The structure and topological stability of membranes is crucial for living cells and plays a key role in numerous vital cellular processes. To achieve its diverse and complex behaviour, the cell membrane is composed of a complex variety of biomolecules, notably lipids and proteins. However, small variations in the lipid architecture can already have large and potentially catastrophic effects on the properties and stability of the membrane. Understanding complex and dynamic cellular processes, such as endocytosis and exocytosis is, whilst urgently needed, difficult and progress is therefore slow.
Schematic illustration of the formation of supported double bilayers: a and b) formation of the proximal layer by adsorption of vesicles containing biotinylated lipids (biotin on a flexible spacer). The formation of the second bilayer: c) streptavidin has four binding sites for biotin and a sufficient number is added so that approximately half the binding sites remain free. d) Subsequently, new biotinylated vesicles are added, which will bind to the streptavidin layer. e) After rupture of the vesicles the double bilayer configuration is formed.