ESEEM STUDIES OF ALCOHOL BINDING TO THE MANGANESE CLUSTER OF THE OXYGEN EVOLVING COMPLEX OF PHOTOSYSTEM II
ESEEM STUDIES OF ALCOHOL BINDING TO THE MANGANESE CLUSTER OF THE OXYGEN EVOLVING COMPLEX OF PHOTOSYSTEM II
复制标题
乙醇与光系统II放氧络合物锰簇结合的ESEEM研究
DOI：
10.1021/ja982713b
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发表时间：
1998
影响因子：
15
通讯作者：
R. Britt
中科院分区：
文献类型：
--
作者：
D. A. Force;D. Randall;G. Lorigan;A. Clemens;R. Britt
使用一系列2H标记的醇进行的ESEEM（电子自旋回波包络调制）光谱研究提供了直接证据，表明小分子醇（甲醇和乙醇）在Kok循环的S2状态下连接到光系统II的放氧复合物（OEC）的Mn簇。本文提出了一种计算交换耦合四核锰团簇超精细相互作用的数值方法。这种方法是用来计算超精细相互作用张量的质子[氘]在附近的两个不同的安排锰离子在一个四核簇：对称立方烷模型和基于EXAFS的伯克利“二聚体的二聚体”模型。从光谱上观察到的甲醇和乙醇质子[氘核]的耦合常数中推导出的Mn−H距离，以及用这些簇模型解释的Mn−H距离，与这些小醇与OEC Mn簇的直接连接一致。具体来说，对于甲醇，我们可以模拟三脉冲ESEEM时域图案…
An ESEEM (electron spin−echo envelope modulation) spectroscopic study employing a series of 2H-labeled alcohols provides direct evidence that small alcohols (methanol and ethanol) ligate to the Mn cluster of the oxygen evolving complex (OEC) of Photosystem II in the S2-state of the Kok cycle. A numerical method for calculating the through-space hyperfine interactions for exchange-coupled tetranuclear Mn clusters is described. This method is used to calculate hyperfine interaction tensors for protons [deuterons] in the vicinity of two different arrangements of Mn ions in a tetranuclear cluster: a symmetric cubane model and the EXAFS-based Berkeley “dimer-of-dimers” model. The Mn−H distances derived from the spectroscopically observed coupling constants for methanol and ethanol protons [deuterons] and interpreted with these cluster models are consistent with the direct ligation of these small alcohols to the OEC Mn cluster. Specifically, for methanol we can simulate the three-pulse ESEEM time domain patter...