M-DNA: A novel metal ion complex of DNA studied by fluorescence techniques.
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).
Wettig
Shawn D
SD
College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatoon, Sasketchewan, Canada S7N 5C9.
Wood
David O
DO
Aich
Palok
P
Lee
Jeremy S
JS
D000818:Animals; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D008670:Metals / Q000737:chemistry* / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
D008670:Metals; D004247:DNA