Membrane dipole potential is sensitive to cholesterol stereospecificity: implications for receptor function
Suman Bandari1, Hirak Chakraborty1, Douglas F Covey2
1CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
Chemistry and Physics of Lipids
|September 16, 2014
Summary
Cholesterol and its stereoisomer ent-cholesterol increase membrane dipole potential. Epi-cholesterol, however, reduces it, showing subtle structural changes significantly impact membrane interface properties.
Area of Science:
- Biophysics
- Membrane Biology
- Biochemistry
Background:
- The membrane dipole potential influences biological membrane functions.
- Cholesterol is known to modulate membrane dipole potential in eukaryotic cells.
Purpose of the Study:
- To investigate the impact of cholesterol stereoisomers (ent-cholesterol and epi-cholesterol) on membrane dipole potential.
- To correlate these effects with G protein-coupled receptor activity.
Main Methods:
- Utilized a dual wavelength ratiometric approach with the fluorescent probe di-8-ANEPPS.
- Monitored changes in membrane dipole potential induced by cholesterol and its stereoisomers.
Main Results:
- Cholesterol and ent-cholesterol exhibited similar increases in membrane dipole potential.
- Epi-cholesterol demonstrated a slight decrease in membrane dipole potential.
- Established a correlation between membrane dipole potential and serotonin1A receptor activity.
Conclusions:
- Subtle alterations in sterol structure significantly affect the membrane's interfacial dipolar field.
- Stereospecificity of cholesterol is crucial for receptor function, offering insights into lipid-protein interactions.
- Membrane dipole potential serves as a sensitive indicator for lipid-protein interactions.
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