E-64d is an irreversible, membrane-permeable inhibitor of lysosomal and cytosolic cysteine proteases and has diverse biological activities.
1,2,3,4 It is a synthetic analog of E-64 (Item No.
10007963) and prodrug form of E-64c (Item No.
10007964) that inhibits calpain and the cysteine proteases cathepsins F, -K, -B, -H, and -L.
1,5 E-64d (20-200 μM) induces cell cycle arrest at the G
2/M phase in A431 human epidermoid carcinoma cells.
2 It inhibits protease-resistant prion protein accumulation in scrapie-infected neuroblastoma cells with an IC
50 value of 0.5 μM.
3 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.
4