Inhibiting Peanut Allergen Digestion with p-Aminobenzamidine Attached to the Allergens

Authors: Chung, Si Yin; Reed, Shawndrika; Zhang, Dunhua; Bechtel, Peter

Submitted to: Journal of Food Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Peanut allergens can be digested into peptide fragments despite being known as resistant proteins. Once absorbed, the peptide fragments from digested allergens could bind to immunoglobulin E (IgE) antibodies and cause an allergic reaction in allergic individuals. To reduce peanut allergy, one approach is to inhibit or limit the digestion of peanut allergens. Our objectives were to make peanut allergens (Ara h 1 and Ara h 2) more resistant to digestion and test them in a model system using trypsin as the digestive enzyme. Ara h 2 with a higher resistance was prepared by incubating p-aminobenzamidine (pABA) (a protease inhibitor) with a peanut extract in the presence of glutaraldehyde. Ara h 1 modified with pABA was prepared on a PVDF membrane due to solubility problem. A control was prepared using glycine instead of pABA or without treatment. Excess pABA or glycine was removed by centrifugation or washing the membranes. The resulting modified allergens were subjected to trypsin digestion and analyzed by gel electrophoresis. IgE binding was performed in Western blot. Results showed that both Ara h 1 and Ara h 2 allergens, when covalently attached with pABA, were more resistant to trypin digestion than native allergens. Treatment of the allergens with glycine (control) instead of pABA did not result in more resistant allergens. The pABA-modified allergens showed some IgE binding or allergenic reactivity which should not be a concern based on the assumption that the modified allergens may not be absorbed. The model system demonstrated that peanut allergens could be made more resistant to digestion and warrants further investigations into more complex systems that may support the concept that making peanut allergens more resistant to digestion could potentially reduce the absorption of allergens and, thereby, allergic responses.