Immunochemical and computational characterization of the major soybean allergen Gly m Bd 30K

CANDREVA, ÁNGELA; CURCIARELLO, RENATA; GONZÁLEZ, VIRGINIA; PARISI, GUSTAVO; PETRUCCELLI, SILVANA; DOCENA, GUILLERMO

Viña del Mar, Chile

Congreso; 9th Latin American Congress of Immunology, Viña del Mar, Chile. November 3 – 7th 2009. XII Chilean Society of Immunology Congress. LVII Argentinean Society of Immunology Satellite Scientific Meeting; 2009

Chilean Society of Immunology

Soy proteins are widely used by food industry. More than 15 allergens have been identified, being Gly m Bd 30K the major soy allergen. Information regarding the structure and allergenic epitopes may be relevant to understand the molecular basis of the pathology and the previously cross-reactivity with bovine caseins described by our group. Our objective was to obtain Gly m Bd 30K as a recombinant protein and to obtain a computational model for epitope mapping. We used a cDNA library of immature soybean, the vectors pENTR SD/TOPO and pDEST-HIS-MBP and several strains of E.coli BL21 for protein expression. It was obtained as soluble protein and then used in different immunoenzymatic methods (EAST, ELISA, immunoblotting) with patient sera and cow s milk-specific polyclonal and monoclonal antibodies. Three peptides containing bioinformatically-proposed IgE epitopes were also cloned and resulted to be recognized by the antibodies. Gly m Bd 30K was modeled and two epitopes were located in the surface. The recombinant Gly m Bd 30K obtained resulted to be immunochemically antigenic and allergenic, two epitopes were mapped and for the first time we built a three dimensional model for this soy allergen. This information may be important to reduce its immunoreactivity by genetic engineering.