Sci. Signal., 6 April 2010
Channels Open and Closed Case
Science, AAAS, Washington, DC 20005, USA
Voltage-dependent ion channels are gated by voltage sensors that show a switchlike response to voltage differences across the membrane. Tao et al. used mutagenesis, electrophysiology, and x-ray crystallography to gain insight into the molecular basis of this response in voltage-dependent potassium channels. An occluded site was identified that catalyzes translation of positive charges across the membrane. The closed channel appears to be associated with a distribution of conformations, depending on the degree of hyperpolarization of the membrane, whereas the open channel appears to be associated with a specific conformation. Thus, the transition of the ion channel from open to closed occurs over a very small voltage difference.
Citation: V. Vinson, Open and Closed Case. Sci. Signal. 3, ec105 (2010).
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