Mouse carboxypeptidase A2(CPA2) is a secreted pancreatic procarboxy -peptidase which belongs to the peptidase M14 family. CPA2 consists of a signal peptide, a pro region and a mature chain. It can be activated after cleavage of the pro peptide. CPA2 cleaves the C-terminal amide or ester bond of peptides that have a free C-terminal carboxyl group. The hydrolytic action of CPA2 was identified with a preference towards long substrates with aromatic amino acids in their C-terminal end, particularly tryptophan.