Aminopeptidase with broad substrate specificity. Has lower activity with substrates that have Asp or Glu in the P2' position, or Pro in the P3' position. Lacks activity with substrates that have both Pro in the P3' position and Asp or Glu in the P2' position . Lacks carboxypeptidase activity. Lacks dipeptidyl-peptidase IV type activity .
Subcellular locations: Apical cell membrane
Ileal brush border membrane.
Detected in small intestine (at protein level) . Detected in ileum . Detected in small intestine, spleen and testis. Isoform 2 and isoform 3 are found in the small intestine and colon .