Department of Physics, Nanchang University, Nanchang 330031, China.
Langmuir. 2021 Mar 30;37(12):3761-3765. doi: 10.1021/acs.langmuir.1c00296. Epub 2021 Mar 16.
A series of nucleobases guanine (G) and cytosine (C) pairing configurations have been fabricated on highly oriented pyrolytic graphite (HOPG) surface by controlling the molar ratio of G and C in water solution. Watson-Crick (WC) base pairing governs the association of C and G nucleobases when the molar ratio of C/G is adjusted to 1:1. Nucleobase-rich is preferentially hydrogen-bonded to the sites exposed around WC motifs with the adjustment of the C/G molar ratio. At a higher C/G molar ratio imbalance, the pairing configurations depend on the combination of interspace and sites of hydrogen binding between G and C bases. The systematic analysis of the high-resolution STM images and DFT calculations reveal that hydrogen bonding plays a dominant role in the formation of these pairing configurations and that the competition between the priority and diversity of hydrogen-bonded configurations bonding between G and C is the key for the pairing structural polymorphism.
通过控制水溶液中 G 和 C 的摩尔比，在高取向热解石墨 (HOPG) 表面上制造了一系列碱基对鸟嘌呤 (G) 和胞嘧啶 (C) 的配对构型。当 C/G 的摩尔比调整为 1:1 时，沃森-克里克 (WC) 碱基对控制着 C 和 G 碱基的缔合。当 C/G 摩尔比失衡时，碱基丰富度优先与 WC 基序周围暴露的位点通过氢键结合。在更高的 C/G 摩尔比失衡下，配对构型取决于 G 和 C 碱基之间的间隔和氢键结合位点的组合。高分辨率 STM 图像和 DFT 计算的系统分析表明，氢键在这些配对构型的形成中起着主导作用，并且 G 和 C 之间氢键结合构型的优先级和多样性之间的竞争是配对结构多态性的关键。
