Grozema Ferdinand C, Tonzani Stefano, Berlin Yuri A, Schatz George C, Siebbeles Laurens D A, Ratner Mark A
Section Opto-electronic Materials, Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
J Am Chem Soc. 2009 Oct 14;131(40):14204-5. doi: 10.1021/ja906863k.
DNA hairpins in which an electron donor and an electron acceptor are attached to the ends are excellent model systems for the study of charge transfer in weakly coupled pi-stacked systems. In this communication we report on a computational study of the effect of the base pair sequence in these DNA hairpins on the kinetics of charge transfer. We show that the rate of charge transfer strongly depends on the actual position of a GC base pair in a sequence that otherwise only contains AT base pairs. This can be explained by evaluating the energy landscape through which the charge travels. It is shown that including the electrostatic interaction between electron and hole can explain the experimentally observed dependence on the position of the GC in the DNA. We conclude that electrostatic interactions are important to consider when explaining the charge transfer kinetics in GC containing DNA sequences.
将电子供体和电子受体连接在末端的DNA发夹是研究弱耦合π堆积体系中电荷转移的优秀模型系统。在本通讯中，我们报告了关于这些DNA发夹中碱基对序列对电荷转移动力学影响的计算研究。我们表明，电荷转移速率强烈依赖于在一个原本只包含AT碱基对的序列中GC碱基对的实际位置。这可以通过评估电荷传输所经过的能量态势来解释。结果表明，考虑电子与空穴之间的静电相互作用能够解释实验观察到的对DNA中GC位置的依赖性。我们得出结论，在解释含GC的DNA序列中的电荷转移动力学时，静电相互作用是需要考虑的重要因素。
