Herpesvirus sylvilagus I. Polypeptides of virions and nucleocapsids

Abstract

Herpesvirus sylvilagus was propagated in juvenile cotton tail rabbit kidney cells and purified from the cytoplasmic fraction of the infected cells. The purification procedure included zonal centrifugation through a 5 to 30% dextran t-10 gradient, followed by equilibrium centrifugation in a 5 to 50% potassium tartrate gradient. H. sylvilagus formed one band after centrifugation through the tartrate gradient at a density of 1.22 g/cm3. Contamination of the purified virus preparation by cellular proteins was less than 0.2% as determined by the removal of radioactivity from an artificially mixed sample containing [35S]methionine-labeled control cells and nonlabeled infected cells. H. sylvilagus nucleocapsids were isolated from infected cell nuclei and purified by sedimentation through a 36% sucrose cushion, followed by equilibrium centrifugation in 5 to 50% tartrate gradient. Forty-four polypeptides ranging in molecular weight from 18,000 to 230,00 were resolved when [35S]methionine-labeled enveloped H. sylvilagus was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Seventeen polypeptides found within the enveloped virus were also identified with the nucleocapsid. Six additional nucleocapsid polypeptides han no counterparts within the enveloped virus. The major polypeptide within both the virus and the nucleocapsid had a molecular weight of 150,000.