The method of crosslinking histones to DNA partly depurinated at neutral pH
✍ Scribed by E.S. Levina; S.G. Bavykin; V.V. Shick; A.D. Mirzabekov
- Book ID
- 102985631
- Publisher
- Elsevier Science
- Year
- 1981
- Tongue
- English
- Weight
- 880 KB
- Volume
- 110
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
The procedure of either reversible or stable "zero-length" crosslinking of histones through their lysine residues directly to DNA partly depurinated under mild conditions at neutral pH is described. DNA in chromatin was methylated with dimethyl sulfate. Methylated purine bases in DNA can be readily excised under mild conditions at neutral pH. Aldehyde groups formed in the depurinated residues of DNA react with the e-amino groups of lysines in histones and crosslink histones to DNA through the SchitT bases. The Schii bases catalyze the j%elimination reactions causing quantitative single-stranded scissions of DNA at the points of crosslinking in such a way that only the S-terminal fragments of DNA formed upon the breakage become attached to histones. These covalent DNA-protein crosslinks are reversible and can be split at pH 3 or stabilized by reduction of the Schiffbases with NaBH,.