Assessing Roles of Cations in G-Quadruplex-Based Nanowires by NMR

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• 作者：Marko Trajkovski ; Janez Plavec
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：November 8, 2012
• 年：2012
• 卷：116
• 期：44
• 页码：23821-23825
• 全文大小：258K
• 年卷期：v.116,no.44(November 8, 2012)
• ISSN：1932-7455

文摘

G-quadruplexes are uncanonical DNA structures exhibiting promising characteristics for designing DNA-based nanomaterial and nanodevices. The present NMR study addresses the role of cations, the requiring factor for G-quadruplex formation, in long G-quadruplexes. We investigated d(TG₈T)₄ and its interactions with ¹⁵NH₄⁺ ions, which provided insights into cation localization within a model of G-quadruplex-based nanowire exhibiting eight stacked G-quartets. All interquartet cavities along the central channel were completely occupied by cations. Determined cation exchange rates demonstrated that ¹⁵NH₄⁺ ions move faster from the binding site between two G-quartets, both composed of all guanine residues in an anti-glycosidic conformation with respect to the binding site between all-syn/all-anti G-quartets. These results not only extend previous findings from calculated models of long G-quadruplexes and experimental studies on shorter G-quadruplexes but also establish correlation of kinetics of cation movement with the mode of G-quartet stacking, a potentially valuable relation for understanding G-quadruplex-type specific electronic properties.