title: Peptide Fragmentation and Surface Structural Analysis by Means of ToF-SIMS Using Large Cluster Ion Sources.
abstract: Peptide or protein structural analysis is crucial for the evaluation of biochips and biodevices, therefore an analytical technique with the ability to detect and identify protein and peptide species directly from surfaces with high lateral resolution is required. In this report, the efficacy of ToF-SIMS to analyze and identify proteins directly from surfaces is evaluated. Although the physics governing the SIMS bombardment process precludes the ability for researchers to detect intact protein or larger peptides of greater than a few thousand mass unit directly, it is possible to obtain information on the partial structures of peptides or proteins using low energy per atom argon cluster ion beams. Large cluster ion beams, such as Ar clusters and C60 ion beams, produce spectra similar to those generated by tandem MS. The SIMS bombardment process also produces peptide fragment ions not detected by conventional MS/MS techniques. In order to clarify appropriate measurement conditions for peptide structural analysis, peptide fragmentation dependency on the energy of a primary ion beam and ToF-SIMS specific fragment ions are evaluated. It was found that the energy range approximately 6 ≤ E/n ≤ 10 eV/atom is most effective for peptide analysis based on peptide fragments and [M + H] ions. We also observed the cleaving of side chain moieties at extremely low-energy E/n ≤ 4 eV/atom.
authors.affiliation: Department of Materials and Life Science, Seikei University , Tokyo 180-8633, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Yokoyama
authors.affiliation: Department of Materials and Life Science, Seikei University , Tokyo 180-8633, Japan.
authors.forename: Satoka
authors.initials: S
authors.lastname: Aoyagi
authors.affiliation: Quantum Science and Engineering Center, Kyoto University , Kyoto 611-0011, Japan.
authors.forename: Makiko
authors.initials: M
authors.lastname: Fujii
authors.affiliation: Quantum Science and Engineering Center, Kyoto University , Kyoto 611-0011, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Matsuo
authors.affiliation: Chemistry and Molecular Biology, University of Gothenburg , 40530 Göteborg, Sweden.
authors.forename: John S
authors.initials: JS
authors.lastname: Fletcher
authors.affiliation: Manchester Institute of Biotechnology and School of Chemistry , Manchester, M13 9PL, United Kingdom.
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Lockyer
authors.affiliation: Manchester Institute of Biotechnology and School of Chemistry , Manchester, M13 9PL, United Kingdom.
authors.forename: John C
authors.initials: JC
authors.lastname: Vickerman
authors.affiliation: Surface and Nanoanalysis, National Physical Laboratory , Teddington, Middlesex, TW11 0LW, United Kingdom.
authors.forename: Melissa K
authors.initials: MK
authors.lastname: Passarelli
authors.affiliation: Surface and Nanoanalysis, National Physical Laboratory , Teddington, Middlesex, TW11 0LW, United Kingdom.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Havelund
authors.affiliation: Surface and Nanoanalysis, National Physical Laboratory , Teddington, Middlesex, TW11 0LW, United Kingdom.
authors.forename: Martin P
authors.initials: MP
authors.lastname: Seah
mesh_terms: D001128:Argon / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis* / Q000737:chemistry*; D011487:Protein Conformation; D018629:Spectrometry, Mass, Secondary Ion; D013499:Surface Properties; D053719:Tandem Mass Spectrometry
chemical_list: D037741:Fullerenes; D007477:Ions; D010446:Peptide Fragments; D001128:Argon; C069837:fullerene C60