IDENTIFICATION OF THE MAJOR ALLERGENS IN WHEAT FLOOR RESPONSIBLE FOR BAKERS ASTHMA

Baker's asthma, a typical occupational allergic disease, is a serious problem in the food industries. In this study, purification and identi fication of major allergens recognized by IgEs in sera of allergic pat ients were performed. Major immunoreactive proteins were purified from the albumin fraction by gel filtration on a Toyopearl HW-50 column fo llowed by reverse-phase HPLC. The N-terminal amino acid sequences and molecular masses measured by MS indicated that the major immunoreactiv e proteins are members of the alpha-amylase inhibitor family, 0.19 and 0.28. Significant leukotriene release by each purified protein was ob served in cell-associated stimulation tests, suggesting in vivo activi ty of these antigens. Carbohydrate analyses of major allergens indicat ed that they are monoglycosylated but not N-glycosylated in spite of t he presence of a potential N-glycosylation site. Recombinant 0.19 expr essed in Escherichia coli showed the same reactivity with IgE as nativ e wheat 0.19 in Western blotting and ELISA using methyl vinyl ether ma leic anhydride co-polymer as an immobilizing reagent, suggesting that the allergenic epitopes are located in the peptide portions.