Purification of superoxide dismutase from human erythrocytes and effect of some pesticide on enzyme activity

Superoxide Dismutase (SOD), (E.C:1.15.1.1) catalyzes the dismutation of the superoxide to hydrogen peroxide. In this study, SOD isolated by using DEAEcellulose chromatography and copper-iminodiacetic acid agarose chromatography. Enzyme was purified 196,3 fold and 33,8 % efficiency. Vmax and Km were found as 5000 U/mg prot. and 3.10-3 mM Xanthine, respectively. Optimum temperature was determined as 15 °C (288 K). Storage stability was investigated. Activation energy was calculated as 16,856 kj/mol and initiation of denaturation temperature was calculated as 19 °C (292 K). Turnover number (kcat) and catalytic efficiency (kcat/Km ) were found as 1667 s-1 and 555 667 s-1.mM-1 Xanthine-1, respectively. Molecular weight of SOD was determined as 20 000. Cyprodinil inhibited SOD competitivly and Fludioxonil inhibited SOD non-competitivly. Key Words: Superoxide Dismutase, Purification, Erythrocyte, Cyprodinil, Fludioxonil.