Degrades neuropeptide proctolin (RYLPT) by cleavage between Tyr and Leu residues. Release of an N-terminal dipeptide from a peptide comprising four or more residues, with broad specificity. Also acts on dipeptidyl 2-naphthylamides. Binds 1 zinc ion per subunit. Optimum pH is 5.1. Purified protein is present in 2 isoforms; 76 kDa and 80 kDa. Belongs to the peptidase M49 family. The order of the last peptide shown is unknown.