title: Synthesis and characterization of ruthenium(II)-oligopyridine-peptide conjugates. Interactions of the diasteromeres Δ- and Λ-[Ru(bpy)2(4-COY-4'-Mebpy)]Cl2 (Y=Gly-Lys(1)-Lys(2)CONH2, Lys(1)-Gly-Lys(2)CONH2, Lys(1)-Lys(2)-GlyCONH2) with the oligonucleotide d(5'-CGCGAATTCGCG-3')2.
abstract: Diastereomeric complexes of the general formulae Λ- and Δ-[Ru(bpy)2(4-COY-4'-Mebpy)]Cl2 where bpy=2,2'-bipyridine and Y=Gly-Lys(1)-Lys(2)CONH2, Lys(1)-Gly-Lys(2)CONH2, Lys(1)-Lys(2)-GlyCONH2, were synthesized and characterized. The ability of these compounds to bind to the oligonucleotide duplex d(5'-CGCGAATTCGCG-3') was studied with NMR techniques. Complex Λ-2, Λ-[Ru(bpy)2(4-COLys(1)-Gly-Lys(2)CONH2),4'-Mebpy)]Cl2 (Mebpy=methyl-2,2'-bipyridine), interacts non-specifically causing changes for both complex and oligonucleotide (1)H NMR signals. Both Λ-1, Λ-[Ru(bpy)2(4-COGly-Lys(1)-Lys(2)CONH2),4'-Mebpy)]Cl2 and Λ-3, Λ-[Ru(bpy)2(4-COLys(1)-Lys(2)-GlyCONH2),4'-Mebpy)]Cl2, were bound to the oligonucleotide through both lysine aliphatic chains, indicating that the side chains of the sequential lysines create a kind of "clamp" to connect the complex with the oligonucleotide. Complex Δ-1, Δ-[Ru(bpy)2(4-COGly-Lys(1)-Lys(2)CONH2),4'-Mebpy)]Cl2, interacts with the oligonucleotide duplex with both lysine side chains in a manner similar to Λ-1. Δ-2, Δ-[Ru(bpy)2(4-COLys(1)-Gly-Lys(2)CONH2),4'-Mebpy)]Cl2, interacts with the oligonucleotide with the bipyridine ligands. In addition, the formation of a hydrogen bond between the Gly-NH and the carbonyl groups of the oligonucleotide bases was detected. A completely different binding mode was observed for Δ-3 Δ-[Ru(bpy)2(4-COLys(1)-Lys(2)-GlyCONH2),4'-Mebpy)]Cl2, which at a ratio of 1:1 ([Ru]/[nucleotide]) opens the oligonucleotide strands. In addition, participation of all three peptidic NH of Δ-3 in hydrogen bonds was observed.
authors.affiliation: Laboratory of Inorganic and General Chemistry, Department of Chemistry, University of Ioannina, Ioannina 45110, Greece.
authors.forename: Konstantina
authors.initials: K
authors.lastname: Karidi
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Ypsilantis
authors.forename: Athanasios
authors.initials: A
authors.lastname: Papakyriakou
authors.forename: Achilleas
authors.initials: A
authors.lastname: Garoufis
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D002942:Circular Dichroism; D004151:Dipeptides / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009841:Oligonucleotides / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D004151:Dipeptides; D009841:Oligonucleotides; D009942:Organometallic Compounds; C103599:bis(bipyridyl)ruthenium(II); D015082:2,2'-Dipyridyl; D012428:Ruthenium; C035809:glycyllysine
keywords: Conjugates; Oligonucleotide; Oligopyridine; Peptide; Ruthenium