MOLECULA MECHANISMS OF GATING IN IONIC CHANNELS

离子通道门控的分子机制

• 批准号: 3278134
• 负责人: WOLFGANG F NONNER
• 金额: $ 12.16万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-08-01 至 1991-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3278134
• 关键词: adenosine triphosphate; biological signal transduction; chloride channels; cyclic AMP; electrophysiology; gamma aminobutyrate; glycine; hippocampus; laboratory rat; membrane permeability; membrane potentials; muscle proteins; myofibrils; potassium channel; tissue /cell culture; voltage /patch clamp; voltage gated channel

We propose to study the molecular mechanisms underlying ionic permeability and gating of C1 and K ion channels. The experiments use embryonic or adult rat central neurons (hippocampus, spinal cord) maintained in primary tissue culture, or obtained by acute dissociation. The patch clamp technique will be used to record macroscopic membrane currents from membrane spheres excised from the cell soma, and to study currents from individual channels in small membrane patches. We will analyze the mechanism of ionic selectivity and permeability of two varieties of C1 channel: C1 channels open in the resting membrane and GABA- or glycine- activated C1 channels. Cation/anion interactions inside the resting C1 channel will be investigated to test a mechanism of joint anion/cation permeation proposed from previous work. The block by Zn ion, and effects of pH will be studied. The ionic selectivity of the transmitter-activated C1 channels will be examined and compared to that of resting C1 channels, to determine whether or not these small-conductance C1 channels achieve ionic selectivity by the same basic mechanism. Molecular channels underlying the rapidly and slowly inactivating components of voltage-activated K current will be identified. We will further study the gating of these channels, assess their role in shaping the somatic excitability, and examine their differential sensitivity to K channel blockers. We will perform kinetic measurements on single-channel gating at subzero temperatures. The behavior of the large Ca-activated K channel will be characterized for temperatures down to -30 degrees C. This new method is expected to greatly enhance the range of kinetic studies possible with ion channels.

我们建议研究离子基于的分子机制 C1和K离子通道的渗透性和门控。 实验 使用胚胎或成年大鼠中央神经元（海马，脊柱 电线）保持在原发性组织培养中，或通过急性获得 解离。 贴片夹技术将用于记录 从膜球中切除的宏观膜电流 细胞体，并从各个通道中研究水流 小膜斑。 我们将分析离子的机制 C1通道的两个品种的选择性和渗透性：C1 通道在静息膜和GABA或甘氨酸中打开 激活的C1通道。 阳离子/阴离子相互作用 将研究静止的C1通道以测试 联合阴离子/阳离子渗透到先前的工作中提出。 这 将研究Zn离子的块，并研究pH的效果。 离子 发射器激活的C1通道的选择性将是 检查并与静止C1通道的检查并进行了比较，以确定 这些小传导C1通道是否达到离子 通过相同的基本机制选择性。 分子通道 迅速而缓慢地灭活的组件的基础 电压激活的K电流将被识别。 我们将进一步 研究这些渠道的门控，评估它们在塑造中的作用 躯体兴奋性，并检查其差异 对K通道阻滞剂的敏感性。 我们将执行动力学 亚零温度下的单渠道门控的测量。 大型CA激活的K通道的行为将是 温度降低到-30度。 预计方法将大大增强动力学研究的范围 离子通道可能。