Absolute cross section for loss of supercoiled topology induced by 10 eV electrons in highly uniform ∕DNA∕1,3-diaminopropane films deposited on highly ordered pyrolitic graphite.

Omar Boulanouar (1) , Michel Fromm (1) , Andrew D Bass (2) , Pierre Cloutier (2) , Léon Sanche (2)

1 LCE - Laboratoire Chrono-environnement (UMR 6249)
2 Centre for Research in Radiooncology

: It was recently shown that the affinity of doubly charged, 1-3 diaminopropane (Dap(2+)) for DNA permits the growth on highly ordered pyrolitic graphite (HOPG) substrates, of plasmid DNA films, of known uniform thickness [O. Boulanouar, A. Khatyr, G. Herlem, F. Palmino, L. Sanche, and M. Fromm, J. Phys. Chem. C 115, 21291-21298 (2011)]. Post-irradiation analysis by electrophoresis of such targets confirms that electron impact at 10 eV produces a maximum in the yield of single strand breaks that can be associated with the formation of a DNA(-) transient anion. Using a well-adapted deterministic survival model for the variation of electron damage with fluence and film thickness, we have determined an absolute cross section for strand-break damage by 10 eV electrons and inelastic scattering attenuation length in DNA-Dap complex films.

Domaines: Chimie théorique et/ou physique

Omar Boulanouar, Michel Fromm, Andrew D Bass, Pierre Cloutier, Léon Sanche. Absolute cross section for loss of supercoiled topology induced by 10 eV electrons in highly uniform ∕DNA∕1,3-diaminopropane films deposited on highly ordered pyrolitic graphite.. Journal of Chemical Physics, 2013, 139 (5), pp.055104. ⟨10.1063/1.4817323⟩. ⟨hal-00858430⟩