CPA2

CPA2 commonly refers to Carboxypeptidase A2, a secreted pancreatic zinc-dependent exopeptidase that participates in protein digestion. In humans, CPA2 is encoded by the CPA2 gene and is one of the pancreatic carboxypeptidases, alongside CPA1. It is produced by pancreatic acinar cells as a zymogen, procarboxypeptidase A2, which is activated in the small intestine by proteolytic cleavage, principally by trypsin.

The enzyme’s primary function is to remove single amino acids from the C-terminus of peptide substrates, contributing to the final steps of dietary protein digestion. It shows a preference for hydrophobic C-terminal residues and operates best in the intestinal lumen. The catalytic mechanism requires a zinc ion in the active site, and the enzyme belongs to the family of metallo-carboxypeptidases.

Biochemically, CPA2 is secreted into pancreatic juice and functions in the lumen of the small intestine. It is synthesized as an inactive precursor and becomes active after proteolytic processing in the digestive tract. The mature enzyme is typically found in the intestinal content where digestionTake place.

Genetically, CPA2 is part of the carboxypeptidase gene family and has vertebrate homologs, with CPA1 representing a closely related paralog. The two genes arose through duplication events and have diverged in substrate preferences and regulatory features across species.

Clinical notes on CPA2 are limited; variants in the CPA2 gene are relatively uncommon, and there is no widely established disease directly attributed to CPA2 deficiency. Pancreatic health and overall digestive tract function influence the level and activity of the enzyme in the gut.