Glycoprotein components of avian and murine RNA tumor viruses

Abstract

Two glycoprotein components containing glucosamine, galactose, and fucose were isolated from different strains of Rous sarcoma virus (RSV) and from Rauscher mouse leukemia virus (MLV). The molecular weight of the major glycoprotein of RSV was estimated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS) to be between 90,000 and 105,000 daltons, depending on the strain of RSV. The minor glycoprotein had an approximate molecular weight of 37,000. Both glycoproteins have higher molecular weights than the proteins of the group-specific antigen of avian tumor viruses. The glycoproteins represent between 10% and 20% of the radioactive protein of purified virus. Disruption of RSV with SDS yields glycoprotein components with sedimentation coefficients between 4 S and 2 S. The glycoprotein derived from Tween 20 disrupted virus was obtained in a 4-2 S form and in an 8 S form. The 8 S component consists predominantly of a multimeric aggregate of the two viral glycoprotein components, and some group-specific antigen. Because both the 8 S and the 4-2 S glycoprotein derived from Tween 20 disrupted RSV specifically inhibited virus neutralizing antibody and because the glycoproteins of different strains of RSV had different electrophoretic mobilities, it was concluded that the glycoproteins of avian tumor viruses are part of or identical with the viral type- or subgroup-specific antigen.