Lateral pressure-mediated protein partitioning into liquid-ordered/liquid-disordered domains

Area of Science:

• Biophysics
• Membrane Biophysics
• Computational Biophysics

Background:

• Biological membranes are composed of liquid-ordered (Lo) and liquid-disordered (Ld) domains.
• Transmembrane proteins are embedded within these domains and their distribution is crucial for cellular function.
• Understanding protein behavior within these domains requires knowledge of elastic energies and lateral pressure.

Purpose of the Study:

• To investigate the influence of stored elastic energies in Lo and Ld domains on transmembrane protein behavior.
• To determine how protein shape and symmetry affect their partitioning into different membrane domains.
• To explore the formation of protein oligomers and the orientation of transmembrane proteins.

Main Methods:

• Utilized the lateral pressure concept to analyze elastic energy contributions.
• Applied experimental data on membrane thickness, intrinsic curvature, and bending elasticities.
• Calculated protein diffusion and oligomerization based on geometric shapes and domain properties.

Main Results:

• Proteins with convex shapes preferentially partition into Ld domains, promoting cluster formation.
• Concave-shaped proteins are enriched in Lo domains as monomers.
• Protein symmetry dictates preference for symmetric or asymmetric domains, influencing orientation.

Conclusions:

• Protein shape and symmetry are key determinants of transmembrane protein localization and oligomerization within membrane domains.
• The lateral pressure concept and stored elastic energies provide a framework for understanding protein-lipid interactions.
• This study offers a mechanism for transmembrane protein orientation based on their asymmetry and domain interactions.