Electron Spin Resonance Study of Electron Transfer in DNA: Inter-Double-Strand Tunneling Processes
Electron Spin Resonance Study of Electron Transfer in DNA: Inter-Double-Strand Tunneling Processes
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DNA 中电子转移的电子自旋共振研究：双链间隧道过程
DOI：
10.1021/jp000956w
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发表时间：
2000
影响因子：
3.3
通讯作者：
M. Sevilla
中科院分区：
文献类型：
--
作者：
Zhongli Cai and;M. Sevilla
在这项工作中，我们使用不同浓度的DNA的冷冻玻璃水溶液来测试DNA双链之间的电子转移，即从一条DNA双链转移到另一条DNA双链。辐射产生的电子被捕获在DNA上，并转移到随机分布的插入器--米托蒽醌(MX)。通过监测在77K下MX自由基的ESR信号的增强和DNA自由基的ESR信号的丢失，可以直接观察电子转移速率(ET)。辐射后MX自由基的分数和表观ET距离随DNA浓度的增加而增大，随时间的延长而增大。提出了一个假设DNA双链(DS‘s)转移的模型，该模型与表观ET距离的浓度依赖关系符合实验结果。β和ET距离的值与我们以前对稀水玻璃介质的结果很好地一致。我们发现e..。
In this work, we employ frozen glassy aqueous (D2O) solutions of DNA at various concentrations in order to test for inter-DNA-double-strand electron transfer, i.e., transfer from one DNA double strand to another. Electrons generated by radiation are trapped on DNA and transfer to a randomly interspersed intercalator, mitoxantrone (MX). The monitoring of the buildup of the ESR signal of the MX radicals and the loss of the ESR signal of the DNA radicals with time at 77 K allows for the direct observation of the rate of electron transfer (ET). The fraction of MX radicals and the apparent ET distances after irradiation are found to increase with the concentration of DNA as well as with time. A model that assumes transfer both along and between DNA double strands (ds's) is proposed and found to fit experimental results for the concentration dependence of apparent ET distances. Values for β and the ET distances found are in good agreement with our previous results for dilute aqueous glassy media. We find that e...