title: Comparative study of three proteinases from the venom of the Chinese habu snake (Trimeresurus mucrosquamatus).
abstract: Three immunochemically distinct proteinases (P-1, 2 and 3) devoid of hemorrhagic activity were isolated from the lyophilized venom of Trimeresurus mucrosquamatus using column chromatography on Sephadex G-100, CM-Sephadex C-50, DEAE-Sephacel, CM-Cellulose and Bio-Rex 70. By these procedures, about 7.6, 7.3 and 8.2 mg of purified P-1, 2 and 3 may be obtained from 1 g of crude venom, respectively. The purified proteinases 1-3 were homogeneous by disc electrophoresis on polyacrylamide gel at pH 4.3, isoelectric focusing and by the presence of one precipitin line on immunodiffusion. The isoelectric point of P-1 was 8.1; P-2, 9.2; P-3, 9.8. The molecular weights of proteinases 1-3 were determined to be 23,000, 23,500 and 23,000, by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, respectively. The purified proteinases 1-3 possessed caseinolytic and fibrinogenolytic activities. These activities were inhibited when the proteinases were incubated with the metal chelators ethylenediaminetetraacetic acid (EDTA), 1,10-phenanthroline or cysteine, but not with egg white trypsin inhibitor (EWTI) or soybean trypsin inhibitor (SBTI). P-1 cleaved the B beta-chain of fibrinogen first and then the A alpha-chain, whereas P-2 and 3 cleaved the A alpha-chain first and then the B beta-chain. However, these three proteinases did not hydrolyze the gamma-chain.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002413:Cations, Divalent; D003435:Crotalid Venoms / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism; D005779:Immunodiffusion; D007700:Kinetics; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D012911:Snakes; D013816:Thermodynamics
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D002413:Cations, Divalent; D003435:Crotalid Venoms; D005340:Fibrinogen; D010447:Peptide Hydrolases