title: Proton transfer reactions for improved peptide characterisation.
abstract: The combination of deprotonation (via ion/molecule and ion/ion reactions) and low-energy collision-induced dissociation (CID) has been explored for the enhanced characterisation of tryptic peptides via access to different precursor charge states. This approach allows instant access to fragmentation properties of singly and doubly protonated precursors (arising from the availability of mobile protons) in a single experiment. Considering both charge states extended our base of structurally informative data (in comparison with considering just a single charge state) due to generation of additional sequence ions and by obtaining supplementary structural information derived from selective cleavages. Roughly 37% of combined data sets (CID spectra of doubly and singly charged precursor) showed a greater database identification confidence than each set alone. Moreover, comparison between a number of sequence ions of the singly charged precursor and the doubly charged precursor provided a mean of distinguishing the two classes of tryptic peptides (arginine or lysine containing).
authors.affiliation: Laboratory for Chemical Kinetics and Atmospheric Chemistry, Ruđer Bošković Institute, Zagreb, Croatia. marko@irb.hr
authors.forename: Marko
authors.initials: M
authors.lastname: Rožman
authors.forename: Andrea
authors.initials: A
authors.lastname: Schneider
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Gaskell
mesh_terms: D000595:Amino Acid Sequence; D005344:Fibrinopeptide A / Q000737:chemistry; D006801:Humans; D006859:Hydrogen / Q000737:chemistry*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*; D011522:Protons; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010446:Peptide Fragments; D011522:Protons; D005344:Fibrinopeptide A; D006859:Hydrogen