Modeling DNA excitons
We have modeled the Franck-Condon excited states of DNA duplexes and G-quadruplexes. Our calculations were performed in the frame of the exciton theory combining molecular dynamics simulations (collaboration with Richard Lavery and Krystyna Zakrzewska) and data from quantum chemistry (atomic transition charges for the calculation of dipolar coupling). The most important outcome is that, despite conformational disorder, the dipolar coupling alone induces delocalization of the excitation energy over several bases. The extent of delocalization depends on the base sequence; it increases when going from AT duplexes to GC duplexes and is relatively higher in G-quadruplexes.