title: DNA and RNA noncovalent interaction of platinum(II) polypyridine complexes.
abstract: A comparative investigation of the noncovalent interaction of the platinum(II) polypyridine complexes [Pt(dipy)(n-Rpy)2]2+ and [Pt(4,4'-Me2dipy)(2-Rpy)2]2+ (dipy = 2,2'-dipyridine; Me = CH3; n = 2-4; R = H or CH3) with double-helical DNA (calf thymus) and RNA [poly(A).poly(U)] has been conducted. With the exception of [Pt(dipy)(2-Mepy)2]2+, all of the complexes interact strongly, by intercalation, with both nucleic acids giving rise to large changes in the electronic spectra and induced circular dichroism signals; in addition, viscosity experiments on rodlike DNA and RNA show that both biopolymers elongate upon interaction with the complexes. The binding constant values, KB, determined at 25 degrees C, indicate that, at 0.101 M ionic strength, the affinity for poly(A).poly(U) is strongly dependent on the complexes nature, while for DNA it is leveled off. [Pt(dipy)(2-Mepy)2]2+ binds to DNA but does not interact appreciably with poly(A).poly(U).
authors.affiliation: Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, University of Messina, 98166 Messina, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Cusumano
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Di Pietro
authors.forename: Antonino
authors.initials: A
authors.lastname: Giannetto
authors.forename: Pasquale Antonio
authors.initials: PA
authors.lastname: Vainiglia
mesh_terms: D004247:DNA / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*
chemical_list: D008024:Ligands; D009944:Organoplatinum Compounds; D011725:Pyridines; D012313:RNA; D004247:DNA