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Published on: July 16, 2018
All-or-none versus graded: single-vesicle analysis reveals lipid composition effects on membrane permeabilization
Beatriz Apellániz1, José L Nieva, Petra Schwille
1Unidad de Biofísica, Consejo Superior de Investigaciones Científicas/University of the Basque Country, Bilbao, Spain.
Biophysical Journal
|November 30, 2010
Summary
CpreTM and NpreTM peptides from HIV gp41 exhibit distinct lipid bilayer permeabilization mechanisms. CpreTM causes all-or-none pore opening, while NpreTM induces transient, graded permeabilization, with cholesterol impacting pore stability.
Area of Science:
- Biophysics
- Membrane Biology
- Virology
Background:
- HIV fusion glycoprotein gp41 plays a critical role in viral entry.
- Understanding the mechanisms of membrane permeabilization is key to inhibiting viral fusion.
Purpose of the Study:
- To compare the single-vesicle permeabilization mechanisms of CpreTM and NpreTM peptides.
- To investigate the role of cholesterol in peptide-induced membrane permeabilization.
Main Methods:
- Single-vesicle assays using giant unilamellar vesicles (GUVs).
- Comparison of permeabilization kinetics, dye filling, and pore stability.
- Quantitative analysis of vesicle population distributions.
- Assessment of cholesterol effects on permeabilization.
Main Results:
- CpreTM induces rapid, all-or-none permeabilization with stable pore formation.
- NpreTM causes transient, graded permeabilization with slower kinetics and partial dye filling.
- Cholesterol increased the stability of peptide-induced permeating structures.
Conclusions:
- Distinct mechanisms of lipid bilayer permeabilization by CpreTM and NpreTM were elucidated at the single-vesicle level.
- Cholesterol's effect on pore stability suggests a role in modulating gp41 fusogenic activity.
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