title: Modulation of sweet taste by umami compounds via sweet taste receptor subunit hT1R2.
abstract: Although the five basic taste qualities-sweet, sour, bitter, salty and umami-can be recognized by the respective gustatory system, interactions between these taste qualities are often experienced when food is consumed. Specifically, the umami taste has been investigated in terms of whether it enhances or reduces the other taste modalities. These studies, however, are based on individual perception and not on a molecular level. In this study we investigated umami-sweet taste interactions using umami compounds including monosodium glutamate (MSG), 5'-mononucleotides and glutamyl-dipeptides, glutamate-glutamate (Glu-Glu) and glutamate-aspartic acid (Glu-Asp), in human sweet taste receptor hT1R2/hT1R3-expressing cells. The sensitivity of sucrose to hT1R2/hT1R3 was significantly attenuated by MSG and umami active peptides but not by umami active nucleotides. Inhibition of sweet receptor activation by MSG and glutamyl peptides is obvious when sweet receptors are activated by sweeteners that target the extracellular domain (ECD) of T1R2, such as sucrose and acesulfame K, but not by cyclamate, which interact with the T1R3 transmembrane domain (TMD). Application of umami compounds with lactisole, inhibitory drugs that target T1R3, exerted a more severe inhibitory effect. The inhibition was also observed with F778A sweet receptor mutant, which have the defect in function of T1R3 TMD. These results suggest that umami peptides affect sweet taste receptors and this interaction prevents sweet receptor agonists from binding to the T1R2 ECD in an allosteric manner, not to the T1R3. This is the first report to define the interaction between umami and sweet taste receptors.
authors: Division of Creative Food Science for Health, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors: Jaewon
authors: J
authors: Shim
authors: Division of Creative Food Science for Health, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors: Hee Jin
authors: HJ
authors: Son
authors: Division of Creative Food Science for Health, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors: Yiseul
authors: Y
authors: Kim
authors: Division of Creative Food Science for Health, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors: Ki Hwa
authors: KH
authors: Kim
authors: Division of Creative Food Science for Health, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors: Jung Tae
authors: JT
authors: Kim
authors: Division of Creative Food Science for Health, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors: Hana
authors: H
authors: Moon
authors: Division of Creative Food Science for Health, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors: Min Jung
authors: MJ
authors: Kim
authors: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors: Takumi
authors: T
authors: Misaka
authors: Division of Creative Food Science for Health, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors: Mee-Ra
authors: MR
authors: Rhyu
mesh_terms: D000494:Allosteric Regulation; D001555:Benzene Derivatives / Q000494:pharmacology; D003494:Cyclamates / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D004347:Drug Interactions; D057809:HEK293 Cells; D006801:Humans; D011485:Protein Binding; D020033:Protein Isoforms / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012970:Sodium Glutamate / Q000494:pharmacology; D013395:Sucrose / Q000819:agonists / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D013549:Sweetening Agents / Q000494:pharmacology; D013649:Taste / Q000502:physiology; D055697:Taste Perception / Q000502:physiology*; D013843:Thiazines / Q000494:pharmacology
chemical_list: D001555:Benzene Derivatives; D003494:Cyclamates; D004151:Dipeptides; D020033:Protein Isoforms; D043562:Receptors, G-Protein-Coupled; D013549:Sweetening Agents; D013843:Thiazines; C431926:taste receptors, type 1; C094686:glutamyl-glutamic acid; D013395:Sucrose; C006362:acetosulfame; D012970:Sodium Glutamate; C495512:lactisole