Dynamics of nonequilibrium membrane bud formation

Area of Science:

• Biophysics
• Soft Matter Physics
• Membrane Biophysics

Background:

• Lipid membranes are fundamental biological structures with complex dynamical behaviors.
• Local perturbations can break the molecular symmetry of lipid bilayers, initiating dynamic responses.
• Understanding these responses is crucial for comprehending membrane function and organization.

Purpose of the Study:

• To theoretically investigate the dynamical response of lipid membranes to local symmetry perturbations.
• To identify the mechanisms governing the release of leaflet density asymmetry.
• To explore the formation and size selection of nonequilibrium structures (buds).

Main Methods:

• Theoretical investigation of lipid membrane dynamics.
• Analysis of in-plane lipid diffusion and membrane curvature as response mechanisms.
• Modeling of nonequilibrium structure formation and dynamical size selection.

Main Results:

• Density asymmetry is released via in-plane lipid diffusion or membrane curvature, dependent on perturbation scale.
• Nonequilibrium structures, termed buds, can form as a result of these dynamics.
• A preferred bud size in the micrometer range is theoretically predicted.

Conclusions:

• The study reveals a crossover in membrane dynamics between membrane-dominated and solvent-dominated regimes.
• The predicted preferred bud size serves as a signature of this dynamic crossover.
• These findings provide theoretical insights into the self-organization and dynamic behavior of lipid membranes.