Na+ block and permeation in a K+ channel of known structure

被引：102

作者：

Nimigean, CM ^{[1
]}

Miller, C ^{[1
]}

机构：

[1] Brandeis Univ, Dept Biochem, Howard Hughes Med Inst, Waltham, MA 02454 USA

来源：

JOURNAL OF GENERAL PHYSIOLOGY | 2002年 / 120卷 / 03期

关键词：

selectivity; KCSA; punchthrough;

D O I：

10.1085/jgp.20028614

中图分类号：

Q4 [生理学];

学科分类号：

071003 ;

摘要：

The effects of intracellular Na+ were studied on K+ and Rb+ currents through single KcsA channels. At low voltage, Na+ produces voltage-dependent block, which becomes relieved at high voltage by a "punch-through" mechanism representing Na+ escaping from its blocking site through the selectivity filter. The Na+ blocking site is located in the wide, hydrated vestibule, and it displays unexpected selectivity for K+ and Rb+ against Na+. The voltage dependence of Na+ block reflects coordinated movements of the blocker with permeant ions in the selectivity filter.

引用

页码：323 / 335

页数：13

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