title: A protease in the venom of king cobra (Ophiophagus hannah): purification, characterization and substrate specificity on oxidized insulin B-chain.
abstract: A protease in the venom of Ophiophagus hannah (king cobra) has been purified to a homogeneous state by successive chromatographies on Sephadex G-100 superfine, DEAE-cellulose, hydroxyapatite and CM-polyvinylalcohol copolymer columns. The mol.wt as determined by SDS-PAGE and gel filtration was approximately 70,000. The purified enzyme possessed a specific activity approximately 1/25 that of crystalline trypsin, whereas it had no hemorrhagic activity. The substrate specificity was determined using oxidized insulin B-chain as a substrate; the enzyme cleaved the Asn3-Gln4, Gln4-His5, His10-Leu11, Ala14-Leu15 and Tyr16-Leu17 positions. The sites cleaved by the protease were compared to proteases from other snake venoms.
authors.affiliation: Department of Applied Immunology, National Institute of Health, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamakawa
authors.forename: T
authors.initials: T
authors.lastname: Omori-Satoh
mesh_terms: D000818:Animals; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004546:Elapid Venoms / Q000633:toxicity*; D004591:Electrophoresis, Polyacrylamide Gel; D007328:Insulin / Q000378:metabolism*; D010084:Oxidation-Reduction; D010447:Peptide Hydrolases / Q000032:analysis / Q000302:isolation & purification*; D010449:Peptide Mapping; D013379:Substrate Specificity
chemical_list: D004546:Elapid Venoms; D007328:Insulin; D010447:Peptide Hydrolases