Site-specific ion occupation in the selectivity filter causes voltage-dependent gating in a viral K⁺ channel.

ABSTRACT: Many potassium channels show voltage-dependent gating without a dedicated voltage sensor domain. This is not fully understood yet, but often explained by voltage-induced changes of ion occupation in the five distinct K⁺ binding sites in the selectivity filter. To better understand this mechanism of filter gating we measured the single-channel current and the rate constant of sub-millisecond channel closure of the viral K⁺ channel Kcv_NTS for a wide range of voltages and symmetric and asymmetric K⁺ concentrations in planar lipid membranes. A model-based analysis employed a global fit of all experimental data, i.e., using a common set of parameters for current and channel closure under all conditions. Three different established models of ion permea

SUBMITTER: Rauh O 

PROVIDER: S-EPMC6039446 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature