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Updated: Oct 15, 2025

Taste Exam: A Brief and Validated Test
Published on: August 17, 2018
Taste and chirality: l-glucose sweetness is mediated by TAS1R2/TAS2R3 receptor
Nitzan Dubovski1, Yaron Ben Shoshan-Galeczki1, Einav Malach1
1The Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel; Fritz Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem, Israel.
Abstract:
Naturally occurring sugars usually have d-chirality. While a change in chirality typically affects ligand-receptor interaction, non-caloric l-glucose was reported as sweet for humans. Here we show that l- and d-glucose have similar sensory detection thresholds (0.041 ± 0.006 M for d-glucose, and 0.032 ± 0.007 M for l-glucose) and similar sweetness intensities at suprathreshold concentrations. We demonstrate that l-glucose acts via the sweet taste receptor TAS1R2/TAS1R3, eliciting a dose-dependent activation in cell-based functional assays. Computational docking of glucose to the VFT domain of TAS1R2 suggests two sub-pockets, each compatible with each of the enantiomers. While some polar residues (Y103, D142, N143, S144, Y215) are unique for sub-pocket A and others (D307, T326, E382, R383) for sub-pocket B, no interaction is unique for only one enantiomer. The many options for creating hydrogen bonds with the hydroxyl moieties of glucose explain how both enantiomers can fit each one of the sub-pockets.
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