Mapping the major B-cell linear epitope of silkworm (Bombyx mori) pupal chitinase and molecular dynamics insights into its IgE-binding stability.

As domestic silkworm (Bombyx mori) pupae emerge as a promising alternative food source, the severe IgE-mediated allergic reactions they trigger have raised significant public health concerns. Despite the identification of the novel allergen Bombyx mori chitinase (BmChi), its precise linear B-cell epitopes and molecular mechanisms of IgE recognition remain uncharacterized. In this hypothesis-generating study, we systematically mapped the linear B-cell epitopes of BmChi and evaluated their structural dynamics. Following bioinformatic predictions, a high-resolution in vitro screening using 109 overlapping peptides successfully identified peptide S31 (residues 536-548) as the major dominant epitope. To gain atomistic insights into the BmChi-IgE interaction, homology modeling and molecular docking were conducted, revealing a structurally stable complex supported by extensive hydrogen-bonding networks within flexible loop regions. Furthermore, molecular dynamics simulations (MDs) and steered molecular dynamics simulations (SMDs) provided dynamic evidence of the complex's remarkable rigidity and mechanical resistance. Additionally, phylogenetic analysis highlighted the conserved nature of BmChi relative to plant panallergens. These findings should be interpreted as computational predictions corroborated by in vitro peptide-level binding data rather than direct clinical evidence of allergenic potency. The predicted consensus epitopes and their elucidated structural robustness provide a precise molecular basis for mitigating insect-derived allergenic risks through directed food processing and immunotherapy design.