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ARS Home » Southeast Area » Raleigh, North Carolina » Soybean and Nitrogen Fixation Research » Research » Publications at this Location » Publication #282112

Title: Identification of a second allergenic epitope in the alpha-Subunit of beta-Conglycinin

item Taliercio, Earl
item KIM, SUNG WOO - North Carolina State University

Submitted to: Journal of Food and Agriculture Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2013
Publication Date: 6/15/2013
Citation: Taliercio, E.W., Kim, S. 2013. Identification of a second allergenic epitope in the alpha-Subunit of beta-Conglycinin. Journal of Food and Agriculture Immunology. DOI 10.1080/09540105.2013.791969.

Interpretive Summary: Pigs fed soymeal early in life often experience a lag in growth making soy an undesirable food for young pigs. This postweaning lag in growth has in part been associated with an allergic reaction to the soybean seed storage protein conglycinin. We have developed an array the represents the amino acid sequences of the alpha subunit of this peptide. We have identified pigs that have antibodies against this protein. Using the peptide array we have identified a second epitope that is associated with the allergic reactions in about half of the pigs tested. Variants of allergenic portions of the alpha subunit of conglyciinin may provide the basis for breeding less allergenic soymeal.

Technical Abstract: Soybean meal in the post weaning diet of pigs results in a growth lag. The growth lag is correlated with IgG production against soybean proteins, including the seed storage protein beta-conglycinin. We identified serum from 30 pigs that had IgG directed against beta-conglycinin. Analysis of the same sera on protein blots identified sera that likely had IgG against the beta-subunit of beta-conglycinin. A tiled peptide array of the beta-subunit of beta-conglycinin was screened to identify the epitopes of the beta-subunit that bind IgG. One major IgG binding epitope previously identified was confirmed. A second major IgG binding epitope was identified that bound IgG from half of the animals tested. Minor epitopes that bound IgG from one or two other sera were also indentified. Binding of IgG to beta -conglycinin in an ELISA was inhibited by peptides that included epitopes of one of the minor epitopes, but not by peptides that included either major epitope.