Extracelluar Potassium Ions Play Important Roles in the Selectivity of Mutant KcsA Channel
Potassium channels are exquisitely selective, allowing K+ to cross cell membranes while blocking other ions, such as Na+ and Cs+. It is now universally accepted that the selectivity filter is the functional unit that allows K+ channels to distinguish potassium and sodium ions. In this paper, we adopted the density functional theory and the Brownian dynamics to study the selectivity mechanism of KcsAD-Ala77 in low and high K+ conditions. The results suggest that the extracelluar potassium ions can change the conformation of the ion channels which can affect the interaction between the ions and the filter of ion channels. It is the interaction that determines the selectivity of potassium ions channels. The KcsAD-Ala77 can permeate potassium and sodium ions in low K+ conditions, but only permeate potassium ions in high K+ conditions. The results are consistent with the experimental data. The results may demonstrate that the selectivity is a property of the channel structure, not only the consensus sequence of amino.
Selectivity Density functional theory Brownian dynamics Ion channels
Yuzhi Liu HailongAn Suhua Zhang Junwei Li Yong Zhan
School of Electrical and Electronics Engineering Shijiazhuang Tiedao University, 050043 Shijiazhuang School of Sciences Hebei University of Technology, 300130 Tianjin, China
国际会议
上海
英文
1856-1859
2011-10-15（万方平台首次上网日期，不代表论文的发表时间）