When do metal complexes protect the biological system from superoxide toxicity and when do they enhance it?
Many copper and iron complexes can be reduced by O2- as well as by H2O2. According to the rates of reduction and the concentration of O2- and H2O2, the metal complexes may serve either as catalyst of O2- dismutation or as catalysts of the reaction between O2- and H2O2 to form OH. radical (Haber-Weiss reaction). Various factors which influence whether metal complexes protect the biological systems from superoxide toxicity or enhance it are discussed.
Czapski
G
G
Department of Physical Chemistry, Hebrew University of Jerusalem, Israel.
Goldstein
S
S
D002614:Chelating Agents; D003300:Copper / Q000378:metabolism; D004492:Edetic Acid / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D008670:Metals / Q000378:metabolism*; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism / Q000633:toxicity*
D002614:Chelating Agents; D008670:Metals; D013481:Superoxides; D017665:Hydroxyl Radical; D003300:Copper; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D007501:Iron; D013482:Superoxide Dismutase