Cystein-dependent aspartate-specific proteases

At the molecular level, apoptosis is tightly regulated and is mainly orchestrated by the activation of caspases [24], Caspases, or cystein-dependent aspartate-specific proteases, are a family of cysteine proteases which have... 

Many elements of complex intrinsic and extrinsic signaling pathways leading to apoptosis have been identified. During apoptosis, a cascade of proteases termed caspases is involved with upstream signaling events and downstream executioner events. Caspases are cysteine-dependent, aspartate-specific proteases that contain highly conserved cysteine residues in their active sites and cleave substrates leaving C terminal Asp residues. Caspase-3 is one of the main effector molecules of the apoptotic process. It cleaves several target proteins and serves as one of the executioner caspases that implement apoptosis. Despite reports of caspase-independent apoptosis (Broker et al. 2005), caspase-3 has become the most widely accepted and most frequently measured apoptosis marker for HTS. 

CASPASE Cysteine-dependent aspartate-specific protease... 

A family of specialized proteases, named caspases, is central to the apoptotic program (review Griitter, 2000). The name caspase is a contraction of cysteine-dependent, aspartate-specific protease. These proteases use a Cys residue as a nucleophile and cleave the substrate after an Asp residue. The only known eukaryotic proteases with this specificity are the caspases themselves and the cytotoxic serine protease granzyme B from T-lymphocytes. 

For some time, the endoproteases Lys-C, Glu-C, and Arg-C have also been used. Lys-C cleaves specifically at the carboxyl terminal side of lysine residues and still works in 5 M urea or 0.1% SDS. Glu-C cleaves at the carboxyl terminal side of glutamate or aspartate residues, depending on the buffer. Arg-C is a cysteine protease that cleaves peptide bindings at the carboxyl terminal side of arginine residues. 

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