Peanut Allergens Attached with p-Aminobenzamidine Are More Resistant to Digestion than Native Allergens

Despite being known as resistant proteins, peanut allergens (Ara h 1 and Ara h 2)can be digested and cause allergic reactions. Making the allergens more resistant todigestion may aid in non-absorption and excretion of the allergens. Our objectiveswere to make Ara h 1 and Ara h 2 more resistant to digestion and test them in amodel system using trypsin as the digestive enzyme. The resistant allergens wereprepared by covalently attaching p-aminobenzamidine (pABA), a protease inhibitor,to peanut allergens in an extract or on a PVDF membrane using glutaraldehyde, andwere then tested for resistance to trypsin digestion. SDS-PAGE and Western blotwere performed to determine the allergenic capacity of the modified allergens. Acontrol was prepared using glycine instead. Results showed that Ara h 2, when covalentlyattached with pABA, was more resistant to trypin digestion than the native allergen.Similarly, Ara h 1, prepared on a PVDF membrane and treated with pABA,displayed a resistance to trypsin digestion. Treatment of the allergens with glycine (acontrol) instead of pABA showed that the modified allergens were as digestible asnative allergens. Blot assays showed that the pABA-treated allergens exhibited a lowerallergenic capacity than native allergens. It was concluded that pABA, when attachedto peanut allergen Ara h 1 or Ara h 2, inhibited digestion of the allergen bytrypsin and reduced their allergenic capacity as well.