| Abstract: | Rabbit antibodies were produced against thaumatin I, a sweet-tastingprotein from plant origin using the technique of double diffusionin agar. Cross-reactions were observed between these antibodiesand thaumatin I, monellin and chemically modified thaumatins.No cross-reaction was observed between the antibodies of thaumatinI and the not sweet-tasting iodinated monellin. This lack ofcross-reaction may be due to the fact that iodination splitsmonellin into its A and B chain, resulting in a disturbanceof the tertiary structure of the molecule. The appearance ofprecipitation lines from thaumatin I as well as from monellinin reaction with the antibodies of thaumatin in the immunodiffusionassay indicates that thaumatin and monellin are immunologicallyclosely related. An identical conformational antigenic determinantin both molecules is probably responsible for this relationship.It is tentatively concluded that the identical conformationaldeterminant coincides with the active site responsible for thesweet-taste sensation. |
