Elastic Membrane Deformations Govern Interleaflet Coupling of Lipid-Ordered Domains

Area of Science:

• Biophysics
• Membrane Biology
• Soft Matter Physics

Background:

• Domain registration in opposing membrane leaflets is poorly understood.
• Existing models do not fully explain the observed alignment of lipid domains.

Purpose of the Study:

• To elucidate the physical mechanism driving domain registration in bilayer membranes.
• To determine the role of line tension and lipid deformation in domain alignment.

Main Methods:

• Continuum elasticity theory was employed.
• Mathematical modeling of lipid domain interfaces was performed.

Main Results:

• Minimum line tension is achieved by shifting rims between ordered and disordered domains in opposing leaflets.
• Increased surface tension leads to increased line tension and larger domains.
• Domain registration is driven by lipid deformation energy, independent of specific lipid types or midplane interactions.

Conclusions:

• Lipid deformation energy, not specific molecular interactions, governs domain registration.
• The model explains domain size regulation by surface tension.
• The findings offer a general mechanism applicable to various membrane systems.