Proteins at curved fluid-fluid interfaces in a coarse-grained model.

Area of Science:

• Biophysics
• Physical Chemistry
• Computational Biology

Background:

• Proteins at fluid-fluid interfaces are crucial for biological processes.
• Understanding protein behavior at curved interfaces (bubbles, droplets) is key but complex.
• Existing models often simplify interface geometry.

Purpose of the Study:

• To model protein behavior at curved air-water and oil-water interfaces.
• To investigate the impact of interface curvature on protein mass distribution and geometry.
• To compare protein adsorption and distortion on bubbles versus droplets.

Main Methods:

• Employed an empirical coarse-grained model.
• Utilized a Gaussian-like interfacial potential.
• Simulated protein G and two lipid transfer proteins at various radii of curvature.

Main Results:

• Protein distortion at curved interfaces differs from flat interfaces.
• Proteins adsorb closer to bubble surfaces than similarly curved droplet surfaces.
• Bubbles exhibit higher protein adsorption compared to droplets.
• Identified specific pinning residues responsible for adsorption.
• Observed a second layer in density profiles for dense solutions.

Conclusions:

• Protein behavior is significantly influenced by interface curvature and type (bubble vs. droplet).
• The model provides insights into protein adsorption mechanisms at curved interfaces.
• Findings are relevant for understanding protein stabilization of emulsions and foams.