title: Experimental and theoretical study of the metastable decay of negatively charged nucleosides in the gas phase.
abstract: Fragmentation of metastable anions of all deoxynucleosides and nucleosides constituting DNA and RNA has been studied experimentally and by computer simulations. The ions were formed through deprotonation in matrix assisted laser desorption/ionisation (MALDI). Clear difference in fragmentation patterns was obtained for nucleosides containing purine vs. pyrimidine bases. To elucidate the role of various potential deprotonation sites, systematic blocking by chemical modification was performed and this gave unambiguous correlation between deprotonation sites and fragments observed. Classical dynamics simulations of the fragmentation process, using density functional theory to describe the electronic degrees of freedom, were performed for the various deprotonation sites. These were found to reproduce the observed fragmentation patterns remarkably well.
authors.affiliation: Science Institute and University of Iceland, Department of Chemistry, Dunhagi 3, 107 Reykjavík, Iceland.
authors.forename: Helga Dögg
authors.initials: HD
authors.lastname: Flosadóttir
authors.forename: Hannes
authors.initials: H
authors.lastname: Jónsson
authors.forename: Snorri Th
authors.initials: ST
authors.lastname: Sigurdsson
authors.forename: Oddur
authors.initials: O
authors.lastname: Ingólfsson
mesh_terms: D004247:DNA / Q000737:chemistry / Q000378:metabolism; D005740:Gases / Q000737:chemistry* / Q000378:metabolism; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D009705:Nucleosides / Q000737:chemistry* / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D005740:Gases; D009705:Nucleosides; D012313:RNA; D004247:DNA