Transmembrane ion channels constructed of cholic acid derivatives.

摘要: A new class of supramolecular transmembrane ion channels was prepared by linking two amphiphilic cholic acid methyl ethers through biscarbamate bonds to afford bis(7,12-dimethyl-24-carboxy-3-cholanyl)-N,N'-xylylene dicarbamate 2 and bis[7,12-dimethyl-24-(N,N,N-trimethylethanaminium-2-carboxylate)-3-cholanyl]-N,N'-xylylene dichloride 3. When incorporated into a planar bilayer membrane, both compounds showed stable (lasting 10 ms s) single channel currents. Only limited numbers relatively small conductances were characterized for these (5-20 pS 5-10 3, 17 2, 9 3 in particular). Both cation selective, permeability ratios potassium chloride anion 7.9 respectively, reflecting the difference ionic species headgroup. significant selectivity over sodium factor 3.1 3.2, respectively. No Li(+) currents observed showing sharp discrimination between Na(+) or K(+).