Investigation of differences in allergenicity of protein from different soybean cultivars through LC/MS-MS.

Soybean allergy is a health-threatening issue and identifying raw soybeans with low allergenicity is important for producing hypoallergenic soybean products. Soybean allergy is mainly triggered by soybean proteins. In this study, the protein profiles, allergen compositions, and epitopes in protein from different soybean cultivars (R1, R2 and R3) were evaluated by SDS-PAGE and LC/MS-MS, and their allergenicity was assessed by indirect ELISA and Western blot analysis using the serum IgE of patients allergic to soybeans. The lowest allergenicity was observed in R3, probably resulting from the low concentration of Gly m 4-Gly m 6. The allergenicity of soybeans is affected by multiple allergens rather than a single allergen. Venn diagram, PCA, heatmap, and peptide map analyses have shown the differences in protein and peptide profiles among soybean proteins from different soybean cultivars. Epitope analysis further demonstrated that low contents of dominant epitopes in Gly m 4 and Gly m 5 contributed to low allergenicity in R3, although R3 contained high contents of no-dominant epitopes.