title: Anchorage of oligonucleotide hybridization by tethered phenazine nucleoside analogue.
abstract: UV absorption and fluorescence techniques with a thermal denaturation procedure were used in studies of the anchorage of an oligonucleotide hybridization by a covalently tethered nucleoside analogue of an intercalating imidazophenazine derivative (Pzn). The formation by the (dT)(10)Pzn conjugate of the duplex complex with (dA)(15) and the triplex complex with (dA)(15) or poly(dA).poly(dT) was studied in buffered solutions with 0.11 and/or 1M sodium ions at the oligomer strand concentration of 10 microM. Because of the Pzn emission sensitivity to the interaction with adenine bases, a fluorescence technique was found to be effective in the detection of melting transitions. The attached Pzn substantially enhanced the thermal stability of complexes formed by (dT)(10) because of the intercalation mechanism, which increased the temperature of half-dissociation of the duplex by 10-12 degrees C and of the triplexes by approximately 13 degrees C. With the assumption of a two-state model of transition, the thermodynamic parameters for duplex formations were derived. The investigated variant of conjugation has a certain advantage over the widely used attachment via a flexible linker, consisting of a predetermined location of the Pzn chromophore in target sequences that makes it useful as a fluorescent reporter of the hybridization correctness. Molecular modeling was used to construct the geometries of the intercalation sites that turned out to be in conformity with the behavior of the Pzn fluorescence.
authors.affiliation: Institute for Low Temperature Physics and Engineering, NAS of Ukraine, 47 Lenin Avenue, Kharkov, 61103, Ukraine.
authors.forename: V
authors.initials: V
authors.lastname: Zozulya
authors.forename: Yu
authors.initials: Y
authors.lastname: Blagoi
authors.forename: I
authors.initials: I
authors.lastname: Dubey
authors.forename: D
authors.initials: D
authors.lastname: Fedoryak
authors.forename: V
authors.initials: V
authors.lastname: Makitruk
authors.forename: O
authors.initials: O
authors.lastname: Ryazanova
authors.forename: A
authors.initials: A
authors.lastname: Shcherbakova
mesh_terms: D005453:Fluorescence; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009693:Nucleic Acid Hybridization / Q000379:methods*; D009705:Nucleosides / Q000737:chemistry / Q000378:metabolism*; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism*; D010619:Phenazines / Q000378:metabolism*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D009705:Nucleosides; D009841:Oligonucleotides; D010619:Phenazines