Recent developments in the characterization and biotechnological production of sweet-tasting proteins

The state of the art regarding the six known sweet-tasting proteins (thauma tin, monellin, mabinlin, pentadin, brazzein and curculin) and the taste-mod ifying protein miraculin is reviewed. Their biochemical properties, molecul ar genetics and biotechnological production are assessed. All of these prot eins have been isolated from plants that grow in tropical rainforests. They share no sequence homology or structural similarities. Nonetheless, one of them, thaumatin, shares extensive homology with certain non-sweet proteins found in other plants. The potential industrial applications of the sweet- tasting proteins are also discussed, placing special emphasis on the barrie rs that a recombinant product of these characteristics will have to overcom e before it reaches the market.