Transmembrane Fluoride Transport: Direct Measurement and Selectivity Studies
Harriet J Clarke1, Ethan N W Howe1, Xin Wu1
1Chemistry, University of Southampton , Southampton SO17 1BJ, U.K.
Journal of the American Chemical Society
|December 22, 2016
Summary
Synthetic anion transporters can now target fluoride. Strapped calix[4]pyrroles facilitate electrogenic fluoride transport across lipid bilayers, with selectivity over other ions.
Area of Science:
- Supramolecular Chemistry
- Membrane Transport
- Synthetic Biology
Background:
- Natural fluoride transport channels have been recently identified.
- Synthetic anion transporters have largely overlooked fluoride as a target.
- Calix[4]pyrrole derivatives are known for their anion binding properties.
Purpose of the Study:
- To investigate the potential of strapped calix[4]pyrroles as synthetic fluoride transporters.
- To directly measure fluoride transport across lipid bilayers facilitated by these compounds.
- To elucidate the mechanism and selectivity of the transport process.
Main Methods:
- Direct measurement of fluoride transport across lipid bilayers.
- Valinomycin and monensin coupled transport assays to determine the transport mechanism.
- HPTS (8-hydroxypyrene-1,3,6-trisulfonic acid) fluorescence assay for quantification and selectivity studies.
Main Results:
- Strapped calix[4]pyrroles were shown to facilitate direct fluoride transport across lipid bilayers.
- The transport mechanism was determined to be electrogenic.
- The assay quantified the transport process and demonstrated selectivity for chloride over protons/hydroxide, with interference from fatty acids noted.
Conclusions:
- Strapped calix[4]pyrroles represent a novel class of synthetic transporters capable of facilitating electrogenic fluoride transport.
- This work opens new avenues for developing synthetic transporters targeting fluoride.
- Understanding transport selectivity and potential interferences is crucial for designing effective anion transporters.
