Benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethylketone (Z-VAD.FMK) inhibits apoptosis by blocking the processing of CPP32

Interleukin-1β converting enzyme (ICE)-like proteases, which are synthesized as inactive precursors, play a key role in the induction of apoptosis. We now demonstrate that benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethylketone (Z-VAD.FMK), an ICE-like protease inhibitor, inhibits apoptosis by preventing the processing of CPP32 to its active form. These results suggest that novel inhibitors of apoptosis can be developed which prevent processing of proforms of ICE-like proteases.