Structural proteins of Herpesvirus saimiri.

Herpesvirus saimiri particles were purified from productively infected owl monkey kidney cell cultures, and the virion polypeptides were analyzed by polyacrylamide gel electrophoresis. A total of 21 predominant proteins were found in lysates of H. saimiri 11 particles by Coomassie blue staining or by [35S]methionine labeling and autoradiography; all proteins were between 160,000 and 12,000 daltons in size. They are most probably virion constituents, as most of them were precipitated by immune sera, and no dominant proteins of equivalent sizes were found in mock-infected cultures. Four glycoproteins (gp 155/160, gp 128, gp 84/90, gp 55) and three polypeptides that appeared not to be glycosylated (p71, p35, p28) were assigned to the envelope or matrix of virions, whereas at least four phosphoproteins (pp132, pp118, pp55, pp13) and ten polypeptides without apparent secondary modification (p155/160, p106, p96, p67, p53, p36, p32, p15, p14, p12) were found in the nucleocapsid fraction. Analysis of virion proteins from different H. saimiri strains did not reveal appreciable differences in the migration behavior of most polypeptides, including all glycoproteins; however, determination of a strain-specific size pattern was possible for three of four phosphoproteins. The overall similarity in protein architecture of H. saimiri strains obviously does not reflect the variability in biology, such as oncogenic properties. In comparison, DNA sequence divergences appear to remain a better taxonomic criterion for strain distinction.