Observation of "Remote Knock-On", a New Permeation-Enhancement Mechanism in Ion Channels
Observation of "Remote Knock-On", a New Permeation-Enhancement Mechanism in Ion Channels
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离子通道中新型渗透增强机制“远程敲击”的观察
DOI：
10.1016/j.bpj.2013.11.783
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发表时间：
2014
影响因子：
3.4
通讯作者：
Luchinsky D
中科院分区：
文献类型：
--
作者：
Luchinsky D
我们报道了在简单模型离子通道的布朗动力学模拟中观察到的一种新的“远程敲击”机制，以增强渗透。与传统的敲击不同的是，需要相同物种的第二个离子进入通道以向前敲击并替换通道中已有的离子，新的机制不需要激发离子进入通道，也不要求离子具有相同的物种。图中绘制了条件概率分布，作为初始捕获的离子在x=0处向右逃逸时渗透瞬间激发离子位置x的函数。绘制了不同溶质浓度CL下的曲线。激发离子最有可能的位置显然是在通道的左口(x=-15？)。对于足够高的CL，对应于常规敲打的第二个小峰出现在x=0处。
We report observation of a novel “remote knock-on” mechanism for enhancement of permeation in Brownian dynamics simulations of a simple model ion channel. Unlike conventional knock-on, which requires a second ion of the same species to enter the channel in order to knock forward and replace an ion already in the channel, the new mechanism does not require the instigating ion to enter the channel, nor that it be of the same species.The figure plots the conditional probability distribution as a function of the position x of the instigating ion at the instant of permeation when the ion initially trapped at x= 0 escapes to the right. The curves are plotted for different solute concentrations CL. The most probable position of the instigating ion is clearly at the left mouth of the channel (x=-15Å). A 2nd small peak corresponding to conventional knock-on appears at x= 0 for high enough CL.