Steady state cyclic electron transfer through solubilized Rhodobacter sphaeroides reaction centres
| Autor: | Hans V. Westerhoff, Michael R. Jones, Klaas J. Hellingwerf, Bart J. van Rotterdam, R.W. Visschers, Wim Crielaard |
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| Přispěvatelé: | Structural Biology, Molecular Cell Physiology, Biophysics Photosynthesis/Energy, Molecular Microbial Physiology (SILS, FNWI) |
| Rok vydání: | 2000 |
| Předmět: |
Photosynthetic reaction centre
Cytochrome Ubiquinone Photosynthetic Reaction Center Complex Proteins Kinetics Light-Harvesting Protein Complexes Biophysics Cytochrome c Group Rhodobacter sphaeroides macromolecular substances Photochemistry Biochemistry Electron Transport Electron transfer Animals Bacteriochlorophylls biology Chemistry Myocardium Cytochrome c Organic Chemistry biology.organism_classification Electron transport chain biology.protein Thermodynamics Steady state (chemistry) Protons |
| Zdroj: | Biophysical Chemistry, 88, 137-152. Elsevier van Rotterdam, B J, Visschers, R W, Westerhoff, H V, Crielaard, W & Hellingwerf, K J 2000, ' Steady-state cyclic electron transfer through solubilized Rhodobacter sphaeroides reaction centers. ', Biophysical Chemistry, vol. 88, pp. 137-152 . https://doi.org/10.1016/S0301-4622(00)00206-4 |
| ISSN: | 1873-4200 0301-4622 |
| DOI: | 10.1016/S0301-4622(00)00206-4 |
| Popis: | The mechanism, thermodynamics and kinetics of light-induced cyclic electron transfer have been studied in a model energy-transducing system consisting of solubilized Rhodobacter sphaeroides reaction center/light harvesting-1 complexes (so-called core complexes), horse heart cytochrome c and a ubiquinone-0/ubiquinol-0 pool. An analysis of the steady-state kinetics of cytochrome c reduction by ubiquinol-0, after a light-induced steady-state electron flow had been attained, showed that the rate of this reaction is primarily controlled by the one-electron oxidation of the ubiquinol-anion. Re-reduction of the light-oxidized reaction center primary donor by cytochrome c was measured at different reduction levels of the ubiquinone-0/ubiquinol-0 pool. These experiments involved single turnover flash excitation on top of background illumination that elicited steady-state cyclic electron transfer. At low reduction levels of the ubiquinone-0/ubiquinol-0 pool, the total cytochrome c concentration had a major control over the rate of reduction of the primary donor. This control was lost at higher reduction levels of the ubiquinone/ubiquinol-pool, and possible reasons for this behaviour are discussed. (C) 2000 Elsevier Science B.V. |
| Databáze: | OpenAIRE |
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