Learning by building: constructing voltage gated ion channels from individual modular components

电压依赖性钾离子通道（Voltage dependent K+ channels，Kv）是一种模块化的蛋白质，由通道孔、电压感受器通道蛋白和连接后两者的连接体组成。尽管有关于这些重要蛋白质的详细结构信息，但关于电压传感器运动导致孔打开的机制仍存在许多未解决的问题。在这里，我们提出了一种新的方法来解决的基本机制，电机械耦合之间的孔和电压传感器在千伏通道。它是基于成功构建了一个由无关元件合成的Kv通道、一个电压不敏感的微型K+通道孔和被囊海鞘磷酸酶的电压传感器。在边学习边构建的过程中，我们将通过系统地改变孔、电压传感器和连接体的结构和/或功能特性来构建和表征新的合成通道。合成通道中这些限定的元件的天然组合将与基于理论的粗粒计算组合提供关于i）连接体在机电耦合中的影响ii）传感器域对于整流的重要性iii）电压传感器对门控机制的影响的机械信息，这是孔中固有的。

Voltage dependent K+ channels (Kv) are modular proteins; they are composed of a channel pore, a voltage sensor dornain and a linker, which connects the latter two parts. ln spite of detailed structui:al information on these important proteins there are still rnany open questions on the mechanism by which the voltage sensor movement results in an opening of the pore. Here we propose a new approach for tackling the basic mechanism of etectromechanical coupling between pore and voltage sensor in Kv channels. lt is based on the successful constructlon of a synthetic Kv channel from unrelated elements, a voltage indepenclent miniature K+ channel pore and the voltage sensor of the phosphatase from the tunicate Ciona intestinalis. ln a learning-by-building procedure we will construct and characterize new synthetic channels by systematically varying lhe structural and/or functional character of the pore, the voltage sensor and the linker respectively. The native combination of these defined elements in synthetic channels will provide in combination with theoreticaly based coarsed grain calculations mechanistic information on i) the impact of the linker in electromechanical coupling ii) the importance of the sensor domain for rectification iii) the impact of the voltage sensor on gating mechanisms, which are inherent in the pore.