Multiple valence electron detachment following Auger decay of inner-shell vacancies in gas-phase DNA.

Autor:	Li W; University of Groningen, Zernike Institute for Advanced Materials Nijenborgh 4 9747AG Groningen Netherlands t.a.schlatholter@rug.nl., Kavatsyuk O; University College Groningen Hoendiep 23/24 9718BG Groningen Netherlands., Douma W; University of Groningen, Zernike Institute for Advanced Materials Nijenborgh 4 9747AG Groningen Netherlands t.a.schlatholter@rug.nl., Wang X; University of Groningen, Zernike Institute for Advanced Materials Nijenborgh 4 9747AG Groningen Netherlands t.a.schlatholter@rug.nl., Hoekstra R; University of Groningen, Zernike Institute for Advanced Materials Nijenborgh 4 9747AG Groningen Netherlands t.a.schlatholter@rug.nl., Mayer D; Universität Potsdam, Institut für Physik und Astronomie 14476 Potsdam Germany., Robinson MS; Universität Potsdam, Institut für Physik und Astronomie 14476 Potsdam Germany.; Centre for Free Electron Lasers (CFEL), DESY Notkestraße 85 22607 Hamburg Germany., Gühr M; Universität Potsdam, Institut für Physik und Astronomie 14476 Potsdam Germany., Lalande M; CIMAP UMR 6252 (CEA/CNRS/ENSICAEN/Université de Caen Normandie) Boulevard Becquerel 14070 Caen Cedex 5 France., Abdelmouleh M; CIMAP UMR 6252 (CEA/CNRS/ENSICAEN/Université de Caen Normandie) Boulevard Becquerel 14070 Caen Cedex 5 France., Ryszka M; CIMAP UMR 6252 (CEA/CNRS/ENSICAEN/Université de Caen Normandie) Boulevard Becquerel 14070 Caen Cedex 5 France., Poully JC; CIMAP UMR 6252 (CEA/CNRS/ENSICAEN/Université de Caen Normandie) Boulevard Becquerel 14070 Caen Cedex 5 France., Schlathölter T; University of Groningen, Zernike Institute for Advanced Materials Nijenborgh 4 9747AG Groningen Netherlands t.a.schlatholter@rug.nl.
Jazyk:	angličtina
Zdroj:	Chemical science [Chem Sci] 2021 Sep 10; Vol. 12 (39), pp. 13177-13186. Date of Electronic Publication: 2021 Sep 10 (Print Publication: 2021).
DOI:	10.1039/d1sc02885e
Abstrakt:	We have studied soft X-ray photoabsorption in the doubly deprotonated gas-phase oligonucleotide [dTGGGGT-2H] 2- . The dominating decay mechanism of the X-ray induced inner shell vacancy was found to be Auger decay with detachment of at least three electrons, leading to charge reversal of the anionic precursor and the formation of positively charged photofragment ions. The same process is observed in heavy ion (12 MeV C 4+ ) collisions with [dTGGGGT-2H] 2- where inner shell vacancies are generated as well, but with smaller probability. Auger decay of a single K-vacancy in DNA, followed by detachment of three or more low energy electrons instead of a single high energy electron has profound implications for DNA damage and damage modelling. The production of three low kinetic energy electrons with short mean free path instead of one high kinetic energy electron with long mean free path implies that electron-induced DNA damage will be much more localized around the initial K-shell vacancy. The fragmentation channels, triggered by triple electron detachment Auger decay are predominantly related to protonated guanine base loss and even loss of protonated guanine dimers is tentatively observed. The fragmentation is not a consequence of the initial K-shell vacancy but purely due to multiple detachment of valence electrons, as a very similar positive ion fragmentation pattern is observed in femtosecond laser-induced dissociation experiments. Competing Interests: There are no conflicts to declare. (This journal is © The Royal Society of Chemistry.)
Databáze:	MEDLINE
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