Purification of isozymes of superoxide dismutase from groundnut (Arachis hypogea) seedlings.

Groundnut seedlings contain five isozymes of superoxide dismutase. These isozymes were purified to homogeneity by ammonium sulfate precipitation, ionexchange chromatography on diethyl amino ethyl cellulose, gel filtration using Sephadex G100 and preparative gel electrophoresis. Manganese containing superoxide dismutase showed optimal activity at pH 7.8 whereas activity was one fifth at pH 9.8. This difference in the activity was not observed in case of copper-zinc enzymes.