ABSTRACT
Numerous studies in this field have revealed that membrane lipids display rich lyotropic and thermotropic polymorphism characterized by a large set of lamellar and non-lamellar phases. The data about solute effects summarized in this article show that the composition of the aqueous phase is another important factor strongly modulating the relative stability of the lipid lamellar and non-lamellar phases. Best studied at present are the effects of chaotropic and kosmotropic solutes on the phase behavior of phosphatidylethanolamines. The solutes used in these studies include inorganic salts, mono- and disaccharides, sugar alcohols, some polyols, proline, and urea. A noteworthy consequence of the greater sensitivity of the pretransition to solutes is that it merges with the main transition at high enough solute concentrations. Solute effects on the glycolipid phase behavior have been recently measured in our laboratory by differential scanning calorimetry for several synthetic ether-linked glycoglycerolipids with saturated chains of equal length.
