Proteomic and in silico characterization identifies conarachin as a major IgE-reactive peanut allergen

Abstract

Peanut allergy is a major health issue, and detailed molecular insights are essential to understand allergenicity. In this study, an integrated immunoproteomic and in silico docking workflow was applied to characterize allergens from six Algerian peanut varieties. Protein profiling by 2-DE (pI 4.8-10.1, 9-68 kDa), followed by immunoblotting, revealed strong IgE binding to low-molecular-weight proteins (20-25 kDa). Sixteen distinct protein spots were excised and analyzed by LC-MS/MS, identifying key allergens including Ara h 1, Ara h 2, Ara h 3, and Ara h 6, with peptide coverages ranging from 34% (Ara h 1) to 70% (Ara h 2). Four highly reactive allergens were prioritized, and nine were further investigated through molecular docking against the human IgE receptor. Computational analyses uncovered novel epitope interactions, with conarachin (Q647H1) emerging as the strongest binder (cluster score -625.4), showing stable contacts at epitopes 26-50, 112-151, and 185-491. Chain-specific docking highlighted high affinity toward both IgE heavy and light chains, underlining its structural adaptability.