Base sequence effects in radical cation migration in duplex DNA: Support for the polaron-like hopping model
Base sequence effects in radical cation migration in duplex DNA: Support for the polaron-like hopping model
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DOI：
10.1021/ja029333h
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发表时间：
2003-05-21
影响因子：
15
通讯作者：
Schuster, GB
中科院分区：
文献类型：
--
作者：
Liu, CS;Schuster, GB
制备并研究了一系列蒽醌连接 (AQ) 双链 DNA 寡聚物。 AQ 的照射将自由基阳离子注入 DNA 中。自由基阳离子迁移穿过 DNA 并在 GG 步骤选择性反应，导致哌啶处理后链断裂。选择本工作中研究的低聚物来评估将 T 碱基（或多个碱基）置于重复嘌呤碱基链中对长距离电荷传输的影响。除了明显的例外，链断裂的量随着 AQ 和 GG 步骤之间的距离的增加而减少。结果仅与长距离传输模型一致，例如热激活的类极化子跳跃，其中包含两个或多个相邻碱基上的自由基阳离子离域。
A series of anthraquinone-linked (AQ) duplex DNA oligomers were prepared and investigated. Irradiation of the AQ injects a radical cation into the DNA. The radical cation migrates through the DNA and reacts selectively at GG steps, which leads to strand cleavage after treatment with piperidine. The oligomers investigated in this work were selected to assess the effect on long-distance charge transport of placing a T base (or bases) in a strand of repeating purine bases. With notable exceptions, the amount of strand scission decreases with the distance between the AQ and the GG step. The results are consistent only with models for long-distance transport, such as thermally activated polaron-like hopping, that incorporate radical cation delocalization over two or more adjacent bases.