A Preliminary Study of Tobacco Mosaic Virus by the Gel Diffusion Precipitin Tests

Abstract

SUMMARY: A number of proteins can be separated from purified preparations of tobacco mosaic virus; they differ from each other antigenically and all differ from the intact virus by not possessing all antigenic determinant groups possessed by the virus. Some of these proteins are easily detached from the virus by such mild treatments as placing it in a protein solution or in agar gel. These are antigenically identical with the ‘X-protein’ which remains in the supernatant fluid when the virus is sedimented by ultracentrifugation from sap of infected plants. More of these proteins are detached from the virus by placing it in borate buffer at c. pH 8·7. When a more drastic treatment is applied, such as incubation at c. pH 10, which disintegrates a proportion of the virus, still more of these proteins are released, but then some proteins antigenically different from those of ‘X-protein’ are also released.