May be involved in the proteolytic inactivation of enkephalins and neurotensin in some brain areas. May convert inactive angiotensin I into the biologically active angiotensin II (PubMed:18178555). Releases a C-terminal amino acid, with preference for large hydrophobic C-terminal amino acids and shows only very weak activity toward small amino acids and histidine (PubMed:20855895). . This is the function of CPA6 (carboxypeptidase A6, Ensembl gene identifier ENSG00000165078).