title: Mammalian chromatin substructure studies with the calcium-magnesium endonuclease and two-dimensional polyacrylamide-gel electrophoresis.
abstract: The basic regularity of chromatin substructure that has been reported in rat liver chromatin (Hewish & Burgoyne, 1973b) was also detected in mouse chromatin. The regular series of DNA fragments produced by the action of Ca-Mg endonuclease on rat chromatin were studied further. The smallest single-stranded class has a molecular weight of approx. 45000-63000 and the smallest double-stranded class has a molecular weight of approx. 120000-150000. Studies of the substructure of the DNA fragments produced by the Ca-Mg endonuclease have shown that the regular series of double-stranded fragments have regular series of single-stranded fragments within them. It was concluded that the regular series of double-stranded fragments was probably a consequence of the regular series of single-stranded fragments. Digestion time-courses are presented for mouse and rat nuclear DNA.
mesh_terms: D000818:Animals; D002118:Calcium; D002467:Cell Nucleus / Q000032:analysis; D002499:Centrifugation, Density Gradient; D002843:Chromatin / Q000032:analysis*; D004247:DNA / Q000032:analysis / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004720:Endonucleases; D008099:Liver / Q000032:analysis; D008274:Magnesium; D008722:Methods; D051379:Mice; D008970:Molecular Weight; D009691:Nucleic Acid Denaturation; D051381:Rats
chemical_list: D002843:Chromatin; D004247:DNA; D004720:Endonucleases; D008274:Magnesium; D002118:Calcium