Two-dimensional components and hidden dependencies provide insight into ion channel gating mechanisms.
Two-dimensional components and hidden dependencies provide insight into ion channel gating mechanisms.
复制标题
二维组件和隐藏的依赖性提供了对离子通道门控机制的深入了解。
DOI：
10.1016/s0006-3495(97)78897-0
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Magleby,KL
中科院分区：
文献类型：
--
作者：
Rothberg,BS;Bello,RA;Magleby,KL
从离子通道记录的相邻开放和关闭间隔的持续时间之间的相关性包含关于潜在门控机制的信息。这项研究提出了一种额外的方法来提取相关信息。详细的相关性信息直接从单通道数据中获得，并以可以提供对门控背后的状态之间的连接的洞察的方式进行量化。除了马尔可夫门控的一般假设之外，独立于任何特定的动力学方案获得信息。相邻的打开和关闭间隔的持续时间被合并成二维（2-D）驻留时间分布。2-D（联合）分布与2-D指数分量的总和拟合，以确定2-D分量的数量、它们的体积以及它们的开放和闭合时间常数。每个2-D分量的依赖性通过将其观察到的体积与如果打开和关闭间隔独立配对时预期的体积进行比较来计算。估计的组件依赖关系，然后用于建议门控机制，并提供一个强大的手段，检查是否建议的门控机制有正确的状态之间的连接。2-D方法的灵敏度可以识别隐藏的组件和依赖性，可以通过以前的相关方法检测不到。
Correlations between the durations of adjacent open and shut intervals recorded from ion channels contain information about the underlying gating mechanism. This study presents an additional approach to extracting the correlation information. Detailed correlation information is obtained directly from single-channel data and quantified in a manner that can provide insight into the connections among the states underlying the gating. The information is obtained independently of any specific kinetic scheme, except for the general assumption of Markov gating. The durations of adjacent open and shut intervals are binned into two-dimensional (2-D) dwell-time distributions. The 2-D (joint) distributions are fitted with sums of 2-D exponential components to determine the number of 2-D components, their volumes, and their open and closed time constants. The dependency of each 2-D component is calculated by comparing its observed volume to the volume that would be expected if open and shut intervals paired independently. The estimated component dependencies are then used to suggest gating mechanisms and to provide a powerful means of examining whether proposed gating mechanisms have the correct connections among states. The sensitivity of the 2-D method can identify hidden components and dependencies that can go undetected by previous correlation methods.