  Virus binding to a surface results at least locally, at the contact area, in
stress and potential structural perturbation of the virus cage. Here we address
the question of the role of substrate-induced deformation in the overall virus
mechanical response to the adsorption event. This question may be especially
important for the broad category of viruses that have their shells stabilized
by weak, non-covalent interactions. We utilize atomic force microscopy to
measure the height change distributions of the brome mosaic virus upon
adsorption from liquid on atomically flat substrates and present a continuum
model which captures well the behavior. Height data fitting according the model
provides, without recourse to indentation, estimates of virus elastic
properties and of the interfacial energy.
