Engineering a Transmitter Binding Site

项目摘要/摘要 生物医学的一个基本原理是小分子可以与特定的 以触发生理反应的受体。我们试图理解能量的本质 发生在神经递质结合部位的分子事件 神经肌肉乙酰胆碱受体当这一通道在非传导通道之间‘门’ 和离子传导构象。这些知识将帮助我们理解 配体-蛋白质复合体的生物物理机制，并将提高我们的能力 为尼古丁(和其他)受体设计新药。基于结构的药物发现 应纳入药物作用依赖于配体的不同结合这一事实 受体的非活性构象与活性构象。为了解决这一点，我们将使用 单通道电生理学和动力学分析研究非配基门控， 将允许我们测量所有显著的活化平衡常数，并 确定两个发射器中每一个侧链的能量贡献 结合部位。我们还将估算小配体探针的微分结合能， 在野生型和突变型受体中。最终，这些知识将被用来 改造乙酰胆碱受体，可预测地对任意配体做出反应。

PROJECT SUMMARY/ABSTRACT A fundamental principle of biomedicine is that small molecules can bind to specific receptors to trigger physiological responses. We seek to understand the energetic nature of the molecular events that occur at the neurotransmitter binding sites of the neuromuscular acetylcholine receptor when this channel 'gates' between non-conducting and ion-conducting conformations. This knowledge will help us understand the biophysical mechanisms of ligand-protein complexes, and will advance our ability to design new drugs for nicotinic (and other) receptors. Structure-based drug discovery should incorporate the fact that drug action depends on the differential binding of ligands to inactive vs. active conformations of a receptor. To address this point we will use single-channel electrophysiology and kinetic analysis to study unliganded gating, which will allow us to measure all of the salient activation equilibrium constants and to ascertain the energetic contributions of the side chains at each of the two transmitter binding sites. We will also estimate differential binding energies for small ligand probes, in both wild type and mutant receptors. Eventually, this knowledge will be used to engineer acetylcholine receptors that respond predictably to arbitrary ligands.