Characterisation of monoclonal antibodies against β‐conglycinin from soya bean (Glycine max) and their use as probes for thermal denaturation

A panel of four monoclonal antibodies (Mabs) was raised against β‐conglycinin, the 7S globulin from soya bean. The antibodies were characterised by using direct and competitive enzyme‐linked immunosorbent assays (ELISAs), immunoblotting procedures and by analysis of subunit fractions obtained after anion exchange chromatography. All the Mabs were specific for β‐conglycinin, recognising the acidic α‐and α‐subunits. One of the Mabs (IRFN 0089) was used to probe the structural changes that take place during thermal denaturation of β‐conglycinin. A two‐site ELISA was developed to observe structural changes in β‐conglycinin with heating. Antibody recognition of heated conglycinin increased with temperature reaching a maximum at 65°C; β‐conglycinin heated to this temperature was recognised three‐fold better than unheated β‐conglycinin. At a higher temperature (65–95°C) β‐conglycinin immunoreactivity remained at least two‐fold higher than that of the unheated protein. Differential scanning calorim‐etry data showed the maximum binding of Mab 0089 to correspond with the thermal transition of the β‐conglycinin molecule. The use of the panel of antibodies as structural probes is discussed together with further possible applications of this technology in food chemistry.