1-2-oleoylphosphatidylcholine and betadex

Mechanosensitive channels sense mechanical forces in cell membranes and underlie many biological sensing processes

Topics: beta-Cyclodextrins; Cryoelectron Microscopy; Detergents; Escherichia coli; Escherichia coli Proteins; Hydrophobic and Hydrophilic Interactions; Ion Channels; Lipid Bilayers; Mechanotransduction, Cellular; Membranes, Artificial; Models, Molecular; Mutation; Nanostructures; Phosphatidylcholines; Protein Conformation

We report a simple method to obtain stable asymmetric giant unilamellar vesicles (GUVs). Fluorescence correlation spectroscopy was used to quantitatively characterize vesicle properties. After brain sphingomyelin (bSM) was exchanged into dioleoylphosphatidylcholine (DOPC) GUVs, lateral diffusion in the bSM-containing outer leaflet decreased, whereas that in the DOPC-containing inner leaflet was largely unchanged, confirming asymmetry and a lack of coupling between the physical states of the inner and outer leaflets. In contrast, after bSM was exchanged into brain phosphatidylcholine vesicles, lateral diffusion decreased in both leaflets. Thus, asymmetric GUVs should be useful for investigating the molecular mechanisms behind interleaflet coupling.

Topics: beta-Cyclodextrins; Brain; Diffusion; Lipids; Phosphatidylcholines; Spectrometry, Fluorescence; Sphingomyelins; Unilamellar Liposomes