E-64d is an irreversible, membrane-permeable inhibitor of lysosomal and cytosolic cysteine proteases and has diverse biological activities. It is a synthetic analog of E-64 and prodrug form of E-64c that inhibits calpain and the cysteine proteases cathepsins F, -K, -B, -H, and -L. E-64d (20-200 μM) induces cell cycle arrest at the G2/M phase in A431 human epidermoid carcinoma cells. It inhibits protease-resistant prion protein accumulation in scrapie-infected neuroblastoma cells with an IC50 value of 0.5 μM. E-46d also inhibits entry of vesicular stomatitis virus (VSV) particles pseudotyped with severe acute respiratory syndrome coronavirus (SARS-CoV) or SARS-CoV-2 spike glycoprotein into Vero cells, an effect that is reduced by expression of the serine protease TMPRSS2.
E-64d has been used as a lysosomal inhibitor in human acute promyelocytic leukemia NB4 cells and Huh-7?cells. It has also been used as a protease inhibitor in free calcium physiological tyrode solution for perfusion into the isolated heart samples.
E-64d is an inhibitor of cathepsins B and L as well as a potential inhibitor of calpain. E-64d has been shown to inhibit lysosomal proteases. E-64d has been used in combination with Prepstatin A to interfere with autolysosomal digestion. E-64d displays neurovascular and neuronal protective effects after focal cerebral ischemia in rats.
ChEBI: An L-leucine derivative that is the amide obtained by formal condensation of the carboxy group of (2S,3S)-3-(ethoxycarbonyl)oxirane-2-carboxylic acid with the amino group of N-(3-methylb
tyl)-L-leucinamide.
E-64d is an epoxysuccinyl peptide and an inhibitor of cysteine protease cathepsin B, calpains 1 and 2. E-64d by its cathepsin B protease inhibition functionality, may serve as a potential drug for treating traumatic brain injury (TBI) and Alzheimer′s disease (AD). It inhibits gametocyte surface antigen resulting in a decreased oocyst production in Plasmodium falciparum.
Moderately toxic by intraperitoneal route. An experimental teratogen. Experimental reproductive effects. Mutation data reported. Whenheated to decomposition it emits toxic fumes of NOx.
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