REVERSE VESICLES - COUNTER STRUCTURE OF BIOLOGICAL-MEMBRANES

It was found that stable reverse vesicles of sucrose monoal-kanoate form in decane + hexanol in the presence of a small amount of water. They are the dispersion of lamellar liquid crystal which swell a considerable amount of oil. The interlayer spacing of the bilayers is increased upon addition of hexanol. As a result, hexanol is effective in making the bilayers flexible and in dispersing the liquid crystal as reverse vesicles. The structure of the reverse vesicles was confirmed by video-enhanced microscopy, fluorescence microscopy, and freeze-fracture transmission electron microscopy(Cryo-TEM). The orientation of amphiphilic molecules is completely opposite to that in normal vesicles, i.e., with the hydrophilic part located inward. The thickness of the bilayers (about 10 nm) observed from Cryo-TEM photography is in good agreement with SAXS (small-angle X-ray scattering) data. The smaller vesicles with sizes of submicrometer order are very stable and are not precipitated for several months. © 1993 by Academic Press, Inc.