title: [Modification of guanine residues in double-stranded DNA by aminomethylol compounds without denaturation of nucleic acid].
abstract: With the application of radioactive formaldehyde and glycine the ability of aminomethylol compounds to combine with S1 nuclease treated DNA at 25 degrees and pH 5.8--7.4 has been shown. The reaction leads to modification of 22--26% of base pairs without changes of the DNA UV-absorption spectrum. Besides that the flexibility coefficient, the kinetics of despiralization under the action of formaldehyde and the stability of DNA molecule towards the S1 nuclease action permit to conclude that modification does not cause DNA despiralization. In experiments with the use of synthetic double-stranded polynucleotides poly(dA) times poly(dT), poly(rC) times poly(rl), poly(rG) times poly(dC) and poly(dC-dG) times poly(dC-dG) it has been shown that binding of methylol compounds to nucleic acids is due to reaction with guanine residues. Methylol derivatives of glycine reacts with guanine residues of double-stranded DNA only 10 times slower than with the monomer--deoxyguanosine-5'-phosphate. The studied reaction is reversible and the half-period of modified DNA reduction is found to be 5 hours at 25 degrees and pH 6.5. The rate constants of forward and reverse reactions and equilibrium constants of the reaction between methylolglycine and native DNA were determined.
mesh_terms: D000605:Amino Alcohols; D000818:Animals; D001482:Base Composition; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA; D004720:Endonucleases; D005557:Formaldehyde; D005998:Glycine; D006147:Guanine; D011089:Polydeoxyribonucleotides; D011131:Polyribonucleotides; D015719:Single-Strand Specific DNA and RNA Endonucleases; D013056:Spectrophotometry, Ultraviolet; D013950:Thymus Gland
chemical_list: D000605:Amino Alcohols; D011089:Polydeoxyribonucleotides; D011131:Polyribonucleotides; D005557:Formaldehyde; D006147:Guanine; D004247:DNA; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases; D005998:Glycine
vernacular_title: Modifikatsiia ostatkov guanina v dvuspiral'noĭ DNK aminometilol'nymi soedineniiami, ne soprovozhdaiushchaiasia denaturatsieĭ nukleinovoĭ kisloty.