Purification and partial characterisation of superoxide dismutase from chicken erythrocytes

Superoxide dismutase (SOD), which plays a very important role in protecting organisms from oxygen toxicity, was purified from chicken erythrocyte and partially characterised. Erythrocyte membranes were disintegrated via freez e-thaw methods in the presence of Triton X-100. Following ethanol precipita tion, SOD-containing solution was applied to DEAE-cellulose and then Sephad ex G-100 gel columns. Chicken erythrocyte SOD was purified 508-fold with a specific activity of 8,480 units per mg. The molecular weight was estimated to be 30.6 kDa +/- 0.4 by gel filtration. The enzyme was composed of two s ubunits of equal size and contained one atom of copper and one atom of zinc per molecule. Maximum SOD activity was observed between pH 7.0 to 9.0 at 2 5 degreesC. The enzyme has high thermal stability.