Collision induced dissociation of deuterium enriched protonated 2′-deoxyguanosine
Department of Chemistry, B6c, University of Liège, 6700 Liège, Belgium
Corresponding author: a email@example.com
Revised: 25 May 2008
Published online: 6 August 2008
Collision induced dissociation in mass spectrometry of protonated nucleosides typically yields as charged fragment the protonated nucleobase augmented by one hydrogen transferred from the 2'-deoxyribose, [ bH2] . The origin of the hydrogen transfer for the protonated 2'-deoxyguanosine has been investigated by collision induced dissociation of deuterium enriched molecules. [ 1'-2H] 2'-deoxyguanosine, [ 2',2''-2H2] 2'-deoxyguanosine, and [ 5',5''-2H2] 2'-deoxyguanosine have been studied and deuterium/hydrogen back exchange has been used following complete or partial exchange of the 2'-deoxyguanosine in solution. Based on the fragmentation of the deuterated molecular ions, the hydrogen transferred from the 2'-deoxyribose to the guanine is found to originate from the O5' atom on the 2'-deoxyribose. A fragmentation mechanism involving a hydrogen shift from the 2' position to the oxygen atom O5' and supported by the kinetic isotope effect on the survival yield curves is proposed. The influence of the 2'-deoxyguanosine conformation on the hydrogen transfer and the fragmentation mechanism is discussed.
PACS: 82.30.Fi – Ion-molecule, ion-ion, and charge-transfer reactions / 82.30.Lp – Decomposition reactions / 82.80.Ms – Mass spectrometry
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008