Ag^+与Hg^(2+)对G-四链体DNA结构的破坏及其对构筑DNA逻辑门的应用(英文)

Disruption of G-Quadruplex DNA by Ag^+ and Hg^(2+) and Its Application to DNA Logic Gate

本工作利用圆二色光谱研究了Ag+与Hg2+对4种代表性G-四链体DNA结构的破坏作用。结果表明Ag+可能通过与碱基G螯合从而破坏G-四链体结构;Hg2+能通过形成T-Hg2+-T碱基对,及其他方式破坏G-四链体结构。含巯基(-SH)的半胱氨酸与Ag+与Hg2+可以发生较强的配位作用,从而使被Ag+与Hg2+破坏后的G-四链体DNA结构得以回复。基于此,一个新颖的Ag+/Hg2+-半胱氨酸-DNA逻辑门得以构筑。

The G-quadruplex-disrupting abilities of Ag＋ and Hg2＋ ions were investigated by utilizing the metal ions-mediated circular dichroism （CD） spectrum changes of four representative G-quadruplexes. The resuhs show that Ag＋ ion can disrupt G-quadruplexes by chelating to G bases and thus can be used as a general G- quadruplex-disrupting agent. The results also suggest that Hg2＋ ion may disrupt G-quadruplexes by formation of T-Hg〉-T base pairs as well as other species. The G-quadruplexes disrupted by Ag＋ and Hg2＋ can be recovered by cysteine （Cys）, a thiol-containing amino acid, due to the tight binding interactions between Cys and the metal ions. Thus, the system by using Ag＋ （or Hg2＋） and Cys as two inputs and CD signal as output can behave as a DNA IMPLICATION logic gate.