The molecular receptive ranges of human TAS2R bitter taste receptors

Chem Senses. 2010 Feb;35(2):157-70. doi: 10.1093/chemse/bjp092. Epub 2009 Dec 18.


Humans perceive thousands of compounds as bitter. In sharp contrast, only approximately 25 taste 2 receptors (TAS2R) bitter taste receptors have been identified, raising the question as to how the vast array of bitter compounds can be detected by such a limited number of sensors. To address this issue, we have challenged 25 human taste 2 receptors (hTAS2Rs) with 104 natural or synthetic bitter chemicals in a heterologous expression system. Thirteen cognate bitter compounds for 5 orphan receptors and 64 new compounds for previously identified receptors were discovered. Whereas some receptors recognized only few agonists, others displayed moderate or extreme tuning broadness. Thus, 3 hTAS2Rs together were able to detect approximately 50% of the substances used. Conversely, though 63 bitter substances activated only 1-3 receptors, 19 compounds stimulated up to 15 hTAS2Rs. Our data suggest that the detection of the numerous bitter chemicals is related to the molecular receptive ranges of hTAS2Rs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / pharmacology
  • Calcium Signaling / drug effects
  • Cell Line
  • Fluorescent Dyes / pharmacology
  • Humans
  • Receptors, G-Protein-Coupled / agonists
  • Receptors, G-Protein-Coupled / metabolism*
  • Taste / drug effects
  • Taste / physiology*
  • Taste Threshold
  • Xanthenes / pharmacology


  • Aniline Compounds
  • Fluo 4
  • Fluorescent Dyes
  • Receptors, G-Protein-Coupled
  • Xanthenes
  • taste receptors, type 2