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Atomic Force Microscopy Imaging and Force Spectroscopy of Supported Lipid Bilayers
Published on: July 22, 2015
Phase behavior of lipid bilayers under tension
Mark J Uline1, M Schick, Igal Szleifer
1Department of Chemical Engineering, University of South Carolina, Columbia, South Carolina, USA. uline@cec.sc.edu
Biophysical Journal
|February 14, 2012
Summary
Finite surface tension impacts lipid bilayer phase transitions. Increased tension lowers the liquid-to-gel transition temperature in DPPC systems and the liquid-disordered to liquid-ordered transition in DPPC/DOPC/Cholesterol bilayers.
Area of Science:
- Biophysics
- Materials Science
- Computational Chemistry
Background:
- Membrane tension is crucial for cellular functions.
- Understanding lipid bilayer phase behavior is essential for cell biology.
Purpose of the Study:
- To investigate the influence of finite surface tension on lipid bilayer phase equilibrium.
- To quantitatively analyze the effect of tension on the phase diagram of DPPC/DOPC/Cholesterol lipid bilayers.
Main Methods:
- Utilized a molecular theory to model lipid bilayer systems.
- Analyzed the phase diagram of tensionless and finite surface tension systems.
- Calculated transition temperatures for liquid-to-gel and liquid-disordered to liquid-ordered phases.
Main Results:
- Increased surface tension decreased the liquid-to-gel transition temperature in pure DPPC by ~1.0 K/(mN/m).
- Surface tension also decreased the liquid-disordered to liquid-ordered transition at constant chemical potentials by a similar magnitude.
- The study quantitatively isolated the role of tension compared to pressure in lipid bilayer phase behavior.
Conclusions:
- Finite surface tension significantly alters lipid bilayer phase transitions.
- Molecular theory provides a quantitative framework for understanding tension's role in membrane biophysics.
- Results offer insights into the regulation of cellular functions by membrane tension.
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