Phenylglyoxal-induced Ana o 3 Modification Reduces Antibody Binding with Minimal Alteration in Protein Structure

The nutritional benefits of nut consumption are complicated by the presence of allergens. Food processing techniques can modify the food protein properties by altering their biophysical characteristics and allergen activity. This study examines the phenylglyoxal-based chemical modification of the cashew nut allergen Ana o 3. Immunoassays with multiple antibodies demonstrate reduced recognition of phenylglyoxal-modified Ana o 3. Mass spectrometry identified multiple Ana o 3 modification sites, including arginine 41, 54, 85, and 111. Circular dichroism, biochemical assays, and molecular simulation indicate that the modifications resulted in minimal protein structure alteration. The research presented here provides insight into Ana o 3 surface chemistry and structure, and it could be applied in the design of alternative forms of immunotherapy to treat cashew nuts and other food allergies.