Topographically smooth and stable supported lipid bilayer for high-resolution AFM studies

Area of Science:

• Biophysics
• Cell Biology
• Materials Science

Background:

• Cellular membranes are crucial for biological processes and exhibit varied lipid compositions.
• Supported lipid bilayers serve as models for membrane studies using single-molecule techniques.
• Atomic force microscopy (AFM) is vital for observing molecular processes on membranes.

Purpose of the Study:

• To present a methodology for preparing smooth, stable, and homogeneous lipid bilayers.
• To apply these bilayers for studying early aggregation stages of amyloid proteins.
• To enable investigation of lipid composition effects on aggregation kinetics.

Main Methods:

• Preparation of supported lipid bilayers with sub-nanometer smooth morphology.
• Utilizing Atomic Force Microscopy (AFM) for topographic imaging and molecular observation.
• Incorporating various lipids, including cholesterol, to create bilayers with diverse compositions.

Main Results:

• Successfully prepared smooth, stable, and structurally homogeneous lipid bilayers without trapped vesicles.
• Demonstrated the application of these bilayers to probe time-dependent early aggregation of amyloid proteins.
• Enabled monitoring of amyloid aggregation at physiologically relevant low protein concentrations.

Conclusions:

• The developed methodology provides a robust platform for studying membrane-associated molecular processes.
• Altering membrane composition allows for detailed investigation into the role of specific lipids in aggregation kinetics.
• This approach offers insights into plausible mechanisms of disease development related to protein aggregation.