Vesicle deformations by clusters of transmembrane proteins

Area of Science:

• Biophysics
• Computational Biology
• Materials Science

Background:

• Phospholipid vesicles are fundamental biological structures.
• Transmembrane proteins play crucial roles in cellular functions.
• Understanding protein-lipid interactions is key to cell membrane dynamics.

Purpose of the Study:

• To investigate how transmembrane proteins influence phospholipid vesicle shape.
• To quantify the effects of protein clustering on vesicle curvature.
• To explore the roles of depletion forces and vesiculation in protein organization.

Main Methods:

• Coarse-grained molecular dynamics simulations were employed.
• Mean and Gaussian curvatures of protein-embedded vesicles were measured.
• Protein clustering, depletion forces, and vesiculation were analyzed.

Main Results:

• Protein clusters were shown to significantly alter vesicle shapes.
• Increasing protein concentration fragmented large clusters into smaller bundles.
• Higher protein fractions resulted in more symmetric vesicle structures and lower bending energies.
• Formation of large clusters and highly aspherical vesicles was inhibited at high protein-to-lipid ratios.

Conclusions:

• Protein concentration is a critical factor in determining vesicle morphology.
• Vesicle shape is dynamically regulated by protein-lipid interactions and clustering behavior.
• The findings provide insights into the self-assembly and mechanical properties of biological membranes.