SPLTRAK Abstract Submission
An Interruption of Umami Peptide to the Salicin Binding to T2R16 Bitter Taste Receptor Can be Enhanced by IMP
MeeRa Rhyu, Yiseul Kim, Minji Woo
Korea Food Research Institute, Jeollabuk-do, South Korea

Bitter-masking effect of umami peptides has long been found in human taste test. Yet we have only recently provided the evidence that umami peptides suppress bitterness via direct binding to bitter taste receptor in cells expressing T2R16. Similar bitter-masking effect through direct binding to bitter taste receptor was verified for other umami compounds including MSG, N-geranyl cyclopropylcarboxamide, and theanine. A distinct characteristic of umami taste is strong synergism by 5’ ribonucleotides, such as IMP or GMP. To test whether the synergism of umami taste applies to the bitter-masking, we investigated the interaction between IMP and MSG or Glu-Glu to the salicin-induced Ca2+ influx in cells expressing T2R16 using Ca2+-flux signaling assay. We maintained pH 7.4~7.25 of all assay systems with 100 mM HEPES (pH 7.4) to exclude acidic effect coming from samples. IMP itself has little effect on salicin-induced intracellular Ca2+ influx, whereas the efficacy of MSG suppressing salicin-induced Ca2+ influx can be enhanced by IMP in a dose-dependent manner. Also, the efficacy of Glu-Glu suppressing salicin-induced Ca2+ influx was effectively enhanced by pretreatment of IMP. These observations indicate that a distinct synergism of umami taste by 5’ ribonucleotides is crucial for the bitter-masking effect of umami compounds and that the synergism is to be involved in interacting with bitter taste receptor.