Tetrameric bacterial sodium channels: Characterization of structure, stability, and drug binding
Tetrameric bacterial sodium channels: Characterization of structure, stability, and drug binding
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DOI：
10.1021/bi800645w
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发表时间：
2008-08-05
期刊：
影响因子：
2.9
通讯作者：
Wallace, B. A.
中科院分区：
文献类型：
--
作者：
Nurani, Ghasem;Radford, Matthew;Wallace, B. A.
来自耐盐芽孢杆菌的NaChBac是哺乳动物电压门控钠通道的细菌同系物。有人提出，NaChBac单体对应于哺乳动物钠通道的单个结构域，并且与钾通道一样，四个单体形成四聚体通道。然而，到目前为止，虽然NaChBac已经很好地表征了功能特性的电生理测量的蛋白质在组织培养中表达，很少有关于其结构特性的信息存在，因为在大量表达的蛋白质的困难。在这项研究中，我们目前的研究在大肠杆菌中过表达的NaChBac，纯化的功能洗涤剂溶解的通道，其鉴定为四聚体，其二级结构，药物结合和热稳定性的表征。这些研究与为蛋白质产生的模型相关，并为这种钠通道的结构-功能关系提供了新的见解。
NaChBac from Bacillus halodurans is a bacterial homologue of mammalian voltage-gated sodium channels. It has been proposed that a NaChBac monomer corresponds to a single domain of the mammalian sodium channel and that, like potassium channels, four monomers form a tetrameric channel. However, to date, although NaChBac has been well-characterized for functional properties by electro-physiological measurements on protein expressed in tissue culture, little information about its structural properties exists because of the difficulties in expressing the protein in large quantities. In this study, we present studies on the overexpression of NaChBac in Escherichia coli, purification of the functional detergent-solubilized channel, its identification as a tetramer, and characterization of its secondary structure, drug binding, and thermal stability. These studies are correlated with a model produced for the protein and provide new insights into the structure-function relationships of this sodium channel.