Human Caspase‑9 Alexa Fluor™ Plus 488‑conjugated Antibody

Caspase-9 (Cysteine-aspartic acid protease 9/Casp-9; also APAF-3, Mch6 and ICE-LAP6) is a 35-37 kDa member of the peptidase C14A family of enzymes. Casp-9 is an initiator caspase that is part of the intrinsic apoptosis pathway. It is widely expressed and is particularly important during development. Human proCaspase-9 is a 47-48 kDa, 416 amino acid (aa) protein and it contains one CARD region (aa 1-92) and catalytic residues at His237 and Cys287. Following mitochondrial disruption, cytochrome c is released from mitochrondria. Cytochrome c acts on APAF-1, which induces procaspase-9 dimerization. The act of dimerization activates proCasp-9, leading to either the activation of Casp-3, or the autocleavage of proCasp-9, generating a 35 kDa subunit (aa 1-315) and a 12 kDa subunit. Activated Casp-3 will also act on proCasp-9, generating a 37 kDa subunit (aa 1-330) and a 10 kDa subunit (aa 331-416). These subunits associate to form an active heterotetramer. Casp-9 has an alternative start site at Met84 and a deletion of aa 140-289 that generates a dominant negative, 31 kDa isoform. Over aa 1-134, human Casp-9 shares 81% aa identity with mouse Casp-9; over aa 139-330, human Casp-9 shares 73% aa identity with mouse Casp-9.