4.1.1.75 Ca2+ activates, half-maximal activity at 0.6 mM 288074 4.1.1.75 Co2+ activates, half-maximal activity at 0.3 mM 288074 4.1.1.75 Mg2+ activates, half-maximal activity at 0.3 mM 288074 4.1.1.75 Mn2+ activates, half-maximal activity at 0.03 mM 288074 4.1.1.75 Ni2+ activates 288074 4.1.1.75 Zn2+ activates 288074