Identification of epitopes in the α and β subunits of soybean β-conglycinin immunogenic in chickens

Soy meal is a valuable protein supplement for humans and animals. An abundant proteins in soy meal is the seed storage protein β-conglycinin, a trimer composed of different combinations of β, α and α’ subunits. Allergic responses to β-conglycinin reduce soy meal’s value as a feed because they are associated with poor performance in animals. Allergies begin with an inappropriate immune response to food. To assess immune response to β-conglycinin, we identify epitopes that bind immunoglobulins (Ig) Y, M and A isolated from chicken eggs. We identified specific immunogenic epitopes in β-conglycinin that were commonly antigenic in multiple eggs. Generally, epitopes bound multiple types of Ig. Comparison of the protein sequences suggest that immunogenic epitopes are conserved between subunits. We propose ways that variants of these immunogenic regions could be used to develop soybean lines to determine if creating less immunogenic soybean improves growth of animals fed soymeal.