2012年7月
The structure and activation of substrate water molecules in the S-2 state of photosystem II studied by hyperfine sublevel correlation spectroscopy
ENERGY & ENVIRONMENTAL SCIENCE
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- 巻
- 5
- 号
- 7
- 開始ページ
- 7747
- 終了ページ
- 7756
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1039/c2ee21210b
- 出版者・発行元
- ROYAL SOC CHEMISTRY
The water-splitting protein, photosystem II, catalyzes the light-driven oxidation of water to dioxygen. The solar water oxidation reaction takes place at the catalytic center, referred to as the oxygen-evolving complex, of photosystem II. During the catalytic cycle, the oxygen-evolving complex cycles through five distinct intermediate states, S-0-S-4. In this study, we trap the oxygen-evolving complex in the S-2 intermediate state by low temperature illumination of photosystem II isolated from three different species, Thermosynechococcus vulcanus, the PsbB variant of Synechocystis PCC 6803 and spinach. We apply two-dimensional hyperfine sublevel correlation spectroscopy to detect weak magnetic interactions between the paramagnetic tetra-nuclear manganese cluster of the S-2 state of the OEC and the surrounding protons. We identify five groups of protons that are interacting with the tetra-nuclear manganese cluster. From the values of hyperfine interactions and using the recently reported 1.9 angstrom resolution X-ray structure of the OEC in the S-1 state [Umena et al., Nature, 2011, 473, 55], we discuss the assignments of the five groups of protons and draw important conclusions on the structure of the oxygen-evolving complex in the S-2 state. In addition, we conclude that the structure of OEC is nearly identical in photosystem II from Thermosynechococcus vulcanus, the PsbB variant of Synechocystis PCC 6803 and spinach.
- リンク情報
- ID情報
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- DOI : 10.1039/c2ee21210b
- ISSN : 1754-5692
- eISSN : 1754-5706
- Web of Science ID : WOS:000305530900008