Unique residues in the ATP gated human P2X7 receptor define a novel allosteric binding pocket for the selective antagonist AZ10606120.
Unique residues in the ATP gated human P2X7 receptor define a novel allosteric binding pocket for the selective antagonist AZ10606120.
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DOI：
10.1038/s41598-017-00732-5
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发表时间：
2017-04-07
影响因子：
4.6
通讯作者：
Evans RJ
中科院分区：
文献类型：
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作者：
Allsopp RC;Dayl S;Schmid R;Evans RJ
ATP的P2X7受体(P2X7R)是治疗炎症、疼痛和癫痫等病理生理状态的靶点。由于激活受体所需的高浓度ATP通常只在细胞损伤/疾病后才被发现，因此P2X7Rs对“危险”信号做出反应，通常情况下并不活跃，因此预测的低副作用特征促进了这一点。AZ10606120是一种选择性的P2X7Rs拮抗剂(IC_(50)为~10 NM)，对P2X1R没有作用(10 μM)。为了确定选择性的分子基础，我们产生了一系列的P2X7/1R嵌合体和突变体。高亲和力拮抗作用需要两个P2X7R独有的区域，即环插入(残基73-79)和苏氨酸残基T90和T94。点突变排除了正构体拮抗剂的位置。突变和分子模拟确定了在受体顶端的亚基界面上形成的变构结合位点。分子动力学模拟表明，独特的P2X7R功能调节AZ10606120对变构位点的访问。变构口袋的表征为合理的P2X7R药物开发提供了一个新的新靶点。
The P2X7 receptor (P2X7R) for ATP is a therapeutic target for pathophysiological states including inflammation, pain management and epilepsy. This is facilitated by the predicted low side effect profile as the high concentrations of ATP required to activate the receptor are usually only found following cell damage/disease and so P2X7Rs respond to a “danger” signal and are not normally active. AZ10606120 is a selective antagonist for P2X7Rs (IC50 of ~10 nM) and ineffective at the P2X1R (at 10 μM). To determine the molecular basis of selectivity we generated a series of P2X7/1R chimeras and mutants. Two regions that are unique to the P2X7R, a loop insertion (residues 73–79) and threonine residues T90 and T94, are required for high affinity antagonist action. Point mutations ruled out an orthosteric antagonist site. Mutations and molecular modelling identified an allosteric binding site that forms at the subunit interface at the apex of the receptor. Molecular dynamics simulations indicated that unique P2X7R features regulate access of AZ10606120 to the allosteric site. The characterisation of the allosteric pocket provides a new and novel target for rational P2X7R drug development.