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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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DIRECT SPECTROPHOTOMETRIC DETERMINATION OF MIDPOINT REDOX POTENTIALS OF PRIMARY AND SECONDARY QUINONES IN THE PHOTOSYNTHETIC REACTION CENTER OF RHODOSPIRILLUM-RUBRUM CHROMATOPHORESстатья
- Авторы: SLED' V.D., MULKIDZHANYAN A.Y., SHINKAREV V.P., VERKHOVSKII M.I., KAUROV B.S.
- Журнал: Biokhimiya
- Том: 49
- Номер: 2
- Год издания: 1984
- Первая страница: 204
- Последняя страница: 208
- Аннотация: In chromatophores of nonsulfur purple bacteria R. rubrum, the redox titration of the flash-induced absorbance changes at 450 nm was carried out. These absorbance changes are known to correlate with the formation of semiquinone forms of primary (QI) and secondary (QII) quinone acceptors in the photosynthetic reaction center. Midpoint redox potentials at pH 7.2 (Em 7.2) of couples QI/QI- and QII/QIIH2 were determined as -70 mV and +55 mV, correspondingly. Neither of the semiquinone forms of either acceptor binds protons at physiological pH values. A kinetic analysis of the flash-induced redox changes of QI and QII at different ambient redox potentials (100 mV .ltoreq. Eh .ltoreq. 250 mV) shows that in the chromatophore preparations under study there is no specific mechanism of semiquinone reduction by the components of the bacteriochlorophyll complex.
- Добавил в систему: Мулкиджанян Армен Яковлевич