title: 4-HNE adduct stability characterized by collision-induced dissociation and electron transfer dissociation mass spectrometry.
abstract: 4-Hydroxynonenal (4-HNE) alters numerous proteomic and genomic processes. Understanding chemical mechanisms of 4-HNE interactions with biomolecules and their respective stabilities may lead to new discoveries in biomarkers for numerous diseases of oxidative stress. Collision-induced dissociation (CID) and electron transfer dissociation (ETD) MS/MS were utilized to examine the stability of a 4-HNE-Cys Michael adduct. CID conditions resulted in the neutral loss of 4-HNE, also known as a retro-Michael addition reaction (RMA). Consequently, performing ETD fragmentation on this same adduct did not result in RMA. Interestingly, 4-HNE adduct reduction via sodium borohydride (NaBH₄) treatment stabilized against the CID induced RMA. In a direct comparison of three forms of 4-HNE adducts, computational modeling revealed sizable shifts in the shape and orientation of the lowest unoccupied molecular orbital (LUMO) density around the 4-HNE-Cys moiety. These findings demonstrate that ETD MS/MS analysis can be used to improve the detection of 4-HNE-protein modifications by preventing RMA reactions from occurring.
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
authors.forename: Kristofer S
authors.initials: KS
authors.lastname: Fritz
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Kellersberger
authors.forename: Jose D
authors.initials: JD
authors.lastname: Gomez
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Petersen
mesh_terms: D000447:Aldehydes / Q000737:chemistry / Q000378:metabolism*; D003553:Cystine / Q000737:chemistry; D004579:Electron Transport; D013058:Mass Spectrometry; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D011789:Quantum Theory
chemical_list: D000447:Aldehydes; D010455:Peptides; D011506:Proteins; D003553:Cystine; C027576:4-hydroxy-2-nonenal