On the Role of Electrostatic Interactions in Stabilization of Oxidized Nucleic Acid Base Complexes

摘要

n this study we analyze, using ab initio methods, the nature of intermolecular interactions in adenine-cytosine complexes in conformations that mimick those appearing in B-DNA. In particular, we focus on the changes of the electrostatic component upon modification of the adenine by the hydroxyl radical. We have found significant variations of first-order electrostatic interactions, ranging from -6 kcal/mol to +2 kcal/mol, for various structures of oxidized complexes. None the less, the dispersion energy is the largest in magnitude as far as the stabilization contributions are concerned.