title: Enhanced Approaches for Identifying Amadori Products: Application to Peanut Allergens.
abstract: The dry roasting of peanuts is suggested to influence allergic sensitization as a result of the formation of advanced glycation end products (AGEs) on peanut proteins. Identifying AGEs is technically challenging. The AGEs of a peanut allergen were probed with nano-scale liquid chromatography-electrospray ionization-mass spectrometry (nanoLC-ESI-MS) and tandem mass spectrometry (MS/MS) analyses. Amadori product ions matched to expected peptides and yielded fragments that included a loss of three waters and HCHO. As a result of the paucity of b and y ions in the MS/MS spectrum, standard search algorithms do not perform well. Reactions with isotopically labeled sugars confirmed that the peptides contained Amadori products. An algorithm was developed on the basis of information content (Shannon entropy) and the loss of water and HCHO. Results with test data show that the algorithm finds the correct spectra with high precision, reducing the time needed to manually inspect data. Computational and technical improvements allowed for better identification of the chemical differences between modified and unmodified proteins.
authors.forename: Katina L
authors.initials: KL
authors.lastname: Johnson
authors.forename: Jason G
authors.initials: JG
authors.lastname: Williams
authors.affiliation: Agricultural Research Service, United States Department of Agriculture , 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, United States.
authors.forename: Soheila J
authors.initials: SJ
authors.lastname: Maleki
authors.affiliation: Agricultural Research Service, United States Department of Agriculture , 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, United States.
authors.forename: Barry K
authors.initials: BK
authors.lastname: Hurlburt
authors.forename: Robert E
authors.initials: RE
authors.lastname: London
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Mueller
mesh_terms: D000595:Amino Acid Sequence; D010367:Arachis / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D002853:Chromatography, Liquid; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D011499:Protein Processing, Post-Translational; D053719:Tandem Mass Spectrometry
chemical_list: D010940:Plant Proteins
keywords: Amadori products; Maillard reactions; Shannon entropy; advanced glycation end products; allergen; peanuts (Arachis hypogaea)
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