Simulation of MscL Gating in a bilayer under stress
Simulation of MscL Gating in a bilayer under stress
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DOI：
10.1016/s0006-3495(03)75038-3
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发表时间：
2003-04-01
影响因子：
3.4
通讯作者：
Mark, AE
中科院分区：
文献类型：
--
作者：
Colombo, G;Marrink, SJ;Mark, AE
用分子动力学模拟技术对结核分枝杆菌大电导机械选择通道选通的初始阶段进行了详细的原子研究。在不同的压力条件下，模拟了棕榈酰油酰磷脂酰胆碱脂双层中被显性水包围的蛋白质复合体的截断形式，以模拟膜内张力和压缩对蛋白质的影响。作为施加到膜上的侧向张力的直接结果，观察到跨膜螺旋的一个子集的倾斜增加。这反过来导致孔的扩大和由残基Ile-14和Val-21组成的疏水门的破坏。模拟表明，开启过程是一个连续的阶段性过程。这种机制可以用来解释在膜片钳实验中观察到的部分开放或阶段性电导。
The initial stages of the gating of the mechanoselective channel of large conductance from Mycobacterium tuberculosis have been studied in atomic detail using molecular dynamics simulation techniques. A truncated form of the protein complex embedded in a palmitoyloleoylphosphatidylcholine lipid bilayer and surrounded by explicit water was simulated under different pressure conditions to mimic the effects of tension and compression within the membrane on the protein. As a direct result of lateral tension being applied to the membrane, an increase in the tilt of a subset of the transmembrane helices was observed. This in turn led to the enlargement of the pore and the disruption of the hydrophobic gate consisting of residues Ile-14 and Val-21. The simulations suggest that opening occurs in a sequential staged process. Such a mechanism could explain the partial opening or staged conductance observed in patch-clamp experiments using related large conductance mechanosensitive channel complexes.