MG-132 (Z-Leu-Leu-Leu-al) is a potent proteasome and calpain inhibitor with IC50s of 100 nM and 1.2 μM, respectively. MG-132 effectively blocks the proteolytic activity of the 26S proteasome complex. MG-132, a peptide aldehyde, also is an autophagy activato MG-132 also induces apoptosis

1, Braun HA, et al. Tripeptide mimetics inhibit the 20 S proteasome by covalent bonding to the active threonines. J Biol Chem. 2005 Aug 5;280(31):28394-401.