IgE-binding abilities of pentapeptides, QQPFP and PQQPF, in wheat gliadin.

Wheat gliadin is known mainly as the causative substance for enteropathy accompanied by diarrhea (celiac disease) and food-dependent exercise-induced anaphylaxis. However, little is known in regards to the allergenicity of gliadin in atopic dermatitis. In this study, the allergenicity of gliadin was demonstrated using sera of wheat-allergic patients with atopic dermatitis. Since there are many repeated sequences in gliadin, peptides containing each motif were synthesized to evaluate their IgE-binding abilities. As a result, QQPFP and PQQPF were found to be epitopes (minimum structures for the IgE-binding). Gliadin might crosslink patient's IgE-antibodies via these epitopes and trigger subsequent allergic reactions.