Tautomeric equilibrium, stability, and hydrogen bonding in 2 '-deoxyguanosine monophosphate complexed with Mg2+

Časopis: JOURNAL OF PHYSICAL CHEMISTRY B 112, 150-157
Autoři: Kosenkov, D., Gorb, L., Shishkin, OV., Sponer, J., Leszczynski, J.
Rok: 2008

Abstrakt

The tautomeric equilibrium and hydrogen bonding in nucleotide 2'-deoxyguanosine monophosphate that interacts with hydrated Mg2+ cation (4H(2)O center dot Mg[dGMP]) were studied at the MP2/cc-pVDZ//B3LYP/cc-pVDZ and B3LYP/aug-cc-pVTZ//B3LYP/cc-pVDZ levels of theory. The Mg2+ ion forms two inner-shell contacts with the nucleotide, similar to small phosphorylated molecules under physiological conditions. The presence of the phosphate group and the hydrated magnesium cation leads to a change in guanine tautomeric equilibrium of 4H(2)O center dot Mg[dGMP] in comparison to free guanine. The influence of the phosphate group and the magnesium cation on tautomeric equilibrium is larger in the anti conformation where the P=O ->Mg and Mg