title: Identification and partial characterization of new antigens from simian virus 40-transformed mouse cells.
abstract: Two new species of antigens were detected in simian virus 40-transformed mouse cells, in addition to the large (94,000 daltons) and small (20,000 daltons) tumor antigens. These antigens were immunoprecipitated from cell extracts by using anti-T serum and not normal, nonimmune serum. One of these was a protein with a molecular weight of approximately 130,000 and was present in some but not all SV40-transformed mouse cells. The other, which we have named Tau antigen, has a molecular weight of 56,000 as estimated by electrophoresis through acrylamide gels and was found in all virus-transformed cells examined. The 13,000-daltons antigen contained about 15 methionine-tryptic peptides which were also present in the large SV40 tumor antigen as determined by ion-exchange chromatography. This strongly suggested that the protein was virus coded. The 56,000-dalton Tau antigen appeared to share only two methionine-tryptic peptides with the large species of SV40 tumor antigen, as determined by ion-exchange and paper chromatographies. Our results are compatible with a cellular origin for Tau antigen. However, our data do not exclude the possibility that this protein contains sequences specified by the virus DNA.
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis*; D000956:Antigens, Viral / Q000032:analysis*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002472:Cell Transformation, Viral; D005347:Fibroblasts; D051379:Mice; D010455:Peptides / Q000032:analysis; D010766:Phosphorylation; D013539:Simian virus 40 / Q000276:immunology*
chemical_list: D000951:Antigens, Neoplasm; D000956:Antigens, Viral; D010455:Peptides