1. Localization and antigenicity reduction of immunodominant conformational IgE epitopes on αs1-casein.
- Author
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Zeng J, Zou J, Yi H, He J, Zhao J, Zhu S, Li B, Dudu OE, Zhang L, and Gong P
- Subjects
- Milk chemistry, Milk immunology, Molecular Dynamics Simulation, Protein Conformation, alpha-Helical, Protein Binding immunology, Humans, Child, Molecular Docking Simulation, Male, Female, Infant, Child, Preschool, Cell Line, Papain metabolism, Caseins blood, Caseins chemistry, Caseins immunology, Caseins metabolism, Allergens blood, Allergens chemistry, Allergens immunology, Allergens metabolism, Milk Hypersensitivity blood, Milk Hypersensitivity immunology, Immunoglobulin E blood, Immunoglobulin E immunology, Immunoglobulin E metabolism, Immunodominant Epitopes blood, Immunodominant Epitopes chemistry, Immunodominant Epitopes immunology, Immunodominant Epitopes metabolism
- Abstract
αs1-Casein (αs1-CN) is the major allergen in cow milk; however, the understanding of its conformational epitopes remains limited due to the absence of a well-defined three-dimensional structure, which has impeded efforts to effectively reduce its antigenicity. This study employed molecular dynamics simulations (MD), ELISA, cell assays and peptidomes analysis to investigate the critical conformational epitopes of αs1-Casein. MD and immunological analyses identified a dominant conformational epitope encompassing the regions S55-E75 & Y154-T174 & F179-W199, which exhibited strong binding affinity to IgE and triggered the releasing of β-hexosaminidase, histamine and IL-6 in KU812 cells, thereby inducing allergic responses. Notably, the segments Y154-T174 and F179-W199 were particularly impactful. Furthermore, the presence of helical structures within the epitopes enhanced their binding to IgE to a certain extent. Peptidomes analysis further revealed that papain efficiently disrupted the key epitope (Y154-T174) by selectively cleaving the hotspot amino acid residues (Y154 and Y165), thereby significantly reducing the antigenicity of αs1-CN, decreasing IgE and IgG binding to 7.28 % and 10.39 %, respectively. These findings enhance the understanding of αs1-CN's antigenic epitopes and provides a theoretical and technical foundation for the targeted reduction of its antigenicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
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