Electron transfer between bases in double helical DNA
Electron transfer between bases in double helical DNA
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DOI：
10.1126/science.283.5400.375
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发表时间：
1999-01-15
期刊：
影响因子：
56.9
通讯作者：
Barton, JK
中科院分区：
文献类型：
--
作者：
Kelley, SO;Barton, JK
用选择性氧化鸟嘌呤的腺嘌呤荧光类似物研究了通过DNA pi堆叠的光诱导电子转移作为反应物堆积和能量学的函数。这些因素的微小变化导致了DNA介导的电子转移反应的动力学和距离依赖性的深刻变化。反映电子转移对距离的依赖关系的参数β的值在每埃0.1到1.0之间。强烈的堆积作用导致最快的电子转移动力学。因此，电子优先通过链内路径而不是链间路径进行传输。反应物能量学也调节DNA介导的电荷传输的距离依赖性。这些研究可能会解决以前报道的一系列不同的结果，现在必须开发范例来描述DNA pi堆叠的这些属性，其范围可以从绝缘体到“导线”状。
Fluorescent analogs of adenine that selectively oxidize guanine were used to investigate photoinduced electron transfer through the DNA pi-stack as a function of reactant stacking and energetics. Small variations in these factors led to profound changes in the kinetics and distance dependences of DNA-mediated electron-transfer reactions. Values of beta, a parameter reflecting the dependence of electron transfer on distance, ranged from 0.1 to 1.0 per angstrom. Strong stacking interactions result in the fastest electron-transfer kinetics. Electrons are thus transported preferentially through an intrastrand rather than interstrand pathway. Reactant energetics also modulate the distance dependence of DNA-mediated charge transport. These studies may resolve the range of disparate results previously reported, and paradigms must now be developed to describe these properties of the DNA pi-stack, which can range from insulator- to "wire"-like.