Biopolymers and cell. 1989. Volume 5. № 3. 49 - 53

V. V. Vlassov, N. D. Kobetz, E. L. Chernolovskaya, E. M. Ivanovo, V. M. Subbotin, L. A. Yakubov

AFFINITY MODIFICATION OF CHROMATIN WJTH AN ALKYLATING HEXADECADEOXYRIBOTHYMIDYLATE DERIVATIVE

Summary

    Alkylating derivative of hexadecadeoxyribothymidylate bearing 4-(N-2-chloroethyl-N-methylamino) benzylamine residue on its 5'-terminal phosphate was used for affinity modification of complementary poly (A) sequences in chromatin DNA. The DNA reactivi¬ty was not influenced by transcription and replication processes. DNA in suspension chromatin fraction and in intact nuclei was more readily alkylated as compared to that from the soluble chromatin fraction. This effect was attributed to higher superhelicity of DNA in intact nuclear DNA-protein structures. Protein-free isolated DNA was by seve¬ral orders of magnitude less reactive than the chromatin DNA. Reaction of alkylating oligonucleotide derivatives with DNA is the sequence specific process, since it is supp¬ressed by excess of an arbitrary hexadecanucleotide.