title: Tandem mass spectrometry of model peptides modified with trans-2-hexenal, a product of lipid peroxidation.
abstract: Small molecules formed during lipid peroxidation can react with the basic groups in proteins through different mechanisms. Recently, substituted pyridinium moieties were observed during in vitro incubations of lysine-containing peptides with 2-alkenals. To explore the dissociation behavior of peptides with pyridinium-derivatized lysine residues, the peptide ions created through either matrix-assisted laser desorption/ionization or electrospray ionization were studied with tandem mass spectrometry. The permanently charged pyridinium ions fragment primarily through the charge-remote processes. Under high energy collision-induced dissociation, a number of diagnostic ions were observed that could potentially be used to identify modified residues in proteins. The origins of these ions were studied using deuterium exchange and higher-order mass spectrometry experiments using an ion trap instrument. Rational structures for these ions are proposed.
authors.affiliation: Department of Chemistry, Indiana University, Bloomington 47405, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Baker
authors.forename: D
authors.initials: D
authors.lastname: Wiesler
authors.forename: M V
authors.initials: MV
authors.lastname: Novotny
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D003432:Cross-Linking Reagents; D004151:Dipeptides / Q000737:chemistry; D006639:Histidine / Q000737:chemistry; D007202:Indicators and Reagents; D015227:Lipid Peroxidation; D013058:Mass Spectrometry; D008956:Models, Chemical; D010455:Peptides / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000447:Aldehydes; D003432:Cross-Linking Reagents; D004151:Dipeptides; D007202:Indicators and Reagents; D010455:Peptides; D011726:Pyridinium Compounds; C006430:N(alpha)-acetylglycyllysyl methyl ester; C045934:4-hydroxy-2-hexenal; D006639:Histidine