Mini-Spotlight: E-64

E-64 (IES-4096, IES-4096-v) is an irreversible cysteine protease inhibitor. It reacts with the active site cysteine thiol to form a thioether. E-64 stimulates endothelial cell response to wounds1 and has been found to inhibit calpain, cathepsin B, H,and L, and papain, to name a few.

Synonym/Product Alternate Name: (L-3-trans-Ethoxycarbonyloxirane-2-Carbonyl)-L-Leucine (3-Methylbutyl)Amide


We also carry the analogs, E-64c (IEC-4320-v) and E-64d (IED-4321-v). E-64d is a potent and irreversible cathepsin B inhibitor with greater cell-permeability than E-64.

New publication mentioning E-64:

Anionic Phospholipids Induce Conformational Changes in Phosphoenolpyruvate Carboxylase to Increase Sensitivity to Cathepsin Proteases

  1. R. N. Mascardo & G. Eilon, Journal of Pharmacology and Experimental Therapeutics, 244 (1), 361(1988).