Miraculin

• UniProt: P13087

Miraculin is a glycoprotein from the fruit of the miracle berry.

Structure

The primary structure consisting of 191 amino acids. The quaternary structure consists of two homodimers that assemble into a tetramer.

Effect

Miraculin itself is tasteless, but if the human tongue is exposed to miraculin, it actually takes acidic foods such as citrus fruits true as sweet. If Miraculin simultaneously consumed with acids, so it takes a moment to adjust the effect. Until the miraculin acts, tasting a mixture with acids first sour, after a delay then provides a sweet taste.

Is responsible for the confusion a drug with the aptly named miraculin. The glycoprotein attaches itself to the sweet taste receptor, but does not trigger any reaction - at least not at neutral pH, as Japanese researchers at the University of Tokyo reported in October 2011. But then you eat an acidic food, the environment moves in the mouth into the acidic range - and Miraculin assumes a new form. As a result, it switches on the sweet taste receptor, the downstream neurons fire and the brain ends up the message " intensely sweet " - even though you've just bitten into a lemon for example.

History

Since the miracle berry itself has little taste of its own, the flavor conversion hence the name was regarded as a miracle. In West Africa, the miracle berry has been used to improve the taste of acidic foods.

The active substance isolated Japanese scientist Kenzo Kurihara, was after the miracle berry (English miracle fruit ) named, when he published his work in 1968 in Science.

Miraculin could be used in future as a low calorie, suitable for diabetics sweetener. The production is currently still too expensive. Attempts to produce miraculin gene-based, could contribute to establishing a new sugar-free sweetener. Japanese scientists for example, were successful with the generation of genetically modified plants such as the garden salad, which produce miraculin. Also approaches to production using genetically modified bacteria (Escherichia coli) have been described.