title: Gln-Gly cleavage: a dominant dissociation site in the fragmentation of protonated peptides.
abstract: An understanding of the gas-phase dissociation of protonated peptides within the mass spectrometer is essential for automated high-throughput protein identification. In this communication we describe a facile cleavage of the Gln-Gly peptide bond under low-collisional energy conditions. A variety of synthetic peptides have been analysed where key amino acids have been substituted within the sequence PQGPPQQGGR, which is a consensus repeat present in the tryptic peptides of acidic proline-rich protein 1 (PRP-1). The collision-induced dissociation spectra obtained from the PRP-1 tryptic peptides and the synthetic peptides indicate that facile Gln-Gly cleavage occurs when an X-Gln-Gly-Y sequence is present in a peptide, where X is any amino acid and Y any amino acid other than Gly.
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden. andreas.jonsson@mbb.ki.se
authors.forename: A P
authors.initials: AP
authors.lastname: Jonsson
authors.forename: T
authors.initials: T
authors.lastname: Bergman
authors.forename: H
authors.initials: H
authors.lastname: Jörnvall
authors.forename: W J
authors.initials: WJ
authors.lastname: Griffiths
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D004151:Dipeptides / Q000737:chemistry*; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D014357:Trypsin
chemical_list: D004151:Dipeptides; D010455:Peptides; C432806:glutaminyl-glycine; D014357:Trypsin