X-RAY STRUCTURES OF PENTAMERIC ION CHANNELS IN THE ABSENCE AND PRESENCE OF ANEST

不存在和存在 Anest 时五聚体离子通道的 X 射线结构

• 批准号: 8170297
• 负责人: PEI TANG
• 金额: $ 0.03万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8170297
• 关键词: Affinity; Anesthetics; Binding; Binding Sites; Breathing; Bromides; Cations; Chloride Ion; Chlorides; Complex; Computer Retrieval of Information on Scientific Projects Database; Data; Dose; Family; Funding; Gated Ion Channel; General Anesthesia; General anesthetic drugs; Grant; Halothane; Homologous Gene; Institution; Intravenous Anesthetics; Ion Channel; Ketamine; Ligands; Molecular; Proteins; Research; Research Personnel; Resolution; Resources; Source; Structure; Sulfur; Thiopental; United States National Institutes of Health; base; beamline; molecular size; novel; protein function

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The molecular mechanism of general anesthesia remains an enigma. Although a superfamily of pentameric ligand gated ion channels (pLGICs) has been identified as putative targets of general anesthetics, the lack of high-resolution structures of these pLGICs hinders the understanding where anesthetic binding sites are in these proteins and how anesthetic bindings impact on protein functions. An exciting platform for getting the answers has recently emerged as the x-ray structures of two bacterial homologs to the pLGIC family, GLIC and ELIC, were solved with resolutions of 2.9 and 3.3 ¿. As cation channels, GLIC and ELIC can be crystallized in the open- and close-channel states, respectively. Similar to mammalian pLGIC cation channels, cation conductance of GLIC could be inhibited by a variety of anesthetics at subclinical doses. Here we propose to co-crystallize GLIC and ELIC with general anesthetics. No anesthetic has been crystallized with any pLGICs in the past. The x-ray structures of GLIC- and ELIC-anesthetics complexes will provide novel structural basis to explain the functional impact of general anesthetics to the pLGICs. Inhaled anesthetic halothane and intravenous anesthetics thiopental and ketamine are chosen for the study. We have crystallized GLIC and ELIC in the absence and presence of anesthetics. Our preliminary data show that the resolutions up to 2.7 ¿ and 2.9 ¿ have been achieved for GLIC in the presence of thiopental and ketamine. Despite tangible protein resolutions, to define precise anesthetic binding sites in the proteins remains challenging because of small anesthetic molecular sizes and relatively low anesthetic binding affinities (~100 ?M). Thus, we request to use specific beamlines that provide high sensitivity and resolution to bromide, sulfur, and possibly chloride atoms. These atoms are contained in the selected anesthetics and can serve as marks for anesthetics in the proteinanesthetic complexes.

这个子项目是众多研究子项目之一