Effect of bridging ligand structure on the thermal stability and DNA binding properties of iron(II) triple helicates.
Triple helical di-iron complexes, readily prepared through interaction of iron(II) ions with imine-based ligands, are cylinder-shaped tetracations comparable in size and shape to common protein DNA recognition units. They have a strong tendency to coil DNA, and have recently been found to induce formation of three-way junctions in palindromic oligonucleotides. To introduce potential H bond acceptor units onto the surface of triple-helicates, new iron(II) complexes have been synthesized in which the central linking unit in the bridging ligand is S or O, instead of CH(2). The DNA binding properties of these new metallo-helicates were studied using UV-vis spectroscopy and circular and linear dichroism. Results show that the three iron triple helicates bind the DNA in a similar way but that the stability of the triple helicate unit is decreased with the O linked bridging ligand.
Parajó
Yolanda
Y
Department of Chemistry and Bioscience, Chalmers University of Technology, Gothenburg, Sweden.
Malina
Jaroslav
J
Meistermann
Isabelle
I
Clarkson
Guy J
GJ
Pascu
Mirela
M
Rodger
Alison
A
Hannon
Michael J
MJ
Lincoln
Per
P
D000818:Animals; D001667:Binding, Competitive; D002412:Cations / Q000737:chemistry; D002417:Cattle; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004996:Ethidium / Q000378:metabolism; D005296:Ferrous Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D007097:Imines / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
D002412:Cations; D005296:Ferrous Compounds; D007097:Imines; D008024:Ligands; D004247:DNA; C427203:calf thymus DNA; D004996:Ethidium