Comparative Study on O-linked Oligosaccharides of Glycoprotein D of Herpes Simplex Virus Types 1 and 2

Abstract

SUMMARYGlycoproteins D1 (gD1) and D2 (gD2) of herpes simplex virus type 1 and type 2, respectively, were purified from infected HEp-2 cells labelled with [3H]glucosamine for 14 h followed by a 3 h chase using HD1 monoclonal antibody linked to Sepharose. Olinked oligosaccharides were found to be present in both glycoproteins. The identification of N-acetyl [3H]galactosaminitol as the major labelled component in the oligosaccharides generated by mild alkaline borohydride treatment demonstrated that these chains have N-acetylgalactosamine at the reducing end. These oligosaccharides consist of mono-and disialylated species with a predominance of the latter species in gD1. Size analysis and radioactive amino sugar composition strongly suggest a structure in which the galactosyl-N-acetylgalactosamine core is substituted with one or two sialic acid residues. In terms of [3H]glucosamine-derived radioactivity, O-linked oligosaccharides are less represented than N-linked oligosaccharides. The O-linked oligosaccharide number determination showed that gD1 and gD2 carry two and three chains, respectively.

Characterization of the high Mr glycoprotein (gP300) of equine herpesvirus type 1 as a novel glycoprotein with extensive O-linked carbohydrate

“…Further experiments are in progress to determine the cause of the gp300 alteration, which is of particular interest as Rhinomune has been used as a live vaccine and has reduced pathogenicity (Bass et al, 1973). Many other herpesvirus glycoproteins have been shown to be partly composed of O-linked carbohydrate, such as HSV-1 gB, gC, gD and gE (Johnson & Spear, 1983;Olofsson et al, 1983;Wenske & Courtney, 1983;Serafini-Cessi et al, 1988), but this is of low abundance in comparison with N-linked carbohydrate. The EBV gp350 has approximately 50~ of its carbohydrate present as O-linkages (Serafini-Cessi et al, 1989), but the only characterized alphaherpesvirus glycoprotein in which O-linked carbohydrate predominates is HSV-2 gG (Serafini-Cessi et al, 1985), which has approximately 25 times as much carbohydrate present in the O-linkage form than in the N-linkage form.…”

Sialic Acid on Herpes Simplex Virus Type 1 Envelope Glycoproteins Is Required for Efficient Infection of Cells

“…Sialic acids have a stabilizing effect on glycoproteins and enzymatic desialylation often results in significant changes in the structure and function of these proteins (13,27,40,46,47,58,82). Previous studies have shown that gC, gD, and gH are sialylated but the specific linkages and possible functions of sialic acids on these proteins have not been determined (11,22,25,51,61,68). The goal of the present study was to determine whether sialylation of HSV-1 envelope proteins is important for infectivity.…”

Glycoprotein 60 of equine herpesvirus type 1 is a homologue of herpes simplex virus glycoprotein D and plays a major role in penetration of cells

“…Whereas HSV-1 gD is both N-and O-glycosylated (Cohen et al, 1986, Serafini-Cessi et al, 1988, pseudorabies virus (PRV) gp50 is glycosylated by O-linked carbohydrate only (Petrovskis et al, 1986). This protein has also been shown to protect both mice and pigs against PRV infection (Marchioli et al, 1987).…”

“…implicates gD in the entry process, because entry of HSV-1 into gD-expressing cells is blocked at the level of penetration (Campadelli-Fiume et al, 1988, Johnson & Spear, 1989. Two explanations have been proposed to account for this effect.…”

“…Two explanations have been proposed to account for this effect. Either expressed gD competes for the binding of viral gD to a host cell receptor necessary for penetration of the virus (Campadelli-Fiume et al, 1988;Johnson et al, 1990), or recombinant (or viral) gD acts to prevent re-infection of cells by released virus (Campadelli-Fiume et al, 1990). Furthermore, a role in virus egress has been postulated (Johnson & Spear, 1989).…”