FIG 5.

Purification and protein composition of viral particles lacking pE199L. Extracellular vE199Li virus particles generated in the presence or absence of 1 mM IPTG were obtained from infection supernatants and purified by the use of Percoll density gradients. (A) EM micrographs of negatively stained control vE199Li⁺ and defective vE199Li⁻ purified virus particles. Insets show details at a higher magnification. Bars, 200 nm (insets). (B) Equal amounts of control vE199Li⁺ and defective vE199Li⁻ particles were subjected to SDS-polyacrylamide gel electrophoresis analysis and Coomassie blue staining. Note that the samples display similar overall protein patterns. (C) Equal amounts of vE199Li⁺ and vE199Li⁻ virions were analyzed by immunoblotting with a panel of antibodies against some representative major ASFV structural proteins located at the five virus structural domains (indicated on the right). No differences were detected except for the absence of pE199L protein (in red) in vE199Li⁻ particles.