Description
Carboxypeptidases are zinccontaining exopeptidases that catalyze the release of carboxyterminal amino acids, and are synthesized as zymogens that are activated by proteolytic cleavage. Carboxypeptidases cleave amino acids from the Cterminus of proteins and peptides and many are metalloproteases. They have distinct expression patterns and different specificities for example, preferentially cleaving aromatic (carboxypeptidase As) or basic (carboxypeptidase Bs) residues. Several, such as carboxypeptidase Xs, have lost their catalytic activity. Carboxypeptidases play important roles in digestion of food, processing of bioactive peptides and blood coagulation. In contrast to procarboxypeptidase B which was always secreted by the pancreas as a monomer, procarboxypeptidase A occurs as a monomer and/or associated to one or two functionally different proteins, such as zymogen E, and is involved in zymogen inhibition