CHARACTERIZATION OF THE AFRICAN SWINE FEVER VIRION PROTEIN J18L

The African swine fever virus (ASFV) open reading frame (ORF) that is named j18L in the Malawi (LII20/1) isolate and E199L in the Ba71V isol ate encodes a cysteine rich protein of 195 amino acids with a predicte d molecular mass of 21.7 kDa and a hydrophobic domain near the C termi nus. There are several possible motifs for glycosylation, phosphorylat ion and myristoylation. Rabbit antisera and monoclonal antibodies rais ed against a recombinant ASFV j18L protein expressed as a fusion prote in with glutathione S-transfer;ase (GST) identified proteins of 19.0-2 0 kDa in cells infected with different ASFV strains and with a recombi nant vaccinia virus expressing j18L. The monoclonal antibodies detecte d a protein of 20.0 kDa whereas rabbit antisera detected two proteins with relative molecular masses of 15.0 and 20.0 kDa in purified extrac ellular ASF virions. In ASEV-infected cells, the j18L protein was expr essed late post-infection and was localized mainly in the viral factor ies.