Proteomic analysis of wheat flour allergens.
Wheat can cause severe IgE-mediated systematic reactions, but knowledge on relevant wheat allergens at the molecular level is scanty. The aim of the present study was to achieve a more detailed and comprehensive characterization of the wheat allergens involved in food allergy to wheat using proteomic strategies, referred to as "allergenomics". Whole flour proteins were separated by two-dimensional gel electrophoresis with isoelectric focusing and lithium dodecyl sulfate-polyacrylamide gel electrophoresis. Then, IgE-binding proteins were detected by immunoblotting with sera of patients with a food allergy to wheat. After tryptic digestion, the peptides of IgE-binding proteins were analyzed by matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry. In this study, we identified four previously reported wheat allergens or their sequentially homologous proteins [serpin, alpha-amylase inhibitor, gamma-gliadin, and low molecular weight (LMW) glutenin] by a database search. As a result of the high resolution of two-dimensional gel electrophoresis, nine subunits of LMW glutenins were identified as the most predominant IgE-binding antigens. The two-dimensional allergen map can be beneficial in many ways. It could be used, for example, for precise diagnosis of wheat-allergic patients and assessment of wheat allergens in food. Additionally, we compared allergenomics to conventional biochemical methods and evaluated the usefulness of a proteomic strategy for identifying putative allergens to wheat allergy.
Akagawa
Mitsugu
M
Department of Biological Chemistry, Division of Applied Life Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai 599-8531, Japan. akagawa@biochem.osakafu-u.ac.jp
Handoyo
Tri
T
Ishii
Takeshi
T
Kumazawa
Shigenori
S
Morita
Naofumi
N
Suyama
Kyozo
K
D000485:Allergens / Q000032:analysis*; D000595:Amino Acid Sequence; D001798:Blood Proteins / Q000032:analysis; D005433:Flour / Q000032:analysis*; D005983:Glutens / Q000097:blood / Q000737:chemistry / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000032:analysis* / Q000737:chemistry / Q000276:immunology*; D040901:Proteomics; D014908:Triticum / Q000737:chemistry*; D021182:Wheat Hypersensitivity / Q000097:blood / Q000276:immunology
D000485:Allergens; D001798:Blood Proteins; D010940:Plant Proteins; D007073:Immunoglobulin E; D005983:Glutens; C037302:glutenin