ELECTROPHYSIOLOGICAL STUDIES OF VOLTAGE GATED CHANNELS

这个项目的目的是描述和表征分子 电压相关工艺的基础。特别是，目标是 理解导致电压依赖的物理事件 钠、钾通道和钠/钙交换。 这些实验使用电生理技术来描述 通过大量通道的电流(宏观电流)，通过 几个通道(噪声测量)，通过单通道和 由通道的带电基团重新排列产生的电流 大分子。将修改通道(钠通道为BTX，通道为ATP 钾)，试图获得更多关于他们身体状况的信息 各州。结果将使用包含能量的动力学模型进行解释 的位置表示的物理状态之间的障碍 大分子中的带电粒子。参数将适用于这些 使用来自电气测量的所有信息的模型和它们 将根据配件的结果进行修改。此外, 标记的ATP将被用来标记K通道并尝试其提取 和角色塑造。Na/Ca交换的特征是 膜电位控制和电流控制下的同位素通量测量 由交易所生产。我们将尝试确定其 化学计量学和电压依赖性。 实验将使用鱿鱼的巨大轴突在 灌流型、透析型或切开型。后一种技术 允许从膜的内侧进行膜片钳。这个 将进行需要更多膜材料的实验 从鱿鱼的视网膜神经提取的膜中。这项研究 预计将提供有关以下详细机制的新信息 电压门控通道与钠/钙交换的运行 这将有助于理解电压的分子机制 从属进程。预计这些研究将在 神经、肌肉、可兴奋组织和细胞的生理学。

The object of this project is to describe and characterize the molecular basis of voltage dependent processes. In particular, the aim is an understanding of the physical events responsible for the voltage dependence of sodium and potassium channels and the sodium/calcium exchange. The experiments use electrophysiological techniques to describe the currents through a large number of channels (macroscopic currents), through a few channels (noise measurements), through single channels and the currents produced by the rearrangement of the charged groups of the channel macromolecule. Channels will be modified (BTX for sodium and ATP for potassium) in an attempt to gain more information about their physical states. Results will be interpreted using kinetic models with energy barriers between the physical states represented by the positions of the charged particles in the macromolecule. Parameters will be fitted to these models using all the information from the electrical measurements and they will be modified according to the results of the fitting. In addition, labelled ATP will be used to mark the K channel and attempt its extraction and characterization. The Na/Ca exchange will be characterized by measuring isotopic fluxes under membrane potential control and the currents produced by the exchange. We will attempt the determination of its stoichiometry and voltage dependence. Experiments will be performed using the giant axon of the squid in perfused, dialyzed or cut-open configurations. This latter technique allows patch clamping from the internal side of the membrane. The experiments requiring larger amounts of membrane material will be performed in membranes extracted from the retinal nerve of the squid. This research is expected to provide new information on the detailed mechanisms of voltage gated channels and on the operation of the sodium/calcium exchange which will help in the understanding of the molecular mechanisms of voltage dependent processes. These studies are expected to have relevance in the physiology of nerve, muscle, excitable tissues and cells in general.