Computational evaluation of the specific interaction between cation and mismatch base pair

Ab initio calculations were carried out to characterize the structure and energetic of silver cation (Ag (I)) complex with cytosine (C:Ag:C) and mercury cation (Hg (II)) complex with thymine (T:Hg:T) systems. These metal-modified mismatch base pairs have been optimized using Hatree-Fock method without any symmetry constrains. Using above methods, the models of Ag (I) in a crosslink between O2 carbonyl oxygen of cytosine, O2(C):Ag:O2(C), and Hg (II) in a crosslink between N3 nitrogen atom of thymine, N3(T):Hg:N3(T) were obtained. Furthermore, the interaction energies of C:Ag:C and T:Hg:T models were estimated. The result showed that the coordination silver (I) cation with cytosine is more stable than hydrate state.