Moreover, the activity was stimulated in the presence of Ca2+, Co2+and Cu2+. Thelevels of the three ions in AmyASS were determined by flame atomic absorption spectrometry. The AmyASS protein contained only oneCa2+ion. The results indicated that AmyASS was a metalloenzyme,although EDTA (5 mM) had a slightly inhibitory effect on the activity(77 ± 1.0% of the original activity).