title: Investigation of pH-dependent DNA-metal ion interactions by surface plasmon resonance.
abstract: Ni(II) and Zn(II) M-DNA formation and denaturation of double-stranded DNA (dsDNA) by Cd(2+) were monitored by surface plasmon resonance (SPR). When exposed to immobilized 30 bp 50% GC dsDNA, Zn(2+) and Ni(2+) were found to give signals indicative of a conformational change at pH 8.5 but not 7.5, while Mg(2+) and Ca(2+) caused small changes at both pHs. The concentrations that gave 50% of the maximum responses were 0.06 and 0.50 mM for Zn(2+) and Ni(2+), respectively. At pH 8.5, Cd(2+) denatured over 40% of the dsDNA, while other metals denatured less than 5% of the DNA. Smaller pH-dependent signals were induced by Zn(2+), Ni(2+) or Cd(2+) with 50% GC single-stranded DNA (ssDNA), and with a homopolymer of d(T)30. Homopolymers d(A)30 and d(C)30 showed small signals that were largely independent of pH in the presence of Zn(2+) or Ni(2+).
authors.affiliation: Department of Biochemistry, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Canada S7N 5E5.
authors.forename: David O
authors.initials: DO
authors.lastname: Wood
authors.forename: Jeremy S
authors.initials: JS
authors.lastname: Lee
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008670:Metals / Q000737:chemistry* / Q000494:pharmacology*; D009532:Nickel / Q000737:chemistry / Q000494:pharmacology; D009690:Nucleic Acid Conformation / Q000187:drug effects; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D020349:Surface Plasmon Resonance; D015032:Zinc / Q000737:chemistry / Q000494:pharmacology
chemical_list: D008670:Metals; D009838:Oligodeoxyribonucleotides; D009532:Nickel; D004247:DNA; D015032:Zinc