title: Malarial dihydroorotate dehydrogenase mediates superoxide radical production.
abstract: Dihydroorotate dehydrogenase purified from mitochondria of Plasmodium berghei, a rodent malaria parasite, mediates production of superoxide radical during oxidation of dihydroorotate to orotate. Reduction of dichlorophenolindophenol or cytochrome c or nitroblue tetrazolium was significantly inhibited by superoxide dismutase or theonyltrifluoroacetone, a specific iron chelator of the enzyme. These results, together with the recent evidence of manganese-superoxide dismutase activity in malarial mitochondria [Ranz, A., and Meshnick, S.R. (1989) Exp. Parasitol. 69, 125-128], suggest that the production of superoxide radical may occur in vivo.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: J
authors.initials: J
authors.lastname: Krungkrai
mesh_terms: D015086:2,6-Dichloroindophenol / Q000378:metabolism; D000818:Animals; D003574:Cytochrome c Group / Q000378:metabolism; D004081:Dihydroorotate Oxidase / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008928:Mitochondria / Q000378:metabolism; D009580:Nitroblue Tetrazolium / Q000378:metabolism; D009963:Orotic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D010084:Oxidation-Reduction; D010962:Plasmodium berghei / Q000201:enzymology*; D010963:Plasmodium falciparum / Q000201:enzymology*; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*
chemical_list: D003574:Cytochrome c Group; D013481:Superoxides; C004768:4,5-dihydroorotic acid; D009580:Nitroblue Tetrazolium; D009963:Orotic Acid; D015086:2,6-Dichloroindophenol; D013482:Superoxide Dismutase; D004081:Dihydroorotate Oxidase