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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food Processing and Sensory Quality Research » Research » Publications at this Location » Publication #391939
Research Project: Reducing the Development and Severity of Allergy to Peanuts and Tree Nuts

Location: Food Processing and Sensory Quality Research

Title: Structure, immunogenicity, and IgE cross-reactivity among walnut and peanut vicilin buried peptides

Author
item FOO, ALEXANDER - National Institute Of Environmental Health Sciences (NIEHS, NIH)
item Nesbit, Jacqueline
item GIPSON, STEPHEN - Oak Ridge Institute For Science And Education (ORISE)
item Cheng, Hsiaopo
item BUSCHEL, PETER - National Institute Of Environmental Health Sciences (NIEHS, NIH)
item DEROSE, EUGENE - National Institute Of Environmental Health Sciences (NIEHS, NIH)
item SCHEIN, CATHERINE - University Of Texas Medical Branch
item TEUBER, SUZANNE - University Of California, Davis
item Hurlburt, Barry
item Maleki, Soheila
item MUELLER, GEOFFREY - National Institute Of Environmental Health Sciences (NIEHS, NIH)

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2022
Publication Date: 2/9/2022
Citation: Foo, A.C.Y., Nesbit, J.B., Gipson, S.A.Y., Cheng, H., Buschel, P., Derose, E.F., Schein, C.H., Teuber, S.S., Hurlburt, B.K., Maleki, S.J., Mueller, G.A. 2022. Structure, immunogenicity, and IgE cross-reactivity among walnut and peanut vicilin buried peptides. Journal of Agricultural and Food Chemistry. 70(7):2389-2400. https://doi.org/10.1021/acs.jafc.1c07225.
DOI: https://doi.org/10.1021/acs.jafc.1c07225

Interpretive Summary: Vicillins are a class of proteins often found to be peanut and tree-nut allergens. Whereas the final the large vicillin protein end product contains several IgE antibody reactive sites, the smaller peptides resulting from post-translational processing also have IgE binding sites or epitopes. In this study, the vicillin precursor VBPs (Vicillin Buried Peptides) from peanut and walnut were characterized for IgE binding and structure. It was found that all four VBPs had similar 3-dimensional folds and bound IgE. Based on these results it is likely that the IgE epitopes which occupy the same structural regions are a likely cause of IgE cross reactivity between peanuts and walnuts.

Technical Abstract: Vicilin Buried Peptides (VBPs) from edible plants are derived from the N-terminal leader sequences (LS) of seed storage proteins. VBPs are defined by a common a-hairpin fold mediated by conserved CxxxCx(10-14)CxxxC motifs. Here, peanut and walnut VBPs were characterized as potential mediators of both peanut/walnut allergenicity and cross-reactivity despite their low (~17%) sequence identify. The structures of one peanut (AH1.1) and 3 walnut (JR2.1, JR2.2, JR2.3) VBPs were solved using solution-NMR, revealing similar a-hairpin structures stabilized by disulfide bonds with high levels of surface similarity. Peptide microarrays identified several peptide sequences primarily on AH1.1 and JR2.1 which were recognized by peanut, walnut, and dual-allergic patient IgE, establishing these peanut and walnut VBPs as potential mediators of allergenicity and cross-reactivity. JR2.2 and JR2.3 displayed extreme resilience against endosomal digestion, likely hindering epitope generation and contributing to their reduced allergic potential.