SODIUM-CHANNELS IN PLANAR LIPID BILAYERS - CHANNEL GATING KINETICS OF PURIFIED SODIUM-CHANNELS MODIFIED BY BATRACHOTOXIN
SODIUM-CHANNELS IN PLANAR LIPID BILAYERS - CHANNEL GATING KINETICS OF PURIFIED SODIUM-CHANNELS MODIFIED BY BATRACHOTOXIN
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DOI：
10.1085/jgp.88.1.1
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发表时间：
1986-07-01
影响因子：
3.8
通讯作者：
MONTAL, M
中科院分区：
文献类型：
--
作者：
KELLER, BU;HARTSHORNE, RP;MONTAL, M
记录从大鼠脑中纯化并重构为平面脂质双层的钠通道的单通道电流。在箭毒毒素存在的情况下研究了通道门控动力学，以消除失活，并在任何给定时间对具有单个活性通道的膜进行分析。去极化有利于通道开放并且强烈依赖于电压。通道的关闭和打开状态下的驻留时间的概率密度分析表明在电压(V)范围-120mV≤120mV内出现一种打开状态和几种不同的关闭状态。 V≤ +120毫伏。对于V≤如图 0 所示，状态之间的转换速率呈指数依赖于所施加的电压，如小鼠神经母细胞瘤细胞中所述（Huang, L. M., N. Moran, and G. Ehrenstein. 1984. Biophysical Journal. 45:313-322）。相反，V .gtoreq。 0，转换速率实际上与电压无关。自相关分析（labarca, P., J. Rice, D. Fredkin, and M. Montal, 1985. Biophysical Journal. 47:469-478）表明连续打开或关闭事件的持续时间不存在相关性。考虑了几种与实验数据一致的动力学方案。这种方法可以提供有关通道激活的电压依赖性的机制的信息。
Single channel currents of sodium channels purified from rat brain and reconstituted into planar lipid bilayers were recorded. The kinetics of channel gating were investigated in the presence of batrachotoxin to eliminate inactivation and an analysis was conducted on membranes with a single active channel at any given time. Channel opening is favored by depolarization and is strongly voltage dependent. Probability density analysis of dwell times in the closed and open states of the channel indicates the occurrence of one open state and several distinct closed states in the voltage (V) range -120 mV .ltoreq. V .ltoreq. +120 mV. For V .ltoreq. 0, the transition rates between states are exponentially dependent on the applied voltage, as described in mouse neuroblastoma cells (Huang, L. M., N. Moran, and G. Ehrenstein. 1984. Biophysical Journal. 45:313-322). In contrast, the V .gtoreq. 0, the transition rates are virtually voltage independent. Autocorrelation analysis (labarca, P., J. Rice, D. Fredkin, and M. Montal, 1985. Biophysical Journal. 47:469-478) shows that there is no correlation in the durations of successive open or closing events. Several kinetic schemes that are consistent with the experimental data are considered. This approach may provide information about the mechanism underlying the voltage dependence of channel activation.