Nature embeds some of its molecular machinery, including ion pumps, within lipid bilayer membranes. This has inspired chemists to attempt to develop synthetic analogues to exploit membrane confinement and transmembrane potential gradients, much like their biological cousins. In this perspective, the authors outline the various strategies by which molecular machines─molecular systems in which a nanomechanical motion is exploited for function─have been designed to be incorporated within lipid membranes and utilized to mediate transmembrane ion transport. The readers obtain a survey on molecular machines spanning both switches and motors, those that act as mobile carriers or that are anchored within the membrane, mechanically interlocked molecules, and examples that are activated in response to external stimuli.
Two CD-based examples are discussed:
- α-cyclodextrin nanotube channels
- β-cyclodextrin-based ion channel that displayed switchable ion transport selectivity in response to the configuration of the appended azobenzene switch
Toby G. Johnson, Matthew J. Langton (2023) Molecular Machines For The Control Of Transmembrane Transport. J. Am. Chem. Soc. 145, 50, 27167–27184. https://doi.org/10.1021/jacs.3c08877