title: Specificity of hemorrhagic proteinase from Crotalus atrox (western diamondback rattlesnake) venom.
abstract: Hemorrhagic proteinase, HTb, isolated from Crotalus atrox (western diamondback rattlesnake) venom was studied for its specificity. HTb showed fibrinogenase activity, hydrolyzing the A alpha chain of fibrinogen first, followed by the cleavage of the B beta chain. HTb is different from thrombin and did not produce a fibrin clot. The degradation products of fibrinogen were found to be different, indicating that the cleavage sites in the A alpha and B beta chains are different from those of thrombin. N-Benzoyl-Phe-Val-Arg-p-nitroanilide was not hydrolyzed by HTb, although this substrate was hydrolyzed by thrombin and reptilase.
mesh_terms: D000818:Animals; D001665:Binding Sites; D003435:Crotalid Venoms / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D005337:Fibrin; D005340:Fibrinogen; D006868:Hydrolysis; D066298:In Vitro Techniques; D008666:Metalloendopeptidases; D009842:Oligopeptides; D013379:Substrate Specificity
chemical_list: D003435:Crotalid Venoms; D009842:Oligopeptides; C006164:S 2160; D005337:Fibrin; D005340:Fibrinogen; D010450:Endopeptidases; D008666:Metalloendopeptidases; C044577:atrolysin A