2.4.1.149 Mn2+ optimum concentration: 2-15 mM, cooperative activating effects by combination of Mn2+ at a low concentration and Mg2+ or Ca2+ 638578 2.4.1.149 additional information enzyme possesses 2 distinct metal binding sites, not activated by Ca2+, Mg2+, Zn2+, Fe2+, Cu2+, Ni2+, K+, Na+ 638578 2.4.1.149 Ca2+ activates, 48% as effective as Mn2+ 638606 2.4.1.149 Co2+ activates, 52% as effective as Mn2+ 638606 2.4.1.149 Mn2+ requirement, Km: 1.25 mM, Mn2+ cannot be replaced by Mg2+, Zn2+, Cu2+ or Cd2+ 638606 2.4.1.149 additional information not activated by Mg2+, Zn2+, Cu2+ or Cd2+ 638606 2.4.1.149 Ca2+ about one third of the activity compared to Mn2+, recombinant enzyme 658728 2.4.1.149 Mg2+ about one third of the activity compared to Mn2+, recombinant enzyme 658728 2.4.1.149 Mn2+ required for activity, recombinant enzyme 658728