title: High molecular weight kininogen as substrate for cathepsin B.
abstract: We investigated the influence of pH and divalent cations (Zn2+, Mg2+ and Ca2+) on high molecular weight kininogen processing by cathepsin B. At pH 6.3, high molecular weight kininogen is hydrolyzed by cathepsin B at three sites generating fragments of 80, 60 and 40 kDa. Cathepsin B has kininogenase activity at this pH which is improved in the absence of divalent cations. At pH 7.35, high molecular weight kininogen is slightly cleaved by cathepsin B into fragments of 60 kDa, and cathepsin B kininogenase activity is impaired. Our results suggest that high molecular weight kininogen is a substrate for cathepsin B under pathophysiological conditions.
authors.affiliation: Departamento de Bioquímica, UNIFESP/EPM, CEP 04044-020, São Paulo, SP, Brazil.
authors.forename: Nilana M T
authors.initials: NM
authors.lastname: Barros
authors.forename: Ivarne L S
authors.initials: IL
authors.lastname: Tersariol
authors.forename: M Luiza V
authors.initials: ML
authors.lastname: Oliva
authors.forename: Mariana S
authors.initials: MS
authors.lastname: Araújo
authors.forename: Claudio A M
authors.initials: CA
authors.lastname: Sampaio
authors.forename: Luiz
authors.initials: L
authors.lastname: Juliano
authors.forename: Guacyara da
authors.initials: G
authors.lastname: Motta
mesh_terms: D002401:Cathepsin B / Q000737:chemistry* / Q000378:metabolism; D002412:Cations / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007610:Kallikreins / Q000378:metabolism; D007704:Kininogens / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D008970:Molecular Weight; D013379:Substrate Specificity
chemical_list: D002412:Cations; D007704:Kininogens; D007610:Kallikreins; D002401:Cathepsin B