Reversible and cell permeable proteasome inhibitor. Specifically inhibits the chymotrypsin-like activity of the proteasome. Calpain and cathepsin inhibitor. Does not inhibit the peptidyl-glutamyl peptide hydrolyzing activity of MPC.Molecular Formula:C29H39N3O5Molecular Weight:509.7Sequence: Z-Leu-Leu-Phe-aldehyde Solubility:Soluble in DMSOStorage and Stability:Stable for at least 1 year after receipt when stored at -20°C.