A zinc containing enzyme of the hydrolase class that catalyzes the removal of the N-terminal amino acid from most L-peptides, particularly those with N-terminal leucine residues but not those with N-terminal lysine or arginine residues. This occurs in tissue cell cytosol, with high activity in the duodenum, liver, and kidney. The activity of this enzyme is commonly assayed using a leucine arylamide chromogenic substrate such as leucyl beta-naphthylamide.

A subclass of EXOPEPTIDASES that act on the free N terminus end of a polypeptide liberating a single amino acid residue. EC 3.4.11.

A ZINC-dependent membrane-bound aminopeptidase that catalyzes the N-terminal peptide cleavage of GLUTAMATE (and to a lesser extent ASPARTATE). The enzyme appears to play a role in the catabolic pathway of the RENIN-ANGIOTENSIN SYSTEM.