Carbohydrate moieties on the in vitro immunoreactivity of soy b-conglycinin

• Published in: Food research international Vol. 42; no. 7; pp. 819 - 825
• Main Authors: Amigo-Benavent, Miryam, Athanasopoulos, Vasileios I, Ferranti, Pasquale, Villamiel, Mar, Del Castillo, M Dolores
• Format: Journal Article
• Language: English
• Published: 01.08.2009
• ISSN: 0963-9969
• DOI: 10.1016/j.foodres.2009.03.003

b-Conglycinin is a functional glycoprotein and one of the most important soybean allergens. The aim of the present research was to investigate the role of the N-glycans moieties of b-conglycinin on its in vitro immunoreactivity. The soy allergen was obtained by isoelectric precipitation from commercial soy protein isolate and was enzymatically deglycosylated by PNGase F (Peptide N-Glycosidase F EC 3.5.1.52). In order to optimize deglycosylation conditions different reaction times and allergen concentrations were tested. The extent of deglycosylation was estimated by SDS-PAGE, CZE, RP-HPLC, and MALDI-TOF MS analyses, which provided information related to changes in protein structure. The antigenicity of both native b-conglycinin and its deglycosylated form was evaluated by western-blotting and indirect ELISA employing polyclonal rabbit anti-soybean sera and horseradish peroxidase-labeled goat anti- rabbit IgG while the in vitro allergenicity was assessed by means of indirect competitive inhibition ELISA employing human sera (IgE) of soy allergics. b-Conglycinin was effectively deglycosylated by PNGase F. Data on immunological tests suggested that glycosyl moieties forming this glycoprotein might be involved in its immunoreactivity.