Vacuum-UV and Low-Energy Electron-Induced DNA Strand Breaks
- DNA is effectively damaged by radiation, which can on the one hand lead to cancer and is on the other hand directly exploited in the treatment of tumor tissue. DNA strand breaks are already induced by photons having an energy below the ionization energy of DNA. At high photon energies, most of the DNA strand breaks are induced by low-energy secondary electrons. In the present study we quantified photon and electron induced DNA strand breaks in four different 12mer oligonucleotides. They are irradiated directly with 8.44 eV vacuum ultraviolet (VUV) photons and 8.8 eV low energy electrons (LEE). By using Si instead of VUV transparent CaF2 as a substrate the VUV exposure leads to an additional release of LEEs, which have a maximum energy of 3.6 eV and can significantly enhance strand break cross sections. Atomic force microscopy is used to visualize strand breaks on DNA origami platforms and to determine absolute values for the strand break cross sections. Upon irradiation with 8.44 eV photons all the investigated sequences show veryDNA is effectively damaged by radiation, which can on the one hand lead to cancer and is on the other hand directly exploited in the treatment of tumor tissue. DNA strand breaks are already induced by photons having an energy below the ionization energy of DNA. At high photon energies, most of the DNA strand breaks are induced by low-energy secondary electrons. In the present study we quantified photon and electron induced DNA strand breaks in four different 12mer oligonucleotides. They are irradiated directly with 8.44 eV vacuum ultraviolet (VUV) photons and 8.8 eV low energy electrons (LEE). By using Si instead of VUV transparent CaF2 as a substrate the VUV exposure leads to an additional release of LEEs, which have a maximum energy of 3.6 eV and can significantly enhance strand break cross sections. Atomic force microscopy is used to visualize strand breaks on DNA origami platforms and to determine absolute values for the strand break cross sections. Upon irradiation with 8.44 eV photons all the investigated sequences show very similar strand break cross sections in the range of 1.7-2.3x10(-16) cm(2). The strand break cross sections for LEE irradiation at 8.8 eV are one to two orders of magnitude larger than the ones for VUV photons, and a slight sequence dependence is observed. The sequence dependence is even more pronounced for LEEs with energies <3.6 eV. The present results help to assess DNA damage by photons and electrons close to the ionization threshold.…
Author details: | Stefanie VogelORCiDGND, Kenny EbelORCiD, Robin Mathis SchürmannORCiDGND, Christian HeckORCiDGND, Till MeilingORCiDGND, Aleksandar R. Milosavljevic, Alexandre Giuliani, Ilko BaldORCiDGND |
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DOI: | https://doi.org/10.1002/cphc.201801152 |
ISSN: | 1439-4235 |
ISSN: | 1439-7641 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/30719805 |
Title of parent work (English): | ChemPhysChem : a European journal of chemical physics and physical chemistry |
Subtitle (English): | Influence of the DNA Sequence and Substrate |
Publisher: | Wiley-VCH |
Place of publishing: | Weinheim |
Publication type: | Article |
Language: | English |
Year of first publication: | 2019 |
Publication year: | 2019 |
Release date: | 2021/03/16 |
Tag: | DNA origami; DNA radiation damage; DNA strand breaks; low-energy electrons; vacuum-UV radiation |
Volume: | 20 |
Issue: | 6 |
Number of pages: | 8 |
First page: | 823 |
Last Page: | 830 |
Funding institution: | German Research Foundation (DFG)German Research Foundation (DFG) [281049597]; Federal Institute for Materials Research and Testing (BAM); DFGGerman Research Foundation (DFG) [GSC 1013]; [20141108] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Peer review: | Referiert |