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From Fast Fluorescence Imaging to Molecular Diffusion Law on Live Cell Membranes in a Commercial Microscope
Published on: October 9, 2014
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Transmembrane protein diffusion in gel-supported dual-leaflet membranes
Chih-Ying Wang1, Reghan J Hill1
1Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada.
Biophysical Journal
|November 25, 2014
Summary
This study presents a theoretical model for transmembrane-protein diffusion in supported lipid bilayers, accounting for friction between membrane leaflets. The findings offer a foundation for future experiments on tracer diffusion in gel-supported membranes.
Area of Science:
- Biophysics
- Materials Science
- Soft Matter Physics
Background:
- Advancements in measuring transmembrane-protein diffusion necessitate predictive theoretical models.
- Interleaflet friction significantly impacts tracer mobility in lipid bilayers.
Purpose of the Study:
- To develop a theoretical framework for three-dimensional flows driven by transmembrane proteins in dual-leaflet membranes supported by soft porous materials.
- To investigate the role of interleaflet friction and support properties on protein diffusion.
Main Methods:
- Developed a fully three-dimensional theoretical model for fluid flow.
- Incorporated parameters for soft porous supports (permeability, solvent viscosity).
- Analyzed asymmetric support configurations and their effect on diffusion coefficients.
Main Results:
- The diffusion coefficient in asymmetric configurations can reflect interleaflet friction.
- A recent phenomenological theory provides reasonable approximations for large tracers on low-permeability supports.
- Literature data interpretation supports the phenomenological Stokes drag law and highlights nonhydrodynamic interactions.
Conclusions:
- The developed theory provides a foundation for experimental studies on tracer diffusion in gel-supported membranes.
- Nonhydrodynamic interactions may lead to overestimations of membrane viscosity in supported bilayer systems.
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