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.