title: Fragmentation of alpha- and beta-alanine molecules by ions at Bragg-peak energies.
abstract: The interaction of keV He(+), He(2+), and O(5+) ions with isolated alpha and beta isomers of the amino acid alanine was studied by means of high resolution coincidence time-of-flight mass spectrometry. We observed a strong isomer dependence of characteristic fragmentation channels which manifests in strongly altered branching ratios. Despite the ultrashort initial perturbation by the incoming ion, evidence for molecular rearrangement leading to the formation of H(3)(+) was found. The measured kinetic energies of ionic alanine fragments can be sufficient to induce secondary damage to DNA in a biological environment.
authors.affiliation: KVI Atomic Physics, University of Groningen, Zernikelaan 25, Groningen, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Bari
authors.forename: P
authors.initials: P
authors.lastname: Sobocinski
authors.forename: J
authors.initials: J
authors.lastname: Postma
authors.forename: F
authors.initials: F
authors.lastname: Alvarado
authors.forename: R
authors.initials: R
authors.lastname: Hoekstra
authors.forename: V
authors.initials: V
authors.lastname: Bernigaud
authors.forename: B
authors.initials: B
authors.lastname: Manil
authors.forename: J
authors.initials: J
authors.lastname: Rangama
authors.forename: B
authors.initials: B
authors.lastname: Huber
authors.forename: T
authors.initials: T
authors.lastname: Schlathölter
mesh_terms: D000409:Alanine / Q000737:chemistry*; D003198:Computer Simulation; D007477:Ions; D007536:Isomerism; D013058:Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation
chemical_list: D007477:Ions; D000409:Alanine