title: Diffusion in low-dimensional lipid membranes.
abstract: The diffusion behavior of biological components in cellular membranes is vital to the function of cells. By collapsing the complexity of planar 2D membranes down to one dimension, fundamental investigations of bimolecular behavior become possible in one dimension. Here we develop lipid nanolithography methods to produce membranes, under fluid, with widths as low as 6 nm but extending to microns in length. We find reduced lipid mobility, as the width is reduced below 50 nm, suggesting different lipid packing in the vicinity of boundaries. The insertion of a membrane protein, M2, into these systems, allowed characterization of protein diffusion using high-speed AFM to demonstrate the first membrane protein 1D random walk. These quasi-1D lipid bilayers are ideal for testing and understanding fundamental concepts about the roles of dimensionality and size on physical properties of membranes from energy transfer to lipid packing.
authors.affiliation: School of Physics and Astronomy, University of Leeds , Leeds LS2 9JT, United Kingdom.
authors.forename: George R
authors.initials: GR
authors.lastname: Heath
authors.forename: Johannes
authors.initials: J
authors.lastname: Roth
authors.forename: Simon D
authors.initials: SD
authors.lastname: Connell
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Evans
mesh_terms: D004058:Diffusion; D006801:Humans; D009980:Influenza A virus / Q000737:chemistry; D007251:Influenza, Human / Q000821:virology; D008051:Lipid Bilayers / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D010713:Phosphatidylcholines / Q000737:chemistry*; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D014763:Viral Matrix Proteins / Q000737:chemistry; D000086082:Viroporin Proteins
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins; C007510:1,2-dipalmitoyl-3-phosphatidylethanolamine; C028694:1-palmitoyl-2-oleoylphosphatidylcholine
keywords: Lipid membranes; high-speed AFM; lipid diffusion; molecular crowding; nanolithography