On the importance of electrostatics in stabilization of stacked guanine-adenine complexes appearing in B-DNA crystals

In this paper, the importance of the first-order electrostatic energy in stabilization of stacked guanine-adenine complexes is discussed for conformations of the complexes appearing in B-DNA crystals. The interaction energy components were calculated at the SCF level of theory using variational-perturbational scheme and compared with the total MP2 intermolecular interaction energy. It is demonstrated that electrostatic energy plays an important role in the stabilization of analyzed structures. Moreover, the results of calculations show that the electrostatic component is much more dependent on the conformations of guanine-adenine complexes than the total MP2 interaction energy. (C) 2008 Elsevier B.V. All rights reserved.