Model Membrane Formations : Interaction of Sialoglycoprotein from Human Red Cell Membranes with Lipid monolayers

Abstract

By penetration of enriched sialoglycoprotein preparations from human red cell membranes into a monolayer of red cell membrane lipids it is possible to form planar lipoprotein complexes. By deposition of two such monolayers on mica a bilayer is formed which, after freeze-fracturing and etching, closely resembles fractured red cell membranes with respect to the size and distribution of intramembrane particles. A clear correlation is seen between the particle number per unit area and the increase of surface pressure by the penetration of the protein into the lipid film. The amount of penetrated protein strongly depends on the initial film pressure of the lipid. Above 30 dynes/cm progressively less protein can penetrate the film. The results strongly support the hypothesis that the sialoglycoprotein fractions represent the particles seen in the native membrane.