Coiling of Cylindrical Membrane Stacks with Anchored Polymers

TL;DR

This paper investigates how anchored polymers induce coiling in cylindrical membrane stacks, combining experiments and a coupled curvature-polymer concentration model to explain the formation of tight coils without twist.

Contribution

It introduces a novel experimental system and a coupled model explaining polymer-induced coiling in membrane stacks without twist.

Findings

Maximally tight coils form above a threshold polymer occupancy.

Experimental observations match the model predictions.

Coiling occurs without membrane twist.

Abstract

We study experimentally a coiling instability of cylindrical multilamellar stacks of phospholipid membranes, induced by polymers with hydrophobic anchors grafted along their hydrophilic backbone. We interpret our experimental results in terms of a model, in which local membrane curvature and polymer concentration are coupled. The model predicts the occurence of maximally tight coils above a threshold anchor occupancy. Indeed, only maximally tight coils are observed experimentally. Our system is unique in that coils form in the absence of twist.