Porcine Carboxypeptidase B catalyzes hydrolysis of the basic amino acids lysine, arginine and ornithine from the C-terminal end of polypeptides. The molecular weight is 34,500 daltons, the pH optimum is 7.9, and the pI is 6.0. Carboxypeptidase B is competitively inhibited by arginine, lysine and ornithine. The enzyme is not inhibited by di-isopropylfluorophosphate (DFP), but it is inhibited by metal chelating agents, e.g., 1,10-phenanthroline.