skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Simple, Direct Routes to Polymer Brush Traps and Nanostructures for Studies of Diffusional Transport in Supported Lipid Bilayers

Authors:
 [1];  [2];  [3];  [4];  [2]; ORCiD logo [4]; ORCiD logo [1]
  1. Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, United Kingdom; Krebs Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
  2. Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
  3. Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, United Kingdom
  4. Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Photosynthetic Antenna Research Center (PARC)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1388375
DOE Contract Number:
SC0001035
Resource Type:
Journal Article
Resource Relation:
Journal Name: Langmuir; Journal Volume: 33; Journal Issue: 15; Related Information: PARC partners with Washington University in St. Louis (lead); University of California, Riverside; University of Glasgow, UK; Los Alamos National Laboratory; University of New Mexico; New Mexico Corsortium; North Carolina State University; Northwestern University; Oak Ridge National Laboratory; University of Pennsylvania; Sandia National Laboratories; University of Sheffield, UK
Country of Publication:
United States
Language:
English
Subject:
solar (fuels), photosynthesis (natural and artificial), biofuels (including algae and biomass), bio-inspired, charge transport, membrane, synthesis (novel materials), synthesis (self-assembly)

Citation Formats

Johnson, Alexander, Bao, Peng, Hurley, Claire R., Cartron, Michaël, Evans, Stephen D., Hunter, C. Neil, and Leggett, Graham J. Simple, Direct Routes to Polymer Brush Traps and Nanostructures for Studies of Diffusional Transport in Supported Lipid Bilayers. United States: N. p., 2017. Web. doi:10.1021/acs.langmuir.7b00497.
Johnson, Alexander, Bao, Peng, Hurley, Claire R., Cartron, Michaël, Evans, Stephen D., Hunter, C. Neil, & Leggett, Graham J. Simple, Direct Routes to Polymer Brush Traps and Nanostructures for Studies of Diffusional Transport in Supported Lipid Bilayers. United States. doi:10.1021/acs.langmuir.7b00497.
Johnson, Alexander, Bao, Peng, Hurley, Claire R., Cartron, Michaël, Evans, Stephen D., Hunter, C. Neil, and Leggett, Graham J. Tue . "Simple, Direct Routes to Polymer Brush Traps and Nanostructures for Studies of Diffusional Transport in Supported Lipid Bilayers". United States. doi:10.1021/acs.langmuir.7b00497.
@article{osti_1388375,
title = {Simple, Direct Routes to Polymer Brush Traps and Nanostructures for Studies of Diffusional Transport in Supported Lipid Bilayers},
author = {Johnson, Alexander and Bao, Peng and Hurley, Claire R. and Cartron, Michaël and Evans, Stephen D. and Hunter, C. Neil and Leggett, Graham J.},
abstractNote = {},
doi = {10.1021/acs.langmuir.7b00497},
journal = {Langmuir},
number = 15,
volume = 33,
place = {United States},
year = {Tue Apr 04 00:00:00 EDT 2017},
month = {Tue Apr 04 00:00:00 EDT 2017}
}
  • Binary polymer brush patterns were fabricated using aminosilanes with photo-cleavable protecting groups.
  • Binary polymer brush microstructures incorporating ratiometric fluorescent pH indicators enable in situ studies of light-activated transmembrane proton transport by proteorhodopsin.
  • A fundamental attribute of cell membranes is transmembrane asymmetry, specifically the formation of ordered phase domains in one leaflet that are compositionally different from the opposing leaflet of the bilayer. Using model membrane systems, many previous studies have demonstrated the formation of ordered phase domains that display complete transmembrane symmetry but there have been few reports on the more biologically relevant asymmetric membrane structures. Here we report on a combined atomic force microscopy (AFM) and fluorescence microscopy study whereby we observe three different states of transmembrane symmetry in phase-separated supported bilayers formed by vesicle fusion. We find that if themore » leaflets differ in gel-phase area fraction, then the smaller domains in one leaflet are in registry with the larger domains in the other leaflet and the system is dynamic. In a presumed lipid flip-flop process similar to Ostwald Ripening, the smaller domains in one leaflet erode away while the large domains in the other leaflet grow until complete compositional asymmetry is reached and remains stable. We have quantified this evolution and determined that the lipid flip-flop event happens most frequently at the interface between symmetric and asymmetric DSPC domains. If both leaflets have nearly identical area fraction of gel-phase, gel-phase domains are in registry and are static in comparison to the first state. The stability of these three DSPC domain distributions, the degree of registry observed, and the domain immobility have direct biological significance with regards to maintenance of lipid asymmetry in living cell membranes, communication between inner leaflet and outer leaflet, membrane adhesion, and raft mobility.« less
  • Lipid bilayers supported by substrates with nanometer-scale surface corrugations holds interest in understanding both nanoparticle-membrane interactions and the challenges of constructing models of cell membranes on surfaces with desirable properties, e.g. porosity. Here, we successfully form a two-phase (gel-fluid) lipid bilayer supported by nanoporous silica xerogel. Surface topology, diffusion, and lipid density in comparison to mica-supported lipid bilayers were characterized by AFM, FRAP, FCS, and quantitative fluorescence microscopy, respectively. We found that the two-phase lipid bilayer follows the xerogel surface contours. The corrugation imparted on the lipid bilayer results in a lipid density that is twice that on a flatmore » mica surface. In direct agreement with the doubling of actual bilayer area in a projected area, we find that the lateral diffusion coefficient (D) of lipids on xerogel ({approx}1.7 {micro}m{sup 2}/s) is predictably lower than on mica ({approx}4.1 {micro}m{sup 2}/s) by both FRAP and FCS techniques. Furthermore, the gel-phase domains on xerogel compared to mica were larger and less numerous. Overall, our results suggest the presence of a relatively defect-free continuous two-phase bilayer that penetrates approximately midway into the first layer of {approx}50 nm xerogel beads.« less