A fetal protein in chromatin of Novikoff hepatoma and Walker 256 carcinosarcoma tumors that is absent from normal and regenerating rat liver

Proc Natl Acad Sci U S A. 1976 Sep;73(9):3258-62. doi: 10.1073/pnas.73.9.3258.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Neoplasm / analysis*
  • Antigens, Neoplasm / isolation & purification
  • Carcinoma 256, Walker / immunology*
  • Carcinoma, Hepatocellular / immunology*
  • Chromatin / immunology*
  • Glycoproteins / immunology
  • Isoelectric Point
  • Liver / embryology
  • Liver / immunology*
  • Liver Neoplasms
  • Liver Regeneration
  • Microsomes / immunology
  • Microsomes, Liver / immunology
  • Molecular Weight
  • Neoplasms, Experimental / immunology
  • Rats


  • Antigens, Neoplasm
  • Chromatin
  • Glycoproteins