Recombinant Mouse Active Cathepsin C/DPPI Protein, CF

Cathepsin C (CTSC) is a cysteine protease of the papain family (1). It sequentially removes dipeptides from the free N-termini of proteins and peptides. It has broad specificity except that it does not cleave a basic amino acid (Arg or Lys) in the N-terminal position or Pro on either side of the scissle bond. It requires halide ions for activity. The pro form contains a pro region and a mature region, which are further cleaved during activation to remove the prodomain and split the catalytic domain into heavy and light chains. The N-terminal domain of the pro region is also called the exclusion domain, which remains connected to the heavy chain through non-covalent bonds to the mature, active enzyme. Broadly distributed, CTSC plays a major role in lysosomal degradation and enzyme activation. For example, it activates granule serine proteases in cytotoxic T lymphocytes and natural killer cells (granzymes A and B), mast cells (tryptase and chymase), and neutrophils (Cathepsin G and elastase) by removing their N-terminal activation dipeptides (2).