Na+ Block and Permeation in a K+ Channel of Known Structure
Open Access
- 12 August 2002
- journal article
- Published by Rockefeller University Press in The Journal of general physiology
- Vol. 120 (3) , 323-335
- https://doi.org/10.1085/jgp.20028614
Abstract
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 “punchthrough” 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.Keywords
This publication has 32 references indexed in Scilit:
- Energetics of ion conduction through the K+ channelNature, 2001
- Perspectives on Ion PermeationThe Journal of general physiology, 1999
- The Structure of the Potassium Channel: Molecular Basis of K + Conduction and SelectivityScience, 1998
- pH-Dependent Gating in the Streptomyces lividans K+ ChannelBiochemistry, 1998
- Nonequilibrium gating and voltage dependence of the ClC-0 Cl- channel.The Journal of general physiology, 1996
- Constant fields and constant gradients in open ionic channelsBiophysical Journal, 1992
- An ion's view of the potassium channel. The structure of the permeation pathway as sensed by a variety of blocking ions.The Journal of general physiology, 1985
- Voltage-dependent caesium blockade of a cation channel from fragmented sarcoplasmic reticulumNature, 1979
- Negative Conductance Caused by Entry of Sodium and Cesium Ions into the Potassium Channels of Squid AxonsThe Journal of general physiology, 1972
- Interaction of Tetraethylammonium Ion Derivatives with the Potassium Channels of Giant AxonsThe Journal of general physiology, 1971