Dynamics of membranes with immobile inclusions

TL;DR

This paper studies how immobile inclusions in cell membranes affect the movement of proteins, showing they reduce diffusion and correlation effects even at low concentrations due to membrane flow dynamics.

Contribution

It provides a theoretical analysis of how immobile inclusions influence membrane dynamics, highlighting effects at low area fractions.

Findings

Immobile inclusions decrease the diffusion coefficient of mobile proteins.

They suppress correlated diffusion of protein pairs.

Effects are significant at area fractions below 1%.

Abstract

Cell membranes are anchored to the cytoskeleton via immobile inclusions. We investigate the effect of such anchors on the in-plane dynamics of a fluid membrane and mobile inclusions (proteins) embedded in it. The immobile particles lead to a decreased diffusion coefficient of mobile ones and suppress the correlated diffusion of particle pairs. Due to the long-range, quasi-two-dimensional nature of membrane flows, these effects become significant at a low area fraction (below one percent) of immobile inclusions.