Issue 22, 2014

Cyclodextrin ion channels


Seventeen derivatives of α- and β-cyclodextrins were prepared from the cyclodextrin per-6-azide by “click” cyclization with terminal alkynes. Sixteen of these “half-channel” compounds showed significant activity as ion channels in planar bilayer members as assessed by the voltage-clamp technique. Activity ranged from persistent square-top openings to highly erratic conductance; mixed behaviours were evident in virtually all data recorded. Some of the erratic behaviours were shown to follow an apparent power-law distribution of open duration times. The activities observed for the suite were summarized using a model-free activity grid method which displays conductance, duration, and opening behaviour. The overall activity shows the clustering of conductance–duration indicating that activity arises from system properties rather that solely as a property of the compound. The activity grids also support an analysis of structure–activity relationships as they apply to the global behaviour of the compounds and reveal the complexity of a single structure change in controlling the distribution of concurrent conductance behaviours. Transient blockage of channel activity by the hydrophobic guest of the cyclodextrin (1-adamantyl carboxylate) is consistent with the formation of an end-to-end dimer channel among several other competing and interconverting structures.

Graphical abstract: Cyclodextrin ion channels

Supplementary files

Article information

Article type
03 Mar 2014
08 Apr 2014
First published
09 Apr 2014
This article is Open Access
Creative Commons BY license

Org. Biomol. Chem., 2014,12, 3622-3634

Author version available

Cyclodextrin ion channels

J. K. W. Chui and T. M. Fyles, Org. Biomol. Chem., 2014, 12, 3622 DOI: 10.1039/C4OB00480A

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