title: M-DNA: A novel metal ion complex of DNA studied by fluorescence techniques.
abstract: M-DNA, a complex formed in solution between divalent metal ions (M) and duplex DNA, has been studied extensively using fluorescence quenching. This review examines the methods used to examine the formation of M-DNA, and its ability to serve as a pathway for electron transfer between donor and acceptor chromaphores. A mass action model for M-DNA formation is presented based upon the results of fluorescence quenching studies using fluorescein/QSY-7 labeled duplexes. From the mass action analysis, it was determined that approximately 1.4 protons are released per base pair, with k(eq) on the order of 10(-8), indicative of a strong interaction. As resonance energy transfer is shown to be unlikely over the distances involved in this work, the observed quenching in M-DNA is discussed in terms of an electron hopping mechanism for electron transfer, with k(hop)=2.5 x 10(11)s(-1).
authors.affiliation: College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatoon, Sasketchewan, Canada S7N 5C9.
authors.forename: Shawn D
authors.initials: SD
authors.lastname: Wettig
authors.forename: David O
authors.initials: DO
authors.lastname: Wood
authors.forename: Palok
authors.initials: P
authors.lastname: Aich
authors.forename: Jeremy S
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D008670:Metals / Q000737:chemistry* / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D008670:Metals; D004247:DNA