title: [Kinetics of formaldehyde splitting off from the hydroxymethylated amino groups of nitrogen bases incorporated into double-helical DNA].
abstract: We studied the kinetics of formaldehyde dissociation from hydroxymethylated amino groups of nitrous bases on native DNA. Compared with monomers, the rate constant of formaldehyde dissociation from such bases integrate in the double helix proved to be 20 times smaller for adenine and 4 times smaller for cytidine within the temperature range of 15 to 40 degrees C. The kinetic pattern suggests that the dissociation of formaldehyde from hydroxymethylated amino groups does not occur in the direction of the base plane nor through a full fluctuational opening of base pairs. It is presumed that formaldehyde dissociation from modified amino groups is due to softer fluctuational changes which however, make it possible for formaldehyde to attack amino groups perpendicularly to the base plane.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D004279:DNA, Viral / Q000302:isolation & purification; D005557:Formaldehyde; D007700:Kinetics; D009690:Nucleic Acid Conformation; D011067:Poly dA-dT; D011089:Polydeoxyribonucleotides; D013604:T-Phages / Q000032:analysis; D013816:Thermodynamics
chemical_list: D004279:DNA, Viral; D011089:Polydeoxyribonucleotides; D005557:Formaldehyde; D011067:Poly dA-dT
vernacular_title: Issledovanie kinetiki otshchepleniia formal'degida ot gidroksimetilirovannykh aminogrupp azotistykh osnovaniĭ, vstroennykh v dvoĭnuiu spiral' DNK.