Structural Basis of IgE Binding to alpha- and gamma-Gliadins: Contribution of Disulfide Bonds and Repetitive and Nonrepetitive Domains

Hamza Mameri (1, 2) , Chantal Brossard (2) , Jean-Charles Gaudin (2) , Yann Gohon (1) , Evelyne Paty (3) , Etienne Beaudouin (4) , Denise-Anne Moneret-Vautrin (4) , Martine Drouet (5) , Véronique Solé-Jamault (2) , Frank Wien (6) , Roberta Lupi (2) , Colette Larré (2) , Jacques Snegaroff (1) , Sandra Denery-Papini (2)

1 IJPB - Institut Jean-Pierre Bourgin
2 BIA - Unité de recherche sur les Biopolymères, Interactions Assemblages
3 Service de Pneumologie Allergologie [CHU Necker]
4 CH Epinal / CHED - Centre Hospitalier Emile Durkheim [Epinal]
5 CHU Angers - Centre Hospitalier Universitaire d'Angers
6 SSOLEIL - Synchrotron SOLEIL

Wheat products cause IgE-mediated allergies. The present study aimed to decipher the molecular basis of alpha- and gamma-gliadin allergenicity. Gliadins and their domains, the repetitive N-terminal and the nonrepetitive C-terminal domains, were cloned and expressed in Escherichia coli. Their secondary structures and their IgE binding capacity were compared with those of natural proteins before and after reduction/alkylation. Allergenicity was evaluated with sera from patients who had wheat food allergy or baker's asthma: The secondary structures of natural and recombinant proteins were slightly different. Compared with natural gliadins, recombinant proteins retained IgE binding but with reduced reactivity. Reduction/alkylation decreased IgE binding for both natural and recombinant gliadins. Although more continuous epitopes were identified in the N-terminal domains, of alpha- and gamma-gliadins, both the N-terminal and C-terminal domains contributed to IgE binding. As for other Members of the prolamin: superfamily, disulfide bonds appear to be of high importance for IgE binding.

Mots clés: MAJOR ALLERGEN; CELIAC-DISEASE; IgE epitopes; recombinant wheat allergens; synchrotron radiation circular dichroism; wheat allergy; wheat gliadins; EXERCISE-INDUCED ANAPHYLAXIS; MOLECULAR-WEIGHT GLUTENIN; RECOMBINANT OMEGA-5 GLIADIN; PROTEIN SECONDARY STRUCTURE; FOOD ALLERGY; WHEAT-FLOUR; IMMUNOLOGICAL CHARACTERIZATION; BAKERS ASTHMA

Domaines: Alimentation et Nutrition

Hamza Mameri, Chantal Brossard, Jean-Charles Gaudin, Yann Gohon, Evelyne Paty, et al.. Structural Basis of IgE Binding to alpha- and gamma-Gliadins: Contribution of Disulfide Bonds and Repetitive and Nonrepetitive Domains. Journal of Agricultural and Food Chemistry, 2015, 63 (29), pp.6546 - 6554. ⟨10.1021/acs.jafc.5b01922⟩. ⟨hal-01204207⟩