Modification of structure, epitope and allergenicity on heat-stressed ovalbumin by resveratrol

Abstract

Allergen modification is a novel strategy for preventing and treating food allergy. Resveratrol (RES) can be used as a modifying ligand for allergens, but the interaction mechanism between RES and allergens is still not detailed, and the ramifications of this interaction on the structure, epitope and allergenicity of allergens are also lacking a clear explanation. In addition, the application of heat can promote protein structure to unfold and expose more binding sites to facilitate interaction. Therefore, in this study, ovalbumin (OVA) was selected as the allergen model and was heated to expose more binding sites. The effects of the interaction between RES and heat-stressed ovalbumin (HOVA) on allergen structure, epitope and allergenicity were investigated by combining routine experimental analysis and computer simulation. Results showed heat stress at 323 K for 15 min could better unfold the molecular structure of OVA. On this basis, the interaction between RES and OVA was strengthened, which showed a static quenching of the ground state complex with binding affinity of 1.25 × 106 L/mol. The binding of RES induced the variation of protein microenvironment, and the overall structure tended to disordered direction. Computer simulation had shown RES could directly act on the IgE epitope region (AA251-260) of the OVA. The allergenicity evaluation experiment further indicated the combination of RES alleviated the IgE binding capacity of HOVA. These findings are helpful to further study the mechanism of RES ligand modification to change food allergy.