Physical Ingredients Controlling Stability and Structural Selection of Empty Viral Capsids

Area of Science:

• Biophysics
• Computational Biology
• Structural Biology

Background:

• Viral replication involves the self-assembly of protein shells (capsids).
• Viral coat proteins can self-assemble into various structures in vitro, but the selection mechanisms for native capsid shapes are not fully understood.
• Understanding capsid assembly is crucial for applications in medicine and bionanotechnology.

Purpose of the Study:

• To analyze and understand the physical mechanisms governing size and structure selection during empty viral capsid assembly.
• To investigate the factors influencing capsid shape determination (spherical, faceted, elongated, or decapsidated).

Main Methods:

• Development of a coarse-grained model for viral capsid assembly.
• Utilizing Monte Carlo simulations to analyze the model.
• Characterization of the phase diagram and stability of T = 1, 3, 4, 7, and snub cube shells.

Main Results:

• The study characterized the phase diagram and stability of various viral shells (T = 1, 3, 4, 7, and snub cube).
• The model identified physical parameters influencing shell assembly and stability, including strategies for inducing misassembly.
• Factors determining capsid shape selection were elucidated.

Conclusions:

• The coarse-grained model provides insights into the physical principles governing viral capsid assembly and stability.
• This understanding is key for engineering capsids with specific sizes and structures for biotechnological applications.
• The research sheds light on how viruses select their unique architectures during replication.