Large-scale QM/MM calculations of the CaMn4O5 cluster in the S3 state of the oxygen evolving complex of photosystem II. Comparison between water-inserted and no water-inserted structures.
Large-scale QM/MM calculations of the CaMn4O5 cluster in the S3 state of the oxygen evolving complex of photosystem II. Comparison between water-inserted and no water-inserted structures.
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DOI：
10.1039/c6fd00230g
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发表时间：
2017-06
影响因子：
3.4
通讯作者：
M. Shoji;H. Isobe;T. Nakajima;Y. Shigeta;M. Suga;F. Akita;Jian-Ren Shen;K. Yamaguchi
中科院分区：
文献类型：
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作者：
M. Shoji;H. Isobe;T. Nakajima;Y. Shigeta;M. Suga;F. Akita;Jian-Ren Shen;K. Yamaguchi
大规模的QM/MM计算进行阐明优化的几何结构的CaMn 4 O 5团簇有和没有水插入的光系统II（PSII）的放氧复合物（OEC）的S3状态。在假设S3态中没有氢氧阴离子插入的情况下，发现左（L）-打开的结构是稳定的，而如果一个水分子插入Mn 4Ca簇中，则右（R）-打开的结构变得更稳定。对于没有插入氢氧根阴离子的S3结构，通过QM/MM确定的最佳Mna（4）-Mnd（1）距离约为5.0 μ m，但插入后延长了0.2-0.3 μ m。这些计算结果进行了讨论有关的O-O键形成的可能机制，在水氧化的OEC的PSII。
Large-scale QM/MM calculations were performed to elucidate an optimized geometrical structure of a CaMn4O5 cluster with and without water insertion in the S3 state of the oxygen evolving complex (OEC) of photosystem II (PSII). The left (L)-opened structure was found to be stable under the assumption of no hydroxide anion insertion in the S3 state, whereas the right (R)-opened structure became more stable if one water molecule is inserted to the Mn4Ca cluster. The optimized Mna(4)-Mnd(1) distance determined by QM/MM was about 5.0 Å for the S3 structure without an inserted hydroxide anion, but this is elongated by 0.2-0.3 Å after insertion. These computational results are discussed in relation to the possible mechanisms of O-O bond formation in water oxidation by the OEC of PSII.