These authors contributed equally to this work.
Direct Manipulation of a Single Potassium Channel Gate with an Atomic Force Microscope Probe
Article first published online: 8 JUN 2011
Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Volume 7, Issue 16, pages 2379–2383, August 22, 2011
How to Cite
Kitta, M., Ide, T., Hirano, M., Tanaka, H., Yanagida, T. and Kawai, T. (2011), Direct Manipulation of a Single Potassium Channel Gate with an Atomic Force Microscope Probe. Small, 7: 2379–2383. doi: 10.1002/smll.201002337
- Issue published online: 16 AUG 2011
- Article first published online: 8 JUN 2011
- Manuscript Revised: 21 FEB 2011
- Manuscript Received: 12 DEC 2010
- atomic force microscopy;
- ion channels;
- protein structures;
- single-molecule studies
Ion channels are membrane proteins that regulate cell functions by controlling the ion permeability of cell membranes. An ion channel contains an ion-selective pore that permeates ions and a sensor that senses a specific stimulus such as ligand binding to regulate the permeability. The detailed molecular mechanisms of this regulation, or gating, are unknown. Gating is thought to occur from conformational changes in the sensor domain in response to the stimulus, which results in opening the gate to permit ion conduction. Using an atomic force microscope and artificial bilayer system, a mechanical stimulus is applied to a potassium channel, and its gating is monitored in real time. The channel-open probability increases greatly when pushing the cytoplasmic domain toward the membrane. This result shows that a mechanical stimulus at the cytoplasmic domain causes changes in the gating and is the first to show direct evidence of coupling between conformational changes in the cytoplasmic domain and channel gating. This novel technology has the potential to be a powerful tool for investigating the activation dynamics in channel proteins.