3.4.17.B4	Cu2+	0.2 mM, about 90% loss of activity, the inhibitory effect is not overcome by the presence of Co2+	
3.4.17.B4	EDTA	1 mM, complete inactivation	
3.4.17.B4	Fe2+	0.2 mM, about 70% loss of activity, the inhibitory effect is not overcome by the presence of Co2+	
3.4.17.B4	Ni2+	0.2 mM, about 75% loss of activity, the inhibitory effect is not overcome by the presence of Co2+	
3.4.17.B4	Zn2+	0.2 mM, about 90% loss of activity, the inhibitory effect is not overcome by the presence of Co2+