Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 5, 2007
Publication Date: May 5, 2007
Citation: Xu, C., Caperna, T.J., Garrett, W.M., Cregan, P.B., Bae, H., Luthria, D.L., Natarajan, S.S. 2007. Proteomic analysis of the distribution of the major seed allergens in sixteen soybean genotypes. Journal of the Science of Food and Agriculture. 87:2511-2518.
Interpretive Summary: Soybean is a rich and inexpensive source of proteins for humans and animals. However, some people have severe allergic reactions to soybean because of the presence of major allergen proteins. There is limited data available that describe the natural variation in allergen proteins that occur in soybean. For a better understanding of the variation of allergen proteins expected to occur in genetically modified (GM) soybeans, it is important to determine the natural variation of protein composition, both in wild and cultivated soybeans. Therefore, we have conducted studies to determine and compare the composition of major allergen proteins in a diverse group of soybeans including the wild soybean from which cultivated soybean originated. We observed that the wild soybean has more allergenic proteins with a higher number of polypeptides than the cultivated soybeans we examined. These results can be used by scientists and food technologists to determine that the amounts of allergen proteins accumulated in GM soybeans exceed the level of similar proteins in non-GM soybean varieties.
We investigated the distribution of the three major allergens (Gly m Bd 60K, Gly m Bd 30K and Gly m Bd 28K) in sixteen soybean genotypes from four groups (wild, landraces, ancestors, and modern). Four genotypes were investigated from each group. All allergenic proteins were well separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and characterized using mass spectrometry (MS). Variations in the overall distribution of allergens were observed among different genotypes. Gly m Bd 60K allergens consist of alpha-subunits of beta-conglycinin and G2 subunits of glycinin. In wild genotypes, alpha-subunits of beta-conglycinin separated into 6-7 protein spots whereas 5-7 spots were observed in landrace genotypes. All genotypes of modern and ancestral groups showed 3-5 protein spots of alpha-subunits of beta-conglycinin. All genotypes showed 8 spots of glycinin G2 subunits except one ancestral genotype which had 7 spots. Two protein spots were detected for Gly m Bd 30K in fourteen genotypes but only one spot was detected in two wild genotypes. Two protein spots were detected for Gly m Bd 28K in all sixteen genotypes. The majority of proteomic variation of allergenic proteins was observed between wild and cultivated soybean genotypes rather than among genotypes within the same group.