Carboxypeptidase B

Carboxypeptidase B (, "protaminase", "pancreatic carboxypeptidase B", "tissue carboxypeptidase B", "peptidyl-L-lysine [L-arginine]hydrolase") is a carboxypeptidase that preferentially acts upon basic amino acids, such as arginine and lysine. This serum enzyme is also responsible for rapidly metabolizing the C5a protein into C5a des-Arg, with one less amino acid.