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Membrane Elastic Deformations Modulate Gramicidin A Transbilayer Dimerization and Lateral Clustering
Oleg V Kondrashov1, Timur R Galimzyanov2, Konstantin V Pavlov3
1Laboratory of Bioelectrochemistry, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia; Department of Theoretical Physics, Moscow Institute of Physics and Technology, Dolgoprudniy, Moscow Region, Russia.
Biophysical Journal
|July 28, 2018
Summary
Gramicidin A (gA) monomers interact via membrane deformation, forming attractive and repulsive forces. This interaction influences gA channel formation and stability in lipid membranes.
Area of Science:
- Biophysics
- Membrane Biophysics
Background:
- Gramicidin A (gA) forms conducting channels in lipid membranes through transbilayer dimerization.
- gA's interaction with lipid bilayers involves membrane deformation due to its size relative to bilayer thickness.
Purpose of the Study:
- To calculate the energy of membrane deformation caused by Gramicidin A monomers and dimers.
- To investigate the interaction energy profiles between gA monomers in lipid membranes.
- To understand the factors influencing gA cluster formation and stability.
Main Methods:
- Continuum elasticity theory applied to membrane deformation.
- Calculation of interaction energy profiles for gA monomers.
- Analysis of elastic properties including splay, tilt, and lateral stretching.
Main Results:
- gA monomers exhibit long-range attraction and short-range repulsion due to membrane deformation.
- Identified conditions where gA monomer clusters resist dissipation by diffusion.
- Calculated dimer formation and decay energy barriers align with experimental data.
Conclusions:
- Membrane elastic energy significantly contributes to gA dimer formation.
- The study provides insights into the stability of gA aggregates in lipid bilayers.
- Findings offer a potential explanation for previously debated phenomena related to gA channel formation.
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