Abstract: A heparin skeleton synthase originates from Neisseria animaloris, with an amino acid sequence as shown in SEQ ID NO.2 and a nucleotide sequence of the coding gene as shown in SEQ ID NO.1. Its recombinant expression level is 6.8 times that of the existing heparin skeleton synthase KfiA from Escherichia coli K5, and total enzyme activity per fermentation liquor is 5.22 times that of the heparin skeleton synthase KfiA. The heparin skeleton synthase mutants obtained through site-directed mutagenesis of the sites No. 16, No. 25, No. 30, No. 111, No. 165, and No. 172 in the amino acid sequence of the said heparin skeleton synthase all have high expression levels.

Abstract: The present invention provides a snake venom thrombin marker peptide of Agkistrodon Halys Pallas and an application of the snake venom thrombin-like enzyme in identifying species of Hemocoagulase for Injection. The application includes the following steps of: dissolving a to-be-detected sample and a reference substance of the marker peptide respectively to prepare a test solution and a reference solution, and conducting alkylation reduction on the test solution and the reference solution with dithiothreitol and iodoacetamide; after diluting products with an ammonium bicarbonate solution, adding enzyme for hydrolysis; and after enzymolysis is finished, conducting centrifugation at a high speed, and injecting a supernatan into a liquid chromatography-mass spectrometer for analysis. This method is simple, convenient and rapid, is strong in specificity, fills the gap in identifying the source of species of the snake venom thrombin-like enzyme of Agkistrodon Halys Pallas and improves the quality control level.

Abstract: A method for preparing chondroitin sulfate oligosaccharides with a C5 protein targeting property, and an application thereof, relating to the technical field of biomedicine. The method uses squid chondroitin sulfate as a raw material to prepare chondroitin sulfate oligosaccharides using enzymatic hydrolysis, using the method to screen the activity of various types of oligosaccharides in order to obtain the fragment with the best activity; the method is highly scientific and feasible. The method further uses the screened chondroitin sulfate disaccharides; the mechanism of chondroitin sulfate disaccharides in the treatment of osteoarthritis by regulating the complement system is explored and revealed by in vitro and in vivo experiments to finally provide a new way of treating osteoarthritis, thus having good practical application value.

Abstract: The present invention relates to the field of chemical analysis detection and application, in particular to a marker peptide of snake venom thrombin-like enzymes (SVTLEs) from Agkistrodon Halys Pallas and an application thereof. The amino acid sequence of the marker peptide of snake venom thrombin-like enzymes (SVTLEs) from Agkistrodon Halys Pallas is TLCAGVMEGGIDTCNR. Characterizing the source of species and a content of the SVTLEs in a to-be-detected sample by using the marker peptide includes the following steps of: pretreating the to-be-detected sample by trypsin through enzymolysis, and taking a supernatant of an enzymolysis liquid as a test solution; and injecting the test solution and a reference solution into a liquid chromatography-mass spectrometer, and selecting a qualitative ion pair and a quantitative ion pair for detecting the source of species and a content of the SVTLEs in the to-be-detected sample.

Abstract: A heparin skeleton synthase originates from Neisseria animaloris, with an amino acid sequence as shown in SEQ ID NO.2 and a nucleotide sequence of the coding gene as shown in SEQ ID NO.1. Its recombinant expression level is 6.8 times that of the existing heparin skeleton synthase KfiA from Escherichia coli K5, and total enzyme activity per fermentation liquor is 5.22 times that of the heparin skeleton synthase KfiA. The heparin skeleton synthase mutants obtained through site-directed mutagenesis of the sites No. 16, No. 25, No. 30, No. 111, No. 165, and No. 172 in the amino acid sequence of the said heparin skeleton synthase all have high expression levels.

Abstract: The present invention provides a snake venom thrombin marker peptide of Agkistrodon Halys Pallas and an application of the snake venom thrombin-like enzyme in identifying species of Hemocoagulase for Injection. The application includes the following steps of: dissolving a to-be-detected sample and a reference substance of the marker peptide respectively to prepare a test solution and a reference solution, and conducting alkylation reduction on the test solution and the reference solution with dithiothreitol and iodoacetamide; after diluting products with an ammonium bicarbonate solution, adding enzyme for hydrolysis; and after enzymolysis is finished, conducting centrifugation at a high speed, and injecting a supernatan into a liquid chromatography-mass spectrometer for analysis. This method is simple, convenient and rapid, is strong in specificity, fills the gap in identifying the source of species of the snake venom thrombin-like enzyme of Agkistrodon Halys Pallas and improves the quality control level.

Abstract: The present invention relates to the field of chemical analysis detection and application, in particular to a marker peptide of snake venom thrombin-like enzymes (SVTLEs) from Agkistrodon Halys Pallas and an application thereof. The amino acid sequence of the marker peptide of snake venom thrombin-like enzymes (SVTLEs) from Agkistrodon Halys Pallas is TLCAGVMEGGIDTCNR. Characterizing the source of species and a content of the SVTLEs in a to-be-detected sample by using the marker peptide includes the following steps of: pretreating the to-be-detected sample by trypsin through enzymolysis, and taking a supernatant of an enzymolysis liquid as a test solution; and injecting the test solution and a reference solution into a liquid chromatography-mass spectrometer, and selecting a qualitative ion pair and a quantitative ion pair for detecting the source of species and a content of the SVTLEs in the to-be-detected sample.