Starikov E B, Quintilla A, Lee K H, Wenzel W
Forschungszentrum Karlsruhe, Institut fur Nanotechnologie, P. O. Box 3640, D-76021 Karlsruhe, Germany.
J Chem Phys. 2008 Oct 7;129(13):131101. doi: 10.1063/1.2985612.
With the atomistic Kubo-Verges method we calculate the ballistic conductance of various conformers of DNA (A,B,Z), as well as intermediate and composite conformations, using experimental structures and model complexes. For duplexes with 6 and 15 base pairs, we find that the valence band conductivity near the Fermi edge varies dramatically between the different conformations, most notably for the B-to-Z transition. The latter conductivity differences are largely unchanged both in the presence and in the absence of trimethylthiol linkers between DNA and gold electrodes in vacuo, but become much less drastic when explicit molecular dynamics and water-counterion surrounding of B- and Z-DNA are taken into account. Based on atomistic structural models, we argue that changes in the electrostatic energy in the presence of an applied external electric field can induce conformational switching that may be exploited in novel DNA-based memory devices of high packing density.
利用原子论的久保 - 韦尔热斯方法，我们使用实验结构和模型复合物计算了DNA的各种构象（A、B、Z）以及中间和复合构象的弹道电导。对于具有6个和15个碱基对的双链体，我们发现费米边缘附近的价带电导率在不同构象之间变化很大，最显著的是在B型到Z型转变时。在真空中，无论DNA与金电极之间是否存在三甲基硫醇连接体，后者的电导率差异基本不变，但当考虑到B型和Z型DNA的明确分子动力学以及水 - 抗衡离子环境时，差异就变得不那么明显了。基于原子结构模型，我们认为在施加外部电场时静电能的变化可以诱导构象转换，这可能在新型的高堆积密度DNA基存储设备中得到应用。
