Characterization of the synthesis and processing of the herpes simplex virus type 2 glycoprotein, gG

The synthesis and processing of herpes simplex virus type 2 glycoprotein gG was studied with the aid of a variety of techniques including the use of monospecific, monoclonal and polyclonal antibodies in immunoprecipitation, immunoblotting and immunofluorescence studies. The intermediates of gG processing were characterized by in vitro translation studies as well as the use of glycosidic enzymes and inhibitors of glycoprotein processing. The results of this study showed a number of components were involved in the synthesis of gG. These included a 100,000 molecular weight unglycosylated polypeptide (designated 100K), three high-mannose containing components designated 104K, 72K and 31K (104,000, 72,000, and 31,0000 molecular weight, respectively) and the fully glycosylated mature gG of 108,000 molecular weight (108K). Based on these results as well as kinetic studies and pulse-chase experiments, the following scheme of events in the synthesis and processing of gG is suggested. The gG glycoprotein is synthesized as a cotranslationally glycosylated 104K high-mannose intermediate that is cleaved into the 72K and 31K high-mannose containing glycoproteins. The high-mannose intermediate is then further glycosylated to generate the mature 108K gG.