title: Mouse mammary tumor virus polypeptide precursors in intracytoplasmic A particles.
abstract: Intracytoplasmic A particles were analyzed by immunodiffusion and sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS--PAGE) before and after enzymatic cleavage with trypsin. A common antigen in A particles was detected by antisera prepared against purified intracytoplasmic A particles, purified mouse mammary tumor virus (MMTV), and a purified MMTV core polypeptide (p28). Despite this correlation, no SDS--polyacrylamide band migrating at p28 was observed in purified intracytoplasmic A particles. However, after incubation with trypsin, A particles subjected to SDS--PAGE produced only two polypeptide bands. They were observed at p28 and p15-10. Ouchterlony analysis of the trypsin-cleaved A particles revealed no alteration in the antigenicity of the particles. These results suggested that some structural components of intracytoplasmic A particles are polypeptide precursors of MMTV core proteins.
mesh_terms: D000818:Animals; D000941:Antigens; D002478:Cells, Cultured; D003429:Cross Reactions; D005260:Female; D007181:Inclusion Bodies, Viral / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D008324:Mammary Tumor Virus, Mouse / Q000254:growth & development* / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D014764:Viral Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*
chemical_list: D000941:Antigens; D014764:Viral Proteins