Characterization of ASFV Proteins

Abstract

The analysis of polypeptides made in cells infected with African swine fever virus (ASFV) by high-resolution polyacrylamide gel electrophoresis revealed the synthesis of at least 44 polypeptides ranging in molecular weight from 9.5 K to 243 K. Most of the proteins are synthesized within the first eight hours after infection and can be classified as immediate-early, early or late proteins. Some are modified by the incorporation of prosthetic groups: of these, at least eight were phosphorylated, and three specific viral glycoproteins were detected by immunoprecipitation. The polypeptides are localized in the nucleus and cytoplasm of infected cells, but their function is unknown. They were classified as structural and nonstructural polypeptides on the basis of their mobility in relation to the virion. Of the 28 polypeptides identified in intracellular virus, 23 are structural polypeptides. The other five could be cell polypeptides associated with the virus,as is the case with VP42 identified as cell actin. At least 34 polypeptides have been identified in extracellular virus where most of the major structural polypeptides correspond to those of the intracellular virus. The localization of these polypeptides in the virus was achieved by treatment with detergents and NaCl. No polypeptide that induces neutralizing antibodies has been found, but the major structural protein (VP73) could be important as an effective antigen in ELISA studies in the control of the disease.