1 0 0 0 OA 光合成光化学系II における水分解・酸素発生の反応メカニズム
- 著者
- 沈 建仁
- 出版者
- 錯体化学会
- 雑誌
- Bulletin of Japan Society of Coordination Chemistry (ISSN:18826954)
- 巻号頁・発行日
- vol.72, pp.3-14, 2018-11-30 (Released:2019-04-01)
- 参考文献数
- 62
- 被引用文献数
- 1 1
Photosystem II (PSII) is a huge membrane-protein complex catalyzing light-induced electron transfer and water oxidation reactions, leading to the conversion of light energy into chemical energy and the evolution of molecular oxygen, two products indispensable for sustaining almost all life forms on the earth. This account describes the structure of PSII with the focus on that of the catalytic center for water oxidation, a Mn4CaO5-cluster embedded in the protein matrix of PSII, revealed by conventional highresolution X-ray crystallography and femtosecond X-ray free electron laser (XFEL) crystallography. Latest results on the structural changes of the Mn4CaO5-cluster during the water oxidation reaction cycle obtained by the femtosecond XFEL crystallography are also described. Based on these results as well as those obtained with other approaches, the mechanism of water oxidation and oxygen evolution is discussed. Other functions of PSII such as proton release pathways and light energy absorption and transfer are also discussed briefly.
1 0 0 0 OA 放射光X線結晶構造解析による光合成・光化学系IIの水分解・酸素発生機構の解明
- 著者
- 神谷 信夫 沈 建仁
- 出版者
- 日本結晶学会
- 雑誌
- 日本結晶学会誌 (ISSN:03694585)
- 巻号頁・発行日
- vol.59, no.2-3, pp.64-71, 2017-06-30 (Released:2017-07-01)
- 参考文献数
- 45
- 被引用文献数
- 4
Photosystem II (PSII) is a multi-subunit protein complex embedded in the thylakoid membrane and splits water molecules, producing electrons, protons and molecular oxygen in photosynthesis. We started to purify and crystallize PSII in 1990, which led to the first crystal structure analysis at a resolution of 3.7 Å in 2003 using SPring-8. The resolution of the structure was raised to 1.9 Å in 2011, which was considered a breakthrough in the filed of photosynthesis because, on the basis of this atomic resolution structure, it became possible to discuss the molecular mechanism of the water-splitting reaction. We are continuing our studies to obtain much more precise information on the oxygen-evolving complex (OEC) at the S1-state of the Kok cycle and to analyze the intermediate state structures using femtosecond X-ray pulses from XFEL of SACLA.