Molecular Amphiphile Bilayers Forming a Cubic Phase in Amphiphile-Water Systems

Structural properties are discussed of the cubic phase in monoglyceride-water systems, which is proposed to consist of a continuous lipid bilayer separating two not connected water channel systems. This cubic phase can solubilize large amounts of other lipids, such as cholesterol and lecithin, and a hydrophobic protein, A-gliadin. The same type of cubic phase occurs also in galacto-lipid systems and in systems of lysolecithin. The biological significance of this phase is discussed, and a general mechanism for fusion of cell membranes or liposomes based on a lamellar -- cubic transition is proposed.