Carboxypeptidase

The  inactive  zymogen  procarboxypeptidase  is  activated  by  trypsin .The further action on the polypeptides is carried out by carboxypeptidase which  attacks the  carboxy  terminal  peptide  bond,  liberating single amino acids. So you  realize that carboxypeptidase hydrolyses peptide bonds from  the end of the peptide chain. Therefore, it is called as an exopeptidase  (unlike trypsin, chymotrypsin and  elastase). Further, since this enzyme acts on  the peptide bonds of the  peptide chain containing free  COOH  (carboxylic) group,  it  is specifically called carboxypeptidase.