LARGE SCALE MD SIMULATIONS OF ANESTHETIC EFFECTS ON ION CHANNELS

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 该更新提案寻求NCSA的持续支持，以确保我们正在进行的由NIH资助的研究（R 01 GM 056257 -11，R 01 GM 66358 -09，R37 GM 049202）的进展。我们研究的最终目标是通过我们结合实验和计算的努力来了解全身麻醉的分子机制。我们的近期目标是阐明全身麻醉药如何与其假定的靶点相互作用并影响蛋白质的结构和运动。我们的中心假设是全身麻醉剂通过调节功能相关蛋白质运动来改变这些蛋白质的功能。正如我们在第三节的研究进展报告中所反映的，我们已经通过MD模拟在麻醉剂氟烷存在和不存在的情况下对神经元nAChR和Gloeetum violaceus五聚体配体门控离子通道（GLIC）进行了研究。与我们的计算研究平行，我们对GLIC进行了许多组结构和功能测量，以确定全身麻醉剂与GLIC结合的位置以及它们如何抑制GLIC通道。我们可以把GLIC变成一个阴离子通道，通过在几个关键的残基突变，并确定是否麻醉剂抑制或增强Cl？渗透性GLIC（GLICCl）。在本申请中，我们有三个目的。目的1是确定在长MD模拟期间可以保持GLIC处于开放信道状态的重要因素。目的2是相关的重新分配的全球动力学概况，由于麻醉剂结合与通道电导的变化，使用长时间尺度模拟。在目标3中，我们将确定潜在的平均力（PMF）运输一个单一的氯？离子沿着GLIC通道和（B）确定实验观察到的麻醉剂增强或抑制GLIC通道的根本原因。总的来说，我们将把新的实验结果整合到我们的计算研究中，并揭示麻醉剂对五聚体配体门控离子通道作用的潜在机制。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. This renewal proposal seeks a continuing support from NCSA to ensure the progress of our on-going research funded by NIH (R01GM056257-11, R01GM66358-09, R37GM049202). The ultimate goal of our study is to understand the molecular mechanisms of general anesthesia through our combined experimental and computational efforts. Our immediate objective is to elucidate how general anesthetics interact with their putative targets and affect protein structures and motions. Our central hypothesis is that general anesthetics alter functions of these proteins by modulating functional relevant protein motions. As reflected in our research progress report in section III, we have worked on neuronal nAChRs and Gloeobacter violaceus pentameric ligand-gated ion channel (GLIC) in the presence and absence of anesthetic halothane through MD simulations. Parallel to our computational studies, we have conducted many sets of structural and functional measurements on GLIC to determine where general anesthetics bind to GLIC and how they inhibit GLIC channel. We can turn GLIC into an anion channel through mutation at several critical residues and determine whether anesthetics inhibit or potentiate Cl? permeable GLIC (GLICCl). In this application, we have three aims. Aim 1 is to determine the important factors that can keep GLIC in an open-channel state during long MD simulations. Aim 2 is to correlate the redistribution of global dynamics profiles due to anesthetic binding with changes in channel conductance using long-timescale simulations. In Aim 3, we will determine the potential of mean force (PMF) for transporting a single Cl? ion along the GLIC channel and (B) determine the underlying cause of the experimentally observed potentiation or inhibition of GLIC channel by anesthetics. Collectively, we will integrate new experimental findings into our computational studies and reveal underlying mechanisms of anesthetic action on the pentameric ligand gated ion channels.