Supramolecular ion channels from a transmembrane bischolic acid derivative showing two discrete conductances.
Bischolic acid derivative 1 linked by m-xylylene dicarbamate at the 3,3'-position was synthesized and the single ion channel properties were examined. Compound 1 showed two clearly distinct conductances, 9.5 (type A) and 25.3 pS (type B), under 500 mM KCl symmetric salt conditions, whereas various conductances, ranging from 5-20 pS, were observed in the tetramethylether analogue reported previously. Results indicate that the replacement of four methylether groups with hydroxyls at the 7, 7', 12, and 12' positions in the bischolic acid framework influences the stability of aggregated (supramolecular) ion channel structures. Ion permeability ratios (potassium/chloride and potassium/sodium) for each type of channel were also determined.
Yoshii
Mami
M
Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
Yamamura
Mika
M
Satake
Akiharu
A
Kobuke
Yoshiaki
Y
D002463:Cell Membrane Permeability; D002793:Cholic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D007473:Ion Channels / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008567:Membranes, Artificial; D008958:Models, Molecular; D015394:Molecular Structure
D002793:Cholic Acids; D007473:Ion Channels; D008567:Membranes, Artificial