FTIR Microspectroscopic Analysis of the Water Oxidation Reaction in a Single Photosystem II Microcrystal
FTIR Microspectroscopic Analysis of the Water Oxidation Reaction in a Single Photosystem II Microcrystal
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单光系统 II 微晶中水氧化反应的 FTIR 显微光谱分析
DOI：
10.1021/acs.jpcb.9b10154
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Noguchi Takumi
中科院分区：
文献类型：
--
作者：
Kato Yuki;Haniu Satoshi;Nakajima Yoshiki;Akita Fusamichi;Shen Jian-Ren;Noguchi Takumi
微晶的光系统II（PSII）最近已被用于调查的水氧化复合物的中间结构，在水氧化过程中，通过连续飞秒晶体学，使用X射线自由电子激光。为了阐明水的氧化机理，关键是要知道反应是否在微晶中正常进行。在这项工作中，我们监测水的氧化反应在一个单一的PSII微晶使用傅里叶变换红外（FTIR）显微光谱与透射法。闪光诱导的微观FTIR差光谱的S-状态转换中的PSII微晶显示功能几乎相同的对应的光谱先前获得的多个微晶，代表附近的晶体表面的反应，以及在溶液中的光谱使用衰减全反射法。该观察结果表明，水氧化的反应过程以相对高的效率进行，在PSII微晶的整个内部保留天然中间结构。
Microcrystals of photosystem II (PSII) have recently been used to investigate the intermediate structures of the water oxidizing complex during water oxidation by serial femtosecond crystallography using X-ray free electron lasers. To clarify the water oxidation mechanism, it is crucial to know whether the reaction proceeds properly in the microcrystals. In this work, we monitored the water oxidation reaction in a single PSII microcrystal using Fourier transform infrared (FTIR) microspectroscopy with the transmission method. Flash-induced micro-FTIR difference spectra of S-state transitions in a PSII microcrystal showed features virtually identical to the corresponding spectra previously obtained using the attenuated total reflection method for multiple microcrystals, representing the reactions near the crystal surface, as well as the spectra in solution. This observation indicates that the reaction processes of water oxidation proceed with relatively high efficiencies retaining native intermediate structures in the entire inside of a PSII microcrystal.