FeS-Induced Radical Formation and Its Effect on Plasmid DNA
  • 【DOI】

    10.1007/s10498-010-9116-x

  • 【摘要】

    Plasmid DNA was incubated at 25°C with aqueous solutions of dissolved Fe(II), S(-II), and nanoparticulate FeS with a mackinawite structure, FeSm. At ≥0.1?mM total dissolved Fe(I... 展开>>Plasmid DNA was incubated at 25°C with aqueous solutions of dissolved Fe(II), S(-II), and nanoparticulate FeS with a mackinawite structure, FeSm. At ≥0.1?mM total dissolved Fe(II) and S(-II), an increase in the proportion of the relaxed plasmid DNA occurs, through scission of the DNA backbone. In solutions where FeSm was precipitated, nanoparticulate FeSm binds to the DNA molecules. In solutions with concentrations below the FeSm solubility product, nicking of supercoiled pDNA occurs. Plasmid DNA appears to be a sensitive proxy for radical reactions. The reactant is proposed to be a sulfur-based radical produced from the iron-catalyzed decomposition of bisulfide, in a manner analogous to the Fenton reaction. This is further supported by experiments that suggest that sulfide free radicals are produced during the photolysis of aqueous solutions of polysulfides. Supercoiling of DNA affe 收起<<

  • 【作者】

  • 【刊期】

    Aquatic Geochemistry 2011年4-5期

  • 【语种】

    eng