Carboxypeptidase B

Carboxypeptidase B (EC 3.4.17.2, protaminase, pancreatic carboxypeptidase B, tissue carboxypeptidase B, peptidyl-L-lysine [L-arginine]hydrolase) is a carboxypeptidase that preferentially cleaves off basic amino acids arginine and lysine from the C-terminus of a peptide. This enzyme is secreted by the pancreas, and it travels to the small intestine, where it aids in protein digestion. Plasma carboxypeptidase B (carboxypeptidase B2) is responsible for converting the C5a protein into C5a des-Arg, with one less amino acid.