Human Caspase-8 Alexa Fluor™ Plus 594-conjugated Antibody

Caspase-8 (Cysteine-aspartic acid protease 8/Casp8; also MCH5 and FLICA) is a 28 kDa member of the peptidase C14A family of enzymes. It is known as the initiating caspase for the apoptotic cascade. Caspase-8 acts on procaspases-3, 4, 6, 7, 9 and 10, in addition to c-FLIPL and procaspase-8 itself. Human procaspase-8 alpha4 is a 58 kDa (predicted), 496 amino acid (aa) protein and contains two N-terminal death domains plus a catalytic site that utilizes His334Gly335 plus Cys377. Following death domain-containing receptor activation, proteolysis generates a 28 kDa heterodimer. This includes a p18 subunit (aa 234-391; or 217-374 of the 8a/standard form) noncovalently linked to a p10 subunit (aa 402-496; or 385-479 of the 8a/standard form). Association with another p18/p10 heterodimer generates active caspase-8. There are two common procaspase-8 isoform variants. One 53 kDa isoform (8b) shows a deletion of aa 103-134, while a second 55 kDa (8a) isoform shows a deletion of aa 103-134 with a 15 aa insertion after Lys183. The p18 and p10 subunits are 68% and 82% aa identical, human to mouse, respectively.