title: Nuclear magnetic resonance structure elucidation of peptide b2 ions.
abstract: Tandem mass spectrometry (MS/MS) is powerful for chemical identification but it is still insufficient for explicit ion structure determination. A strategy is introduced to elucidate MS fragment ion structures using NMR spectroscopy for the first time. In our experiments, precursor ions are dissociated at atmospheric pressure and the resulting fragment ions are identified by mass spectrometry but collected outside the mass spectrometer, making the subsequent NMR measurements possible. This new strategy has been applied to determine the chemical structure of the characteristic b2  fragment ion, a subject of longstanding debate in MS-based proteomics.
authors.affiliation: Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry & Edison Biotechnology Institute, Ohio University, Athens, OH 45701 (USA).
authors.forename: Pengyuan
authors.initials: P
authors.lastname: Liu
authors.forename: R Graham
authors.initials: RG
authors.lastname: Cooks
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D001274:Atmospheric Pressure; D007477:Ions / Q000737:chemistry; D008968:Molecular Conformation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D007477:Ions; D010455:Peptides
keywords: NMR spectroscopy; fragments; mass spectrometry; peptides; structure elucidation