Indirect interactions of membrane-adsorbed cylinders

TL;DR

This paper theoretically investigates how cylindrical objects adhered to biological membranes interact indirectly through membrane shape perturbations, revealing conditions for attractive or repulsive forces depending on membrane tension and external potentials.

Contribution

It provides a theoretical framework for understanding membrane-mediated interactions of cylindrical macromolecules under various physical conditions.

Findings

Repulsive interactions for cylinders on the same membrane side under tension.

Attractive interactions for cylinders on opposite sides under tension.

Always attractive interactions in a harmonic potential, increasing with perpendicular forces.

Abstract

Biological and biomimetic membranes often contain aggregates of embedded or adsorbed macromolecules. In this article, the indirect interactions of cylindrical objects adhering to a planar membrane are considered theoretically. The adhesion of the cylinders causes a local perturbation of the equilibrium membrane shape, which leads to membrane-mediated interactions. For a planar membrane under lateral tension, the interaction is repulsive for a pair of cylinders adhering to the same side of the membrane, and attractive for cylinders adhering at opposite membrane sides. For a membrane in an external harmonic potential, the interaction of adsorbed cylinders is always attractive and increases if forces perpendicular to the membrane act on the cylinders.