Caspase

Caspase (CASP) are cysteine-aspartic proteases (see Protease) which function in apoptosis, necrosis and inflammation. Twelve CASP have been identified in human. CASP is synthesized as an inactive pro-CASP with a prodomain which is being cleaved off to render them active. The X-linked inhibitor of apoptosis protein (XIAP) with its baculoviral IAP repeat (BIR) domain is an inhibitor of CASP.

• CASP-1 (or Interleukin-1 beta converting enzyme, ICE) cleaves precursor cytokine interleukin 1-β and interleukin 18 into mature protein. See Human Caspase-1
  
• CASP-3 or (Apopain; Cysteine protease CPP32) interacts with CASP-8 and CASP-9 during cell apoptosis. See Sandox Bay Serrano, Student Projects for UMass Chemistry 423 Spring 2012-5 and Caspase-3 Regulatory Mechanisms
  
• CASP-6 is involved in the activation of cascade of caspases during apoptosis. See Molecular Playground/Caspase-6 (new) and Caspase-6 and neurodegeneration
  
• CASP-7 is a heterodimer consisting of P20 (human residues 1-198) and P11 (human residues 199-303) subunits. CASP-7 catalytic domain consists of residues 57-303. is an important initiator CASP and drICE is an effector of apoptosis CASP in Drosophila melanogaster. See Molecular Playground/Caspase-7 Dynamics and Molecular Playground/Executioner Caspase-7
  
• CASP-9 is an aspartic protease linked to mitochondrial death pathway. See Molecular Playground/Caspase-9 Regulation.
  
• Metacaspase (MCASP) are arginine/lysine specific CASP. MCASP are found in plants and fungi.

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3D structures of caspase

Caspase 3D structures