Identification of Ligustrum lucidum pollen allergens using a proteomics approach.

Background: Ligustrum spp. are members of the Oleaceae family, one of the most prominent allergic families worldwide. The genus Ligustrum contains approximately fifty species, including Ligustrum lucidum, which have been widely cultivated as ornamental plants, and its pollen is a source of inhalant allergens associated with respiratory allergic diseases. Little is known about the presence of allergenic proteins in L. lucidum.

Methods: The L. lucidum pollen proteins were extracted by a modified phenolic extraction method. A pool of four sera from mono sensitive patients was analyzed by 2DE immunoblotting and mass spectrometric analysis was performed on 6 immunoreactive protein spots.

Results: SDS-PAGE of L. lucidum pollen extract revealed proteins in ranges of 15-150 kDa. The 2DE gel profile of the L. lucidum pollen protein extract showed approximately 180 spots, and the 2DE immunoblots obtained using sera from Ligustrum monosensitive patients as the source of IgE antibodies revealed six allergen protein spots, corresponding to Profilin, Enolase, Fra e 9.01 (β-1,3-glucanase), Pollen-specific Polygalacturonases, Alanine aminotransferase, and two ATP synthase beta subunits.

Conclusion: We report for the first time the identification of IgE-reactive proteins from L. lucidum.