Glycoproteins from murine c-type virus are more acidic in virus derived from transformed cells than from nontransformed cells

Abstract

Viral proteins from Moloney-MSV(MuLV) and M-MuLV were compared by two-dimensional gel electrophoresis, which demonstrates that several of the viral proteins were present in multiple forms differing in charge but not in size. Except for the glycoprotein gp70, the isomers were found to be identical in virus from transformed and nontransformed cells. gp70 from both types of virus showed 10 to 15 spots, indicating great charge heterogeneity. Furthermore, gp70 from virus from transformed cultures had isoelectric points that were on the average one pH unit more acidic than their counterparts from nontransformed cells, and their apparent molecular weight was slightly increased. That the transformed state of the culture is important in this respect was substantiated by using a mutant M-MSV(MuLV)-CP27 which is temperature sensitive for maintenance of transformation.