Related Experiment Video
Updated: Mar 3, 2026
09:52
A Fluorescence-based Assay of Phospholipid Scramblase Activity
Published on: September 20, 2016
14.8K
Regulation of phospholipid scramblases by cholesterol
Sabita Chourasia1, Haodong Wang2, Anant K Menon2
1Department of Biochemistry and Biophysics, Weill Cornell Medical College, New York, NY, United States; Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot, Israel.
Methods in Enzymology
|March 1, 2026
Summary
We developed a new method to study how cholesterol affects membrane protein activity. This protocol allows direct measurement of cholesterol
Area of Science:
- Biochemistry
- Membrane Biology
- Protein Biochemistry
Background:
- Membrane protein activity is influenced by the lipid environment.
- Cholesterol modulates membrane properties and interacts with membrane proteins.
- Studying cholesterol's effects on reconstituted proteins is difficult due to vesicle heterogeneity.
Purpose of the Study:
- To develop a protocol for assessing cholesterol's impact on reconstituted membrane protein activity.
- To enable direct evaluation of cholesterol's effect on protein function, independent of reconstitution.
Main Methods:
- Developed a post-reconstitution cholesterol loading protocol for lipid vesicles.
- Quantified loaded cholesterol using colorimetric assays.
- Measured membrane fluidity to confirm cholesterol incorporation.
Main Results:
- Successfully introduced cholesterol into vesicles after protein reconstitution.
- Demonstrated a method to directly assess cholesterol's effect on G protein-coupled receptor (GPCR) phospholipid scramblase activity.
- Provided sample data illustrating cholesterol's influence on GPCRs.
Conclusions:
- The developed protocol allows for precise investigation of cholesterol's role in membrane protein function.
- This method is broadly applicable to studying cholesterol's effects on various reconstituted membrane proteins.
- Facilitates a deeper understanding of lipid-protein interactions in membrane biology.
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