title: Umami-bitter interactions: the suppression of bitterness by umami peptides via human bitter taste receptor.
abstract: Taste-taste interactions often showed in human psychophysical studies. Considering that each tastant in foodstuffs individually stimulates its responsible gustatory systems to elicit relevant taste modalities, taste-taste interaction should be performed in taste receptor cell-based assay. While umami substances have been proposed to suppress the bitterness of various chemicals in human sensory evaluation, the bitter-umami interaction has not been explored in bitter taste receptors, TAS2Rs. We investigated umami-bitter taste interactions by presenting umami peptides with bitter substance (salicin) on Ca(2+)-flux signaling assay using hTAS2R16-expressing cells. Five representative umami peptides (Glu-Asp, Glu-Glu, Glu-Ser, Asp-Glu-Ser, and Glu-Gly-Ser) derived from soybean markedly attenuated the salicin-induced intracellular calcium influx in a time-dependent manner, respectively, while Gly-Gly, a tasteless peptide did not. The efficacies of Glu-Glu suppressing salicin-induced activation of hTAS2R16 were higher than that of probenecid, a specific antagonist of hTAS2R16. According to Ca(2+)-flux signaling assay using the mixtures of salicin and umami peptides, all five umami peptides suppressed salicin-induced intracellular calcium influx in a noncompetitive manner. These results may provide evidence that umami peptides suppress bitter taste via bitter taste receptor(s). This is the first report which defines the interaction between bitter and umami taste in taste receptor level.
authors.affiliation: Research Group of Food Functionality, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Research Group of Food Functionality, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Son
authors.affiliation: Research Group of Food Functionality, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea.
authors.forename: Yiseul
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Misaka
authors.affiliation: Research Group of Food Functionality, Korea Food Research Institute, Bundang-gu, Sungnam-si, Gyeonggi-do, Republic of Korea. Electronic address: mrrhyu@kfri.re.kr.
authors.forename: Mee-Ra
authors.initials: MR
authors.lastname: Rhyu
mesh_terms: D001592:Benzyl Alcohols / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002460:Cell Line; D004151:Dipeptides / Q000494:pharmacology; D005960:Glucosides / Q000494:pharmacology; D006801:Humans; D009842:Oligopeptides / Q000494:pharmacology*; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013649:Taste / Q000187:drug effects*; D000098706:Taste Receptors, Type 2
chemical_list: D001592:Benzyl Alcohols; D004151:Dipeptides; D005960:Glucosides; D009842:Oligopeptides; D043562:Receptors, G-Protein-Coupled; D000098706:Taste Receptors, Type 2; C021030:gamma-glutamylaspartic acid; C094686:glutamyl-glutamic acid; C005696:salicin; D002118:Calcium
keywords: Bitter taste receptor; Bitterness suppressing effects; Glutamyl peptides; Umami–bitter interaction; hTAS2R16