Zhong Wenyu, Guo Wanlin
Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, China.
Biochem Biophys Res Commun. 2009 Oct 9;388(1):86-90. doi: 10.1016/j.bbrc.2009.07.123. Epub 2009 Jul 29.
Potassium channels conduct K(+) flow selectively across the membrane through a central pore. During a process called gating, the potassium channels undergo a conformational change that opens or closes the ion-conducting pore. The potassium channel KcsA has been structurally determined in its closed state. However, the dynamic mechanism of the gating transition of the KcsA channel is still being investigated. Here, a targeted molecular dynamics simulation up to 150ns is performed to investigate the detailed opening process of the KcsA channel with an open Kv1.2 structure serving as the target. The channel arrived at a self-determined quasi-stable state within 60ns. The rigid-body and hinge-bending modes are observed mixed together in the remaining 90ns long quasi-stable state. The mixed-mode movement seems come from the competition between the helix rigidity and the biased-applied gating force.
钾通道通过中央孔选择性地引导钾离子（K⁺）跨膜流动。在一个称为门控的过程中，钾通道会发生构象变化，从而打开或关闭离子传导孔。钾通道KcsA的结构已在其关闭状态下确定。然而，KcsA通道门控转变的动态机制仍在研究中。在此，进行了长达150纳秒的靶向分子动力学模拟，以具有开放Kv1.2结构作为目标来研究KcsA通道的详细开放过程。该通道在60纳秒内达到了自确定的准稳定状态。在剩余90纳秒长的准稳定状态下，观察到刚体和铰链弯曲模式混合在一起。混合模式运动似乎源于螺旋刚性和施加的偏向门控力之间的竞争。
