Permeation selectivity by competition in a delayed rectifier potassium channel.

S J Korn; S R Ikeda

doi:10.1126/science.7618108

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PubMed · 7618108

Permeation selectivity by competition in a delayed rectifier potassium channel.

S J Korn·S R Ikeda

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Abstract

Permeation selectivity was studied in two human potassium channels, Kv2.1 and Kv1.5, expressed in a mouse cell line. With normal concentrations of potassium and sodium, both channels were highly selective for potassium. On removal of potassium, Kv2.1 displayed a large sodium conductance that was inhibited by low concentrations of potassium. The channel showed a competition mechanism of selectivity similar to that of calcium channels. In contrast, Kv1.5 displayed a negligible sodium conductance on removal of potassium. The observation that structurally similar potassium channels show different abilities to conduct sodium provides a basis for understanding the structural determinants of potassium channel selectivity.

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Animals Binding, Competitive Delayed Rectifier Potassium Channels Humans L Cells Membrane Potentials Mice Potassium Potassium Channels Potassium Channels, Voltage-Gated Shab Potassium Channels Sodium Journal Article Research Support, Non-U.S. Gov't

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S J Korn, S R Ikeda. 1995-07-21. Permeation selectivity by competition in a delayed rectifier potassium channel.. https://doi.org/10.1126/science.7618108

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