Epitope mapping of the major allergen 2S albumin from pine nut.

The epitopes of the major allergen of pine nut, Pin p 1, were analyzed using a peptide library and sera from patients with clinical allergy to pine nut in order to deepen into the allergenic characteristics of Pin p 1. Analyses of epitope similarities and epitopes location in a 3D-model were also performed. Results showed that three main regions of Pin p 1 containing 5 epitopes were recognized by patient sera IgE. The epitopes of Pin p 1 had important similarities with epitopes of allergenic 2S albumins from peanut (Ara h 2 and 6) and Brazil nut (Ber e 1). The epitopes of Pin p 1 were found in α-helices and coils in the 3D protein structure. Interestingly, all epitopes were found to be well-exposed in the protein surface, which suggests facile access for IgE-binding to the structure of Pin p 1 which is known to be highly resistant.