title: Isolation and characterization of a thrombin-like enzyme from the venom of Crotalus durissus terrificus.
abstract: A thrombin-like enzyme was isolated in 6% yield from the venom of Crotalus durissus terrificus by ammonium sulfate precipitation followed by gel filtration on Sephadex G-75 and finally affinity chromatography on Sepharose-1,4-butanediol-diglycyl-p-aminobenzamide eluted with 0.15 M benzamidine. The enzyme behaved like a single component on SDS-PAGE corresponding to a molecular weight of 34 kDa. The specific activity of the enzyme toward bovine fibrinogen was 71 NIH U/mg protein. The pH optimum for the coagulation of human fibrinogen was 8.0. The enzyme hydrolyzes the alpha-chain of fibrinogen, has amidase activity on L-arginine-p-nitroanilide and L-arginine-7-amido-4-methyl-coumarin amino terminal blocked peptides and presents esterolytic activity on N-alpha-tosyl-L-arginine-methylester.
mesh_terms: D001777:Blood Coagulation; D002850:Chromatography, Gel; D003435:Crotalid Venoms / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D013917:Thrombin / Q000302:isolation & purification*
chemical_list: D003435:Crotalid Venoms; D013917:Thrombin