Purity >95% by HPLC. Cell permeable, non-selective broad-spectrum caspase inhibitor. Binds irreversibly to the catalytic site of caspase proteases. The peptide is O-methylated in the P1 position on aspartic acid, providing enhanced stability and increased cell permeability. Inhibits ICE-family protease/caspase processing, leading to apoptosis and autophagy induction. Decreases proteasome activity. Potent inhibitor of caspase-1 activation in NLRP3/NALP3-induced cells. Used in apoptosis and inflammasome studies.