Tuning Viral Capsid Nanoparticle Stability with Symmetrical Morphogenesis.

Area of Science:

• Biophysics
• Nanotechnology
• Structural Biology

Background:

• Virus-like particles (VLPs) are protein-based nanostructures with applications in nanomaterials.
• Understanding the relationship between subunit interactions and overall capsid stability is crucial but poorly resolved.
• Bridging single-nanoscale properties with bulk biochemical behavior requires integrated techniques.

Purpose of the Study:

• To investigate the link between the mechanical properties of individual VLPs and their bulk ensemble behavior.
• To utilize the P22 VLP as a model system for controlled manipulation of subunit interactions.
• To establish a framework for analyzing and manipulating self-assembled protein cages.

Main Methods:

• Single-particle atomic force microscopy (AFM) to probe nanoscale mechanics.
• Bulk chemical perturbations to assess ensemble stability.
• Contrastive analysis of AFM and biochemical data using the P22 VLP system.

Main Results:

• Expulsion of pentons at VLP vertices causes chemical and mechanical destabilization.
• Capsid edges identified as critical points for mechanical fracture.
• Decoration protein binding at edges restores both chemical and mechanical stability.
• Agreement between single-molecule and bulk techniques indicates shared structural determinants.

Conclusions:

• A phenomenological coupling exists between the chemical and mechanical behavior of self-assembled cages.
• The study provides a framework for analyzing and manipulating VLPs and other symmetric self-assembled structures.
• Controlled nanomanipulation of VLPs can influence their bulk properties.