Identification of epitopes of the A1aBx and A5A4B3 subunits of glycinin antigenic in three animal species

Soybean meal is commonly added to a variety of animal feeds to supplement protein sources and to optimise growth. While soybean protein is a valuable food supplement it has been recognised as an important food allergen. The soybean seed storage protein, glycinin, has been identified as an allergen. A tiled peptide array of the A1aBx and A5A4B3 subunits of glycinin was screened to identify the epitopes that bind antibodies from multiple species. We have identified four regions in these two glycinin subunits that are antigenic in most or all of the species tested. One region is implicated in an allergic response in dogs by the dog's ability to bind IgE. Three regions overlap or abut regions that are similar to allergenic epitopes in peanut. It will be critical to identify immunogenic regions able to cause allergies to soy in order to prioritise them for mitigation.