Related Experiment Video
Updated: Jul 17, 2026

Fluorescent Leakage Assay to Investigate Membrane Destabilization by Cell-Penetrating Peptide
Published on: December 19, 2020
Peptide insertion, positioning, and stabilization in a membrane: insight from an all-atom molecular dynamics
Arneh Babakhani1, Alemayehu A Gorfe, Justin Gullingsrud
1Department of Chemistry & Biochemistry, University of California at San Diego, La Jolla, CA 92093-0365,USA. ababakha@mccammon.ucsd.edu
Molecular dynamics simulations reveal how peptides insert and stabilize within lipid membranes. The tryptophan residue
Area of Science:
- Biophysics
- Computational Biology
- Membrane Biophysics
Background:
- Understanding peptide-membrane interactions is crucial for drug design and biological processes.
- Model membrane systems provide a controlled environment to study these interactions.
Purpose of the Study:
- To investigate the insertion, positioning, and stabilization of a model peptide (WL5) in a dimyristoylglycero-3-phosphate (DMPC) membrane.
- To elucidate the role of specific peptide residues, particularly tryptophan, in membrane interactions.
Main Methods:
- All-atom molecular dynamics (MD) simulation of WL5 peptide in a DMPC membrane.
- Analysis of peptide insertion dynamics, localization, orientation, and conformational changes.
- Calculation of peptide diffusion rates.
Main Results:
- Peptides spontaneously inserted and stabilized within the DMPC membrane within 5 ns.
- Peptides localized to the membrane interface, driven by peptide-lipid hydrogen bonds involving the tryptophan residue.
- The membrane induced beta-sheet conformations in the peptide, and the peptide enhanced lipid ordering.
Conclusions:
- The tryptophan residue's indole nitrogen is critical for stabilizing peptides at the membrane interface.
- Peptide-membrane interactions influence both peptide conformation and membrane properties.
- Simulations suggest a 500 ns timescale for intermolecular interactions based on calculated diffusion rates.
Related Concept Videos
Translocation of Proteins into the Mitochondria
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Insertion of Single-pass Transmembrane Proteins in the RER
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Tail-anchoring of Proteins in the ER Membrane
Lipids as Anchors
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
Protein Transport into the Inner Mitochondrial Membrane
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Mechanisms of Membrane Domain Formation
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...

