Relationships between Monolayer and BLM Properties of Biomembranes Components

Monolayers of galactocerebrosides and their mixtures with 1-monooleoyl-glycerol at the air/ water interface were studied as a function of temperature. Information on the bidimensional phases of the pure components and on their miscibility in mixtures was obtained from the spreading isotherms. The conductance and capacitance of bilayer lipid membranes (BLMs) containing 1-monooleoyl-glycerol, 1-monostearoyl-glycerol, galactocerebrosides, 1-monooleoyl-glycerol/1-monostearoyl-glycerol and galactocerebrosides/1-monooleoyl-glycerol in squalene were studied. The results obtained showed that the interfacial orientation was the most important factor for the monolayer miscibility and that it influenced the BLM formation. In fact, at a constant temperature stable BLMs were obtained only from substances giving fluid noncondensed films at the air/water interface and from mixtures whose components were miscible in monolayers at the air/ water interface.