Mitochondrial Production of Oxygen Radical Species and the Role of Coenzyme Q as an Antioxidant
| Autor: | Milena Merlo Pich, Annalisa Biondi, Andrea Bernacchia, G. Formiggini, Giorgio Lenaz, Carla Bovina, Anna Ida Falasca, Maria Luisa Genova, Giovanna Parenti Castelli |
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| Rok vydání: | 2003 |
| Předmět: |
Antioxidant
Ubiquinone medicine.medical_treatment Mitochondrion medicine.disease_cause Antioxidants General Biochemistry Genetics and Molecular Biology Electron Transport 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Oxidoreductase medicine Animals Humans NADH NADPH Oxidoreductases chemistry.chemical_classification Reactive oxygen species Binding Sites Electron Transport Complex I Superoxide Mitochondria Mitochondrial respiratory chain chemistry Biochemistry Coenzyme Q – cytochrome c reductase 030221 ophthalmology & optometry Reactive Oxygen Species Oxidation-Reduction 030217 neurology & neurosurgery Oxidative stress |
| Zdroj: | Experimental Biology and Medicine. 228:506-513 |
| ISSN: | 1535-3699 1535-3702 |
| DOI: | 10.1177/15353702-0322805-14 |
| Popis: | The mitochondrial respiratory chain is a powerful source of reactive oxygen species (ROS), which is considered as the pathogenic agent of many diseases and of aging. We have investigated the role of complex I in superoxide radical production and found by the combined use of specific inhibitors of complex I that the one-electron donor to oxygen in the complex is a redox center located prior to the sites where three different types of Coenzyme Q (CoQ) competitors bind, to be identified with an Fe–S cluster, most probably N2, or possibly an ubisemiquinone intermediate insensitive to all the above inhibitors. Short-chain Coenzyme Q analogs enhance superoxide formation, presumably by mediating electron transfer from N2 to oxygen. The clinically used CoQ analog, idebenone, is particularly effective, raising doubts on its safety as a drug. Cells counteract oxidative stress by antioxidants. CoQ is the only lipophilic antioxidant to be biosynthesized. Exogenous CoQ, however, protects cells from oxidative stress by conversion into its reduced antioxidant form by cellular reductases. The plasma membrane oxidoreductase and DT-diaphorase are two such systems, likewise, they are overexpressed under oxidative stress conditions. |
| Databáze: | OpenAIRE |
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