title: Low energy peptide fragmentations in an ESI-Q-Tof type mass spectrometer.
abstract: Efficient peptide sequencing relies on both high quality MS/MS data acquisition and exhaustive knowledge of gas-phase dissociation mechanisms. We report our contribution to the elaboration of more comprehensive fragmentation models required for efficient automated MS/MS spectra interpretation. Following a statistical approach, various peptides (296 sequences of variable compositions and lengths) were prepared and subjected to low-energy collision-induced dissociations (CID) in an electrospray hybrid instrument (ESI-Q-q-Tof type mass spectrometer) that has retained relatively limited attention so far. Besides, our studies were focused on low molecular weight singly charged peptides that often failed to be identified by sequencing algorithms. Only half of the studied compounds showed charge directed dissociations in accordance with the mobile proton model producing fragment ions directly related to the primary sequence. For the peptides that did not exhibit the expected fragment ion series, alternative dissociation behaviors issued from complex rearrangements were evidenced.
authors.affiliation: Laboratoire des Amino acides, Peptides et Protéines, LAPP-UMR 5810, CNRS, Universités Montpellier I and II, Place E. Bataillon, 34095 Montpellier Cédex 05, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Mouls
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Aubagnac
authors.forename: Jean
authors.initials: J
authors.lastname: Martinez
authors.forename: Christine
authors.initials: C
authors.lastname: Enjalbal
mesh_terms: D000595:Amino Acid Sequence; D004213:Dissociative Disorders; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry*; D010449:Peptide Mapping / Q000379:methods*; D020539:Sequence Analysis, Protein / Q000379:methods*; D012694:Serine / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013912:Threonine / Q000032:analysis
chemical_list: D010446:Peptide Fragments; D013912:Threonine; D012694:Serine