THE GENERATION OF HYDROXYL RADICALS FROM COPPER, ZINC SUPEROXIDE DISMUTASE REACTING WITH H2O2

Abstract:

The generation of .OH from Cu,Znroontaining superoxide dismutase (CuZn-SOD) reacting with H₂O₂ was studied by using deoxyribose degradation method in which deoxyribose reacts with. OH to release TBA-reactive compounds. Cu, ZnSOD could be inactivated by H₂O₂, during which. OH was produced. Formate and benzoate,scavengers of. OH, could partially protect Cu,Zn-SOD against inaCtivation by H₂O₂, and could inhibit the generation of. OH from Cu, Zn-SOD reacting with H₂O₂. Heat inactivated Cu,Zn-SOD could also react with H₂O₂ to generate. OH, and it was more effective in generating .OH than the active Cu,Zn-SOD. Apoprotein of Cu,ZnSOD did not catalyze .OH generation from H₂O₂. Zn²⁺ could hardly react with H₂O₂ to form 'OH, whereas Cu²⁺ was highly effective in generating. OH through Fenton reaction. These observations suggest that the generation of. OH from Cu,Zn-SOD reacting with Hood is due to the Fenton reaction between H₂O₂, and Cu²⁺ in the active center of Cu,Zn-SOD.