MONOCLONAL-ANTIBODIES TO SWEET TASTE PROTEINS .2. DEVELOPMENT OF 2 DIFFERENT IMMUNOASSAYS FOR THAUMATIN AND MONELLIN

Two different types of immunoassays for the detection and quantitation of thaumatin and monellin, plant proteins with intense sweet taste properties, have been developed. A tandem enzyme-linked immunosorbent assay (ELISA) was developed for the quantitation of thaumatin, in which one monoclonal antibody (mAb) raised against thaumatin (TM-1-D) was used as the solid-phase ''capture'' antibody, while the second mAb antibody (TM-1-C) was labeled with biotin. A standard curve for the assay was obtained and had a correlation coefficient of 0.987; the detection limit of the immunoassay was 5 ng/ml. Using a single anti-monellin mAb, a competitive enzyme immunoassay (EIA) was developed for monellin. The competitive binding of biotinylated monellin and known monellin standards with mAb 4.2E was examined; this assay had a minimum detection limit of 30 mug/ml.