Copper complex-assisted DNA hybridization.
2,2'-Bipyridine (bpy) or 1,10-phenanthroline (phen) metal-binding domains were covalently attached to oligonucleotides, and the influence of metal ions on the hybridization of the conjugates was investigated. Metal-binding domains were attached to oligonucleotides at 3'- and 5'-terminal positions, thus placing them in juxtaposed positions after hybridization to a common target strand. While the ligands alone had a positive effect (increased Tm) on hybrid stability, the duplex was further stabilized by the addition of copper(I) and/or copper(II) through the formation of a metal complex in which the two short sequences are linked through {Cu(bpy)2}, {Cu(phen)}, or {Cu(bpy)(phen)} domains. The increase in Tm, due to formation of the {Cu(bpy)2}, {Cu(phen)2}, {Cu(bpy)(phen)} motifs is reversed upon addition of EDTA, consistent with the stripping of copper from the ligands. The effect of metal complex formation on the duplex strength was shown to be highest if the two metal-coordinating ligand strands are placed as close to each other as possible.
Bianké
Gapian
G
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.
Chaurin
Valérie
V
Egorov
Maxim
M
Lebreton
Jacques
J
Constable
Edwin C
EC
Housecroft
Catherine E
CE
Häner
Robert
R
D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004492:Edetic Acid; D007477:Ions / Q000737:chemistry; D008024:Ligands; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009943:Organophosphorus Compounds / Q000737:chemistry; D013696:Temperature
D007477:Ions; D008024:Ligands; D009943:Organophosphorus Compounds; C434331:phosphoramidite; D003300:Copper; D004247:DNA; D004492:Edetic Acid