15N HYSCORE characterization of the fully deprotonated, reduced form of the archaeal Rieske [2Fe-2S] center
15N HYSCORE characterization of the fully deprotonated, reduced form of the archaeal Rieske [2Fe-2S] center
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DOI：
10.1021/ja0562393
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发表时间：
2006-02-22
影响因子：
15
通讯作者：
Dikanov, SA
中科院分区：
文献类型：
--
作者：
Iwasaki, T;Kounosu, A;Dikanov, SA
用超精细亚能级相关（HYSCORE）光谱法测定了pH 13.3时15 N标记的超热稳定古细菌Rieske蛋白还原Rieske [2Fe−2S]中心周围强、弱耦合15 N核的超精细耦合，并与生理pH下的结果进行了比较。这不仅可以通过配体上未成对电子自旋密度的重新分布来解释，而且可以通过完全去质子化的还原簇的混合价态的差异来解释。这些定量数据可用于理论分析，以选择合适的模型的混合价态的还原Rieske中心在非常碱性的pH值。
The hyperfine couplings for strongly and weakly coupled15N nuclei around a reduced Rieske [2Fe−2S] center of uniformly15N-labeled, hyperthermostable archaeal Rieske protein at pH 13.3 were determined by hyperfine sublevel correlation (HYSCORE) spectroscopy and compared with those at physiological pH. Significant changes in the hyperfine couplings of the terminal histidine Nδligands and Nεnuclei were observed between them, which can be explained by not only the redistribution of the unpaired electron spin density over the ligands but also the difference in the mixed-valence state of the fully deprotonated, reduced cluster. These quantitative data can be used in theoretical analysis for the selection of an appropriate model of the mixed-valence state of the reduced Rieske center at very alkaline pH.