Ab initio calculations of absorption, circular dichroism and electron transfer in DNA derivatives

by Dr Daniele Varsano (Natl. Center S3 INFM-CNR Universita' di Modena e Reggio Emilia)

Monday 14 Sept 2009, 15:00 → 16:00 Europe/Rome

Aula Corbino (Dipartimento di Fisica - Ed. E.Fermi)

Optical absorption and circular dichroism are amongst the most powerful tools for the experimental investigation of biomolecules. The recent theoretical developments of TDDFT enable also to compute (and predcit) such spectra. This progress is relevant for getting insight into structural determination (e.g. protonation states of the biocromophores), as well as for the investigation of electron transfer and UV damage. I will show and discuss results on natural DNA and xDNA base pair stacks, showing how a combination of optical and electronic studies reveals the fingerprints of enhanced stacking interactions in viable DNA derivatives. A recent implementation of a gauge-invariant formalism by real-time real-space TDDFT for computation of circular dichroism will be illustrated, and used to reveal fingerprint of bonfing motifd in DNA duplexes of Adenine and Thymine.