GLYCOPROTEIN-B (GB) OF PSEUDORABIES VIRUS INTERACTS SPECIFICALLY WITHTHE GLYCOSAMINOGLYCAN HEPARIN

We have previously shown that the pseudorabies virus (PrV) glycoprotei ns gB and gC (former PrV-gII and PrV-gIII) exhibit heparin-binding pro perties. While PrV-gC functions as the major adsorption protein, the b iological role of the heparin-binding properties of PrV-gB are not und erstood. We used a gC-deleted PrV-mutant, PrV (dlg92/dltk), to analyse the heparin-binding properties of PrV-gB and the biological role of t he PrV-gB-protein in adsorption. PrV-gB was the only glycoprotein of t his vaccine strain binding to immobilised heparin in in vitro assays. Presence of the gC-protein was not necessary for the interaction of gB with heparin. Soluble heparin also interfered with adsorption of this mutant virus to a similar extent as it blocked adsorption of wild-typ e PrV(Ka), but it had only a minor inhibitory effect on infectivity of the mutant strain. These results show that PrV-gB interacts specifica lly with immobilized heparin and heparin-like structures on the cell s urface, but this interaction is not required for a productive infectio n.