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Method to Visualize and Analyze Membrane Interacting Proteins by Transmission Electron Microscopy
Published on: March 5, 2017
Lipid membrane reorganization induced by chemical recognition
J A Last1, T A Waggoner, D Y Sasaki
1Biomolecular Materials and Interfaces Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
Biophysical Journal
|October 19, 2001
Summary
Chemical recognition triggers nanoscale changes in lipid membranes. Copper ion binding alters lipid domains, and EDTA removes ions, reversing the effect, demonstrating dynamic membrane reorganization.
Area of Science:
- Biophysics
- Materials Science
- Nanotechnology
Background:
- Lipid bilayer membranes exhibit complex nanoscale structures.
- Chemical recognition events can influence membrane organization.
- Atomic Force Microscopy (AFM) allows high-resolution imaging of membrane surfaces.
Purpose of the Study:
- To image nanoscale structural reorganization in lipid bilayers induced by chemical recognition.
- To investigate the effect of copper ion (Cu2+) binding on lipid membrane domains.
- To demonstrate the reversibility of chemically induced membrane structural changes.
Main Methods:
- In situ Atomic Force Microscopy (AFM) for high-resolution imaging.
- Utilizing supported lipid bilayers composed of distearoylphosphatidylcholine (DSPC) and a synthetic Cu2+ receptor-functionalized lipid.
- Inducing changes via Cu2+ binding and reversing them using EDTA.
Main Results:
- Phase separation into nanoscale domains with a 9 A height difference was observed.
- Cu2+ binding altered the receptor's electrostatic nature, leading to dispersion.
- Receptor dispersion caused shrinking of membrane structural features defined by receptors.
- EDTA successfully removed metal ions, demonstrating complete process reversibility.
Conclusions:
- Chemical recognition events can induce dynamic nanoscale structural reorganization in lipid membranes.
- The study visualizes the reversible dispersion of functionalized lipids upon metal ion binding.
- AFM is a powerful tool for observing real-time, chemically induced changes in lipid bilayer nanostructures.
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