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A ra h 1 structure is retained after roasting and is important for enhanced binding to I g E
Author(s) -
Nesbit Jacqueline B.,
Hurlburt Barry K.,
Schein Catherine H.,
Cheng Hsiaopo,
Wei Hui,
Maleki Soheila J.
Publication year - 2012
Publication title -
molecular nutrition and food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.495
H-Index - 131
eISSN - 1613-4133
pISSN - 1613-4125
DOI - 10.1002/mnfr.201100815
Subject(s) - epitope , chemistry , circular dichroism , protein secondary structure , biochemistry , roasting , binding site , microbiology and biotechnology , stereochemistry , antibody , biology , immunology
Scope A ra h 1 from roasted peanut binds higher levels of serum immunoglobulin E than raw peanuts and this is likely due to the M aillard reaction. While Ara h 1 linear I g E epitopes have been mapped, the presence and importance of structural epitopes is not clear. Methods and results Mass spectrometry, immunoblot, ELISA , circular dichroism ( CD ), and structural analysis were used to compare structural and subsequent I g E ‐binding differences in A ra h 1 purified from raw ( N ) and roasted peanuts ( R ) and denatured A ra h 1 ( D ). Although N and R had similar CD spectra, the latter bound significantly more I g E . Decreased I g E binding was seen with the loss of secondary structure. This same I g E ‐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 A ra h 1, our study shows that conformational epitopes of A ra h 1 bind better to I g E than linear epitopes. Conclusion Enhanced I g E binding to roasted A ra h 1 could be due to alterations such as chemical modifications to individual amino acids or increased epitope exposure. I g E binding is significantly reduced with loss of structure.