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The Interaction of Water‑Soluble Nitroxide Radicals with Photosystem IIстатья Исследовательская статья
Дата последнего поиска статьи во внешних источниках: 29 января 2024 г.
- Авторы: Trubitsin B.V., Milanovsky G.E., Mamedov M.D., Semenov A.Yu, Tikhonov A.N.
- Журнал: Applied Magnetic Resonance
- Том: 153
- Номер: 53
- Год издания: 2022
- Издательство: Springer Verlag
- Местоположение издательства: Germany
- Первая страница: 1053
- Последняя страница: 1067
- DOI: 10.1007/s00723-021-01425-z
- Аннотация: In this work, we investigated the redox transients of a number of water-soluble spin labels upon their interactions with Photosystem II (PS II) core complexes isolated from spinach leaves. We have found that the reactivity of nitroxide radicals, determined by the rate of their reduction upon illumination of PS II, depends on the chemical structure of radicals and the capability of their coming close to lowpotential redox centers of photoactive PS II complexes. An enhanced capability of nitroxide radicals to accept electrons from PS II correlates with their chemical structure. Nitroxide radicals NTI (2,2,5,5-tetramethyl-4-nitromethylene-3-imidazolidine-N-oxyl) and Tacet (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl-acetate), containing polar groups, appear to be most efcient acceptors of electrons donated by PS II compared to neutral (TEMPOL, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) or positively charged (Tamine, 4-amino-2,2,6,6-tetramethylpiperidine-l-oxyl) spin labels. We assume that enhanced reactivities of polar nitroxide radicals, NTI and Tacet, are determined (1) by their relatively high redox potentials, providing the possibility to accept electrons from PS II, and (2) by their afnities to the closest binding sites on the surface of PS II in the vicinity of the primary plastoquinone acceptor PQA (12–14 Å) or/and in the intraprotein cavity for the secondary plastoquinone PQB (~22 Å)
- Добавил в систему: Тихонов Александр Николаевич