title: Lysine peroxycarbamates: free radical-promoted peptide cleavage.
abstract: Strategies are reported that combine in one step a predictable chemical-based protein digestion with mass spectrometry. Lysine residue amino groups in peptides and proteins are modified by reaction with a peroxycarbonate derived from p-nitrophenol, and tert-butyl hydroperoxide. The peroxycarbonate reacts with lysine residues in peptides and proteins, and the resulting lysine peroxycarbamates undergo homolytic fragmentation under conditions of low-energy collision-induced dissociation (CID). Observed fragmentation of the peptides involves apparent free radical processes including Hofmann-Löffler-type rearrangements that lead to peptide chain fragmentation. Strategies for directed cleavage of peptides by free radical promoted processes are feasible, and such strategies may well simplify schemes for protein analysis.
authors.affiliation: Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Masterson
authors.forename: Huiyong
authors.initials: H
authors.lastname: Yin
authors.forename: Almary
authors.initials: A
authors.lastname: Chacon
authors.forename: David L
authors.initials: DL
authors.lastname: Hachey
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: Norris
authors.forename: Ned A
authors.initials: NA
authors.lastname: Porter
mesh_terms: D000595:Amino Acid Sequence; D002219:Carbamates / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D008239:Lysine / Q000031:analogs & derivatives* / Q000032:analysis; D008969:Molecular Sequence Data; D010449:Peptide Mapping / Q000379:methods; D010455:Peptides / Q000032:analysis / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D002219:Carbamates; D005609:Free Radicals; D010455:Peptides; D010545:Peroxides; D008239:Lysine