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Rapid Degradation of the Tetrameric Mn Cluster in Illuminated, PsbO-Depleted Photosystem II Preparationsстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Semin B.K., Davletshina L.N., Ivanov I.I., Seibert M., Rubin A.B.
- Журнал: Biochemistry (Moscow)
- Том: 77
- Номер: 2
- Год издания: 2012
- Издательство: Pleiades Publishing, Ltd
- Местоположение издательства: Road Town, United Kingdom
- Первая страница: 152
- Последняя страница: 156
- DOI: 10.1134/S0006297912020058
- Аннотация: A "decoupling effect" (light-induced electron transport without O-2 evolution) was observed in Ca-depleted photosystem II (PSII(-Ca)) membranes, which lack PsbP and PsbQ (Semin et al. (2008) Photosynth. Res., 98, 235-249). Here PsbO-depleted PSII (PSII(-PsbO)) membranes (which also lack PsbP and PsbQ) were used to examine effects of PsbO on the decoupling. PSII(-PsbO) membranes do not reduce the acceptor 2,6-dichlorophenolindophenol (DCIP), in contrast to PSII(-Ca) membranes. To understand why DCIP reduction is lost, we studied light effects on the Mn content of PSII(-PsbO) samples and found that when they are first illuminated, Mn cations are rapidly released from the Mn cluster. Addition of an electron acceptor to PSII(-PsbO) samples accelerates the process. No effect of light was found on the Mn cluster in PSII(-Ca) membranes. Our results demonstrate that: (a) the oxidant, which directly oxidizes an as yet undefined substrate in PSII(-Ca) membranes, is the Mn cluster (not the Y-Z radical or P680(+)); (b) light causes rapid release of Mn cations from the Mn cluster in PSII(-PsbO) membranes, and the mechanism is discussed; and (c) rapid degradation of the Mn cluster under illumination is significant for understanding the lack of functional activity in some PSII(-PsbO) samples reported by others.
- Добавил в систему: Иванов Илья Ильич