Mapping B-cell epitopes of major and minor peanut allergens and identifying residues contributing to IgE binding

Abstract

Background: Epitope identification provides valuable information essential for understanding antigen components involved in food allergic reactions. In the present study, an in silico approach is employed to map IgE binding epitopes of major and minor peanut allergens.

Results: B-cell epitopes were identified for peanut (Arachis hypogaea) allergens, namely Ara h 5, 6, 7, 8, 9, 10 and 11. A total of 10 web servers were used in the study and 26 linear and 18 conformational epitopes were predicted by a combination of methods. The majority of the predicted B-cell residues were present in the coil regions and the highest percentage of hydrophilic residues were observed for Ara h 6 (70.49%). The absolute solvent accessibility for all the B-cell epitopes was >70%, indicating antibody recognition. The property distance index assessed for the predicted epitopes using SDAP showed that six linear epitopes shared similarity with soybean, hazelnut, tomato, maize, apple and banana allergens.

Conclusion: These findings suggest that the identified regions may share cross-reactivity with some of the known food allergens or may act as novel antigenic determinants. Further, B-cell epitopes of Ara h 1, 2 and 3 identified by in silico methods correlated well with the experimentally identified regions.

Keywords: b-cell epitopes; cross reactivity; food allergens; homology modeling; in silico tools; peanut (Arachis hypogaea).