2.4.2.42	Co2+	20 mM, 85% loss of activity	
2.4.2.42	Cu2+	20 mM, complete loss of activity	
2.4.2.42	EDTA	-	
2.4.2.42	Fe2+	20 mM, complete loss of activity	
2.4.2.42	Ni2+	20 mM, 90% loss of activity