title: [Calculations of stability of A and B forms of dA6.dT6 and dG6.dC6 duplexes by molecular mechanics method in an aqueous solution and approximation of the statistical model. Analysis of unusual stability of the dA6.dT6 B form].
abstract: The statistical model of the environment for estimating the influence of the aqueous electrolyte solution on the macromolecule has been developed. The energy of the water-fasteners between macromolecule atoms has been calculated. The calculations of A and B form dA6.dT6 and dG6.dC6 duplexes have been made. The unusual stability of B form in dA6.dT6 and their unstability in dG6.dC6 have been analysed. B form duplexes have optimal energy of Van-der-Waals interactions, but a more strained ribose-phosphate backbone, the latter being the reason of its high conformational lability. The aqueous solution stabilizes B form duplexes. The main types of sequence-dependent B form stabilizing interactions are: electrostatic interactions between phosphate groups and bases, the effect of the solvent molecular structure and energy of water fasteners between nucleic bases and ribose-phosphate backbone.
authors.forename: Iu N
authors.initials: IuN
authors.lastname: Vorob'ev
mesh_terms: D004247:DNA; D008958:Models, Molecular; D015233:Models, Statistical; D009692:Nucleic Acid Heteroduplexes; D009838:Oligodeoxyribonucleotides; D011067:Poly dA-dT; D011089:Polydeoxyribonucleotides; D012996:Solutions; D014867:Water
chemical_list: D009692:Nucleic Acid Heteroduplexes; D009838:Oligodeoxyribonucleotides; D011089:Polydeoxyribonucleotides; D012996:Solutions; C016023:oligo(dA-dT); D014867:Water; D011067:Poly dA-dT; C052201:oligo(dG-dC); D004247:DNA
vernacular_title: Raschety stabil'nosti A- i B-form dupleksov dA6.dT6 i dG6.dC6 metodom molekuliarnoĭ mekhaniki v vodnom rastvore v priblizhenii statisticheskoĭ modeli sredy. Analiz neobychnoĭ stabil'nosti B-formy dA6.dT6.