甜味分子的多点结合甜味理论

关于甜味分子生甜机理 ,存在 3种理论解释 ,分别为AH/B理论、AH/B/X理论和多点结合理论。实践证明 ,这 3种理论都能合理解释各类甜味物质的生甜机理。其中多点结合甜味理论认为 ,人体受体蛋白包含 8个基本的甜味识别部位 ,分别为B、AH、XH、G1、G2、G3、G4和D ,它们与甜味分子相应的结合部位发生相互作用 ,受体蛋白由紧密的收缩构象改变为开放的展开构象 ,从而产生甜味刺激传导 ,甜味产生后 ,由于识别部位的极性或离子基团之间的静电作用力 ,将驱散甜味分子 ,使受体蛋白恢复原来的收缩构象。根据这一理论 ,可以合理构造各种糖分子及其衍生物的多点结合模型。蔗糖是B1、B2、AH1、AH2、XH1、XH2、G1、E1、G2、E2、G3、E3、G4、E4型甜味剂 ,D 葡萄糖是B1、B2、AH1、AH2、XH1、XH2型甜味剂 ,D 果糖是E1、E2、E3、E4型甜味剂。

The Multipoint Attachment Theory of Sweet Molecules

Now there are three theories have been put forward to explain the mechanism of sweet taste of the sweet molecule These three theories are AH/B theory, AH/B/X theory and a multipoint attachment theory Many examples have proved that these theories could explain the mechanism of sweet taste of the sweet molecule rationally The multipoint attachment theory assumes the presence, in the human sweetness receptor, of eight fundamental recognition sites able to interact with at least eight fundamental interaction sites of sweeteners These eight fundamental recognition sites are designated as sites B,AH,XH,G1,G2,G3,G4 and D After a sweetener interacts with the receptor, a conformational change of the receptor passes from a contracted conformation to a more open expanded conformation Following the concomitant sweet taste triggering effect, the receptor expels the sweet molecule and returns to its resting state as a result of the electrostatic driving forces existing between the polar or ionic moieties of the recognition According to the theory, the models of multipoint attachment of sugar and its derivatives rationally can be structured Sucrose is a B1,B2,AH1,AH2,XH1,XH2,G1,E1,G2,E2,G3,E3,G4,E4 type sweetener; D glucose is a B1,B2,AH1,AH2,XH1,XH2 type sweetener, And D fructose is a E1,E2,E3,E4 type sweetener