title: Quantitation of soybean allergens using tandem mass spectrometry.
abstract: Soybean (Glycine max) seed contain some proteins that are allergenic to humans and animals. However, the concentration of these allergens and their expression variability among germplasms is presently unknown. To address this problem, 10 allergens were quantified from 20 nongenetically modified commercial soybean varieties using parallel, label-free mass spectrometry approaches. Relative quantitation was performed by spectral counting and absolute quantitation was performed using multiple reaction monitoring (MRM) with synthetic, isotope-labeled peptides as internal standards. During relative quantitation analysis, 10 target allergens were identified, and five of these allergens showed expression levels higher than technical variation observed for bovine serum albumin (BSA) internal standard (∼11%), suggesting expression differences among the varieties. To confirm this observation, absolute quantitation of these allergens from each variety was performed using MRM. Eight of the 10 allergens were quantified for their concentration in seed and ranged from approximately 0.5 to 5.7 μg/mg of soy protein. MRM analysis reduced technical variance of BSA internal standards to approximately 7%, and confirmed differential expression for four allergens across the 20 varieties. This is the first quantitative assessment of all major soybean allergens. The results show the total quantity of allergens measured among the 20 soy varieties was mostly similar.
authors.affiliation: Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Norma L
authors.initials: NL
authors.lastname: Houston
authors.forename: Dong-Gi
authors.initials: DG
authors.lastname: Lee
authors.forename: Severin E
authors.initials: SE
authors.lastname: Stevenson
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Ladics
authors.forename: Gary A
authors.initials: GA
authors.lastname: Bannon
authors.forename: Scott
authors.initials: S
authors.lastname: McClain
authors.forename: Laura
authors.initials: L
authors.lastname: Privalle
authors.forename: Nicola
authors.initials: N
authors.lastname: Stagg
authors.forename: Corinne
authors.initials: C
authors.lastname: Herouet-Guicheney
authors.forename: Susan C
authors.initials: SC
authors.lastname: MacIntosh
authors.forename: Jay J
authors.initials: JJ
authors.lastname: Thelen
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002417:Cattle; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine; D030262:Soybean Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014357:Trypsin / Q000378:metabolism
chemical_list: D000485:Allergens; D010446:Peptide Fragments; D030262:Soybean Proteins; D012710:Serum Albumin, Bovine; D014357:Trypsin