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. 2001 May;80(5):2216–2220. doi: 10.1016/S0006-3495(01)76194-2

Revisiting the role of Ca2+ in Shaker K+ channel gating.

K H Hong 1, C M Armstrong 1, C Miller 1
PMCID: PMC1301413  PMID: 11325724

Abstract

Shaker K+ channels were expressed in outside-out macropatches excised from Xenopus oocytes, and the effects on gating of removal of extracellular Ca2+ were examined in the complete absence of intracellular divalent cations. Removal of extracellular Ca2+ by perfusion with EDTA-containing solution caused a small negative shift in the channel's voltage-activation curve and led to an increased nonselective leak, but did not otherwise alter or disrupt the channels. The results contradict the proposal that Ca2+ is an essential component required for maintenance of ion selectivity and proper gating of Kv-type K+ channels. The large nonselective leak in Ca2+-free conditions was found to be a patch-seal phenomenon related to F- ion in the recording pipette.

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Selected References

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