Aqueous Solution Effects on the Proton-Transfer Processes of GC and AT Base Pairs

作者：Wu Ying Xi; Wang Hong Yan^*; Lin Yue Xia

来源：Acta Physico - Chimica Sinica, 2014, 30(2): 257-264.

DOI：10.3866/PKU.WHXB201312031

• Density functional theory
• Base pair
• Proton-transfer
• First hydration shell
• Bulk solvation effect

The effects of the first hydration shell and the bulk solvation effects on the proton-transfer processes of guanine-cytosine (GC) and adenine-thymine (AT) base pairs are studied based on density functional theory, using the B3LYP method and DZP++ basis set. The proton-transfer mechanisms of the GC and AT base pairs in bulk solvation are first single-proton transfer (SPT1) and stepwise double-proton transfer (DPT). When only the first hydration shell surrounded by five water molecules (GC center dot 5H2O, AT center dot 5H(2)O), or both the first hydration shell and bulk solvation effects through polarizable continuum model (PCM) (GC center dot 5H(2)O+PCM, AT center dot 5H(2)O+PCM) are considered, only the first single-proton-transfer mechanism (SPT1) is found. The proton-transfer activation energies of the GC and the AT base pairs show that the majority of the hydration effects come from the first hydration shell through hydrogen-bond interactions, therefore the first hydration shell greatly influences the base pair structures and proton-transfer mechanism.

• 出版日期2014-2
• 单位西南交通大学