Efficiency in the self-assembly viral capsids

Abstract

[eng] The self-assembly of viral capsids is an essential process for virus replication. Understanding this process is crucial for developing applications such as gene therapy. A minimal model of the interaction potential between capsid structural units, based on geometric constraints with a truncated multipolar expansion, has successfully explained the conformation of capsids in quasi-spherical shapes, as shown by Llorente et al. . This model has the remarkable feature of depending on only one geometric parameter that controls the optimal curvature of the shell. In contrast, other models, like the one proposed by Zandi et al. , assume that the capsomer has two possible states. Also the kinetic and thermodynamic aspects of the self-assembly of these structures were studied by Reguera et al. using Brownian Dynamics. They revealed that the maximum efficiency of the assembly process is achieved for curvatures different from the optimal ones. In this work, we have examined, via extensive Monte-Carlo simulations, the self-assembly process of viral capsids. We employed a coarse-grained model for the capsomer developed by Reguera et al. , and the potential energy surface, originally proposed by Llorente et al. , which accounts for the interaction between capsomers. To analyze the success of the self-assembly, we measured two principal quantities: the mean director vector and the self-assembly efficiency. Our results are in agreement with the findings of Reguera et al. for the first icosahedral shells and the snub cube shape. Additionally, we extended the analysis to shapes not considered in the previous work and predicted by the model of Zandi et al. . Furthermore, we found a strong agreement between the location of the minima of the modulus of the director vector of the aggregates and the maximum efficiency of the assembled structures.