Role of dynamic capsomere supply for viral capsid self-assembly

TL;DR

This study uses simulations to explore how the continuous supply of capsomeres influences the self-assembly of viral capsids, revealing optimal conditions for steady production and the impact of influx rates on assembly efficiency.

Contribution

It demonstrates how dynamic capsomere supply affects viral capsid assembly, highlighting the importance of influx rates and bond strengths in maintaining steady capsid production.

Findings

High capsomere influx narrows optimal bond strength range.

Lower influx broadens bond strength range but reduces production rate.

Dynamic supply reduces the necessity for precise bond strength in vivo.

Abstract

Many viruses rely on the self-assembly of their capsids to protect and transport their genomic material. For many viral systems, in particular for human viruses like hepatitis B, adeno or human immunodeficiency virus, that lead to persistent infections, capsomeres are continuously produced in the cytoplasm of the host cell while completed capsids exit the cell for a new round of infection. Here we use coarse-grained Brownian dynamics simulations of a generic patchy particle model to elucidate the role of the dynamic supply of capsomeres for the reversible self-assembly of empty T1 icosahedral virus capsids. We find that for high rates of capsomere influx only a narrow range of bond strengths exists for which a steady state of continuous capsid production is possible. For bond strengths smaller and larger than this optimal value, the reaction volume becomes crowded by small and large intermediates, respectively. For lower rates of capsomere influx a broader range of bond strengths exists for which a steady state of continuous capsid production is established, although now the production rate of capsids is smaller. Thus our simulations suggest that the importance of an optimal bond strength for viral capsid assembly typical for in vitro conditions can be reduced by the dynamic influx of capsomeres in a cellular environment.