Coiling Instabilities in Multilamellar Tubes

TL;DR

This paper investigates the physical mechanisms behind the coiling and instability phenomena in multilamellar cylindrical membrane stacks, revealing how spontaneous curvature and membrane spacing influence their stability and shape transformations.

Contribution

It demonstrates that multilamellar tubes can develop coiling instabilities due to spontaneous curvature or decreased membrane spacing, breaking chiral symmetry, a novel insight into membrane physics.

Findings

Multilamellar tubes can coil due to spontaneous curvature.

Instability breaks chiral symmetry of membrane stacks.

Unilamellar vesicles show axisymmetric instability, possibly pearling.

Abstract

Myelin figures are densely packed stacks of coaxial cylindrical bilayers that are unstable to the formation of coils or double helices. These myelin figures appear to have no intrinsic chirality. We show that such cylindrical membrane stacks can develop an instability when they acquire a spontaneous curvature or when the equilibrium distance between membranes is decreased. This instability breaks the chiral symmetry of the stack and may result in coiling. A unilamellar cylindrical vesicle, on the other hand, will develop an axisymmetric instability, possibly related to the pearling instability.