Identification, isolation, and characterization of Ole e 7, a new allergenof olive tree pollen

Background: Olive tree (Olea europaea) pollen is an important cause of poll inosis in countries of the Mediterranean area and California. Objective: The aim of this study was to identify and purify a new allergen of olive tree pollen. Methods: Detection of a pollen allergen was done with individual allergic s era by immunoblotting and ELISA tests. Two allergenic fractions were isolat ed from olive pollen extract by using gel filtration and reverse-phase HPLC . Molecular characterization was achieved by acid hydrolysis and amino acid analysis, as well as by mass spectrometry, Sequencing of the N-terminal en d of the allergen was carried out by Edman degradation of the polypeptide c hain. Allergenic characterization was performed with sera from subjects wit h olive allergy by means of ELISA and immunoblotting after SDS-PAGE. Results: The new allergen Ole e 7 exhibits a high degree of polymorphism. I ts molecular mass is in the range of 9875 d to 10,297 d. Twenty-one amino a cid residues from the N-terminal end of 2 isoforms of the allergen have bee n sequenced revealing no homology with proteins contained in database banks . Ole e 7 has an average frequency of about 47% in patients with olive alle rgy, The strategy of purification of Ole e 7 can be useful on the isolation of new allergens. Conclusions: A new olive pollen allergen of clinical significance has been purified and characterized, contributing to the study of the complete aller gogram of the olive tree pollen.