title: Electron-attachment-induced DNA damage: instantaneous strand breaks.
abstract: Low energy electron-attachment-induced damage in DNA, where dissociation channels may involve multiple bonds including complex bond rearrangements and significant nuclear motions, is analyzed here. Quantum mechanics/molecular mechanics (QM/MM) calculations reveal how rearrangements of electron density after vertical electron attachment modulate the position and dynamics of the atomic nuclei in DNA. The nuclear motions involve the elongation of the P-O (P-O(3') and P-O(5')) and C-C (C(3')-C(4') and C(4')-C(5')) bonds for which the acquired kinetic energy becomes high enough so that the neighboring C(3')-O(3') or C(5')-O(5') phosphodiester bond may break almost immediately. Such dynamic behavior should happen on a very short time scale, within 15-30 fs, which is of the same order of magnitude as the time scale predicted for the excess electron to localize around the nucleobases. This result indicates that the C-O phosphodiester bonds can break before electron transfer from the backbone to the base.
authors.affiliation: General Chemistry-Algemene Chemie, Vrije Universiteit Brussel, Brussels, Belgium. ecauet@ulb.ac.be
authors.forename: Emilie
authors.initials: E
authors.lastname: Cauët
authors.forename: Stuart
authors.initials: S
authors.lastname: Bogatko
authors.forename: Jacques
authors.initials: J
authors.lastname: Liévin
authors.forename: Frank
authors.initials: F
authors.lastname: De Proft
authors.forename: Paul
authors.initials: P
authors.lastname: Geerlings
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004249:DNA Damage; D004583:Electrons; D008958:Models, Molecular; D011789:Quantum Theory
chemical_list: D004247:DNA