The 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.
Chem Senses. 2023 Jan 1;48. doi: 10.1093/chemse/bjad032.
Deuterium oxide (D2O) is water in which the heavier and rare isotope deuterium replaces both hydrogens. We have previously shown that D2O has a distinctly sweet taste, mediated by the T1R2/T1R3 sweet taste receptor. Here, we explore the effect of heavy water on T1R2 and T1R3 subunits. We show that D2O activates T1R3-transfected HEK293T cells similarly to T1R2/T1R3-transfected cells. The response to glucose dissolved in D2O is higher than in water. Mutations of phenylalanine at position 7305.40 in the transmembrane domain of T1R3 to alanine, leucine, or tyrosine impair or diminish activation by D2O, suggesting a critical role for T1R3 TMD domain in relaying the heavy water signal.
重水（D2O）是一种水中的氢原子被质量更重且更为稀有的氘原子所取代。我们之前的研究表明，重水有一种独特的甜味，由 T1R2/T1R3 甜味受体所介导。在这里，我们探究了重水对 T1R2 和 T1R3 亚基的影响。我们发现，重水激活转染了 T1R3 的 HEK293T 细胞的效果与转染了 T1R2/T1R3 的细胞类似。在重水中溶解的葡萄糖所引发的反应要比在水中更高。T1R3 跨膜区 7305.40 位的苯丙氨酸突变为丙氨酸、亮氨酸或酪氨酸会削弱或减少重水的激活作用，这表明 T1R3 TMD 结构域在传递重水信号方面起着关键作用。
