X-ray spectroscopy-based structure of the Mn cluster and mechanism of photosynthetic oxygen evolution.
X-ray spectroscopy-based structure of the Mn cluster and mechanism of photosynthetic oxygen evolution.
复制标题
基于X射线光谱的Mn簇结构和光合产氧机制。
DOI：
10.1016/s0005-2728(00)00217-6
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Yachandra,VK
中科院分区：
文献类型：
--
作者：
Robblee,JH;Cinco,RM;Yachandra,VK
含锰析氧络合物（OEC）从水中产生氧气的机制已经引起了40多年的极大兴趣。这篇评论的重点是如何X射线光谱提供了重要的信息，这个锰络合物的结构和它的中间体，或S-状态，在水的氧化循环。X射线吸收近边结构光谱和高分辨率Mn Kβ X射线发射光谱实验已经确定了OEC中Mn在每个中间S态的氧化态，而扩展的X射线吸收精细结构实验表明，OEC中存在2.7 μ Mn-Mn二-μ-氧代基序和3.3 μ Mn-Mn单-μ-氧代基序。X射线光谱也被用来探测OEC中的两个基本辅因子，Ca 2+和Cl−，并表明Ca 2+是OEC的组成部分，与Mn接近。此外，取向PS II膜的二向色性研究提供了关于Mn-Mn和Mn-Ca载体的角度信息。基于这些X射线光谱数据，精细模型的OEC的结构和OEC的析氧机制。
The mechanism by which the Mn-containing oxygen evolving complex (OEC) produces oxygen from water has been of great interest for over 40 years. This review focuses on how X-ray spectroscopy has provided important information about the structure of this Mn complex and its intermediates, or S-states, in the water oxidation cycle. X-ray absorption near-edge structure spectroscopy and high-resolution Mn Kβ X-ray emission spectroscopy experiments have identified the oxidation states of the Mn in the OEC in each of the intermediate S-states, while extended X-ray absorption fine structure experiments have shown that 2.7 Å Mn–Mn di-μ-oxo and 3.3 Å Mn–Mn mono-μ-oxo motifs are present in the OEC. X-ray spectroscopy has also been used to probe the two essential cofactors in the OEC, Ca2+and Cl−, and has shown that Ca2+is an integral component of the OEC and is proximal to Mn. In addition, dichroism studies on oriented PS II membranes have provided angular information about the Mn–Mn and Mn–Ca vectors. Based on these X-ray spectroscopy data, refined models for the structure of the OEC and a mechanism for oxygen evolution by the OEC are presented.