title: Impact of sulfur and vitamin C on the allergenicity of Mal d 2 from apple (Malus domestica).
abstract: Mal d 2 is a minor allergen from apple which shows a high conformational stability due to its eight conserved disulfide bridges. Chemical reduction of disulfide bridges and linearization of Mal d 2 lead to enhanced IgE reactivity in vitro and indicate a higher potential for allergenicity. Since food preservatives such as sulfur and vitamin C are reducing and denaturing agents, their influence on Mal d 2 allergenicity was verified by simulated food processing conditions. The immunoreactivity of purified Mal d 2 was investigated after different treatments in vitro and in vivo using IgG/IgE Western blotting, mediator-releasing cell assay, and skin prick and oral smear tests. The conformational changes of Mal d 2 upon addition of 1% and 5% vitamin C were also monitored by attenuated total reflectance Fourier transform infrared spectroscopy. The results show no positive skin and oral smear test reactivity to native, heated, or vitamin C-treated purified Mal d 2. Furthermore, the results confirm that sulfur in combination with heat treatment can influence the structural integrity and thus the allergenicity of Mal d 2, while vitamin C is too weak as a reducing agent to change allergenicity.
authors.affiliation: Plant Biotechnology Unit and Down-Stream Processing Group, Department of Biotechnology, and ‡Department of Chemistry, Vienna Institute of BioTechnology (VIBT), BOKU (University of Natural Resources and Life Sciences) , Vienna 1190, Austria.
authors.forename: Gorji
authors.initials: G
authors.lastname: Marzban
authors.forename: Tamar
authors.initials: T
authors.lastname: Kinaciyan
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Maghuly
authors.forename: Richard
authors.initials: R
authors.lastname: Brunner
authors.forename: Clemens
authors.initials: C
authors.lastname: Gruber
authors.forename: Rainer
authors.initials: R
authors.lastname: Hahn
authors.forename: Erika
authors.initials: E
authors.lastname: Jensen-Jarolim
authors.forename: Margit
authors.initials: M
authors.lastname: Laimer
mesh_terms: D000485:Allergens / Q000276:immunology* / Q000302:isolation & purification; D000818:Animals; D052179:Antigens, Plant / Q000276:immunology* / Q000302:isolation & purification; D001205:Ascorbic Acid / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004591:Electrophoresis, Polyacrylamide Gel; D005511:Food Handling; D005512:Food Hypersensitivity / Q000276:immunology / Q000517:prevention & control; D006358:Hot Temperature; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D027845:Malus / Q000276:immunology*; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology; D051381:Rats; D012882:Skin Tests / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared; D013455:Sulfur / Q000494:pharmacology*; D014162:Transfection; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; D007073:Immunoglobulin E; D013455:Sulfur; D001619:beta-N-Acetylhexosaminidases; D001205:Ascorbic Acid