Mechanical Limits of Viral Capsids
Dr. Mathias Buenemann
Biophysics, UCSD
Abstract
Viral shells are extremely stable nano-containers. They are able to
sustain internal pressures of ~50 atm as well as point forces
up to ~1 nN. We have numerically studied the stability of
viral capsid in terms of a single dimensionless parameter, the
Foppl-von-Karman (FvK) number \gamma. We are able to
attribute the experimentally observed bimodal distribution of spring
constants to the geometry of viral capsids. A criterion for capsid
breakage is defined, which explains well the experimentally observed
rupture. From our numerics, we find a \gamma^{2/3} dependence of
the rupture force for spherical viruses. The influence of internal
pressure on the stability of capsids is analyzed. Finally, we suggest
a method for determining the spatial distribution of protein binding
potentials from the spatial distribution of rupture events.