Abstract:We report an example of the use of fatty acids to drive chloride transport by creating a pH gradient across a vesicular lipid bilayer membrane. Addition of an unselective squaramide-based chloride transporter (which transports both H + and Cl -) facilitates the transport of HCl from the vesicle (driven by the pH gradient) so creating a chloride gradient. Addition of further aliquots of fatty acid 'fuel' can initiate further transport of chloride out of the vesicle by re-establishing the pH gradient. This is an example of a prototypical chloride pumping system.