Fusion of Large Unilamellar Liposomes Containing Hemocyanin with Planar Bilayer Membranes
Zeitschrift für Naturforschung C - A Journal of Biosciences
Large unilamellar vesicles were prepared by detergent removal from micelles containing phosphatidylcholine, phosphatidylethanolam ine and phosphatidylserine. Liposomes were then interacted with Megathura crenulata hemocyanin, a well studied channel former. Incubation of the resulting proteoliposomes on one side of a phosphatidylserine-containing planar bilayer under fusion conditions yielded strong current increases. Such increase is due to insertion of ionic channels from the liposomes into
... e liposomes into the planar bilayer. Studying the effects of Ba2+ on the electrical properties of the channel we could show that the protein is always inserted into a bilayer during this process, i.e. fusion of proteoliposomes with the artificial membrane occurs. The strong non linearity of the current-voltage curve of the hemocyanin pore could be used as a probe of the extent to which fusion preserves the orientation of the channel through the bilayer.