Jun, 2013
Structural changes of the KcsA potassium channel upon application of the electrode potential studied by surface-enhanced IR absorption spectroscopy
CHEMICAL PHYSICS
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- ,
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- Volume
- 419
- Number
- First page
- 224
- Last page
- 228
- Language
- English
- Publishing type
- Research paper (scientific journal)
- DOI
- 10.1016/j.chemphys.2013.02.035
- Publisher
- ELSEVIER SCIENCE BV
Structural changes of the KcsA potassium channel fixed on gold electrode surface in the upright orientation were studied by surface-enhanced IR absorption spectroscopy (SEIRAS). Measurements were performed at neutral pH, where the activation gate is kept closed. Band intensities were enhanced for the asymmetric (1565 cm(-1)) and symmetric (1405 cm(-1)) OCO-carboxylate groups at negative electrode potentials in the K+ solution, but not in the Na+ solution. Even for the reverse-oriented channel, the enhanced OCO-carboxylate band was evident at negative potential. When TBA was loaded in the central cavity, the K+-specific OCO band was not elicited. These results indicate that the negative electrode potential renders the local K+ concentration accumulated at the vicinity of the electrode surface, and the KcsA channel bathed in high K+ changes conformation of the selectivity filter from the collapsed to the open, and OCO-carboxylate groups (D80 and E71) in the back of the filter were rearranged. Crown Copyright (C) 2013 Published by Elsevier B. V. All rights reserved.
- Link information
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- DOI
- https://doi.org/10.1016/j.chemphys.2013.02.035
- J-GLOBAL
- https://jglobal.jst.go.jp/en/detail?JGLOBAL_ID=201302258356420839
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000320700300038&DestApp=WOS_CPL
- URL
- http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=201302258356420839
- ID information
-
- DOI : 10.1016/j.chemphys.2013.02.035
- ISSN : 0301-0104
- J-Global ID : 201302258356420839
- Web of Science ID : WOS:000320700300038