title: The fibrinogenolytic and procoagulant activity of southern copperhead venom enzymes.
abstract: The effect of four isolated proteolytic fractions of Agkistrodon contortrix contortrix venom on fibrinogen and its polymerizing ability was investigated by means of radioimmunoassay for fibrinopeptides A and B (FPA, FPB), fibrinogen fragment B beta 15-42 and by polyacrylamide gel electrophoresis. One enzyme (MW approximately 68,000) predominantly released FPB and activated fibrin stabilizing factor. The relative rates of the FPA/FPB release markedly depended on temperature. Calcium ions caused the decrease of FPB cleavage rate without any noticeable change in cleavage rate of FPA. The enzymes of lower molecular weight degraded fibrinogen into a family of degradation products.
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects; D002118:Calcium / Q000494:pharmacology; D003029:Coagulants / Q000494:pharmacology*; D003435:Crotalid Venoms / Q000032:analysis* / Q000494:pharmacology; D005337:Fibrin / Q000378:metabolism; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D010447:Peptide Hydrolases / Q000494:pharmacology*
chemical_list: D003029:Coagulants; D003435:Crotalid Venoms; D005338:Fibrin Fibrinogen Degradation Products; D005337:Fibrin; D005340:Fibrinogen; D010447:Peptide Hydrolases; D002118:Calcium