Glycoprotein C of herpes simplex virus type 1: characterization of O-linked oligosaccharides

In contrast to other viral glycoproteins, the herpes simplex virus (HSV) glycoprotein C(gC) binds to the N-acetylgalactosamine-specific Helix pomatia lectin (HPA). In the present paper gC was purified by affinity chromatography with monospecific antibodies and the purified glycoprotein was subjected to protease digestion. HPA-binding protease-resistant glycopeptides were isolated by lectin affinity chromatography. The isolated structures did not bind to concanavalin A and seemed to lack charged groups as determined by ion-exchange chromatography. In gel filtration, the glycopeptides appeared in two peaks with molecular weights higher than 4000. The HPA-binding structures of gC were synthesized in the presence of tunicamycin, indicating that they belong to the O-glycosyl class of oligosaccharides. In addition to HPA-binding oligosaccharides, synthesis of tunicamycin-resistant wheat germ lectin-binding gC oligosaccharides was demonstrable. These were sensitive to sialidase and apparently unrelated to the HPA-binding oligosaccharides.