Cleavage and isomerization of UpU promoted by dinuclear metal ion complexes
Cleavage and isomerization of UpU promoted by dinuclear metal ion complexes
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DOI：
10.1021/ja711347w
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发表时间：
2008-04-02
影响因子：
15
通讯作者：
Williams, Nicholas H.
中科院分区：
文献类型：
--
作者：
Linjalahti, Heidi;Feng, Guoqiang;Williams, Nicholas H.
在生物和人工体系中，金属离子对磷酰基转移的催化作用已经得到了深入的研究，但过渡态或中间体的五配位磷酰基物种的状态是相当大的争论的主题。我们报道，双核金属离子配合物，纳入第二球氢键供体不仅促进切割的RNA片段一样有效的活化类似物HPNPP，但也提供了第一个例子的金属离子催化磷酸二酯异构化接近中性pH值。这一观察表明，反应催化这些配合物涉及的正膦中间体的形成，是足够长的-活到了伪旋转
The catalysis of phosphoryl transfer by metal ions has been intensively studied in both biological and artificial systems, but the status of the transient pentacoordinate phosphoryl species (as transition state or intermediate) is the subject of considerable debate. We report that dinuclear metal ion complexes that incorporate second sphere hydrogen bond donors not only promote the cleavage of RNA fragments just as efficiently as the activated analogue HPNPP but also provide the first examples of metal ion catalyzed phosphate diester isomerization close to neutral pH. This observation implies that the reaction catalyzed by these complexes involves the formation of a phosphorane intermediate that is sufficiently long-lived to pseudorotate.