Fig. 6.

Inhibition profiles of three covalent inhibitors versus five human apoptotic caspases. NH-23-C2, Ac-23-C2, and zVAD-fmk inhibitors at various concentration ranges (10 nM—3 μM) were incubated with 50 nM of active caspases for 30 min, followed by addition of a broad-spectrum caspase probe (biotin-LEHD-AOMK, 1 μM) to label all residual caspase activity. Samples were then subjected for SDS-PAGE analysis, transferred to a PVDF membrane, and biotin-LEHD-caspases were detected with streptavidin