Abstract:Miraculin is a glycoprotein with taste-modifying activity and is isolated from miracle fruit (Synsepalum dulcificum), a shrub native to West Africa. The protein can modify human's taste and turn a sour taste to a sweet taste. The mature peptide of miraculin consists of 191 amino acids and has taste-modifying activity in the forms of dimmers or tetramers, but not in monomers. Two histidine residues, exposed on the outside of the protein, are the main functional groups. In addition to the taste-modifying activity, it can also improve sensitivity of diabetic animals to insulin. Several methods have been developed for the purification of miraculin, including dialysis, centrifugation, solvent precipitations and chromatographic separation. Recently, genetic engineering approaches have been applied to its production in transgenic microbes and plants. This paper reviews recent studies on its structure, function, extraction and biosynthesis in transgenic organisms.