title: A fetal protein in chromatin of Novikoff hepatoma and Walker 256 carcinosarcoma tumors that is absent from normal and regenerating rat liver.
abstract: Antibodies to chromatin proteins of Novikoff hepatoma cells formed precipitin bands in the double-diffusion immunoprecipitation assay with chromatin proteins of Novikoff hepatoma, Walker 256 carcinosarcoma, and 18-day fetal rat liver. The antigen used for preparation of antiserum was the chromatin proteins initially extracted with 3 M NaCl-7 M urea and soluble after dialysis to 0.14 M NaCl-0.35 M urea. The chromatin proteins used for analytical studies were extracted with 0.6 M NaCl containing 0.01 M Tris-HCl (pH 8) and 100 muM phenylmethylsulfonyl fluoride. Corresponding chromatin proteins of normal and 18-hr regenerating rat liver, heart, and kidney did not form precipitin bands. The antigen was purified from the chrmatin of Novikoff hepatoma cells by exclusion chromatography on Sephadex G-150 and preparative nondenaturing polyacrylamide gel electrophoresis. Its migration on denaturing sodium dodecyl sulfate-polyacrylamide gels corresponded to a molecular weight of 26,000. Amino acid analysis showed that the ratio of acidic to basic amino acids was 1.4 to 1.0. Evidence for its homogeneity included its migration as a single protein spot on two-dimensional polyacrylamide gel electrophoresis and its single lysine amino-terminal amino acid. This protein is a glycoprotein, as shown by the presence of 15 moles of galactosamine per mole of antigen. These studies demonstrate the presence of a fetal glycoprotein in the chromatin of two tumors that may have an important role in determining their gene products.
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000302:isolation & purification; D002279:Carcinoma 256, Walker / Q000276:immunology*; D006528:Carcinoma, Hepatocellular / Q000276:immunology*; D002843:Chromatin / Q000276:immunology*; D006023:Glycoproteins / Q000276:immunology; D007526:Isoelectric Point; D008099:Liver / Q000196:embryology / Q000276:immunology*; D008113:Liver Neoplasms; D008115:Liver Regeneration; D008861:Microsomes / Q000276:immunology; D008862:Microsomes, Liver / Q000276:immunology; D008970:Molecular Weight; D009374:Neoplasms, Experimental / Q000276:immunology; D051381:Rats
chemical_list: D000951:Antigens, Neoplasm; D002843:Chromatin; D006023:Glycoproteins