title: Chemical stability and reactivity of deprotonated oligonucleotides (DNA) in the gas phase: protonation and solvation with hydrogen bromide.
abstract: Selected deprotonated oligodeoxynucleotides generated by electrospray ionization were exposed to a variety of neutral molecules in the gas phase at room temperature in flowing helium gas at 0.35 Torr. Single-stranded [AGTCTG-nH]n- and single- and double-stranded [GCATGC-nH]n- anions were found to be remarkably unreactive with strong oxidants (O3, O2, N2O) and potential intercalators (benzene, pyridine, toluene, and quinoxaline). Hydration also was observed to be inefficient. However, [AGTCTG-nH]n- anions with n=2, 3, 4, and 5 were seen to be sequentially protonated and/or hydrobrominated with HBr (but not damaged) and displayed an interesting "end effect" against protonation. Measurements are provided for the rate coefficients of reaction and the efficiencies of protonation. These experimental results point toward the exciting prospect of measuring the intrinsic chemistry of other bare DNA-like anions, including double-stranded oligonucleotide anions in the gas phase at room temperature.
authors.affiliation: Department of Chemistry, Centre for Research in Mass Spectrometry, York University, Toronto, Ontario, Canada.
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Feil
authors.forename: Greg K
authors.initials: GK
authors.lastname: Koyanagi
authors.forename: Janna
authors.initials: J
authors.lastname: Anichina
authors.forename: Diethard K
authors.initials: DK
authors.lastname: Bohme
mesh_terms: D000838:Anions; D001966:Bromine / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D005740:Gases; D018054:Hydrobromic Acid / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D009841:Oligonucleotides / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D044367:Phase Transition; D011522:Protons; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D013696:Temperature
chemical_list: D000838:Anions; D005740:Gases; D009841:Oligonucleotides; D011522:Protons; D012997:Solvents; D018054:Hydrobromic Acid; D004247:DNA; D010100:Oxygen; D001966:Bromine