FIG. 1.

ICP0 is an HSV-1 tegument protein. (A) Extracellular s17 virions were centrifuged through a 5 to 15% Ficoll gradient, and fractions were taken across the gradient. Each sample was analyzed for infectivity (top) or subjected to Western blotting for the major capsid protein VP5 or ICP0. (B) Purified extracellular s17 virions were fractionated using detergent and increasing concentrations of NaCl. Soluble (s/n) and insoluble (pellet) fractions were separated by pelleting and then analyzed by SDS-PAGE followed by Coomassie blue staining (top panel) or Western blotting for a range of virus structural proteins. The sizes of the molecular weight markers (in thousands) are indicated on the left. (C) Intranuclear capsids from s17-infected cells were centrifuged through a 15 to 50% sucrose gradient, and fractions were collected across the gradient. Each sample was analyzed by SDS-PAGE followed by silver staining. (D) Equivalent amounts of intact s17 virions and s17 capsids from fraction 8, based on their VP5 content, were analyzed by Western blotting for VP5, VP16, and ICP0.