title: Molecular characterization of Api g 2, a novel allergenic member of the lipid-transfer protein 1 family from celery stalks.
abstract: METHODS
  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).
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Christian Doppler Laboratory for Allergy Diagnosis and Therapy, University of Salzburg, Salzburg, Austria. Gabriele.Gadermaier@sbg.ac.at
authors.forename: Gabriele
authors.initials: G
authors.lastname: Gadermaier
authors.forename: Matthias
authors.initials: M
authors.lastname: Egger
authors.forename: Tamara
authors.initials: T
authors.lastname: Girbl
authors.forename: Anja
authors.initials: A
authors.lastname: Erler
authors.forename: Andrea
authors.initials: A
authors.lastname: Harrer
authors.forename: Eva
authors.initials: E
authors.lastname: Vejvar
authors.forename: Marina
authors.initials: M
authors.lastname: Liso
authors.forename: Klaus
authors.initials: K
authors.lastname: Richter
authors.forename: Laurian
authors.initials: L
authors.lastname: Zuidmeer
authors.forename: Adriano
authors.initials: A
authors.lastname: Mari
authors.forename: Fatima
authors.initials: F
authors.lastname: Ferreira
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000937:Antigen-Antibody Reactions; D052179:Antigens, Plant / Q000737:chemistry* / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D000077102:Apium / Q000737:chemistry* / Q000276:immunology; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D002460:Cell Line; D003429:Cross Reactions; D004063:Digestion; D005512:Food Hypersensitivity / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D018547:Plant Stems / Q000737:chemistry*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D055550:Protein Stability; D017433:Protein Structure, Secondary; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D052179:Antigens, Plant; C559814:Api g 2 allergen, celery; D002352:Carrier Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; C511920:lipid transfer proteins, plant; D007073:Immunoglobulin E