DNA Damage by X-ray and Low Energy Electron Beam Irradiation

X선과 저에너지 전자선에 의한 DNA 손상

  • 박연수 (충남대학교 물리학과) ;
  • 노형아 (충남대학교 물리학과) ;
  • 조혁 (충남대학교 물리학과) ;
  • ;
  • ;
  • ;
  • Published : 2008.06.30


We observed DNA damages as a function of mean absorbed dose to identify the indirect effect of high-energy radiation such as x-ray. Monolayer films of lyophilized pGEM-3Zf(-) plasmid DNA deposited on tantalum foils were exposed to Al $K{\alpha}$ X-ray (1.5 keV) for 0, 3, 7 and 10 min, respectively, in a condition of ultrahigh vacuum state. We compared DNA damages by X-ray irradiation with those by 3 eV electron irradiation. X-ray photons produced low-energy electrons (mainly below 20 eV) from the tantalum foils and DNA damage was induced chiefly by these electrons. For electron beam irradiation, DNA damage was directly caused by 3 eV electrons. Irradiated DNA was analyzed by agarose gel electrophoresis and quantified by ImagaQuant program. The quantities of remained supercoiled DNA after irradiation were linearly decreased as a function of mean absorbed dose. On the other hand, the yields of nicked circular (single strand break, SSB) and interduplex crosslinked form 1 DNA were linearly increased as a function of mean absorbed dose. From this study, it was confirmed that DNA damage was also induced by low energy electrons ($0{\sim}10\;eV$) even below threshold energies for the ionization of DNA.


  1. Ptasinska S, Sanche L. On the mechanism of anion desorption from DNA induced by low energy electrons. J. Chem. Phys. 2006;125:144713 https://doi.org/10.1063/1.2338320
  2. Barrios R, Skurski P, Simons J. Mechanism for Damage to DNA by low-energy electrons. J. Phys. Chem. B 2002; 106:7991-7994 https://doi.org/10.1021/jp013861i
  3. Boudaiffa B, Cloutier P, Hunting D, Huels MA, Sanche L. Resonant formation of DNA strand breaks by low-energy (3-20 eV) electrons. Science 2000;287:1658-1660 https://doi.org/10.1126/science.287.5458.1658
  4. Ptasinska S, Denifl S, Scheier P, Mark TD. Inelastic electron interaction (attachment/ionization) with deoxyribose. J. Chem. Phys. 2004;120(18):8505-8511 https://doi.org/10.1063/1.1690231
  5. Park YS, Cho H, Parenteau L, Bass AD, Sanche L. Cross sections for electron trapping by DNA and its component subunits1: Condensed tetrahydrofuran deposited on Kr. J. Chem. Phys. 2006;125:074714 https://doi.org/10.1063/1.2229201
  6. Simons J. How do low-energy(0.1-2 eV) electrons cause DNA-strand breaks? Acc. Chem. Res. 2006;39:772-779 https://doi.org/10.1021/ar0680769
  7. Rowntree P, Parenteau L, Sanche L. Electron Stimulated Desorption via dissociative attachment in amorphous H$_2$O. J. Chem. Phys. 1991;94(12):8570-8576 https://doi.org/10.1063/1.460090
  8. Levesque PL, Michaud M, Cho WS, Sanche L. Absolute electronic excitation cross sections for low-energy electron (5-12 eV) scattering from condensed thymine. J. Chem. Phys. 2005;122:224704 https://doi.org/10.1063/1.1925610
  9. Levesque PL, Michaud M, Sanche L. Absolute vibrational and electronic cross sections for low-energy electron(2-12 eV) scattering from condensed pyrimidine. J. Chem. Phys. 2004;122:094701 https://doi.org/10.1063/1.1854121
  10. Lepage M, Letarte S, Michaud M, Motte-Tollet F, Hubin- Franskin MJ, Roy D, Sanche L. Electron spectroscopy of resonance-enhanced vibrational excitations of gaseous and solid tetrahydrofuran. J. Chem. Phys. 1998;109:5980-5986 https://doi.org/10.1063/1.477223
  11. Bass AD, Sanche L. Dissociative electron attachment and charge transfer in condensed matter. Rad. Phys. Chem. 2003;68:3-13 https://doi.org/10.1016/S0969-806X(03)00244-5
  12. Pan X, Cloutier P, Hunting D, Sanche L. Dissociative electron attachment to DNA. Phys. Rev. Lett. 2003;90(20):208102 https://doi.org/10.1103/PhysRevLett.90.208102
  13. Martin F, Burrow PD, Cai Z, Cloutier P, Hunting D, Sanche L. DNA strand breaks induced by 0-4 eV electrons: The role of shape resonances. Phys. Rev. Lett. 2004;93(6):068101 https://doi.org/10.1103/PhysRevLett.93.068101
  14. Cai Z, Cloutier P, Hunting D, Sanche L. Enhanced DNA damage induced by secondary electron emission from a tantalum surface exposed to soft X-rays. Rad. Res. 2006; 165:365-371 https://doi.org/10.1667/RR3509.1
  15. Denifl S, Ptasinska S, Hanel G, Gstir B, Probst M, Scheier P, Mark TD. Electron attachment to gas-phase uracil. J. Chem. Phys. 2004;120(14):6557-6565 https://doi.org/10.1063/1.1649724
  16. Denifl S, Ptasinska S, Probst M, Hrusak J, Scheier P, Mark TD. Electron attachment to the gas-phase DNA bases Cytosine and Thymine. J. Phys. Chem. A 2004;108:6562-6569 https://doi.org/10.1021/jp049394x
  17. Cai Z, Cloutier P, Hunting D, Sanche L. Comparison between X-ray photon and secondary electron damage to DNA in vacuum. J. Phys. Chem. B 2005 ;109:4796-4800 https://doi.org/10.1021/jp0459458
  18. Panajotovic R, Martin F, Cloutier P, Hunting D, Sanche L. Effective cross sections for production of single-strand breaks in plasmid DNA by 0.1 to 4.7 eV electrons. Rad. Res. 2006; 165:452-459 https://doi.org/10.1667/RR3521.1
  19. Huels MA, Boudaiffa B, Cloutier P, Hunting D, Sanche L. Single, Double, and Multiple Double Strand Breaks Induced in DNA by 3-100 eV Electrons. J. Am. Chem. Soc. 2003; 125:4467-4477 https://doi.org/10.1021/ja029527x
  20. Boudaiffa B, Cloutier P, Hunting D, Huels MA, Sanche L. Cross sections for Low-Energy (10-50 eV) Electron Damage to DNA. Rad. Res. 2002;157:227-234 https://doi.org/10.1667/0033-7587(2002)157[0227:CSFLEE]2.0.CO;2