Iron(II) Supramolecular Helicates Condense Plasmid DNA and Inhibit Vital DNA-Related Enzymatic Activities

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Colleges, School and Institutes


The dinuclear iron(II) supramolecular helicates [Fe2L3]Cl4 (L = C25H20N4) bind to DNA through noncovalent (i.e. , hydrogen-bonding, electrostatic) interactions and exhib- it antimicrobial and anticancer effects. In this study, we show that the helicates condense plasmid DNA with a much higher potency than conventional DNA-condensing agents. Notably, molecules of DNA in the presence of the M enan- tiomer of [Fe2L3]Cl4 do not form intermolecular aggregates typically formed by other condensing agents, such as spermidine or spermine. The helicates inhibit the activity of sev- eral DNA-processing enzymes, such as RNA polymerase, DNA topoisomerase I, deoxyribonuclease I, and site-specific restriction endonucleases. However, the results also indicate that the DNA condensation induced by the helicates does not play a crucial role in these inhibition reactions. The mechanisms for the inhibitory effects of [Fe2L3]Cl4 helicates on DNA-related enzymatic activities have been proposed.


Original languageEnglish
Pages (from-to)11189-11195
JournalChemistry: A European Journal
Issue number31
Early online date24 Jun 2015
Publication statusPublished - 27 Jul 2015