Pavlov Evgeny, Grigoriev Sergey M, Dejean Laurent M, Zweihorn Chaninah L, Mannella Carmen A, Kinnally Kathleen W
Department of Basic Sciences, New York University, College of Dentistry, 345 East 24th Street, New York, NY 10010, USA.
Biochim Biophys Acta. 2005 Dec 20;1710(2-3):96-102. doi: 10.1016/j.bbabio.2005.09.006. Epub 2005 Oct 26.
The mitochondrial channel VDAC is known to have two major classes of functional states, a large conductance "open" state that is anion selective, and lower conductance substates that are cation selective. The channel can reversibly switch between open and half-open states, with the latter predominant at increasing membrane voltages of either polarity. We report the presence of a new functional state of VDAC, a cation-selective state with conductance approximately equal to that of the canonical open state. This newly described state of VDAC can be reached from either the half-open cation-selective state or from the open anion-selective state. The latter transition implies that a mechanism exists for selectivity gating in VDAC that is separate from partial closure, which may be relevant to the physiological regulation of this channel and mitochondrial outer membrane permeability.
已知线粒体通道电压依赖性阴离子通道（VDAC）有两类主要的功能状态，一种是具有阴离子选择性的大电导“开放”状态，以及具有阳离子选择性的较低电导亚状态。该通道可在开放状态和半开放状态之间可逆切换，在任何一种极性的膜电压升高时，后者占主导。我们报告了VDAC存在一种新的功能状态，即阳离子选择性状态，其电导大约等于典型开放状态的电导。这种新描述的VDAC状态可从半开放阳离子选择性状态或开放阴离子选择性状态达到。后一种转变意味着在VDAC中存在一种与部分关闭分开的选择性门控机制，这可能与该通道的生理调节和线粒体外膜通透性有关。
