Roles of Hydration for Inducing Decomposition of 2-Deoxy-d-ribose by Ionization of Oxygen K-Shell Electrons

• DOI: 10.1667/rr14225.1
• Publication Date: 2018-01-08T16:39:52Z
• Authors: Kentaro Fujii; Yudai Izumi; Ayumi Narita; Krishna Kamol Ghose; Pablo López-Tarifa; Alain Touati; Riccardo Spezia; Rodolphe Vuilleumier; Marie-Pierre Gaigeot; Marie-Françoise P...; Marie-Anne Hervé ...; Akinari Yokoya
• Keywords: Quadrupole mass analyzer; Solvation shell

To experimentally investigate the role of hydration in initial process decomposition 2-deoxy-d-ribose (dR), which is a major component DNA backbone, we used mass spectrometry to monitor ions desorbing from hydrated dR films exposed monochromatic soft X rays (560 eV). The X-ray photons preferentially ionize K-shell electrons oxygen atoms DNA. Hydrated samples were prepared under vacuum by exposing cooled (∼150 K) film deposited on Si substrate water vapor. Using quadrupole spectrometer, observed desorption such as H , CHx C2Hx CHxO C3Hx and C2HxO (x = 1, 2, 3 4). In addition, H2O or H3O was spectra films. Except for yields these decreased when one layer molecules onto film. These are produced C–C C–O bond scission. This result suggests that act quencher, suppressing Coulomb repulsion thus extensive molecular dR. Ab initio dynamics simulations performed rationalize fragments experiments. results dynamical molecule after K-ionization revealed elongation O–H bonds both prior Auger process, resulting ejection ions. strongly suggest very early contributes reducing fragmentation, producing detected desorbed may be involved induction other types damage, oxidatively generated base lesions, concomitantly with strand break