Charge separation in DNA via consecutive adenine hopping
Charge separation in DNA via consecutive adenine hopping
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DOI：
10.1021/ja035730w
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发表时间：
2004-02-04
影响因子：
15
通讯作者：
Majima, T
中科院分区：
文献类型：
--
作者：
Takada, T;Kawai, K;Majima, T
DNA中的电荷转移是目前的研究热点，因为它与DNA氧化损伤和电子分子器件有关。我们研究了以萘二甲酰亚胺（NDI）为电子受体，吩噻嗪（PTZ）为电子供体的DNA的激光闪光光解过程中，腺嘌呤（A）连续跳跃的电荷分离过程。在355 nm激光激发下，观察到NDI与PTZ之间的电荷分离和复合过程。通过连续的A-跳跃的电荷分离的产率轻微依赖于两个发色团之间的A碱基的数量，而电荷重组率强烈依赖于距离。电荷分离状态持续超过300 μ s时，NDI从PTZ分开八个A基地。此外，从取决于A-跳跃步骤的数目的电荷分离的产率的分析确定A-跳跃过程的速率常数为2 × 10（10）s（-1）。
Charge transfer in DNA is of current interest because of the involvement of charge transfer in oxidative DNA damage and electronic molecular devices. We have investigated the charge separation process via the consecutive adenine (A)-hopping mechanism using laser flash photolysis of DNA conjugated with naphthaldiimide (NDI) as an electron acceptor and phenothiazine (PTZ) as a donor. Upon the 355-nm laser flash excitation of NDI, the charge separation and recombination process between NDI and PTZ was observed. The yields of the charge separation via the consecutive A-hopping were slightly dependent upon the number of A bases between the two chromophores, while the charge recombination rate was strongly dependent upon the distance. The charge-separated state persisted over 300 mus when NDI was separated from PTZ by eight A bases. Furthermore, the rate constant of the A-hopping process was determined to be 2 x 10(10) s(-1) from an analysis of the yield of the charge separation depending on the number of A-hopping steps.