Voltage-induced gating of the mechanosensitive MscL ion channel reconstituted in a tethered lipid bilayer membrane
Voltage-induced gating of the mechanosensitive MscL ion channel reconstituted in a tethered lipid bilayer membrane
复制标题
DOI：
10.1016/j.bios.2007.09.014
复制
发表时间：
2008-01-18
影响因子：
12.6
通讯作者：
Duran, Randolph S.
中科院分区：
文献类型：
--
作者：
Andersson, Martin;Okeyo, George;Duran, Randolph S.
机械敏感（MS）离子通道的门控双层变形的变化。它在不存在任何其他蛋白质的情况下是功能性的，并且使用常规的膜片钳技术已经成功地实现了通道的门控，其中在膜上施加电压和压力。在这里，我们第一次分析了大的传导（MscL）通道中的支持膜仅使用外部电场。这是可能使用一种新开发的技术，利用拴系脂质双层膜（tBLM），这是一个工程微电子阵列芯片的一部分。获得了MscL的单离子通道活性特征，尽管电导率较低。仅使用300 mV的跨膜电位门控离子通道。计算表明，这个量的膜电位诱导12达因/厘米的膜张力，相当于计算门控通道膜片钳从压力诱导的双层拉伸。这些结果加强了MscL离子通道门控响应于脂质膜中的应力而不是压力的假设。此外，这些发现说明了使用MscL作为工程膜装置的释放阀的可能性;离模拟活细胞的真实功能更近了一步。(C)2007 Elsevier B. V.保留所有权利。
The mechanosensitive (MS) ion channel is gated by changes in bilayer deformation. It is functional without the presence of any other proteins and gating of the channel has been successfully achieved using conventional patch clamping techniques where a voltage has been applied together with a pressure over the membrane. Here, we have for the first time analyzed the large conducting (MscL) channel in a supported membrane using only an external electrical field. This was made possible using a newly developed technique utilizing a tethered lipid bilayer membrane (tBLM), which is part of an engineered microelectronic array chip. Single ion channel activity characteristic for MscL was obtained, albeit with lower conductivity. The ion channel was gated using solely a transmembrane potential of 300 mV. Computations demonstrate that this amount of membrane potential induces a membrane tension of 12 dyn/cm, equivalent to that calculated to gate the channel in patch clamp from pressure-induced stretching of the bilayer. These results strengthen the supposition that the MscL ion channel gates in response to stress in the lipid membrane rather than pressure across it. Furthermore, these findings illustrate the possibility of using the MscL as a release valve for engineered membrane devices; one step closer to mimicking the true function of the living cell. (C) 2007 Elsevier B.V. All rights reserved.