Three-dimensional structure of Gly m 5 (β-conglycinin) plays an important role in its stability and overall allergenicity

•Gly m 5 generated three major digestion-resistant fragments.•The largest fragment corresponded to main body of the monomer.•Two smaller fragments corresponded to main bodies of two modules of the monomer.•The three-dimensional structure of Gly m 5 contributed to its overall allergenicity.

To date, there is insufficient knowledge regarding the relationship of the allegenicity and the three-dimensional structure of Gly m 5 (β-conglycinin), a major allergen in soybean. In the present study, allergen Gly m 5 was demonstrated to generate three major digestion-resistant fragments when it was subjected to in vitro digestion. The largest fragment corresponded to the main body of the monomer and two smaller fragments corresponded to the main bodies of two modules of the monomer. Two major protease cleavage sites were located in the regions near to the connection between two modules. Coincidentally, the major digestion-resistant fragments were demonstrated to contain intact IgE epitopes and be capable to induce basophil histamine release in Gly m 5 sensitised piglets, indicating that the three-dimensional structure of Gly m 5 afforded the molecule some protection from complete degradation into small peptides and amino acids, and contributed to its overall allergenicity.