title: A Bothrops jararaca plasma cysteine-proteinase inhibitor related to mammalian kininogen.
abstract: A kininogen-like protein was purified from Bothrops jararaca plasma by DEAE-Sephadex ion-exchange and carboxy-methyl-papain-Sepharose affinity chromatography. The molecular weight, estimated by SDS-gel electrophoresis, is about 100,000 and a species of about 75,000 is formed after incubation with horse urinary kallikrein. After incubation with trypsin, only traces of biological activity were detected in tests on guinea pig ileum. The purified protein inhibits papain and bromelain, does not correct the clotting time of a kininogen-depleted human plasma, and does not affect the clotting time of plasma from Waglerophis merremii, a nonpoisonous snake; the same type of inhibitor was found in this nonpoisonous snake. The dissociation constant (Ki) for the papain-inhibitor complex is approximately 1.6 nM.
authors.affiliation: Departamento de Bioquímica, Escola Paulista de Medicina, São Paulo, Brasil.
authors.forename: A M
authors.initials: AM
authors.lastname: Chudzinski
authors.forename: M U
authors.initials: MU
authors.lastname: Sampaio
authors.forename: M L
authors.initials: ML
authors.lastname: Oliva
authors.forename: C A
authors.initials: CA
authors.lastname: Sampaio
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects*; D015853:Cysteine Proteinase Inhibitors / Q000097:blood*; D005260:Female; D006801:Humans; D007704:Kininogens / Q000097:blood / Q000494:pharmacology*; D008297:Male; D008322:Mammals; D009119:Muscle Contraction / Q000187:drug effects; D010206:Papain / Q000037:antagonists & inhibitors; D012911:Snakes / Q000097:blood*
chemical_list: D015853:Cysteine Proteinase Inhibitors; D007704:Kininogens; D010206:Papain