Plasma prekallikrein/kallikrein processing by lysosomal cysteine proteases

Plasma kallikrein plays a role in coagulation, fibrinolysis and inflammation. Cathepsins B and L participate in (patho)physiological processes such as peptide antigen processing, tissue remodeling events, protein turnover in cells, hormone processing and tumor invasion. the present work analyzes the processing of prekallikrein/kallikrein by lysosomal cathepsins. Prekallikrein is not hydrolyzed by catB, and catL generates an inactive fragment of prekallikrein. Both kallikrein chains are hydrolyzed by catL and the light chain is mainly hydrolyzed by catB; kallikrein activity is lower after incubation with catL compared to catB. Our data suggest that the plasma kallikrein/kinin system can be controlled by cathepsins.Universidade Federal de São Paulo, Dept Bioquim, EPM, BR-04044020 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofes, BR-04044020 São Paulo, BrazilUMC, Ctr Interdisciplinar Invest Bioquim, BR-08701970 Mogi Das Cruzes, SP, BrazilUniversidade Federal de São Paulo, Dept Bioquim, EPM, BR-04044020 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofes, BR-04044020 São Paulo, BrazilWeb of Scienc