Druggable negative allosteric site of P2X3 receptors
Druggable negative allosteric site of P2X3 receptors
复制标题
P2X3 受体的可药物负变构位点。
DOI：
10.1073/pnas.1800907115
复制
发表时间：
2018-05-08
影响因子：
11.1
通讯作者：
Yu, Ye
中科院分区：
文献类型：
--
作者：
Wang, Jin;Wang, Yao;Yu, Ye
变构调节为酶、离子通道和G蛋白偶联受体的药物研发带来了令人振奋的机遇。P2X受体作为由细胞外ATP门控的阳离子通道，作为新型药物靶点已备受关注。尽管靶向P2X受体的小分子药物已进入类风湿性关节炎、咳嗽和疼痛等疾病的临床试验阶段，但对这些受体的负性变构调节在很大程度上仍未得到充分研究。在此，通过结合X射线晶体学、计算机建模以及通道突变体的功能研究，我们在P2X3受体上确定了一个负性变构位点，该位点由左鳍状结构域（LF）、下体结构域（LB）和背鳍结构域（DF）共同形成。利用两种结构类似的P2X3亚型特异性变构抑制剂AF - 353和AF - 219（后者是一种处于治疗难治性慢性咳嗽和特发性肺纤维化二期临床试验阶段的候选药物），我们明确了药物与受体之间的分子相互作用，以及LF、DF和LB结构域的变构变化调节P2X3受体ATP激活的机制。我们对这一可成药变构位点的详细表征，有望启发开发用于临床的P2X3特异性变构调节剂的新策略。
Significance Allosteric regulation, produced by the binding of a ligand at an allosteric site topographically distinct from the orthosteric site, represents a direct and efficient means for modulation of biological macromolecule function. Because allosteric modulators have advantages over classic orthosteric ligands as therapeutic agents, understanding the mechanism underlying allosteric modulation may open new therapeutic avenues. Here, we focused on allosteric regulation of P2X receptors, which are implicated in diverse pathophysiological processes, such as blood clotting, pain sensation, inflammation, and rheumatoid arthritis. Combining structural determination, molecular modeling, and mutagenesis, we identified a druggable allosteric site on P2X3. Our findings will facilitate the development of novel therapeutics targeting these receptors. Allosteric modulation provides exciting opportunities for drug discovery of enzymes, ion channels, and G protein-coupled receptors. As cation channels gated by extracellular ATP, P2X receptors have attracted wide attention as new drug targets. Although small molecules targeting P2X receptors have entered into clinical trials for rheumatoid arthritis, cough, and pain, negative allosteric modulation of these receptors remains largely unexplored. Here, combining X-ray crystallography, computational modeling, and functional studies of channel mutants, we identified a negative allosteric site on P2X3 receptors, fostered by the left flipper (LF), lower body (LB), and dorsal fin (DF) domains. Using two structurally analogous subtype-specific allosteric inhibitors of P2X3, AF-353 and AF-219, the latter being a drug candidate under phase II clinical trials for refractory chronic cough and idiopathic pulmonary fibrosis, we defined the molecular interactions between the drugs and receptors and the mechanism by which allosteric changes in the LF, DF, and LB domains modulate ATP activation of P2X3. Our detailed characterization of this druggable allosteric site should inspire new strategies to develop P2X3-specific allosteric modulators for clinical use.