Unit Definition One unit will hydrolyze 1 μmole of Z-lysine p-nitrophenyl ester per min at pH 5.0 at 25 °C.
Physical form Lyophilized powder containing sodium phosphate, sodium chloride and ~6% EDTA as stabilizer.
Biochem/physiol Actions Cathepsin B has been found to cleave procaspase 1 and procaspase 11 and to induce apoptosis in digitonin-permeabilized cells. Translocation of cathepsin B from the cytoplasm to the nucleus contributes to bile salt induced apoptosis of rat hepatocytes. Levels of cathepsin B in PC12 cells significantly decrease 12 to 24 hours after apoptosis is induced.