Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, Tampa, Florida, 33620, United States.
Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai, 200438, P. R. China.
Chem Asian J. 2020 Apr 1;15(7):1030-1034. doi: 10.1002/asia.202000016. Epub 2020 Mar 6.
A reverse-binding-selectivity between monovalent and divalent cations was observed for two different self-assembly G -hexadecamer and G -octamer systems. The dissociation constant between G -quadruplex and monomer was calculated via VT- H NMR experiments. Quantitative energy profiles revealed entropy as the key factor for the weaker binding toward Ba compared with K in the G -octamer system despite stronger ion-dipole interactions. This study is the first direct comparison of the G -quartet binding affinity between mono and divalent cations and will benefit future applications of G-quadruplex-related research. Further competition experiments between the G -octamer and 18-crown-6 with K demonstrated the potential of this G system as a new potassium receptor.
在两个不同的自组装 G-十六聚体和 G-八聚体系统中观察到单价和二价阳离子之间的反向结合选择性。通过 VT-H NMR 实验计算了 G-四链体与单体之间的离解常数。定量能量曲线揭示了在 G-八聚体系统中，尽管离子偶极相互作用更强，但熵是 Ba 与 K 相比结合较弱的关键因素。这项研究是单和二价阳离子与 G-四联体结合亲和力的首次直接比较，将有益于未来 G-四联体相关研究的应用。进一步用 K 进行的 G-八聚体和 18-冠-6 之间的竞争实验表明，该 G 体系作为新型钾受体具有潜力。
