Carboxypeptidase A4, al so known as CPA4, is a secreted, zinc-dependent metallocarboxypeptidase that removes the C-terminal amino acid from peptides having a free C-terminal carboxyl group. CPA4 can hydrolyze both amide and ester bonds and has a preference for cleavage at the amino side of hydrophobic residues. CPA4 is inhibited by latexin, an endogenous inhibitor of carboxypeptidases. The deduced aa sequence of human CPA4 consists of a signal peptide (residues 1-16), a pro region (17-113), and a mature chain (residues 114-421). The CPA4 gene has been associated with prostate cancer aggressiveness and is involved in the histone hyperacetylation signaling pathway. Recent studies show that coding variation in the CPA4 gene is linked to high risk prostate cancer among younger patients. Murine myeloma cell line, NS0-derived. Gly17-Tyr421, with a C-terminal 10-His tag. Molecular Weight: ~48kD (SDA-PAGE, reducing conditions) Biological Activity: Measured by its ability to cleave the colorimetric peptide substrate Ac-Phe-Thiaphe-OH in the presence of 5, 5Dithio-bis (2-nitrobenzoic acid) (DTNB). Specific Activity: >3,500pmoles/min/ug Storage and Stability: Aliquot to avoid repeated freezing and thawing and freeze at -70C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Aliquots are stable for at least 6 months.
