Formation of Nanoporous Lipid Arrays on Mica by Extraction of Bacteriorhodopsins (BRs) from Purple Membrane (PM) Patches

Aiguo Wu1 and Norbert Hampp1,2

1Department of Chemistry, and
2Materials Science Center, Philipps-University, Hans-Meerwein-St., D-35032 Marburg, Germany




Purple membrane (PM) consists of lipids and bacteriorhodosin (BR) as the only protein at a molar ratio of 10:1. The BRs form a hexagonal crystalline array inside PM. A complimentary structure is formed by lipids, but it was not possible to obtain the structured nanoporous lipid array without embedded BRs. Now we present a method, which allows to separate the BR molecules from a complete PM membrane patch from the lipids. By this method microsized nanoporous lipid arrays can be prepared on mica. The method may be applied to other membrane proteins.