Structure of the GABA-A receptor ligand-binding pocket

描述(由申请人提供)：项目摘要：GABA-A受体介导脊椎动物中枢神经系统中大多数快速抑制性突触传递。它们在认知中起着关键作用，也是癫痫和相关癫痫障碍的核心人物。显然，如果我们想要深入了解这些现象，或设计更有效的针对GABA-A受体的药物，我们必须首先破译所有这些过程中最基本的过程，即GABA-A受体与其配体之间的相互作用。因此，P.L.S实验室的长期目标是开发一种关于GABA-A受体与其内源性配体-γ-氨基丁酸之间相互作用的生物物理描述。本研究建议采用一系列技术(定点突变、膜片钳记录、快速配基应用、单通道记录、动力学建模和双突变周期分析)来测量野生型和突变型GABA-A受体中配体的实际结合和解结率。这是一种强大的新方法，它应该揭示关于配体结合口袋的结构以及与受体结合的配体分子的位置和方向的详细信息。这些结果将提供改进分子和动力学模型所需的详细信息，这些模型可以用于智能药物设计。此外，这项研究还将展示突变与动力学分析相结合的力量，希望增加利用这种协同作用的研究人员的数量。GABA-A受体是一种配体门控离子通道，被认为存在于哺乳动物大脑中的每个神经元上。它们在癫痫中起着关键作用，是无数临床相关药物的靶点，包括麻醉药、抗惊厥药、催眠药(助眠药物)和抗焦虑药物(抗焦虑药物)。这里提出的实验将帮助我们更好地了解激活GABA-A受体的神经递质如何与其结合部位相互作用，并应为设计更安全和更有效的药物提供重要的一步。

DESCRIPTION (provided by applicant): Project Summary: GABA-A receptors mediate the majority of rapid inhibitory synaptic transmission in the vertebrate central nervous system. They play a key role in cognition and are also a central figure in epilepsy and related seizure disorders. Clearly, if we wish to either develop a deep understanding of these phenomena, or design more effective drugs that target the GABA-A receptor, it is requisite that we first decipher the most basic process underlying all of these processes, the interaction between GABA-A receptors and their ligands. Therefore, the long-term goal of the P.l.'s laboratory is to develop a biophysical description of the interaction between the GABA-A receptor and its endogenous ligand, gamma-aminobutyric acid (GABA). This study proposes to employ an array of techniques (site-directed mutagenesis, patch-clamp recording, rapid ligand-application, single channel recording, kinetic modeling, and double-mutant cycle analysis) to measure the actual binding and unbinding rates for ligands in both wild type and mutant GABA-A receptors. This is a powerful new approach that should reveal detailed information regarding the structure of the ligand-binding pocket and the position and orientation of ligand molecules bound to the receptor. These results will supply detailed information needed to improve molecular and dynamic models that can be used in intelligent drug design. In addition, this study will also demonstrate the power of combining mutagenesis with kinetic analysis, hopefully increasing the number of investigators that take advantage of this synergy. Relevance GABA-A receptors are ligand-gated ion channels that are thought to be present on every neuron in the mammalian brain. They play a key role in epilepsy and are the target of myriad clinically relevant drugs including anesthetics, anti-convulsants, hypnotics (sleep aids), and anxiolytics (anti-anxiety drugs). The experiments proposed here will help us to better understand how the neurotransmittter that activates GABA- A receptors interacts with its binding site and should provide a significant step towards designing safer and more effective drugs.