Carboxypeptidases have functions ranging from digestion of food to selective biosynthesis of neuroendocrine peptides. Members of the A/B subfamily of carboxypeptidases, such as CPA5, contain an approximately 90-amino acid pro region that assists in the folding of the active carboxypeptidase domain. Cleavage of the pro region activates the enzyme (Wei et al., 2002 [PubMed 11836249]).[supplied by OMIM, Mar 2008].