Regulative effect of water molecules on the switches of guanine-cytosine (GC) Watson-Crick pair

To regulate the switch effect induced by NH- anion substitution at the H8 site of the guanine-cytosine (GC) watson-crick pair and investigate the actual state in the solution, 1-9 water molecules attached G(NH)-C derivatives are probed in the present paper. Results show that the switch effect, i.e., deformation effect of hydrogen bonding between G(NH)- and C pair reduces step-wise as the number of discrete water molecules around the NH- group increases. Thus one can control the switch action of G(NH)-C by regulating the number of water molecules around the NH- group.