Zinc Deficient Bovine Erythrocyte Superoxide Dismutase Has Low Specific Activity

Zinc deficient bovine superoxide dismutase (Cu_2E_2OSD(E=empty)) was prepared and purified by high performance liquid chromatography (HPLC). Each peak was characterized as to protein, copper content and specific activity. The Cu_2E_2SOD peak fractionated by HPLC has a low specific activity at pH 7.8 (about 10% of the native enzyme (Cu_2Zn_2SOD)). With the addition of zinc ions, the specific activity of Cu_2E_2SOD was quantitatively restored to that of the native enzyme. This behavior implies that the zinc ion is very important for the appearance of enzyme activity.