Based on limited published evidence, NAALADL1 encodes a zinc-dependent metallopeptidase with broad aminopeptidase activity 1. The enzyme lacks carboxypeptidase and dipeptidyl-peptidase IV activities, and shows reduced activity toward substrates with Asp/Glu at P2' position or Pro at P3' position 1. NAALADL1 is primarily expressed in the small intestine, suggesting a role in final stages of protein/peptide digestion and absorption 1. The protein functions as a homodimer and binds zinc and calcium ions. NAALADL1 shares structural homology with glutamate carboxypeptidase II but possesses distinct substrate specificity.