On the interpretation of small-angle x-ray solution scattering from spherical viruses.

We have found that small-angle X-ray solution scattering from spherical viruses may sometimes give information about surface organization. Experimental data for two viruses (wild cucumber mosaic virus and polyoma virus) are analysed, and it is shown that in each case the differences between the observed scattering curve and that expected from a solid sphere of uniform density may be accounted for by deviations from spherical symmetry. An analysis in terms of icosahedral harmonics shows how the clustering pattern of the coat protein may be deduced.