Structure-function studies of iron-sulfur clusters and semiquinones in the NADH-Q oxidoreductase segment of the respiratory chain
| Autor: | Tomoko Ohnishi, Takahiro Yano, Andrei D. Vinogradov, Takao Yagi, Dosymzhan Sh. Burbaev, Vladimir D. Sled |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Semiquinone
Stereochemistry Iron Protein subunit Biophysics Respiratory chain Iron–sulfur cluster Biochemistry Electron Transport Structure-Activity Relationship chemistry.chemical_compound Oxidoreductase Complex I Benzoquinones Cluster (physics) Animals Humans NADH NADPH Oxidoreductases Paracoccus denitrificans chemistry.chemical_classification Electron Transport Complex I Myocardium Slow relaxing semiquinone Cell Biology Ligand (biochemistry) NADH-Q oxidoreductase Fast relaxing semiquinone chemistry Cattle Iron-sulfur cluster Sulfur |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1365:301-308 |
| ISSN: | 0005-2728 |
| Popis: | Our recent experimental data on iron-sulfur clusters and semiquinones in the complex I segment of the respiratory chain is presented, focusing on the Paracoccus (P.) denitrificans and bovine heart studies. The iron-sulfur cluster N2 has attracted the attention of investigators in the research field of complex I, since the mid-point redox potential of this cluster is the highest among all clusters in complex I, and is pH dependent (60 mV/pH). It is known that this cluster is located either in the NQO6 (NuoB in E. coli/PSST in bovine heart nomenclature) or in the NQO9 (NuoI/TYKY) subunit in the amphipathic domain of complex I. Our preliminary data indicate that the cluster N2 is located in the NuoB rather than the long-advocated NuoI subunit, and may have a unique ligand structure. We previously reported spin-spin interactions between cluster N2 and two distinct species of semiquinone (designated SQNf and SQNs) associated with complex I. A parallel intensity change was observed between the SQNf (g = 2.00) signal and the N2 split g parallel signal, further supporting our proposed interaction between SQNf and N2 spins. |
| Databáze: | OpenAIRE |
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