[Electrophoretic and sedimentation heterogeneity of the virion antigen of the tick-borne encephalitis virus].

Analysis of tick-borne encephalitis virus virion antigen by cross immunoelectrophoresis showed it to be separated into 2 subpopulations of virions differing by their mobility in the electric field. It was demonstrated that in immunoelectrophoresis the formation of precipitation bands typical of virion antigen occurred due to the movement of soluble immune complexes in the electric field. The immunoelectrophoretic characteristics of TBE virus virions are determined by the membrane E protein which was also found to be heterogeneous in its immunoelectrophoretic characteristics. The nucleocapsid of tick-borne encephalitis virus virions formed no precipitation bands in immunoelectrophoresis. The virion antigen not sedimenting in ultracentrifugation was represented by morphologically intact virions the structural protein composition of which differed from that of the structural proteins of virions sedimentable by ultracentrifugation. The possible causes of electrophoretic and sedimentation heterogeneity of tick-borne encephalitis virus virion antigen are discussed.