PRODUCTION AND CHARACTERIZATION OF MONOCLONAL-ANTIBODIES AGAINST 11S STORAGE PROTEIN FROM PEA-SEEDS

Antibodies can be used as probes to investigate the structure of 11S storage proteins, their subunit composition and structural modifications induced by technological treatments. Monoclonal antibodies have been raised against Pisum sativum legumin (11S storage protein). Their binding characteristics were examined by direct, sandwich and competitive ELISA and by immunoblotting against legumin and 11S type storage proteins from other species. One of the MAbs. reacting with all 11S proteins tested, recognizes a discontinuous epitope accessible on the surface of the native hexameric protein but destroyed in dissociated legumin. Two antibodies recognize sequential epitopes belonging to a region of the acidic polypeptides present on the surface of the native legumin. These two MAbs cross-react only with pea and bean 11S proteins. Two other MAbs are specific for sequential epitopes buried in the native protein, localized, respectively, on acidic and basic polypeptides. The MAb reacting with the acidic polypeptide exhibits very specific binding for pea legumin. By contrast, the MAb specific to the basic polypeptide cross reacts with 11S proteins studied. This work shows the potential of this approach for the characterization of the conformation of the 11S proteins and the investigation of structural modifications.