Lysine peroxycarbamates: free radical-promoted peptide cleavage.
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.
Masterson
Douglas S
DS
Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA.
Yin
Huiyong
H
Chacon
Almary
A
Hachey
David L
DL
Norris
Jeremy L
JL
Porter
Ned A
NA
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
D002219:Carbamates; D005609:Free Radicals; D010455:Peptides; D010545:Peroxides; D008239:Lysine