期刊
SCIENCE
卷 314, 期 5801, 页码 1004-1007出版社
AMER ASSOC ADVANCEMENT SCIENCE
DOI: 10.1126/science.1133415
关键词
-
资金
- NIBIB NIH HHS [EB001991] Funding Source: Medline
- NIGMS NIH HHS [GM43949, GM55843] Funding Source: Medline
Potassium channels are K+-selective protein pores in cell membrane. The selectivity filter is the functional unit that allows K+ channels to distinguish potassium (K+) and sodium (Na+) ions. The filter's structure depends on whether K+ or Na+ ions are bound inside it. We synthesized a K+ channel containing the D-enantiomer of alanine in place of a conserved glycine and found by x-ray crystallography that its filter maintains the K+ (conductive) structure in the presence of Na+ and very low concentrations of K+. This channel conducts Na+ in the absence of K+ but not in the presence of K+. These findings demonstrate that the ability of the channel to adapt its structure differently to K+ and Na+ is a fundamental aspect of ion selectivity, as is the ability of multiple K+ ions to compete effectively with Na+ for the conductive filter.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据