Abstract:
A variety of equilibrium and non-equilibrium methods have been used in a multidisciplinary approach to study the conformational landscape associated with the binding of different cations to the pore of potassium channels. These binding processes, and the conformational changes resulting therefrom, modulate the functional properties of such integral membrane properties, revealing these permeant and blocking cations as true effectors of such integral membrane proteins. KcsA, a prototypic K+ channel from Streptomyces lividans, has been extensively characterized in this regard. Here, we revise several fluorescence-based approaches to monitor cation binding under different experimental conditions in diluted samples, analyzing the advantages and disadvantages of each approach. These studies have contributed to explain the selectivity, conduction, and inactivation properties of K+ channels at the molecular level, together with the allosteric communication between the two gates that control the ion channel flux, and how they are modulated by lipids.
摘要:
在多学科方法中已使用了多种平衡和非平衡方法来研究与不同阳离子与钾通道孔的结合相关的构象景观。这些绑定过程,以及由此产生的构象变化,调节这种整体膜特性的功能特性,揭示这些渗透和阻断阳离子是这种完整膜蛋白的真正效应物。KcsA,来自鱼链霉菌的原型K+通道,在这方面有广泛的特点。这里,我们修订了几种基于荧光的方法来监测稀释样品中不同实验条件下的阳离子结合,分析了每种方法的优缺点。这些研究有助于解释选择性,传导,以及K+通道在分子水平上的失活特性,以及控制离子通道通量的两个门之间的变构通信,以及它们是如何被脂质调节的。