CHARACTERIZATION OF ANTIARRHYTHMIC DRUG BINDING SITES IN VOLTAGE GATED CHANNELS

电压门控通道不仅对无数生理 在心脏的功能，也是作为分子靶点的多种 抗心律失常药。最近的克隆、测序和 电压门控Na和K通道的表达，现在阶段设置为 确定主要参与抗病毒作用的关键氨基酸残基 电压门控性钠、钾通道的心律失常作用。特别是， 电压门控钠通道的野生型和突变型 来自成人骨骼肌(MU1，Trimmer等人，1990)，以及 来自人心脏的电压门控K通道(HK1或Kv1.4，Tamkun 等人，1991)将在哺乳动物细胞系中表达，并通过 膜片钳方法检测大鼠脑缺血后功能改变的影响 内部使用QX-314(用于MU1)和Clofilium(用于HK1)，永久 荷电版本的抗心律失常药。突变将会发生 根据最近的工作，本地化可能的行动地点 内源性抗心律失常药对前庭细胞的作用 Na和K通道(Gingrich等人，1993；Backx等人，1992，Choi等人 Al.，1993)。揭开重要氨基酸的排列 因为毒品行动将是解开 抗心律失常作用的分子水平机制。是这样的 了解这一点在合理的药物治疗和设计中将是无价的。

Voltage-gated channels are not only essential to countless physiological functions in heart, but also serve as the molecular target of diverse anti-arrhythmic agents. With the recent cloning, sequencing, and expression of voltage-gated Na and K channels, the stage is now set to identify the key amino acid residues primarily involved in anti- arrhythmic action on voltage-gated Na and K channels. In particular, wild-type and mutant versions of both a voltage-gated Na channel derived from adult skeletal muscle (mu1, Trimmer et al., 1990), as well as a voltage-gated K channel derived from human heart (HK1, or Kv1.4, Tamkun et al., 1991) will be expressed in a mammalian cell line and probed by patch-clamp methods to detect functional changes in the effects of internally applied QX-314 (for mu1) and clofilium (for HK1), permanently charged versions of anti-arrhythmic agents. Mutations will be made according to recent work localizing the probable site of action of internally active anti-arrhythmic agents to the cytoplasmic vestibule of Na and K channels (Gingrich et al., 1993; Backx et al., 1992, Choi et al., 1993). Unmasking the arrangement of amino acids that are important for drug action would be a crucial prerequisite to unravelling the mechanism of anti-arrhythmic action at the molecular level. Such understanding would be invaluable in rational drug therapy and design.