self-assembly modificatory chitosan antibacterial biological material. The chitosan antibacterial biological material prepared by the method has excellent antibacterial activity; and the method has simple preparation process, easy control, mild preparation conditions and low cost.

The invention discloses a SARS-CoV-2 coronavirus vaccine and a preparation method thereof. An S gene of a SARS-CoV-2 coronavirus is subjected to codon optimization, truncated body and mutant sequences of the S gene are introduced into a secretory defective adenovirus vector, and packaging is conducted to obtain a corresponding recombinant adenovirus; and the recombinant adenovirus can express SARS-CoV-2 virus related protein in vivo, processing, folding, glycosylation and other modifications are completed, the native conformation of S protein is basically maintained, and the characteristics of high biological activity, long half-life period, lasting immunogenicity and the like are achieved. According to the vaccine and the method, by adopting the defective adenovirus vector carrying secretory peptide, a recombinant adenovirus vaccine can be secreted out of cells after being expressed in vivo, so that the humoral immunity is activated.

The invention discloses a liquid phase chip kit which is used for the parallel detection of a plurality of bone metabolism biochemical markers, and the invention mainly includes: coated microspheres, detection antibodies which are respectively labelled by biotin and streptavidin phycoerythrin. The liquid phase chip kit which is used for the parallel detection of a plurality of bone metabolism biochemical markers and is provided by the invention has the advantages of high detection efficiency, fewer required samples, strong specificity, high sensitivity, and so on. At the same time, all the bone metabolism biochemical markers can be combined freely, and the usage is convenient. At the same time, as all the reactions are positioned in the liquid phase environment, the invention is more conductive to the maintenance of the native conformation of protein, the reaction of a probe and the object to be detected is faster and more complete, while the detection sensitivity and the linear range are both greatly improved.

The invention belongs to the technical field of molecular biology and particularly relates to a human platelet antigen genotyping liquid chip and a human platelet antigen genotyping detection method. A human platelet antigen genotyping technique is an important safe and efficient technical means of providing matching platelets for patients and promoting clinic platelet injection, but the conventional human platelet antigen genotyping technique has the problems of low flux, low accuracy, low sensitivity and other low indexes and the like. The liquid chip provided by the invention contains primers numbered from 1 to 24, connecting probes numbered from 25 to 46 and fluorescent coded microspheres coated with detection probes numbered from 47 to 68 and can accomplish human platelet antigen genotyping detection by amplification, chain connection and crossing reaction. The liquid chip and the detection method, which are adopted by the invention, have the advantages of high flux, high sensitivity, high specificity, high repeatability, wide linear range, simple operation, high flexibility and wide application range, and the method is an accurate, efficient and practical human platelet antigen genotyping detection method for use in clinic.

The invention discloses a method for heterologous expression and purification of members of glucose transporter family including CLUT1, CLUT2, and CLUT3 on human cell membrane, which comprises the following steps of: constructing an inducible fusion protein expression vectors of GST-CLUT1, GST-GLUT2, and GST-GLUT3 and transforming fission yeast; identifying transformants of the fission yeast; induced expression of the three fusion proteins of GST-CLUT1, GST-GLUT2, and GST-GLUT3 in the fission yeast; identifying the expression of the genes of GLUT1, GLUT2 and GLUT3 in the fission yeast; separating and purifying the three fusion protein; detecting and identifying the three separated and purified fusion proteins; separating and purifying human proteins of GLUT1, GLUT2 and GLUT3 from the three fusion proteins respectively.

The invention relates to a lipase/polyion liquid-styrene microsphere/hydrogel catalytic material as well as a preparation method and application thereof, and belongs to the field of enzyme immobilization. The preparation method comprises the steps: performing polymerization reaction on styrene and imidazolium bromide to form polyion liquid-styrene microspheres; dispersing the polyion liquid-styrene microspheres into a lipase solution, immobilizing lipase onto the polyion liquid-styrene microspheres through physical adsorption to obtain lipase/polyion liquid-styrene microspheres, and carrying out secondary immobilization on the lipase/polyion liquid-styrene microspheres in hydrogel. The obtained catalytic material is environment-friendly and non-toxic, is easy to separate from a reaction system, and can be recycled, so that the catalytic material has a wide application value in various fields such as biocatalysis and food industry.

The invention discloses an N-cadherin nucleic acid aptamer. The nucleic acid aptamer has a nucleotide sequence as shown in SEQ ID No. 1 or SEQ ID No. 2. Preferably, the nucleotide sequence of the nucleic acid aptamer is as shown in SEQ ID No. 2. The invention also provides a screening method of the N-cadherin nucleic acid aptamer. The N-cadherin aptamer can specifically bind with circulating tumorcells with high expression of N-cadherin, so that the N-cadherin aptamer can be applied to capture of the circulating tumor cells.

The invention discloses a method for united typing detection of a porcine contagious pleuropneumonia antibody. The method comprises the following steps: firstly preparing actinobacillus pleuropneumoniae polysaccharide antigen and rabbit anti-actinobacillus pleuropneumonia hyper-immune serum, and then purifying; coupling a liquid-phase chip microballoon by utilizing the purified rabbit anti-actinobacillus pleuropneumoniae hyper-immune serum, building a method for typing detection of the liquid-phase chip of the porcine pleuropneumonia antibody according to a double-sandwich ELISA principle, and determining the optimum experimental condition; and finally determining the threshold for positive and negative judgment of the liquid-phase chip through statistical analysis. In addition, the invention also discloses a kit for united typing detection of the liquid-phase chip of the porcine contagious pleuropneumoniae antibody. The invention can simultaneously carry out typing detection of the S1-S7-type serum antibody of porcine contagious pleuropneumonia, and the whole reaction can be completed within 3 hours; and the method has the characteristics of rapidly, sensitively, specifically andsimultaneously detecting a plurality of serum types, thus the method can be used for preliminarily screening entry and exit boars and diagnosing and monitoring porcine contagious pleuropneumoniae in hogpens of China.

The present invention relates to Antrodia camphorata immunomodulatory protein ACA1 and a coding gene thereof and application thereof, and the gene provided by the present invention is any one DNA molecule of the following (1) to (3): (1) a DNA molecule as shown in sequence 1 of a sequence table; (2) a DNA molecule that hybridizes with the DNA sequence defined in the (1) under stringent conditionsto code an immunomodulatory protein; (3) a DNA molecule that at least 90%- homologous, or at least 95%-homologous, at least 96%, at least 97%-homologous, at least 98%-homologous, or at least 99%-homologous to the DNA sequence defined in the (1) to code an immunomodulatory protein. The DNA sequence of the ACA1 is optimized, and a method for preparing a biologically active ACA1 recombinant protein is provided.

The invention relates to a production method of toxin Tx4 (6-1) label-free recombinant protein. Gene provided by the invention is DNA molecule shown by a sequence 1 in a sequence table. The production method includes that (1), soluble high-level fusion expression of the toxin gene in Escherichia coli can be realized by utilizing a gene sequence of the sequence table 1; (2), recombinant protein completely identical with naturally mature Tx4 (6-1) protein in amino acid sequence is obtained by cutting and removing non-target protein from soluble protein in fusion expression; (3), the obtained recombinant protein has high bioactivity. By the production method, DNA sequence of Tx4 (6-1) is optimized, and expression strain and expression vector are screened; a method for efficiently producing active Tx4 (6-1) recombinant protein is provided, thereby being conducive to conducting detained research on insect-resistant characteristic and bio-safety of the toxin protein and of important significance in screening corresponding insect-resistant plants and high-toxicity transgenic biological insecticides.

The invention provides a preparation method of graphene immobilized laccase. The graphene immobilized laccase is prepared by immobilizing laccase to a carrier of two-dimensional crystal material having excellent conductivity through nonspecific adsorbing action. The preparation method comprises the steps of preparing the carrier and immobilizing laccase; particularly, the carrier, graphene, is prepared by using a phenol as a raw material to carry out graphitization on sandwiched FePO4/dodecylamine nanolayer composite, and stripping before synthesis; the immobilized laccase is immobilized by adsorbing laccase to the surface of the evenly dispersed graphene in nonspecific manner, centrifuging, washing, and drying to obtain the finished immobilized laccase. The carrier of graphene herein helps increase electron transfer rate of enzymatic catalytic reaction process and improve reaction efficiency; the immobilized laccase prepared via the preparation method has high fixing quantity, high activity and good stability, can be recycled from the reaction system, and is reusable; the preparation process is simple and feasible.