[Isolation of a complex of tick-borne encephalitis viral proteins by affinity chromatography using monoclonal antibodies to proteins NS5 and NS3].

Affinity chromatography of lysates of continuous porcine embryo cells infected with tick-borne encephalitis (TBE) virus on sepharose with immobilized monoclonal antibodies to TBE virus proteins NS5 and NS3 results in isolation of a stable protein complex. This complex contains viral proteins NS5, NS3, p49, and, probably, two more cell proteins. This complex is not detected at the early stage of infection, and 24 h after infection its structure does not depend on the specificity of immobilized monoclonal antibodies used in affinity chromatography and on the time elapsed after the infection. Immunoprecipitates of infected cells phosphorylated TBE virus protein NS5 in vitro, but possessed no RNA-polymerase activity. Elution of the complex with buffers with pH 3.5 or 11.1 or with 2M urea failed to purify the active replicase. The complex of viral and cellular proteins isolated by affinity chromatography on different immunoadsorbents did not possess RNA-polymerase activity because of inactivation or absence of additional subunit(s).