Voltage-induced bending and electromechanical coupling in lipid bilayers

Area of Science:

• Cellular Biophysics
• Electrophysiology
• Membrane Mechanics

Background:

• Cellular membrane electrical properties are crucial for ion transport and electrophysiology.
• Membrane mechanical properties, like resistance to bending and stretching, influence cell shape and forces.
• A known coupling exists between the electrical and mechanical properties of cell membranes.

Purpose of the Study:

• To develop a theory calculating membrane bending deformations and forces in response to changing applied voltage.
• To investigate the role of voltage-dependent ion adsorption in electromechanical coupling within lipid bilayers.
• To explore the potential influence of membrane electromechanical coupling on transmembrane protein function.

Main Methods:

• Theoretical modeling of membrane bending deformations and forces under applied voltage.
• Investigation of a simple model for counter-ion adsorption to phospholipid head groups.
• Utilizing membrane tethers to measure electromechanical coupling and predict membrane tether tension.

Main Results:

• Electromechanical coupling in lipid bilayers is dependent on ion adsorption into the phospholipid head group region.
• A model was developed to predict membrane tether tension as a function of applied voltage.
• The study provides a theoretical framework for understanding voltage-induced mechanical changes in membranes.

Conclusions:

• The theory successfully computes electromechanical coupling effects in lipid bilayers.
• Ion adsorption is identified as a key mechanism underlying electromechanical coupling.
• The findings suggest implications for transmembrane protein function and cellular mechanics.