|
Miraculin is a natural sugar substitute, a glycoprotein extracted from the fruit of ''Synsepalum dulcificum''. The berry, also known as the miracle fruit, was first documented by explorer Chevalier des Marchais, who searched for many different fruits during a 1725 excursion to its native West Africa. Miraculin itself is not sweet. However, after the taste buds are exposed to miraculin (which binds to sweet receptors on the tongue), acidic foods which are ordinarily sour (such as citrus) are perceived as sweet. This effect lasts up to an hour. The active substance, isolated by Prof. Kenzo Kurihara (栗原 堅三 ''Kurihara Kenzō''), a Japanese scientist, was named miraculin after the miracle fruit when Kurihara published his work in ''Science'' in 1968. == Glycoprotein structure == Miraculin was first sequenced in 1989 and was found to be a glycoprotein consisting of 191 amino acids and some carbohydrate chains. Miraculin occurs as a tetramer (98.4 kDa), a combination of 4 monomers group by dimer. Within each dimer 2 miraculin glycoproteins are linked by a disulfide bridge. The molecular weight of the glycoprotein is 24.6 kDa including 3.4 kDa (13.9% of the weight) of sugar constituted (on molar ratio) of glucosamine (31%), mannose (30%), fucose (22%), xylose (10%) and galactose (7%).〔 The taste-modifying protein, miraculin, has seven cystein residues in a molecule composed of 191 amino acid residues. Both tetramer miraculin and native dimer miraculin in its crude state have the taste-modifying activity of turning sour tastes into sweet tastes. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Miraculin」の詳細全文を読む スポンサード リンク
|