Anti-CPE antibodies are used in the immunodetection of the protein carboxypeptidase E. In humans, the canonical protein has a reported length of 476 amino acid residues and a mass of 53.2 kDa. Its subcellular localization is in the cytoplasmic vesicles, membrane, and is secreted. Up to 2 different isoforms have been reported for this protein. It is notably expressed in many tissues, such as the appendix and cerebellum. A member of the Peptidase M14 protein family, CPE is reported to be a sorting receptor that directs prohormones to the regulated secretory pathway. Post-translational modifications have been described, including glycosylation.
The CPE marker can be used to identify Type 1 Descending Thin Limb Cells and Type 3 Descending Thin Limb Cells.* Synonyms for this target antigen include CPH, IDDHH, carbocypeptidase E, carboxypeptidase H, cobalt-stimulated chromaffin granule carboxypeptidase, and BDVS. CPE gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.
*HuBMAP Human Reference Atlas v1.4