Molecular characterization of Api g 2, a novel allergenic member of the lipid-transfer protein 1 family from celery stalks
✍ Scribed by Gabriele Gadermaier; Matthias Egger; Tamara Girbl; Anja Erler; Andrea Harrer; Eva Vejvar; Marina Liso; Klaus Richter; Laurian Zuidmeer; Adriano Mari; Fatima Ferreira
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 873 KB
- Volume
- 55
- Category
- Article
- ISSN
- 1613-4125
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✦ Synopsis
Abstract
Scope: Celery represents a relevant cross‐reactive food allergen source in the adult population. As the currently known allergens are not typical elicitors of severe symptoms, we aimed to identify and characterize a non‐specific lipid transfer protein (nsLTP).
Methods and results: MS and cDNA cloning were applied to obtain the full‐length sequence of a novel allergenic nsLTP from celery stalks. The purified natural molecule consisted of a single isoallergen designated as Api g 2.0101, which was recombinantly produced in Escherichia coli Rosetta‐gami. The natural and recombinant molecules displayed equivalent physicochemical and immunological properties. Circular dichroism revealed a typical α‐helical fold and high thermal stability. Moreover, Api g 2 was highly resistant to simulated gastrointestinal digestion. As assessed by ELISA, thermal denaturation did not affect the IgE binding of Api g 2. Natural and recombinant Api g 2 showed similar allergenic activity in mediator release assays. Api g 2‐specific IgE antibodies cross‐reacted with peach and mugwort pollen nsLTPs.
Conclusion: Based on our results, it can be anticipated that inclusion of recombinant Api g 2 in the current panel of allergens for molecule‐based diagnosis will facilitate the evaluation of the clinical relevance of nsLTP sensitization in celery allergy and help clinicians in the management of food allergic patients.