Caspases are a family of cysteine proteases that are key mediators of programmed cell death or apoptosis.1 The precursor form of all caspases is composed of a prodomain and large and small catalytic subunits. The active forms of caspases are generated by several stimuli including ligand-receptor interactions, growth factor deprivation, and inhibitors of cellular functions. All known caspases require cleavage adjacent to aspartates to liberate one large and one small subunit, which associate into a tetramer to form the active enzyme. The gene for caspase-3 also known as Yama, CPP32, and apopain codes for a 32 kDa protein.2,3,4 Caspase-3 cleaves the death substrate poly(ADP-ribose) polymerase (PARP) to a specific 85 kDa form observed during apoptosis and is inhibitable by the CrmA protein. Other caspase-3 substrates include DNA-PK, actin, GAS2, and pro-caspase-6.5 Caspase-3 is activated by cleavage events at Asp28/Ser29 (between N-terminal pro-domain) and Asp175/Ser176 (between large and small subunits) to generate a large subunit of 17 kDa and a small subunit of 12 kDa.3WARNING This product is not for human or veterinary use.
