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Permeability properties of a multilayer planar membrane
Journal of Biochemistry
|December 1, 1980
Summary
Researchers studied lipid membrane permeability to glucose and calcium ions (Ca2+). Egg yolk lecithin-cholesterol membranes showed reduced permeability with cholesterol but increased permeability with certain alcohols and thymol, suggesting lipid orientation influences transport.
Area of Science:
- Biophysics
- Materials Science
- Membrane Science
Background:
- Understanding lipid membrane permeability is crucial for drug delivery and biological transport.
- Model membranes provide insights into complex biological systems.
- Lipid composition and orientation significantly influence membrane properties.
Purpose of the Study:
- To investigate the permeability coefficients of multilayer lipid membranes.
- To determine the effect of cholesterol, alcohols, and thymol on membrane permeability.
- To explore the correlation between lipid orientation and membrane transport.
Main Methods:
- Fabrication of multilayer planar lipid membranes supported by cellulose sheets.
- Empirical subtraction of cellulose sheet effects on permeation.
- Measurement of Ca2+ and glucose permeability coefficients.
- Assessment of chemical additive effects on membrane permeability.
Main Results:
- Permeability coefficients for Ca2+ and glucose through egg yolk lecithin-cholesterol membranes were determined.
- Cholesterol reduced membrane permeability, while isopropanol, n-butanol, and thymol enhanced it above critical concentrations.
- Glucose permeation was significantly inhibited by Ca2+ in phosphatidylserine membranes but not in egg yolk lecithin-cholesterol membranes.
Conclusions:
- Lipid membrane permeability is influenced by the type and concentration of additives.
- A correlation exists between lipid orientation and membrane permeability.
- Egg yolk lecithin-cholesterol membranes exhibit distinct transport properties compared to phosphatidylserine membranes, particularly in the presence of Ca2+.