Persistent collective motion of a dispersing membrane domain

Area of Science:

• Biophysics
• Soft Matter Physics
• Membrane Biophysics

Background:

• Brownian motion describes particle movement in fluids.
• In fluid membranes, mobile inclusions typically disperse rapidly.
• Center of mass diffusion is usually slower than individual particle dispersal.

Purpose of the Study:

• Investigate the anomalous diffusion of mobile inclusions in fluid membranes.
• Determine the timescale of assembly dispersal versus center of mass diffusion.
• Understand the role of membrane flows in collective particle motion.

Main Methods:

• Analytical modeling of Brownian motion with flow-mediated correlations.
• Brownian dynamics simulations incorporating quasi-two-dimensional membrane flows.
• Analysis of diffusion coefficients and timescales for particle assemblies.

Main Results:

• Assembly dispersal and center of mass diffusion occur on similar timescales.
• Quasi-two-dimensional membrane flows couple motions of inclusions, regardless of distance.
• Flow-mediated correlations lead to slow decay of the diffusion coefficient, causing weak subdiffusion.

Conclusions:

• Membrane flows significantly prolong the lifetime of mobile inclusion assemblies.
• The observed weak subdiffusion has implications for the stability of nanoscale membrane heterogeneities.
• This study reveals a novel mechanism governing collective dynamics in fluid membranes.