Monoclonal Antibodies to Sweet Taste Proteins. I. Analysis of Antigenic Epitopes on Thaumatin by Competitive Inhibition Assays

Abstract

Using a competitive inhibition binding immunoassay, we have examined some of the antigenic epitopes present on thaumatin, an intense sweet tasting protein from the African fruit katemfe. We have developed a library of monoclonal antibodies which react with different surface antigenic epitopes on thaumatin. Some of these monoclonal antibodies also cross-react with monellin, another unrelated sweet tasting protein. The competitive binding immunoassay examines the immunoreactivity of both solid-phase and liquid-phase monoclonal antibodies. At least six major antigenic epitopes on thaumatin were identified by our library of monoclonal antibodies. This type of competitive binding analysis may prove useful in the discovery of "sweet taste determinants" on plant proteins and in the development of tandem immunoassays for quantitation of sweet tasting proteins in plant extracts.

Natural sweet macromolecules: how sweet proteins work

“…Vol. 63,2006 Review Article 1879 ture-activity relationship of thaumatin was reported by Mandal et al [34]. Using a competitive inhibition binding immunoassay, these authors developed a library of monoclonal antibodies, which react with different surface antigenic epitopes on thaumatin.…”

“…This view was explicitly embedded in the Temussi's model of the active site of the receptor [33]. On the basis of ELISA tests, which showed cross-reactivity between antibodies raised against monellin with thaumatin [34,35], the sequence TyrA13-AspA16 of native monellin (corresponding to residues Tyr57-Asp59 of thaumatin in the assays) was suggested as a potential sweet finger [36]. Preliminary structural work on the solution conformation of MNEI showed that the relative spatial arrangement in solution of the side chains of Tyr65 and Asp68 (corresponding to TyrA13-AspA16 of monellin) is consistent with the corresponding arrangement of the side chains of Phe and Asp in aspartame [28].…”

Mecanismos de defensa en plantas. Proteínas relacionadas con la patogenicidad

“…Solo cuando las proteínas PR-5 fueron secuenciadas, fue que se esclareció la no-relación con la taumatina que es una proteína específica del fruto del Katemfe (Thaumatococcus danielli), que por su sabor dulce y su alta homología con la secuencia aminoácida, estuvo muy relacionada con este grupo, actualmente se plantea que esta proteína no tiene actividad antifúngica (Mandal et al, 1991;Koiwa et al, 1997).…”

Le goût des acides aminés, des peptides et des protéines : exemple de peptides sapides dans les hydrolysats de caséines

“…Elle a permis de mettre en évidence plusieurs épitopes. Certains de ces anticorps interagissent également avec la monelline (Mandai et al, 1991). Il est intéressant de noter que la monelline et la thaumatine ont en commun sept séquences de trois acides aminés qui n'existent pas chez les modificateurs de goût, la curculine et la miraculine.…”