Molecular Dynamics Simulations on Barium Blockades in potassium channels

【摘要】：Potassium channels are a broad family of membrane proteins present in almost every cell, and their rapid and highly selective conduction of potassium ions across membranes is central to many biological and physiological processes [1,2]. Notably, potassium channel such as KcsA is specifically blocked by the Ba~(2+), which shares a similar size while twice the charge as that of the K+. Translocation of Ba~(2+) towards the extracellular side is further prevented when an ion binds to the "external lock-in" site. A mechanism of Ba~(2+) blocking was proposed by an experiment on the KcsA channel in 2011 [3], and the very recent studies in2014 of the NaK2 K [4] and MthK [5] channels, which share an identical selectivity filter structure as that of KcsA, are making the mechanisms proposed above seems to be even more interesting. To thoroughly explore the Ba~(2+) blocking behavior and provide a comprehensive picture of the key elements to Ba~(2+) binding in potassium channels, in terms of CHARMM 36 force field, we carried a systematic comparison study on Ba~(2+) blockade in the above ion channels.

【作者单位】：School of Chemistry and Chemical Engineering,Liaoning Normal University Department of Biochemistry and Molecular Biology,University of Chicago
【分类号】：Q25