Structural and intracellular proteins of the porcine transmissible gastroenteritis coronavirus

Author

Karen Christina Moreau

Date of Award

3-1982

Degree Type

Thesis

Degree Name

Master of Science

Major

Microbiology

Major Professor

David A. Brian

Committee Members

Richard J. Courtney, Carl J. Wust

Abstract

The Purdue high-passage strain of TGEV was grown to titers of >10⁸ PFU/ml in the presence of isotopically labeled precursors for the purpose of analyzing the virion structural proteins. Three major species of polypeptides were found when purified virions were denatured and resolved on polyacrylamide gels in the presence of sodium dodecyl sulfate. The major polypeptides had apparent molecular weights of 200,000, 50,000, and 29,000. The 200K and 29K proteins contained carbohydrate, and the 50K protein was phosphorylated. The major virion structural proteins were therefore designated gp200, pp50, and gp29. In addition, two minor virion structural proteins were identified, having apparent molecular weights of 26,000 and 80,000. They were designated p26 and p80.

When tissue culture cells were infected at a multiplicity of 300 PFU/cell and then pulse-labeled with ³⁵S-methionine at various times postinfection the following observations were made: (1) The rate of host protein synthesis was inhibited by 80% at 6 hours postinfection and continued to decrease thereafter. (2) The synthesis of three new proteins with molecular weights of 180,000, 50,000, and 29,000 began by 2 hours postinfection and appeared to occur at a maximal rate between 4 and 6 hours post-infection. (3) Immunoprecipitation using hyperimmune pig-anti-TGEV antiserum confirmed the viral specificity of the 180K and 29K species. (4) No intracellular protein other than the 180K, 50K, and 29K species was observed throughout the infection cycle. On the basis of molecular weight, therefore, the three intracellular proteins appear to be precursors to the virion structural proteins and no putative nonstructural protein(s) was identified. (5) The kinetics of protein synthesis in TGEV-infected cells closely followed the kinetics of TGEV RNA synthesis within infected cells as established by Dennis (1980).

Recommended Citation

Moreau, Karen Christina, "Structural and intracellular proteins of the porcine transmissible gastroenteritis coronavirus. " Master's Thesis, University of Tennessee, 1982.
https://trace.tennessee.edu/utk_gradthes/15064