SODIUM INACTIVATION AND DRUG-INDUCED IMMOBILIZATION OF THE GATING CHARGE IN NERVE MEMBRANE
SODIUM INACTIVATION AND DRUG-INDUCED IMMOBILIZATION OF THE GATING CHARGE IN NERVE MEMBRANE
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DOI：
10.1016/0079-6107(82)90020-7
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发表时间：
1981-01-01
影响因子：
3.8
通讯作者：
KHODOROV, BI
中科院分区：
文献类型：
--
作者：
KHODOROV, BI
神经和肌肉的电兴奋性是基于Na+和K+离子选择性通道能够响应膜电位的变化而打开和关闭的特性。电压依赖性离子通道的分子结构尚未阐明。间接证据表明，每个离子通道，其“电压传感器”，门，“选择性过滤器”，受体，是一个跨膜的多亚基蛋白质聚集体。然而，为了对其结构和功能特性进行生化分析而分离通道蛋白仍处于早期阶段。因此，离子通道的所有现代概念（参见Hille，1976，1978，综述）主要基于在研究各种化学品（药物，毒素，酶等）的作用时获得的数据。关于离子电流、它们的波动（“波动分析”）以及神经和肌肉膜中的门控电流（参见Keynes; 1975，Hille，1976，1978; Ulbricht，1977：Almers，1978; Khoderov，1979 a，B，综述）。去极化的早期激活效应是带电门控结构的快速重排（构象变化），其打开通道的激活（m）门。这种重新排列产生”导通”选通电流（Ig）。在图la中，B展示了鱿鱼巨轴突中这种”响应”和内向钠电流（INa）之间的时间关系。
The electrical excitability of nerve and muscle is based on the properties of Na÷ and K÷ ion-selective channels able to open and close in response to changes of membrane potential. The molecular structure of the voltage-dependent ionic channels is not clarified as yet. Indirect evidence suggests that each ionic channel, with its" voltage-sensor", gates," selectivity filter", receptors, is a multisubunit protein aggregate spanning the membrane. However the isolation of the channel proteins for the purpose of biochemical analysis of their structural and functional properties is still at an early stage. Therefore all the modern conceptions of the ionic channels (see Hille, 1976, 1978, for reviews) are based largely on the data obtained in studying the effects of various chemicals (drugs, toxins, enzymes etc.) on the ionic currents, their fluctuations (" fluctuation analysis") and gating currents in nerve and muscle membranes (see Keynes; 1975, Hille, 1976, 1978; Ulbricht, 1977: Almers, 1978; Khoderov, 1979a, b, for reviews).Membrane depolarization has a dual effect on the gating machinery of the Na channel. The early activating effect of depolarization is a rapid rearrangement (conformational change) of the charged gating structures, which opens the activation (m) gate of the channels. This rearrangement generates the" on" gating current (lg). In Fig. la, b demonstrates the temporal relationship between this" on-response" and the inward sodium current,(INa) in the squid giant axon.