Interdisciplinary Nanoscience Center (iNANO), Centre for DNA Nanotechnology (CDNA), Aarhus University, Denmark.
Small. 2011 Apr 4;7(7):939-49. doi: 10.1002/smll.201002033. Epub 2011 Mar 11.
Methylation of DNA nucleobases is an important control mechanism in biology applied, for example, in the regulation of gene expression. The effect of methylation on the intermolecular interactions between guanine molecules is studied through an interplay between scanning tunneling microscopy (STM) and density functional theory with empirical dispersion correction (DFT-D). The present STM and DFT-D results show that methylation of guanine can have subtle effects on the hydrogen-bond strength with a strong dependence on the position of methylation. It is demonstrated that the methylation of DNA nucleobases is a precise means to tune intermolecular interactions and consequently enables very specific recognition of DNA methylation by enzymes. This scheme is used to generate four different types of artificial 2D nanostructures from methylated guanine. For instance, a 2D guanine windmill motif that is stabilized by cooperative hydrogen bonding is revealed. It forms by self-assembly on a graphite surface under ambient conditions at the liquid-solid interface when the hydrogen-bonding donor at the N1 site of guanine is blocked by a methyl group.
DNA 碱基的甲基化是生物学中一种重要的调控机制，例如在基因表达调控中。通过扫描隧道显微镜（STM）和经验色散校正的密度泛函理论（DFT-D）的相互作用，研究了甲基化对鸟嘌呤分子间相互作用的影响。目前的 STM 和 DFT-D 结果表明，鸟嘌呤的甲基化可以对氢键强度产生微妙的影响，并且强烈依赖于甲基化的位置。研究表明，DNA 碱基的甲基化是调节分子间相互作用的精确手段，从而能够使酶对 DNA 甲基化进行非常特异性的识别。该方案用于从甲基化鸟嘌呤生成四种不同类型的人工 2D 纳米结构。例如，揭示了一种由协同氢键稳定的 2D 鸟嘌呤风车基序。当鸟嘌呤 N1 位的氢键供体被甲基基团阻断时，它在环境条件下在固-液界面的石墨表面上通过自组装形成。
