Asp-AMS is a 500-fold stronger competitive inhibitor of the mitochondrial enzyme than aspartol-AMP (10 nM) and a 35-fold lower competitor of human and bovine cyt-AspRSs (300 nM).It is a strong inhibitor with K i in the nanomolar (nM) range.It has also the highest inhibitory effect for the mitochondrial enzyme.It is the most active inhibitor with K i values in the nanomolar range, with a stronger effect on bacterial AspRSs ( E. coli and P. aeruginosa ) than on human cytosolic AspRS.