Carboxypeptidase A4 (CPA4)

Carboxypeptidase A4 (CPA4) is a secreted, zinc-dependent metallocarboxypeptidase enzyme that specifically removes hydrophobic C-terminal amino acids from peptides with a free carboxyl group. Its activity is extracellular, and it is synthesized as an inactive proenzyme that becomes activated upon proteolytic cleavage. CPA4 expression is induced during cellular differentiation and is upregulated in various cancers, including aggressive forms of prostate cancer. It processes neuropeptides and substrates such as enkephalins, granins, and neurotensin, which play important roles in cell proliferation, differentiation, synaptogenesis, tissue repair, and immune modulation. Structural studies reveal typical features of the MCP A/B subfamily, including an α/β-hydrolase fold and a zinc-coordinating catalytic site with known inhibitor interactions, such as with latexin. CPA4 may be considered a therapeutic target in cancer and related disorders involving peptide regulation.

Other names

Carboxypeptidase A4CPA4Carboxypeptidase A3CPA3EC 3.4.17.1

Inhibition: Competitive inhibitors like latexin block enzymatic activity via steric interaction with the active site. Potential for substrate mimicry or zinc-binding inhibitors (class-wide approach for metallocarboxypeptidases).