Anion Transport by Bambusuril-Bile Acid Conjugates: Drastic Effect of the Cholesterol Content

Abstract

Artificial anion transporters offer a potential way to treat deficiencies in cellular anion transport of genetic origins. In contrast to the large variety of mobile anion carriers and self-assembled anion channels reported, unimolecular anion channels are less investigated. Herein, we present a unique example of a unimolecular anion channel based on a bambusuril (BU) macrocycle, a well-established anion receptor. The BU structure was expanded by appending various bile acid residues allowing a single molecule to span the membrane. Chloride transport mediated by BUs through lipid bilayers was investigated in liposomes and these studies revealed a surprisingly high dependence of the anion transport activity on the cholesterol content in the liposomal membrane.