Abstract
Gating the ion-permeation pathway in K+ channels requires conformational changes in activation and inactivation gates. Here we have investigated the structural alterations associated with pH-dependent inactivation gating of the KcsA-Kv1.3 K+ channel using solid-state NMR spectroscopy in direct reference to electrophysiological and pharmacological experiments. Transition of the KcsA-Kv1.3 K+ channel from a closed state at pH 7.5 to an inactivated state at pH 4.0 revealed distinct structural changes within the pore, correlated with activation-gate opening and inactivation-gate closing. In the inactivated K+ channel, the selectivity filter adopts a nonconductive structure that was also induced by binding of a pore-blocking tetraphenylporphyrin derivative. The results establish a structural link between inactivation and block of a K+ channel in a membrane setting.
Original language | English (US) |
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Pages (from-to) | 605-612 |
Number of pages | 8 |
Journal | Nature Structural and Molecular Biology |
Volume | 15 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2008 |
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology