Human Caspase 8 Synthetic Peptide. Caspase 8 (CASP8) is a member of the cysteine-aspartic acid protease (caspase) family. Sequential activation of caspases play a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes composed of a pro-domain, a large protease subunit, and a small protease subunit. Activation of caspases requires proteolytic processing at conserved internal aspartic residues to generate a heterodimeric enzyme consisting of the large and small subunits. Caspase 8 is involved in the programmed cell death induced by Fas and various apoptotic stimuli. The N-terminal FADD-like death effector domain of Caspase 8 suggests that it may interact with Fas-interacting protein FADD. Caspase 8 was de