[Quantum-chemical study of the relative stability of nucleic acid bases protonation stability]

The influence of protonation on the relative stability of matched and mismatched nucleic base pairs was considered. Protonation of a base has a significant effect on the bond energy and, in some cases, on the geometry of pairs. It was shown that protonation of guanine, adenine and uracil lead to an increased relative stability of matched pairs and, consequently, to decreased probability of mutations. Protonation of cytosine reduced the difference in energy formation of GC and AC complexes.