Membrane alanyl aminopeptidase (ANPEP)

Membrane alanyl aminopeptidase, widely known as CD13 or Aminopeptidase N (APN), is a multifunctional zinc-dependent type II transmembrane metalloprotease (UniProt P15144; NCBI Gene 290) [2, 7, 8]. It is expressed in various tissues, including the brush border of the small intestine and kidney, as well as on the surface of myeloid cells, endothelial cells, and fibroblasts [1, 8]. Its primary enzymatic function involves the cleavage of neutral amino acids from the N-terminus of peptides, playing a key role in protein digestion and the processing of bioactive peptides like angiotensins and enkephalins [2, 8, 9]. Beyond its catalytic role, CD13 acts as a moonlighting protein involved in cell adhesion, migration, and signal transduction [1, 10]. It is a critical regulator of angiogenesis and is frequently overexpressed in the neovasculature of tumors, making it a significant target for anti-cancer therapies [6, 7, 9]. Additionally, CD13 serves as a receptor for several human coronaviruses, such as HCoV-229E, and is implicated in the pathogenesis of inflammatory and autoimmune diseases [1, 4, 8]. Therapeutic interventions targeting CD13 include small molecule inhibitors like bestatin (Ubenimex) and targeted delivery systems that exploit its high expression in diseased tissues [5, 10].

Other names

Aminopeptidase NCD13Alanyl aminopeptidaseMicrosomal aminopeptidasegp150AP-MhAPNAP-N

Inhibition of the zinc-dependent metalloprotease activity to prevent N-terminal amino acid cleavage, modulation of cell signaling and adhesion, and blocking of viral entry or angiogenic progression (Sources: PMC6680645, PMC10055568, PubMed 10676659).