1.7.2.3 about 50% of the activity of the molybdoenzyme is lost in the presence of 0.1 M NaCl, only about 4% of its initial activity is left in the presence of 2 M NaCl, 15% of the initial activity of the tungsten-substituted enzyme is left at 2 M NaCl 1.7.2.3 activity is easily lost on dialysis