Resistance of H1 histone to proteolytic attack in chromatin from rat-ascites hepatoma.
From rat-liver and ascites-hepatoma chromatins, NaCl-soluble fractions were prepared. The 0.35 M NaCl-soluble fraction from the hepatoma (AH) chromatin contained much non-histone protein of high-molecular weight, compared with the fraction from the rat-liver (RL) chromatin. The 0.35 M NaCl-insoluble, but 2 M NaCl/5 M urea-soluble fraction was composed mainly of 5 classes of histones. These histones were quantitatively not different between AH and RL chromatins. However, H1 histone was rather protease-resistant in AH chromatin, but not in RL chromatin. The proteolytic capacity was also lower in AH chromatin. In addition, in the micrococcal-nuclease digest of AH nuclei, the oligonucleosomes were considerably retained even by long-time digestion, but not in that of RL nuclei.
D000818:Animals; D002843:Chromatin / Q000201:enzymology* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D006657:Histones / Q000378:metabolism*; D008099:Liver / Q000648:ultrastructure; D008114:Liver Neoplasms, Experimental / Q000648:ultrastructure*; D008297:Male; D008836:Micrococcal Nuclease / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism*; D051381:Rats
D002843:Chromatin; D006657:Histones; D008836:Micrococcal Nuclease; D010447:Peptide Hydrolases