Radiation Damage to DNA: The Indirect Effect of Low Energy Electrons.

ABSTRACT: We report the effect of DNA hydration level on damage yields induced by soft X-rays and photo-emitted low energy electrons (LEEs) in thin films of plasmid DNA irradiated in N₂ at atmospheric pressure under different humidity levels. Contrary to a dilute solution of DNA, the number of H₂O molecules per nucleotide (Γ) in these films can be varied from Γ=2.5 to ~33, where Γ≤20 corresponds to layers of hydration and Γ=33 to an additional bulk-like water layer. Our results indicate that DNA damage induced by LEEs does not increase significantly until the second hydration shell is formed. However, this damage increases dramatically as DNA coverage approaches bulk-like hydration conditions. A number of phenomena are invoked to account for these behaviors including: dissociat

SUBMITTER: Alizadeh E 

PROVIDER: S-EPMC4071054 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature