Lee Seok-Yong, Letts James A, MacKinnon Roderick
Howard Hughes Medical Institute, Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
J Mol Biol. 2009 Apr 17;387(5):1055-60. doi: 10.1016/j.jmb.2009.02.034. Epub 2009 Feb 21.
Voltage-dependent H(+) (Hv) channels mediate proton conduction into and out of cells under the control of membrane voltage. Hv channels are unusual compared to voltage-dependent K(+), Na(+), and Ca(2+) channels in that Hv channel genes encode a voltage sensor domain (VSD) without a pore domain. The H(+) currents observed when Hv channels are expressed heterologously suggest that the VSD itself provides the pathway for proton conduction. In order to exclude the possibility that the Hv channel VSD assembles with an as yet unknown protein in the cell membrane as a requirement for H(+) conduction, we have purified Hv channels to homogeneity and reconstituted them into synthetic lipid liposomes. The Hv channel VSD by itself supports H(+) flux.
电压依赖性氢离子（Hv）通道在膜电压的控制下介导质子进出细胞。与电压依赖性钾（K⁺）、钠（Na⁺）和钙（Ca²⁺）通道相比，Hv通道不同寻常之处在于，Hv通道基因编码一个没有孔道结构域的电压传感结构域（VSD）。当Hv通道在异源细胞中表达时观察到的氢离子电流表明，VSD自身为质子传导提供了途径。为了排除Hv通道VSD与细胞膜中一种未知蛋白质组装是氢离子传导必要条件的可能性，我们已将Hv通道纯化至同质，并将它们重构成合成脂质脂质体。Hv通道VSD自身就能支持氢离子通量。
