The human bitter taste receptor, hTAS2R16, discriminates slight differences in the configuration of disaccharides.
Sweetness and bitterness are key determinants of food acceptance and rejection, respectively. Sugars, such as sucrose and fructose, are generally recognized as sweet. However, not all sugars are sweet, and even anomers may have quite different tastes. For example, gentiobiose is bitter, whereas its anomer, isomaltose, is sweet. Despite this unique sensory character, the molecular basis of the bitterness of gentiobiose remains to be clarified. In this study, we used calcium imaging analysis of human embryonic kidney 293T cells that heterologously expressed human taste receptors to demonstrate that gentiobiose activated hTAS2R16, a bitter taste receptor, but not hT1R2/hT1R3, a sweet taste receptor. In contrast, isomaltose activated hT1R2/hT1R3. As a result, these anomers elicit different taste sensations. Mutational analysis of hTAS2R16 also indicated that gentiobiose and β-D-glucopyranosides, such as salicin share a common binding site of hTAS2R16.
General Research Institute of Food Science and Technology, Nissin Foods Holdings Co. Ltd., Shiga, Japan.
Takanobu
T
Sakurai
Takumi
T
Misaka
Yohei
Y
Ueno
Masaji
M
Ishiguro
Shinji
S
Matsuo
Yoshiro
Y
Ishimaru
Tomiko
T
Asakura
Keiko
K
Abe
D001592:Benzyl Alcohols / Q000737:chemistry; D001665:Binding Sites; D002460:Cell Line; D004187:Disaccharides / Q000737:chemistry* / Q000378:metabolism; D005960:Glucosides / Q000737:chemistry; D006801:Humans; D008968:Molecular Conformation; D009154:Mutation; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D013649:Taste / Q000502:physiology*; D000098706:Taste Receptors, Type 2
D001592:Benzyl Alcohols; D004187:Disaccharides; D005960:Glucosides; D043562:Receptors, G-Protein-Coupled; D000098706:Taste Receptors, Type 2; C005696:salicin; C100052:gentiobiose