Inactivates puromycin by catalyzing the hydrolysis of the amide linkage between its aminonucleoside and O-methyl-L-tyrosine moieties. May have aminopeptidase activity. Stimulated by DTT. Strongly inhibited by zinc ion, Fe(2+) ion, Cu(2+) ion, mercury ion, N-bromosuccinimide and N-ethylmaleimide. Partially inhibited by cobalt ion. Optimum pH is 8.0. Optimum temperature is 45 degrees Celsius. Monomer.