title: Further studies on the formation of oxygen radicals by potassium superoxide in aqueous medium for biochemical investigations.
abstract: Potassium superoxide (KO2) forms superoxide anion (O2-) in aqueous medium as measured by the superoxide dismutase (SOD)-inhibitable cytochrome c reduction assay of McCord and Fridovich. The reduction of cytochrome c by O2- formed by KO2 was observed only above pH 7.0 and demonstrated a pH optimum at pH 9.6. SOD was an effective inhibitor of the cytochrome c reduction produced by KO2. Hydroxyl radical scavengers and singlet oxygen quenchers did not interfere with the reduction of cytochrome c by KO2. These data demonstrate that addition of KO2 to aqueous medium is an easy chemical method for the production of O2- in controlled amounts.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003574:Cytochrome c Group; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D012996:Solutions; D013481:Superoxides; D013696:Temperature
chemical_list: D003574:Cytochrome c Group; D012996:Solutions; D013481:Superoxides; C039316:potassium superoxide