title: Scrambling of sequence information in collision-induced dissociation of peptides.
abstract: Collision-induced dissociation (CID) of protonated YAGFL-NH2 leads to nondirect sequence fragment ions that cannot directly be derived from the primary peptide structure. Experimental and theoretical evidence indicate that primary fragmentation of the intact peptide leads to the linear YAGFLoxa b5 ion with a C-terminal oxazolone ring that is attacked by the N-terminal amino group to induce formation of a cyclic peptide b5 isomer. The latter can undergo various proton transfer reactions and opens up to form something other than the YAGFLoxa linear b5 isomer, leading to scrambling of sequence information in the CID of protonated YAGFL-NH2.
authors.affiliation: Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada. aharriso@chem.utoronto.ca
authors.forename: Alex G
authors.initials: AG
authors.lastname: Harrison
authors.forename: Alex B
authors.initials: AB
authors.lastname: Young
authors.forename: Christian
authors.initials: C
authors.lastname: Bleiholder
authors.forename: Sandor
authors.initials: S
authors.lastname: Suhai
authors.forename: Béla
authors.initials: B
authors.lastname: Paizs
mesh_terms: D000595:Amino Acid Sequence; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D010455:Peptides