Driving a planar model system into the 3(rd) dimension: generation and control of curved pore-spanning membrane arrays

Soft Matter. 2014 Sep 7;10(33):6228-36. doi: 10.1039/c4sm00702f. Epub 2014 Jul 11.

Abstract

The generation of a regular array of micrometre-sized pore-spanning membranes that protrude from the underlying surface as a function of osmotic pressure is reported. Giant unilamellar vesicles are spread onto non-functionalized Si/SiO(2) substrates containing a highly ordered array of cavities with pore diameters of 850 nm, an interpore distance of 4 μm and a pore depth of 10 μm. The shape of the resulting pore-spanning membranes is controlled by applying an osmotic pressure difference between the bulk solution and the femtoliter-sized cavity underneath each membrane. By applying Young-Laplace's law assuming moderate lateral membrane tensions, the response of the membranes to the osmotic pressure difference can be theoretically well described. Protruded pore-spanning membranes containing the receptor lipid PIP(2) specifically bind the ENTH domain of epsin resulting in an enlargement of the protrusions and disappearance as a result of ENTH-domain induced defects in the membranes. These results are discussed in the context of an ENTH-domain induced reduction of lateral membrane tension and formation of defects as a result of helix insertion of the protein in the bilayer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Vesicular Transport / chemistry
  • Animals
  • Ions / chemistry
  • Lipid Bilayers / chemistry
  • Materials Testing
  • Membranes, Artificial*
  • Microscopy, Confocal
  • Osmosis
  • Phosphatidylcholines / chemistry
  • Pressure
  • Protein Structure, Tertiary
  • Proteins / chemistry
  • Rats
  • Silicon / chemistry*
  • Silicon Dioxide / chemistry*
  • Solvents / chemistry
  • Temperature
  • Tin Compounds / chemistry

Substances

  • Adaptor Proteins, Vesicular Transport
  • Ions
  • Lipid Bilayers
  • Membranes, Artificial
  • Phosphatidylcholines
  • Proteins
  • Solvents
  • Tin Compounds
  • epsin
  • indium tin oxide
  • Silicon Dioxide
  • 1-palmitoyl-2-oleoylphosphatidylcholine
  • Silicon