ENEA, a peach IgE-binding protein cross-reacting with the latex major allergen Hev b 5

Background : Peach fruit can cause allergic reactions with symptoms ranging from mild to very severe. With the aim of contributing to the improvement of allergy diagnosis at the molecular level, the specific objective of this study was the characterization of ENEA, a still un-known peach IgE- binding protein. Method : ENEA protein was isolated from the natural source by chro-matographic separations, identified by direct protein sequencing and produced as a recombinant molecule by cloning the sequence of the homologous protein from apricot, that shows a 97% identity. The structural characterization revealed that ENEA is an intrinsically disordered protein showing similarities with the major allergen Hev b 5 from rubber latex and with Man e 5 from manioc. The immuno-logical properties were investigated by dot blotting, the ABA system and the FABER test. Results : The data obtained indicated that ENEA is recognized by specific IgE, but the prevalence of positive patients is lower com-pared to the homologous allergen Hev b 5. In addition, 78% of the ENEA IgE positive patients were positive also to Hev b 5 and both the natural and recombinant molecules partially inhibit the IgE bind-ing to the latex allergen. Conclusion : ENEA, a new IgE binding protein from peach has been identified and characterized. Studies are needed to understand whether ENEA is involved in a latex- associated peach and apricot allergy. A recombinant form of ENEA has been produced and char-acterized and will be used for diagnostic purposes using a multiplex test.