LY2087101 and dFBr share transmembrane binding sites in the (α4)3(β2)2 Nicotinic Acetylcholine Receptor
LY2087101 and dFBr share transmembrane binding sites in the (α4)3(β2)2 Nicotinic Acetylcholine Receptor
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DOI：
10.1038/s41598-018-19790-4
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发表时间：
2018-01-19
影响因子：
4.6
通讯作者：
Hamouda, Ayman K.
中科院分区：
文献类型：
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作者：
Deba, Farah;Ali, Hamed I.;Hamouda, Ayman K.
烟碱型乙酰胆碱受体(NAChRs)的正变构调节剂(PAM)在与nAChRs功能降低或丢失相关的神经病理中具有潜在的治疗应用前景。在本研究中，我们使用突变和计算分析表征了nAChRs PAM LY2087101与α4β2 nAChR的药理相互作用。LY2087101增强ACh诱发的低敏感性(α4)3(β2)2和高敏感性(α4)2(β2)3nAChRs电流，其强度相似，但最大增强作用不同(增强I-max分别类似于840和450%)。α4亚基跨膜区的氨基酸替换[例如，跨膜螺旋1(TM1)内的α4Leu256和α4Leu260；TM3内的α4Phe316；TM4内的α4Gly613]显著降低了(α4)3(β2)2 nAChR的LY2087101增强。这些氨基酸残基的位置和LY2087101的计算对接分析确定了两个LY2087101结合位点：在α4亚基的跨膜螺旋束内的α4Leu260/α4Phe316水平的亚基内结合位点和在α4：α4亚单位界面的α4Leu256/α4Ile315水平的亚基间结合位点，这两个结合位点都延伸到跨膜结构域的胞外端。我们还发现去甲酰氟溴(DFBr)与LY2087101的这两个位点结合。这些结果为基于结构的nAChR变构调节器的设计提供了结构信息。
Positive allosteric modulators (PAMs) of nicotinic acetylcholine receptors (nAChRs) have potential therapeutic application in neuropathologies associated with decrease in function or loss of nAChRs. In this study, we characterize the pharmacological interactions of the nAChRs PAM, LY2087101, with the alpha 4 beta 2 nAChR using mutational and computational analyses. LY2087101 potentiated ACh-induced currents of low-sensitivity (alpha 4) 3(beta 2)2 and high-sensitivity (alpha 4) 2(beta 2) 3 nAChRs with similar potencies albeit to a different maximum potentiation (potentiation I-max = similar to 840 and 450%, respectively). Amino acid substitutions within the alpha 4 subunit transmembrane domain [e.g. alpha 4Leu256 and alpha 4Leu260 within the transmembrane helix 1 (TM1); alpha 4Phe316 within the TM3; and alpha 4Gly613 within TM4] significantly reduced LY2087101 potentiation of (alpha 4) 3(beta 2) 2 nAChR. The locations of these amino acid residues and LY2087101 computational docking analyses identify two LY2087101 binding sites: an intrasubunit binding site within the transmembrane helix bundle of alpha 4 subunit at the level of alpha 4Leu260/alpha 4Phe316 and intersubunit binding site at the alpha 4: alpha 4 subunit interface at the level of alpha 4Leu256/alpha 4Ile315 with both sites extending toward the extracellular end of the transmembrane domain. We also show that desformylflustrabromine (dFBr) binds to these two sites identified for LY2087101. These results provide structural information that are pertinent to structure-based design of nAChR allosteric modulators.