Membrane curvature based lipid sorting using a nanoparticle patterned substrate

Soft Matter. 2014 Mar 28;10(12):2016-23. doi: 10.1039/c3sm52522h.

Abstract

Cellular membranes contain a variety of shapes that likely act as motifs for sorting lipids and proteins. To understand the sorting that takes place within cells, a continuous, fluid bilayer with regions of membrane curvature was designed and characterized using confocal fluorescence and total internal reflection fluorescence microscopy techniques. A supported lipid bilayer was formed over fluorescently labelled nanoparticles deposited on a glass surface. The lipid composition and membrane shape are separately controlled and the nanoparticle dimensions (d = 40-200 nm) determine the extent of curvature. The bulk membrane is fluid as demonstrated by fluorescence recovery after photobleaching (FRAP) using dye labelled lipids. In bilayers that contain fluorescently labelled, single-tailed lipids, accumulation is observed at regions of curvature, yet the molecules retain fluidity. Using single particle imaging methods, lipids are observed to visit regions of curvature and exchange with the surrounding flat membrane. The nanoparticle patterned substrate described here allows for quantitative measurement of the transient interactions between fluorescently labelled biomolecules and regions of membrane curvature.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cell Membrane / chemistry*
  • Fluorescence Recovery After Photobleaching
  • Lipid Bilayers / chemistry
  • Lipids / chemistry*
  • Membrane Fluidity
  • Nanoparticles / chemistry*
  • Proteins / chemistry*
  • Substrate Specificity

Substances

  • Lipid Bilayers
  • Lipids
  • Proteins