Dissociation of single-stranded DNA from nucleosomes following modification with acetic anhydride.
Modification with acetic anhydride of nucleosomes from chicken erythrocytes at low ionic strength (less than 0.1 M NaCl) is accompanied by the formation of residual particles and the release of free DNA. This DNA has been identified as single-stranded by thermal denaturation, digestion with nuclease S1, and elution from hydroxyapatite. In contrast, if modification takes place at 0.6 M NaCl, the liberated DNA is mainly double-stranded. The release of the free energy stored in folded nucleosomal DNA, triggered by the weakening of lysine-DNA interactions which takes place upon modification, might be responsible for the observed denaturation of DNA at low ionic strength.
D000085:Acetates; D000089:Acetic Anhydrides; D000818:Animals; D002499:Centrifugation, Density Gradient; D002645:Chickens; D004277:DNA, Single-Stranded / Q000097:blood / Q000302:isolation & purification*; D004912:Erythrocytes / Q000032:analysis*; D006358:Hot Temperature; D009691:Nucleic Acid Denaturation; D009707:Nucleosomes / Q000032:analysis*; D009994:Osmolar Concentration
D000085:Acetates; D000089:Acetic Anhydrides; D004277:DNA, Single-Stranded; D009707:Nucleosomes; C031800:acetic anhydride