期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1976
卷号：73
期号：9
页码：3258-3262
DOI：10.1073/pnas.73.9.3258
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：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.
