Positive cooperativity of the specific binding between Hg ~(2+) ion and T:T mismatched base pairs in duplex DNA (Conference Paper)

摘要

Metal-mediated base pairs by the interaction between metal ions and artificial bases in oligonucleotides have been developed for their potential applications in nanotechnology. We recently found that a natural T:T mismatched base pair bound with Hg ~(2+) ion to form a novel T-Hg-T base pair. Here, we examined the thermodynamic properties of the binding between Hg ~(2+) and each of the single and double T:T mismatched base pair duplex DNAs by isothermal titration calorimetry. Hg ~(2+) specifically bound with the T:T mismatched base pair at 1:1 molar ratio with 10 ~6 M ~(-1) binding constant, which was significantly larger than those for nonspecific metal ion-DNA interactions. In the Hg ~(2+)-double T:T mismatched base pair interaction, the affinity for the second Hg ~(2+) binding was significantly larger than that for the first Hg ~(2+) binding. The positively cooperative binding may be favorable to align multiple Hg ~(2+) in duplex DNA for the application of the metal-mediated base pairs in nanotechnology.