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Updated: May 14, 2025
A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics
Published on: September 2, 2020
Integrating Cryo-Electron Microscopy and Molecular Dynamics Simulations to Investigate Membrane Binding of Influenza
Piotr Setny1, Paulina Borkowska2, Remigiusz Worch2
1Centre of New Technologies, University of Warsaw, 2C Banacha St., Warsaw, Poland 02-097, Poland.
Abstract:
We propose an approach for determining the positioning of membrane-active peptides within a lipid bilayer. It is based on a combination of cryogenic electron microscopy (cryo-EM) with molecular dynamics (MD) simulations. Cryo-EM image intensity profiles across peptide-containing liposome membranes are analyzed by comparing them to synthetic images that are derived from MD trajectories of peptide-membrane systems representing different assumed binding modes. These simulated profiles serve as baseline models, which are then used to classify experimentally obtained images into respective categories. The approach was applied to influenza virus fusion peptides, providing evidence for predominantly transmembrane binding in pure POPC membranes and a transition toward surface-bound configurations upon the addition of cholesterol.
Insights
We developed a new method combining cryo-electron microscopy (cryo-EM) and molecular dynamics (MD) simulations to determine how membrane-active peptides bind to lipid bilayers. This approach reveals peptide positioning, showing influenza fusion peptides shift from transmembrane to surface binding with cholesterol.
Area of Science:
- Biophysics
- Structural Biology
- Computational Biology
Background:
- Understanding how peptides interact with lipid bilayers is crucial for drug development and understanding biological processes.
- Accurate determination of peptide positioning within membranes remains a challenge.
Purpose of the Study:
- To present a novel computational and experimental approach for determining peptide positioning within lipid bilayers.
- To investigate the binding modes of influenza virus fusion peptides in different lipid environments.
Main Methods:
- Combining cryogenic electron microscopy (cryo-EM) for experimental data with molecular dynamics (MD) simulations for computational modeling.
- Analyzing cryo-EM intensity profiles against simulated profiles from MD trajectories representing various peptide-membrane binding modes.
- Classifying experimental images based on comparisons with simulated baseline models.
Main Results:
- The proposed method successfully determined peptide positioning within liposome membranes.
- Influenza virus fusion peptides were found to predominantly adopt transmembrane binding in pure POPC membranes.
- The addition of cholesterol to POPC membranes induced a transition in influenza fusion peptide binding from transmembrane to surface-bound configurations.
Conclusions:
- The integrated cryo-EM and MD simulation approach is effective for elucidating peptide-membrane interactions.
- Cholesterol plays a significant role in modulating the binding orientation of influenza fusion peptides.
- This methodology provides valuable insights into the structural basis of membrane protein and peptide function.
