| Summary: | Thesis (M.Sc.)--Memorial University of Newfoundland, 1981. Medicine Bibliography: leaves 155-170. Attachment, the first stage of viral infection, was investigated using Encephalomyocarditis (EMC) virus and Krebs II ascites tumour cells (Krebs cells). The initial stage of the research was concerned with the Krebs cell surface, which was found to consist of a plasma membrane and a glycocalyx. Plasma membranes from Krebs cells, the purity of which was determined by marker enzyme assays, electron microscopy and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), contained about 20 coomassie blue staining components (proteins) and one periodic acid Schiff’s (PAS) staining component (glycoprotein) of apparent molecular weight 225,000 daltons as revealed by SDS-PAGE. Three of the major proteins were labeled when Krebs plasma membranes were iodinated but the glycoprotein component was not labeled. SDS-PAGE of the glycocalyx was shown to influence cell surface activities since it partially blocked the iodination of whole cells and the action of neuraminidase on the cell surface. - The Krebs cell receptor for EMC virus was not found to be a glycocalyx component because attachment, growth and haemagglutination of EMC virus were unaffected by the presence or absence of the glycocalyx. EMC virus attached equally well to whole Krebs cells, isolated plasma membranes and human erythrocytes. Neuraminidase or trypsin treatment of Krebs cells or plasma membranes reduced EMC virus attachment and infectivity suggesting that the virus was attaching to a sialoglycoprotein component. - Glycoprotein preparations from Krebs cells and plasma membranes examined by SDS-PAGE contained a single PAS positive component of apparent molecular weight 215,000 daltons which is very similar to that of the membrane PAS component. These preparations inhibited virus attachment, infectivity and haemagglutination and inhibition was reduced by treating the preparations with trypsin or neuraminidase. It is, therefore, probable that EMC virus attaches to the sialoglycoprotein component of the Krebs plasma membrane.
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