Statistical and Biological Physics, International School for Advanced Studies and DEMOCRITOS Modeling, Center for Research in Atomistic Simulations, Trieste, Italy.
PLoS One. 2010 Aug 25;5(8):e12394. doi: 10.1371/journal.pone.0012394.
Humans' bitter taste perception is mediated by the hTAS2R subfamily of the G protein-coupled membrane receptors (GPCRs). Structural information on these receptors is currently limited. Here we identify residues involved in the binding of phenylthiocarbamide (PTC) and in receptor activation in one of the most widely studied hTAS2Rs (hTAS2R38) by means of structural bioinformatics and molecular docking. The predictions are validated by site-directed mutagenesis experiments that involve specific residues located in the putative binding site and trans-membrane (TM) helices 6 and 7 putatively involved in receptor activation. Based on our measurements, we suggest that (i) residue N103 participates actively in PTC binding, in line with previous computational studies. (ii) W99, M100 and S259 contribute to define the size and shape of the binding cavity. (iii) W99 and M100, along with F255 and V296, play a key role for receptor activation, providing insights on bitter taste receptor activation not emerging from the previously reported computational models.
人类的苦味感知是由 G 蛋白偶联膜受体 (GPCR) 的 hTAS2R 亚家族介导的。这些受体的结构信息目前有限。在这里，我们通过结构生物信息学和分子对接的方法，确定了在研究最广泛的 hTAS2R 之一（hTAS2R38）中参与苯硫脲 (PTC) 结合和受体激活的残基。通过涉及位于假定结合位点和跨膜 (TM) 6 和 7 螺旋中特定残基的定点突变实验验证了这些预测，这些残基假定参与受体激活。基于我们的测量结果，我们建议：(i) 残基 N103 积极参与 PTC 结合，与先前的计算研究一致。(ii) W99、M100 和 S259 有助于定义结合腔的大小和形状。(iii) W99 和 M100 与 F255 和 V296 一起，在受体激活中发挥关键作用，为苦味受体激活提供了以前报道的计算模型中没有出现的见解。
