Figure 7.

Unwinding of negatively supercoiled pUC19 plasmid DNA by [Fe₂(L-CF₃)₃]⁴⁺ (lanes 1–5) and [Fe₂(L-Ph)₃]⁴⁺ (lanes 6–10). The plasmid at the concentration of 2 × 10⁻⁴ M (this concentration is related to the monomeric nucleotide content) was mixed with increasing concentrations of the cylinders in 10 mM Tris·HCl (pH 7.4) incubated for 30 min at 25°C and analysed on 1% agarose gel. Lanes C, control (nonmodified DNA); lanes 1–5 and 6–10, cylinder:base ratio was 0.1, 0.15, 0.20, 0.25, 0.30, respectively; sc and oc (open circle) indicate supercoiled and relaxed (nicked) forms of plasmid DNA respectively, and prc indicates precipitated DNA.