4.4.1.20	Ca2+	stimulates	
4.4.1.20	Co2+	inhibits the enzyme	
4.4.1.20	Mg2+	-	
4.4.1.20	Mg2+	enhances activity	
4.4.1.20	Mg2+	30 mM, 1.8fold stimulation of partially purified enzyme	
4.4.1.20	Mg2+	augments the enzyme