Phospholipid Membrane Formation Templated by Coacervate Droplets.

Area of Science:

• Biophysics
• Origin of Life Research
• Biotechnology

Background:

• Coacervates are liquid-liquid phase-separated droplets with a high concentration of macromolecules.
• Phospholipid membranes form the basis of biological cells and organelles.
• Understanding the interplay between internal cellular phases and surrounding membranes is crucial for cell function.

Purpose of the Study:

• To develop a novel method for creating coacervate-supported phospholipid membranes.
• To characterize the structure and properties of these coacervate-templated artificial cells.
• To explore their potential as models for prebiotic protocells and biotechnological applications.

Main Methods:

• Hydrating dried lipid films in the presence of coacervate droplets.
• Characterization using fluorescence imaging, polarization, and fluorescence recovery after photobleaching.
• Assessing membrane integrity and solute permeability through lipid quenching and uptake experiments.

Main Results:

• Successfully formed coacervate-supported phospholipid membranes, with many droplets fully coated by lipid bilayers.
• Coacervate-templated vesicles exhibited greater uniformity in size, shape, and lamellarity compared to traditional giant lipid vesicles.
• Demonstrated tunable membrane properties, including defects for solute entry and multilayered membranes.
• Protein-based coacervate droplets were protected from external protease by their surrounding membranes.

Conclusions:

• Coacervate-supported phospholipid membranes provide a simple and reproducible model system for artificial cells.
• These structures serve as valuable tools for investigating prebiotic protocell formation and intracellular phase-membrane interactions.
• The system holds promise for biotechnological applications requiring controlled compartmentalization and macromolecular crowding.