Broad specificity aminopeptidase which preferentially hydrolyzes an N-terminal methionine, citrulline or glutamine. Release of N-terminal amino acids, preferentially methionine, from peptides and arylamides. Binds 1 zinc ion per subunit. Inhibited by calcium but not affected by chloride ions. Inhibited by amastatin and to a lower extent by bestatin. Weakly inhibited by puromycin. Optimum pH is 6.6-8.0. Ubiquitously expressed. Expressed at relatively higher levels in heart and skeletal muscle. Belongs to the peptidase M1 family. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus.