The Mechanical Properties of Spherical Viral Capsids

Abstract

This study lays the foundation for examining various mechanical properties of spherical viral capsids. The icosahedral modes of various T = 1 through T = 4 spherical capsids were calculated and characterized using a rotation translation blocks (RTB) method. Furthermore, the eigenvalue scaling between each mode was calculated to determine the stiffening between each mode. MATLAB was also utilized to calculate the thickness of the capsids that were examined. It was found that there may be a relationship between the thickness and the eigenvalue scaling for two particular capsids, Bacteriophage Q-beta Capsid and Turnip Yellow Mosaic Virus. Moreover, no distinguishable pattern was found between the eigenvalue scaling and the the behavior of the modes (e.g. the breathing mode or the proteins on the 5-fold axis poking out while the 3- and 2-folds poke in), although there may be a relationship between the behavior and the thickness of the capsid. This observation is due to the slightly different mode behavior between two capsids that are in the same family, namely Infectious Bursal Disease Virus VP2 Subparticle is thicker at the 5-folds relative to IPNV Subviral Particle. Further studies are recommended in the future to further examine this topic since the relationship between thickness, the eigenvalue scaling, and the mode behavior may have implications for bioengineering applications such as drug delivery, and structural modification in medical applications.