title: Effect of heating and glycation on the allergenicity of 2S albumins (Ara h 2/6) from peanut.
abstract: BACKGROUND
  Peanut allergy is one of the most common and severe food allergies, and processing is known to influence the allergenicity of peanut proteins. We aimed to establish the effect of heating and glycation on the IgE-binding properties and biological activity of 2S albumins (Ara h 2/6) from peanut.
  
  
  RESULTS
  Native Ara h 2/6 was purified from raw peanuts and heated in solution (15 min, 110°C) in the presence or absence of glucose. Ara h 2 and 6 were also purified from roasted peanut. Using PBMC and sera from peanut-allergic patients, the cellular proliferative potency and IgE reactivity (reverse EAST inhibition) and functionality (basophil degranulation capacity) of allergens were assessed. Heating Ara h 2/6 at 110°C resulted in extensive denaturation, hydrolysis and aggregation of the protein, whilst Ara h 2 and 6 isolated from roasted peanut retained its native conformation. Allergen stimulation of PBMC induced proliferation and Th2 cytokine secretion which was unaffected by thermal processing. Conversely, IgE reactivity and functionality of Ara h 2/6 was decreased by heating. Whilst heating-glycation further reduced the IgE binding capacity of the proteins, it moderated their loss of histamine releasing capacity. Ara h 2 and 6 purified from roasted peanut demonstrated the same IgE reactivity as unheated, native Ara h 2/6.
  
  
  CONCLUSIONS
  Although no effect of processing on T-cell reactivity was observed, heat induced denaturation reduced the IgE reactivity and subsequent functionality of Ara h 2/6. Conversely, Ara h 2 and 6 purified from roasted peanut retained the structure and IgE reactivity/functionality of the native protein which may explain the allergenic potency of this protein. Through detailed molecular study and allergenicity assessment approaches, this work then gives new insights into the effect of thermal processing on structure/allergenicity of peanut proteins.
authors: Cell Biology and Immunology Group, Wageningen University and Research Centre, Wageningen, The Netherlands.
authors: Yvonne M
authors: YM
authors: Vissers
authors: Fany
authors: F
authors: Blanc
authors: Per Stahl
authors: PS
authors: Skov
authors: Phil E
authors: PE
authors: Johnson
authors: Neil M
authors: NM
authors: Rigby
authors: Laetitia
authors: L
authors: Przybylski-Nicaise
authors: Hervé
authors: H
authors: Bernard
authors: Jean-Michel
authors: JM
authors: Wal
authors: Barbara
authors: B
authors: Ballmer-Weber
authors: Laurian
authors: L
authors: Zuidmeer-Jongejan
authors: Zsolt
authors: Z
authors: Szépfalusi
authors: Janneke
authors: J
authors: Ruinemans-Koerts
authors: Ad P H
authors: AP
authors: Jansen
authors: Huub F J
authors: HF
authors: Savelkoul
authors: Harry J
authors: HJ
authors: Wichers
authors: Alan R
authors: AR
authors: Mackie
authors: Clare E N
authors: CE
authors: Mills
authors: Karine
authors: K
authors: Adel-Patient
mesh_terms: D000418:Albumins / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D000485:Allergens / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D052179:Antigens, Plant / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D010367:Arachis / Q000276:immunology* / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D007073:Immunoglobulin E / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary
chemical_list: D000418:Albumins; D000485:Allergens; D052179:Antigens, Plant; D007073:Immunoglobulin E; D005947:Glucose