7results about How to "Maintain native conformation" patented technology

The invention relates to the technical field of animal vaccines, in particular to a recombinant porcine epidemic diarrhea virus S1 protein and transferrin fusion protein as well as a preparation method and application thereof. According to the present invention, the SpyTag sequence is inserted into the S1 gene sequence, the eukaryotic cell HEK293 is adopted to express the protein, such that the obtained recombinant S1 protein has sufficient glycosylation modification, and when the recombinant S1 protein is mixed with the recombinant transferrin containing the SpyCatcher sequence, the K31 on the SpyTag and the N117 on the SpyCatcher are subjected to spontaneous condensation to form the isomeric peptide so as to display the antigen on the transferrin 24 polymer surface; the technical system not only maintains the natural conformation of the virus antigen protein, but also has the advantage of stimulating the innate and adaptive immune response functions of the host, and has a better protection effect on the host.

The application discloses a kind of for sweat glucose concentration monitoring method, it is related to sweat monitoring field, comprising the following steps: step 1, enzyme-fixed chain conjugate synthesis: glucose dehydrogenase is reacted with bilirubin oxidase respectively with bifunctional crosslinking agent and is purified, obtain enzyme-crosslinking agent intermediate;It is clicked with azide modified DNA fixed chain chemistry reaction again, and after purification, obtain GDH-fixed chain and BOx-fixed chain conjugate;Step 2, preparation of circular DNA template: after annealing hybridization of phosphorylated template chain and primer chain, it is connected into ring by T4 DNA ligase;Step 3, rolling circle amplification self-assembly package enzyme DNA hydrogel;The present application uses super-flexible DNA hydrogel as flexible electrode material, realizes the efficient fixation and continuous stable catalysis of GDH and BOx, and constructs flexible sweat-based EBFC self-powered sensor as flexible bioelectrode, to realize continuous non-invasive blood glucose monitoring.

The present invention discloses a recombinant protein and its application in anti-Hu antibody by cell immunofluorescence method, belonging to the field of biomedical engineering technology, wherein the recombinant protein is a fusion protein obtained by fusing a partial sequence of HuD protein, a partial sequence of HuC protein and a partial sequence of HuB protein with a secretion signal peptide, a linker, a transmembrane sequence and a fluorescent tag, and its sequence is shown in SEQ ID NO: 1. The recombinant protein provided by the present invention is obtained by redesigning and fusion expressing partial sequences of HuD, HuC and HuB proteins, and the fusion-expressed protein can be stably overexpressed on the cell membrane of eukaryotic cells, thereby achieving high accuracy and high sensitivity of anti-Hu antibody detection in cell immunofluorescence method (CBA method).

The invention belongs to the technical field of biology, and particularly relates to a hybridoma cell strain capable of secreting a clostridium perfringens ETX monoclonal antibody with neutralizing activity and application of the hybridoma cell strain. On the basis of natural toxin, an indirect ELISA (enzyme-linked immunosorbent assay) detection method is established by utilizing a non-toxic ETX single amino acid site protein mutant, and a series of hybridoma cell strains secreting an anti-clostridium perfringens ETX monoclonal antibody are screened; the hybridoma cell strain can stably and efficiently secrete a monoclonal antibody with neutralizing activity and a monoclonal antibody without neutralizing resistance respectively, and large-scale batch production can be realized. According to the present invention, the clostridium perfringens ETX monoclonal antibody is firstly utilized to establish the ETX antigen ELISA detection method, and the method has characteristics of simple sample operation, low cost, rapid reaction, strong specificity and the like, can provide the reference for the diagnosis of clostridium perfringens, and provides the basis for the research of the related vaccine potency test substitution method.

The invention belongs to the technical field of electrochemical biosensors, and discloses an insulin affinity determination device based on a cell membrane directional reconstruction technology, a detection method and application of the insulin affinity determination device based on the cell membrane directional reconstruction technology. The measuring electrode comprises a measuring layer made of a conductive material, a directional connecting layer formed by chemically modifying the measuring layer, and a cell membrane layer formed by spreading a cell membrane from bottom to top. The measuring layer transmits an electric signal to external signal recording equipment, the directional connection layer is combined with specific molecules distributed on the inner side of a cell membrane through chemical bonds, the cell membrane layer is directionally fixed to the surface of the measuring electrode, insulin receptor protein on the cell membrane is exposed to the outer side of the cell membrane layer, and insulin molecules are captured; the measuring cavity comprises a sample feeding pipeline and a sample discharging pipeline and is used for placing a measuring electrode during measurement. The device is simple in structure, the detection method is convenient, and the device can be applied to screening of diabetes-related compounds and research of pathological mechanisms of diabetes and has good application prospects.

The invention relates to a method for purifying influenza viruses cultured by chick embryos, and belongs to the technical field of biological medicines. The method comprises the following steps: specifically capturing inactivated virus liquid from a chick embryo through microspheres; the microspheres swell and adsorb viruses at low temperature, the network structure of the microspheres is triggered to shrink through temperature control, complete virus particles are released, and damage caused by chemical competitive elution is avoided; and after the released virus is split, refining and purifying through sucrose density gradient centrifugation and molecular sieve chromatography. Through the synergistic effect of impurity removal, specific capture and mild release, ovalbumin residues are reduced, virus hemagglutinin is kept, and an industrialized feasible path is provided for preparing influenza vaccine antigens with high purity and high immunogenicity.

The application provides a method for preparing apocynum venetum polysaccharide with a triple helix structure through fermentation of bacillus velezensis and application thereof. The apocynum venetum is subjected to fermentation treatment by bacillus velezensis, and through synergistic effect of various extracellular enzymes secreted by the strain, efficient degradation of the cell wall of the apocynum venetum and sufficient release of the polysaccharide are realized. Experiments show that the polysaccharide obtained by the application has a significant triple helix structure feature, and the polysaccharide obtained by ultrasonic cellulase complex method and cellulase method does not have the structure. It is found for the first time that fermentation of bacillus velezensis can induce apocynum venetum polysaccharide to form a stable triple helix structure, and directional construction of the higher structure of the apocynum venetum polysaccharide is realized. The apocynum venetum polysaccharide with the triple helix structure can be used as a probiotic preparation for promoting generation of short-chain fatty acids in the intestinal tract and improving intestinal microecology, and can be applied to the fields of functional food and intestinal health.