Calpeptin is a potent, cell-permeable calpain inhibitor with ID50 of 52 nM, 34 nM, 138 nM, and 40 nM for Calpain I (porcine erythrocytes), Calpain II (porcine kidney), Papainb, and Calpain I (human platelets), respectively. Calpeptin attenuates apoptosis and intracellular inflammatory changes in muscle cells.
