title: Effect of low-energy electron irradiation on DNA damage by Fe3+ ion.
abstract: We investigated the combined effects of low-energy electron irradiation and Fe(3+) ion on DNA damage. We used lyophilized pBR322 plasmid DNA films with various concentrations (0 ~ 7 mM) of Fe(3+) ions and irradiation with monochromatic, low-energy 3 or 5 eV electrons for these studies. DNA-Fe(3+) films were recovered and analyzed by agarose gel electrophoresis to identify and compare the effects of Fe(3+) ions and/or low-energy electrons alone or in combination on DNA damage. In nonirradiated DNA-Fe(3+) films, there was little DNA damage observed (less than 10% of the total DNA loaded on the gel appeared damaged) for Fe(3+) ion up to 7 mM concentration. In irradiated DNA films without Fe(3+) ions, there was also very little DNA damage observed (less than 3% of the total DNA loaded on the gel appeared damaged). However, when DNA-Fe(3+) films, were irradiated with low-energy electrons, DNA damage was significantly increased compared to the sum of the damage caused both by either Fe(3+) ion or low-energy electrons irradiation alone. We proposed that both DEA and/or electron transfer processes might play a role in the enhanced DNA damage when DNA-Fe(3+) films were irradiated by low-energy electrons.
authors.affiliation: Department of Physics, Chungnam National University, Daejeon, South Korea.
authors.forename: Yeunsoo
authors.initials: Y
authors.lastname: Park
authors.forename: Hyung Ah
authors.initials: HA
authors.lastname: Noh
authors.forename: Hyuck
authors.initials: H
authors.lastname: Cho
mesh_terms: D004249:DNA Damage; D004278:DNA, Superhelical / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D004583:Electrons / Q000009:adverse effects*; D004586:Electrophoresis; D005612:Freeze Drying; D007501:Iron / Q000009:adverse effects* / Q000378:metabolism
chemical_list: D004278:DNA, Superhelical; D007501:Iron