Synthesis and processing of herpes simplex virus type 1 glycoproteins gB and gC

Author

Elizabeth Ann Wenske

Date of Award

12-1982

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Microbiology

Major Professor

Richard J. Courtney

Committee Members

Jeffrey Becker, Steve Kennel, David Brian, Richard Eberle

Abstract

The glycoproteins of herpes simplex virus type 1 (HSV-1) range in molecular weight from 44,000 to 130,000. The objective of this research was to define the sequence of events involved in the synthesis of the high molecular HSV-1 glycoproteins gB (120,000 MW) and gC (130,000 MW). The studies focused on: (a) the identification and characterization of the partially-glycosylated precursors to gB and gC; (b) the manner in which the precursors were processed to the mature glycoproteins; and (c) the identification of the nonglycosylated forms of gB and gC.

The enzyme endo-β-N-acetylglucosaminidase H was used to identify the presence of mannose-rich oligosaccharides on the mature glycoproteins and their precursors. The gB glycoprotein contained both mannose-rich and complex-type oligosaccharides, whereas its proposed precursor, gA, contained only mannose-rich N-glycosidically linked oligosaccharides. The gB glycoprotein synthesized in tunicamycin- or deoxyglucose-treated cells had an approximate molecular weight of 92,000 and represented the nonglycosylated form of gB.

Only N-linked oligosaccharides of the complex-type were detected on the gC glycoprotein. In addition, the presence of O-linked oligosaccharides was indicated by the incorporation of isotopically-labeled glucosamine and galactose into a gC-related glycoprotein synthesized in the presence of tunicamycin and the susceptibility of gC associated oligosaccharides to alkaline hydrolysis. Only mannose-rich N-glycosidically linked oligosaccharides were associated with the precursor of gC, designated pgC₍₁₀₅₎ (105,000 MW). Endo H digestion of pgC₍₁₀₅₎ demonstrated that the nonglycosylated form of gC had a molecular weight of 75,000. In addition, a 75,000 and a 92,000 molecular weight protein were synthesized in the presence of tunicamycin which suggests the posttranslational addition of O-linked oligosaccharides to the 75,000 MW protein. In the absence of tunicamycin, it is proposed that the O-linked oligosaccharides are added during the processing of pgC₍₁₀₅₎ to gC.

The incorporation of [³H]mannose into gB and gC glycoproteins synthesized in the presence of deoxyglucose was also examined. Glycoproteins synthesized in the presence of deoxyglucose contained both endo H sensitive and resistant oligosaccharides.

Based on this research a biosynthetic pathway for glycoproteins gB and gC is proposed.

Recommended Citation

Wenske, Elizabeth Ann, "Synthesis and processing of herpes simplex virus type 1 glycoproteins gB and gC. " PhD diss., University of Tennessee, 1982.
https://trace.tennessee.edu/utk_graddiss/13344