Immunochemical studies of infectious mononucleosis II. Sodium dodecyl sulfate gel electrophoresis of membrane glycoprotein antigens

1. 1.|Four membrane glycoprotein antigens and the corresponding stroma from horse, sheep, bovine and human erythrocytes were examined by disc gel electrophoresis in sodium dodecyl sulfate. Two of the antigen preparations, horse and human, appeared almost homogeneous and the mobility of the glycoprotein band was the same as that of the predominant glycoprotein of the stroma. The extracts of bovine and sheep stroma each showed a major glycoprotein band and a peptide band of faster mobility. The mobility of the glycoprotein of sheep stroma corresponded to that of the extracted antigen whereas the apparent size of the glycoprotein of bovine stroma was much larger than that of the isolated antigen. 2. 2.|The behavior of these membrane glycoproteins on sodium dodecyl sulfate gels was found to be anomalous when compared to standard proteins. Ferguson plots of relative mobility at five acrylamide gel concentrations for both standard proteins and glycoproteins revealed that the apparent free mobility of the glycoproteins was lower than that of the standards. Experimentally, determined retardation coefficients were used, therefore, to estimate subunit size of the four antigens.