title: Does the metal influence non-covalent binding of complexes to DNA?
abstract: Electrospray ionisation mass spectrometry, absorption spectrophotometry and circular dichroism spectroscopy were used to investigate the binding of a series of nickel complexes with the general formula [Ni(phen)2L]2+ (L = phen, dpq, dpqC and dppz) to a double stranded DNA hexadecamer. In addition, the binding of the complexes to pUC9 negatively supercoiled plasmid DNA was examined using gel electrophoresis, and their ability to inhibit DNA transcription was measured. Each of the above techniques showed that DNA binding strengthened as the size of the unique ligand L was increased. Comparison of the above results with those obtained previously, and presented here for the first time for the analogous series of ruthenium complexes [Ru(phen)2L]2+, showed that changing the metal ion from nickel to ruthenium consistently resulted in significant increases in DNA binding affinity.
authors.affiliation: School of Chemistry, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
authors.forename: Jihan
authors.initials: J
authors.lastname: Talib
authors.forename: David G
authors.initials: DG
authors.lastname: Harman
authors.forename: Carolyn T
authors.initials: CT
authors.lastname: Dillon
authors.forename: Janice
authors.initials: J
authors.lastname: Aldrich-Wright
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Beck
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Ralph
mesh_terms: D002621:Chemistry / Q000379:methods; D002942:Circular Dichroism; D018360:Crystallography, X-Ray / Q000379:methods; D004247:DNA / Q000737:chemistry*; D007477:Ions; D007700:Kinetics; D013058:Mass Spectrometry / Q000379:methods; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013053:Spectrophotometry / Q000379:methods; D014158:Transcription, Genetic
chemical_list: D007477:Ions; D008670:Metals; D009532:Nickel; D012428:Ruthenium; D004247:DNA