title: Ara h 1 structure is retained after roasting and is important for enhanced binding to IgE.
abstract: METHODS
  Ara h 1 from roasted peanut binds higher levels of serum immunoglobulin E than raw peanuts and this is likely due to the Maillard reaction. While Ara h 1 linear IgE epitopes have been mapped, the presence and importance of structural epitopes is not clear.
  
  
  RESULTS
  Mass spectrometry, immunoblot, ELISA, circular dichroism (CD), and structural analysis were used to compare structural and subsequent IgE-binding differences in Ara h 1 purified from raw (N) and roasted peanuts (R) and denatured Ara h 1 (D). Although N and R had similar CD spectra, the latter bound significantly more IgE. Decreased IgE binding was seen with the loss of secondary structure. This same IgE-binding pattern [R > N > D] was seen for the sera of ten peanut allergic patients. While the majority of linear epitopes are located on surface and structured regions of Ara h 1, our study shows that conformational epitopes of Ara h 1 bind better to IgE than linear epitopes.
  
  
  CONCLUSIONS
  Enhanced IgE binding to roasted Ara h 1 could be due to alterations such as chemical modifications to individual amino acids or increased epitope exposure. IgE binding is significantly reduced with loss of structure.
authors.affiliation: US Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA 70124, USA.
authors.forename: Jacqueline B
authors.initials: JB
authors.lastname: Nesbit
authors.forename: Barry K
authors.initials: BK
authors.lastname: Hurlburt
authors.forename: Catherine H
authors.initials: CH
authors.lastname: Schein
authors.forename: Hsiaopo
authors.initials: H
authors.lastname: Cheng
authors.forename: Hui
authors.initials: H
authors.lastname: Wei
authors.forename: Soheila J
authors.initials: SJ
authors.lastname: Maleki
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000737:chemistry* / Q000378:metabolism*; D010367:Arachis / Q000737:chemistry* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D002942:Circular Dichroism; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology; D005260:Female; D005511:Food Handling / Q000379:methods; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism*; D011489:Protein Denaturation; D017433:Protein Structure, Secondary
chemical_list: D052179:Antigens, Plant; C500889:Ara h 1 protein, Arachis hypogaea; D000939:Epitopes; D006023:Glycoproteins; D008565:Membrane Proteins; D010940:Plant Proteins; D007073:Immunoglobulin E