ELECTROPHYSIOLOGICAL STUDIES OF VOLTAGE GATED CHANNELS

长期目标是了解电压 离子通道在分子水平上的依赖性。这项研究将是 首先通过完成对电学表达式的描述 用电生理技术研究鱿鱼的钠通道和钾通道。 将寻找鱿鱼钠通道和钾通道的初级序列 具有相同的基本结构和功能信息 准备工作。此外，结构与结构的相关性 功能将完成突变特定的氨基酸，这些氨基酸被认为是 负责振动器K通道中的电压传感。评估 的突变将通过测量门控电流和门控来完成 大量通道的电荷波动以 非洲爪哇卵母细胞和荷电特定氨基酸的作用 根据门控费用进行评估。关于英语词汇结构的研究 通道蛋白将用圆二色谱和电子 用纯化的钠离子通道进行顺磁共振 电鳗。将使用这些光谱技术进行研究 在开放和闭合构象中使用巴曲霉毒素作为通道 一种化学通道开放剂，具有施加的膜电位。这个 电生理结果将使用动力学方案和 它们将与从结构模型中出现的物理模型相关联 分析。电压依赖通道的运行知识 在分子水平上对理解修饰具有重要意义 由药物、毒素和麻醉剂产生，可能有助于设计 在病理条件下调整经络运行的药物。

The long term objective is the understanding of the voltage dependence of ionic channels at the molecular level. The study will be done first by completing the description of the electrical expression of Na and K channels of the squid using electrophysiological techniques. The primary sequences of Na and K channels of the squid will be sought to have basic structural and functional information from the same preparation. In addition, correlations of the structure with the function will be done mutating specific aminoacids that are thought to be responsible for voltage sensing in the Shaker K channel. The evaluation of the mutations will be done by measuring gating currents and gating charge fluctuations from large populations of channels expressed in Xenopus oocytes and the role of charges of specific aminoacids will be assessed in term of the gating charge. The study of the structure of the channel protein will be done with circular dichroism and electron paramagnetic resonance using the purified sodium channel from the electric eel. The study with these spectroscopic techniques will be done with channels in the open and closed conformations using batrachotoxin as a chemical channel opener and with an imposed membrane potential. The electrophysiological results will be modelled using kinetic schemes and they will be correlated with physical models emerging from the structural analysis. The knowledge of the operation of voltage dependent channels at the molecular level has importance in understanding modifications produced by drugs, toxins and anaesthetics and may help in designing drugs to modify the operation of channel in pathological conditions.