E64D

E64D is a cell permeable derivative of E64-C, an inhibitor of calpain and other cysteine proteases, such as papain, cathepsin B and cathepsin L. Addition of E64D to cell cultures should be done in serum-free media, as esterases in serum will cleave the ethyl ester and reduce cell permeability. Typical working concentration of E64D is 0.5-10 μg/ml. E64D inhibits degradation of autophagic cargo inside autolysosomes.