Metalloprotease that specifically hydrolyzes peptides with N-terminal alanine, arginine and leucine residues. Binds 1 zinc ion per subunit. Inactivated by metal-chelating agents phenanthroline and EDTA. Inhibited by bestatin, an aminopeptidase inhibitor. Not inhibited by pepstatin A and PMSF, inhibitors of aspartic and the serine proteases, respectively. Not inhibited by carboxypeptidase inhibitor. Optimum pH is 7.2. Optimum temperature is 30 degrees Celsius. Belongs to the peptidase M1 family.