title: Interaction of Lambda- and Delta-[Ru(bpy)2(pbmz)](PF6)2 with the oligonucleotide duplex d(CGCGAATTCGCG)2.
abstract: The interaction of the enantiomeric complexes Lambda- and Delta-[Ru(bpy)(2)(pbmz)](PF(6))(2) (bpy=2,2'-bipyridine, pbmz=2-(2'-pyridyl)benzimidazole) with the DNA duplex d(CGCGAATTCGCG)(2) was investigated by means of 2D NMR techniques. The synthesis of the enantiomers was based on the optically pure complexes Lambda- and Delta-[Ru(bpy)(2)(py)(2)](2+) and were characterized by CD and NMR spectroscopy. NMR data indicate that both enantiomers bind weakly to the oligonucleotide, approaching from the minor groove at the centre of the helix. The perturbation of the B-DNA conformation is minor with an apparent absence of enantioselectivity. Molecular modelling calculations in conjunction with the NOE data support the suggestion that more than one binding modes are present. The imidazole amine group of the pbmz ligand is probably hydrogen bonded to the DNA phosphodiesteric backbone at the AATT step, and this may provide an explanation for the diminished enantioselectivity observed.
authors.affiliation: Laboratory of Inorganic Chemistry, Department of Chemistry, University of Ioannina, Ioannina 45210, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Papakyriakou
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Malandrinos
authors.forename: Achilleas
authors.initials: A
authors.lastname: Garoufis
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry* / Q000235:genetics; D017975:Ruthenium Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D009841:Oligonucleotides; D017975:Ruthenium Compounds; D004247:DNA