Comment on "Elastic Membrane Deformations Govern Interleaflet Coupling of Lipid-Ordered Domains"

TL;DR

This paper critiques a recent study on lipid bilayer domain registration, emphasizing the importance of combining line tensions with interfacial lengths to accurately predict equilibrium states, challenging the original claim that line tensions alone suffice.

Contribution

It clarifies the role of inter-leaflet interactions and corrects the interpretation of line tension effects in lipid bilayer domain registration.

Findings

Line tensions alone do not explain domain registration.

Inter-leaflet interactions are necessary for accurate predictions.

Previous analysis omitted the combination of line tensions with interfacial lengths.

Abstract

In lieu of abstract, first paragraph reads: Galimzyanov et al. [1] find that line tension between thick liquid-ordered ($L_{o}$) and thinner liquid-disordered ($L_{d}$) registered lipid bilayer phases is minimised by an asymmetric "slip region", length $L\!\sim\!5\,\textrm{nm}$ (Fig. 1). They claim that line tensions alone explain domain registration, without "direct" (area-dependent) inter-leaflet interaction [2,3]. We show this is unfounded, without direct interaction their results would predict \textit{antiregistration}, dependent on composition. To find equilibrium from line energies, line \textit{tensions} must be combined with interfacial lengths for given states at given composition. This was not done in [1].