Since heterobimetallic complexes 3 shows maximum binding
propensity with CT DNA, therefore the DNA cleavage activity of 3
was evaluated by agarose gel electrophoresis using supercoiled
pBR322 plasmid DNA in a medium of 5 mM TriseHCl/50 mM NaCl
buffer solution (pH 7.2). The reaction mixture was subjected to
agarose gel electrophoresis with increasing complex concentrations
incubated at 310 K for 45 min. The activity of complex 3 was
assessed by the conversion of DNA from Form I (Supercoiled Form)
to Form II (Nicked Circular Form) and then to Form III (Linear Form).
As shown in Fig. 1a, it was observed that the complex 3 was found
to exhibits nuclease activity at different concentration (10e30 mM),
followed by conversion of supercoiled DNA (Form I) into NC DNA
(Form II) without concurrent formation of Form III, suggesting
single strand DNA cleavage.