Elastic deformation of a fluid membrane upon colloid binding

Area of Science:

• Biophysics
• Soft Matter Physics
• Computational Biology

Background:

• Colloidal particles interacting with fluid membranes induce membrane deformations.
• These deformations influence the binding energetics and stability.
• Understanding these interactions is crucial for biological processes like viral budding.

Purpose of the Study:

• To investigate the structural and energetic aspects of colloidal particle-membrane interactions.
• To identify and characterize different binding and envelopment transition regimes.
• To explore the relevance of these interactions in biological systems.

Main Methods:

• Utilizing a Helfrich Hamiltonian framework for membrane elasticity.
• Solving nonlinear shape equations for the membrane profile.
• Employing analytical methods (small gradient expansion) and scaling arguments for different tension regimes.

Main Results:

• Identification of a line of continuous binding transitions and a line of discontinuous envelopment transitions.
• Discovery of an unusual triple point where these transition lines meet.
• Quantification of phase boundary, degree of wrapping, and energy barrier behavior under varying membrane tension.

Conclusions:

• The study provides a comprehensive theoretical framework for colloid-membrane interactions.
• The findings elucidate the complex interplay between particle binding and membrane elasticity.
• Viral maturation via budding is presented as a relevant biological example of these phenomena.