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

共 34 条

[1] Perspectives on ion permeation [J].

Andersen, OS .

JOURNAL OF GENERAL PHYSIOLOGY, 1999, 113 (06) :763-764

[2] INTERACTION OF TETRAETHYLAMMONIUM ION DERIVATIVES WITH POTASSIUM CHANNELS OF GIANT AXONS [J].

ARMSTRONG, CM .

JOURNAL OF GENERAL PHYSIOLOGY, 1971, 58 (04) :413-+

[3] Energetics of ion conduction through the K+ channel [J].

Bernèche, S ;

Roux, B .

NATURE, 2001, 414 (6859) :73-77

[4] NEGATIVE CONDUCTANCE CAUSED BY ENTRY OF SODIUM AND CESIUM IONS INTO POTASSIUM CHANNELS OF SQUID AXONS [J].

BEZANILLA, F ;

ARMSTRONG, CM .

JOURNAL OF GENERAL PHYSIOLOGY, 1972, 60 (05) :588-+

[5] CONSTANT FIELDS AND CONSTANT GRADIENTS IN OPEN IONIC CHANNELS [J].

CHEN, DP ;

BARCILON, V ;

EISENBERG, RS .

BIOPHYSICAL JOURNAL, 1992, 61 (05) :1372-1393

[6] Nonequilibrium gating and voltage dependence of the ClC-0 Cl- channel [J].

Chen, TY ;

Miller, C .

JOURNAL OF GENERAL PHYSIOLOGY, 1996, 108 (04) :237-250

[7] VOLTAGE-DEPENDENT CESIUM BLOCKADE OF A CATION CHANNEL FROM FRAGMENTED SARCOPLASMIC-RETICULUM [J].

CORONADO, R ;

MILLER, C .

NATURE, 1979, 280 (5725) :807-810

[8] pH-dependent gating in the Streptomyces lividans K+ channel [J].

Cuello, LG ;

Romero, JG ;

Cortes, DM ;

Perozo, E .

BIOCHEMISTRY, 1998, 37 (10) :3229-3236

[9] The structure of the potassium channel:: Molecular basis of K+ conduction and selectivity [J].

Doyle, DA ;

Cabral, JM ;

Pfuetzner, RA ;

Kuo, AL ;

Gulbis, JM ;

Cohen, SL ;

Chait, BT ;

MacKinnon, R .

SCIENCE, 1998, 280 (5360) :69-77

[10] AN IONS VIEW OF THE POTASSIUM CHANNEL - THE STRUCTURE OF THE PERMEATION PATHWAY AS SENSED BY A VARIETY OF BLOCKING IONS [J].

FRENCH, RJ ;

SHOUKIMAS, JJ .

JOURNAL OF GENERAL PHYSIOLOGY, 1985, 85 (05) :669-698

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