Caspase-4 (also know as Ich-4, ICErelII, TX) is a member of the caspase-family of cysteine proteases. Similar to other caspases, caspase-4 exists in cells as an inactive proenzyme which is matured by proteolysis to yield large and small subunits. The active caspase-4 is a heterotetramer consisting of two large and two small subunits. To date the mechanism of caspase-4 activation and roles of caspase-4 in apoptosis are poorly understood. The recombinant active human caspase-4 was expressed in E. coli. The active caspase-4 is routinely tested at BioVision for its ability to enzymatically cleave these two substrates Ac-WEHD-pNA (Cat. #1102-200) or Ac-WEHD-AFC (1101-200). Purity ≥95%