2.3.1.8	Fe2+	required, Fe2+ or Mn2+, Mn2+ is 50-75% as effective as Fe2+	487529	
2.3.1.8	K+	-	487517, 487521	
2.3.1.8	K+	3.4fold stimulation at 10 mM	487527	
2.3.1.8	K+	activates	487515, 487525, 487533, 94495	
2.3.1.8	K+	enzyme is activated by low concentrations of NH4+, K+ and Na+, sequence of effectiveness: NH4+, K+, Na+	487519	
2.3.1.8	K+	enzyme is inactive in absence of K+ or NH4+, maximal activation at about 0.02 M	487513	
2.3.1.8	K+	K+ or NH4+ at concentration above 10 mM required for maximum activity	487526	
2.3.1.8	K+	KCl activates	487525	
2.3.1.8	K+	maximum activity in the presence of 20 mM KCl	736033	
2.3.1.8	K+	no effect	487524