[Mn2+-dependent endonuclease activity of chromatin].
The endogenous endonuclease activity of chromatin in isolated rat liver nuclei in the presence of Mn2+, Mg2+ and Ca2+ + Mg2+ was studied. The existence of a Mn2+-dependent endonuclease activity not coupled with the Ca2+, Mg2+-dependent endonuclease was demonstrated, which was weaker than the former one in isolated cell nuclei but higher than in the preparation of Ca2+, Mg2+-dependent nuclease obtained by gel filtration through Toyopearl HW 60F. The Mn2+-dependent splitting of chromatin predominantly occurs at linker DNA of distal parts of chromatin loops. A split-off of purified DNA was more universal than in the presence of Ca2+, Mg2+-dependent endonuclease; the hydrolysis rate of native and denaturated DNA appeared to be the same.
D000818:Animals; D002843:Chromatin / Q000032:analysis / Q000201:enzymology*; D004247:DNA / Q000032:analysis; D004720:Endonucleases / Q000302:isolation & purification / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008099:Liver / Q000032:analysis / Q000201:enzymology*; D008274:Magnesium / Q000378:metabolism*; D008297:Male; D009691:Nucleic Acid Denaturation; D051381:Rats
D002843:Chromatin; D004247:DNA; D004720:Endonucleases; D008274:Magnesium
Mn2+-zavisimaia éndonukleaznaia aktivnost' khromatina.