MD Simulations of Viruslike Particles with Supra CG Solvation Affordable to Desktop Computers.

Abstract

Viruses are tremendously efficient molecular devices that optimize the packing of genetic material using a minimalistic number of proteins to form a capsid or envelope that protects them from external threats, being also part of cell recognition, fusion, and budding machineries. Progress in experimental techniques has provided a large number of high-resolution structures of viruses and viruslike particles (VLP), while molecular dynamics simulations may furnish lively and complementary insights on the fundamental forces ruling viral assembly, stability, and dynamics. However, the large size and complexity of these macromolecular assemblies pose significant computational challenges. Alternatively, Coarse-Grained (CG) methods, which resign atomistic resolution privileging computational efficiency, can be used to characterize the dynamics of VLPs. Still, the massive amount of solvent present in empty capsids or envelopes suggests that hybrid schemes keeping a higher resolution on regions of interest (i.e., the viral proteins and their surroundings) and a progressively coarser description on the bulk may further improve efficiency. Here we introduce a mesoscale explicit water model to be used in double- or triple-scale simulations in combination with popular atomistic parameters and the CG water used by the SIRAH force field. Simulations performed on VLPs of different sizes, along with a comprehensive analysis of the PDB, indicate that most of the VLPs so far reported are amenable to be handled on a GPU-accelerated desktop computer using this simulation scheme.