Quantifying the Relationship between Curvature and Electric Potential in Lipid Bilayers

Area of Science:

• Biophysics and cellular membrane dynamics.

Background:

• Cellular membranes are crucial for cellular functions, influenced by curvature and electrical potentials.
• Flexoelectricity, the coupling of electrical polarization and mechanical strain, is a known phenomenon in liquid crystals.

Purpose of the Study:

• To quantify the coupling between lipid bilayer curvature and transmembrane electrical potentials.
• To extend existing flexoelectricity theory to biological membranes.

Main Methods:

• Utilizing molecular dynamics simulations to model lipid bilayers.
• Analyzing changes in headgroup dipole moments, lateral pressure profiles, and spontaneous curvature under varying membrane potentials.

Main Results:

• Membrane potentials induce systematic changes in lipid bilayer properties, including headgroup dipole moments and spontaneous curvature.
• A linear relationship was observed between bending moment and applied membrane potentials.
• Biologically relevant membrane potentials were shown to induce significant membrane curvatures (radii ~500 nm).

Conclusions:

• Flexoelectricity in lipid bilayers is a significant factor influencing membrane curvature and electrical potential.
• This phenomenon has substantial implications for both biological systems and model lipid bilayer studies.
• Understanding flexoelectricity is key to comprehending membrane mechanics and function.