碱基的氢键网络及其互变异构体识别研究

Tautomerism of nucleobases is partially responsible for spontaneous mutation in DNA and RNA. To investigate the mechanism of the spontaneous mutation, it is of great importance to identify the structure of the tautomers and the hydrogen bonding (H-bonding) network and to elucidate the influence of surrounding environments. Recent advances in noncontact atomic force microscopy (NC-AFM) provide a direct method to visualize the chemical structure and intermolecular H-bonds in real space. More detailed structural information at the atomic scale could be acquired. In this project, we will investigate the structures of the nucleobase H-bonding networks and the configurations of the involved tautomers supported on metal surfaces under the influence of metal ions using NC-AFM and elucidate the effect of the interactions between nucleobases and substrate/cation on the tautomeric equilibrium and the corresponding H-bonding networks. These findings may help to elucidate the nucleobase-cation interaction and possible pathways of proton transfer involved in the H-bonding network formation.

碱基的氢互变异构是DNA和RNA自发突变的来源之一。不同环境下可能的互变异构结构和氢键网络的研究对于自发突变的机制研究极为重要。近年来,非接触原子力显微技术(noncontact atomic force microscopy, NC-AFM)飞速发展，已实现了有机分子的化学骨架结构成像和分子间氢键的实空间成像，可以为碱基互变异构体的研究提供更详细而准确的结构信息。本项目拟利用NC-AFM研究金属离子影响下金属单晶表面上沉积的碱基氢键组装结构和其可能的互变异构体构型，进而考察氢键、分子与金属离子以及衬底之间的相互作用等因素对互变异构平衡以及氢键组装的影响。这方面的研究将有助于金属离子-碱基作用以及质子传输机理的研究。