Modelling the Self-Assembly of Virus Capsids

TL;DR

This study uses computer simulations to explore the self-assembly process of virus capsids, revealing how thermodynamic factors, crowding, and structural complexity influence assembly efficiency and dynamics.

Contribution

It introduces a coarse-grained model for virus capsid assembly, analyzing effects of thermodynamics, crowding, and structural complexity on assembly behavior.

Findings

Assembly dynamics are sigmoidal and exhibit hysteresis.

Crowding agents can both decrease and increase yields depending on conditions.

More complex assembly behaviors are observed in larger T=3 capsids.

Abstract

We use computer simulations to study a model, first proposed by Wales [1], for the reversible and monodisperse self-assembly of simple icosahedral virus capsid structures. The success and efficiency of assembly as a function of thermodynamic and geometric factors can be qualitatively related to the potential energy landscape structure of the assembling system. Even though the model is strongly coarse-grained, it exhibits a number of features also observed in experiments, such as sigmoidal assembly dynamics, hysteresis in capsid formation and numerous kinetic traps. We also investigate the effect of macromolecular crowding on the assembly dynamics. Crowding agents generally reduce capsid yields at optimal conditions for non-crowded assembly, but may increase yields for parameter regimes away from the optimum. Finally, we generalize the model to a larger triangulation number T = 3, and observe more complex assembly dynamics than that seen for the original T = 1 model.