Mechanical limits of viral capsids

Abstract

We study the elastic properties and mechanical stability of viral capsids under external force-loading with computer simulations. Our approach allows the implementation of specific geometries corresponding to specific phages such as $\varphi$29 and CCMV. We demonstrate how in a combined numerical and experimental approach the elastic parameters can be determined with high precision. The experimentally observed bimodality of elastic spring constants is shown to be of geometrical origin, namely the presence of pentavalent units in the viral shell. A criterion for capsid breakage is defined, which explains well the experimentally observed rupture. From our numerics we find for the dependence of the rupture force on the Föppl-von Kármán (FvK) number a crossover from ${\gamma }^{2/3}$ to ${\gamma }^{1/2}$. For filled capsids high internal pressures lead to a stronger destabilization of viruses with a buckled ground state than unbuckled ones. Finally, we show how our numerically calculated energy maps can be used to extract information about the strength of protein-protein interactions from rupture experiments.

6 pages, 9 figures

References in corpus (5)

• Virus shapes and buckling transitions in spherical shells
• Forces During Bacteriophage DNA Packaging and Ejection
• Mechanical Properties of Viral Capsids
• Properties of Ridges in Elastic Membranes
• Anomalous strength of membranes with elastic ridges

Cited by in corpus (7)

• Membrane simulation models from nm to $\mu$m scale
• Fluctuating shells under pressure
• Soft modes near the buckling transition of icosahedral shells
• Contact Mechanics of a Small Icosahedral Virus
• Structural transitions and energy landscape for Cowpea Chlorotic Mottle Virus capsid mechanics from nanomanipulation in vitro and in silico
• Nanoindentation of virus capsids in a molecular model
• Buckling of thermally fluctuating spherical shells: Parameter renormalization and thermally activated barrier crossing