High molecular weight kininogen as substrate for cathepsin B

• Published in: Biological chemistry Vol. 385; no. 6; p. 551
• Main Authors: Barros, Nilana M T, Tersariol, Ivarne L S, Oliva, M Luiza V, Araújo, Mariana S, Sampaio, Claudio A M, Juliano, Luiz, Motta, Guacyara da
• Format: Journal Article
• Language: English
• Published: Germany 01-06-2004
• Subjects: Cathepsin B - chemistry; Cathepsin B - metabolism; Cations - pharmacology; Electrophoresis, Polyacrylamide Gel; Humans; Hydrogen-Ion Concentration; Hydrolysis; Kallikreins - metabolism; Kininogens - chemistry; Kininogens - drug effects; Kininogens - metabolism; Molecular Weight; Substrate Specificity
• ISSN: 1431-6730
• DOI: 10.1515/BC.2004.066

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.