Influence of base stacking on excited-state behavior of polyadenine in water, based on time-dependent density functional calculations.

ABSTRACT: A thorough study of the excited-state properties of the stacked dimers and trimers of 9-methyladenine in B-DNA conformation has been performed in aqueous solution by using time-dependent density functional calculations and the solvent polarizable continuum model, and results were compared with experimental results on polyadenine oligomers. The effect of base stacking on the absorption and emission spectra is fully reproduced by our calculations. Although light absorption leads to a state (S(B)) delocalized over several nucleobases, excited-state geometry optimization indicates that S(B) subsequently evolves into a state in which the excitation is localized on a single base. Analysis of the excited-state potential energy surfaces shows that S(B) can easily decay into the lowest energy excit

SUBMITTER: Santoro F 

PROVIDER: S-EPMC1891264 | biostudies-literature | 2007 Jun

REPOSITORIES: biostudies-literature