Biochem/physiol Actions

Caspase 8 is at the top of the hierarchy of the caspase cascade and is considered an initiator caspase. It exists in the cell as an inactive 55 kDa proenzyme. It is converted to the active form, consisting of 18 kDa and 11 kDa subunits, upon its recruitment to the cytoplasmic domain of activated death receptors such as CD95 or TNFR via the adapter protein FADD. The activation of the proenzyme is triggered by the protein′s aggregation, which leads to auto- or transprocessing. Caspase 8 activates downstream caspases (caspases 3, 6, and 7) that cleave key cellular substrates and lead to apoptotic death of the cells.

General description

Human recombinant C−terminal histidine tagged caspase 8 is expressed as the truncated pro-caspase 8 (amino acids 213−496). It is a fully active protein consisting of 18 kDa and 12.4 kDa subunits; the 12.4 kDa subunit contains the histidine tag.

Packaging

10 µg in poly bottle

Physical form

Solution in 10% sucrose containing 20 mM Tris-HCl, 150 mM imidazole-HCl, pH 8.0, 20 mM 2-mercaptoethanol, 500 mM NaCl, 2.5 mM EDTA, and 0.1% CHAPS.

Unit Definition

One unit will cleave 1.0 nmol of Ac-Ile-Glu-Thr-Asp-pNA per min at pH 7.4 at 25 °C.