Mutagenicity of the nuclease activity of 1,10-phenanthroline-copper ion

The nuclease activity of 1,10-phenanthroline-copper functions intracellularly. This was shown by its mutagenicity in the Ames Test using the tester strain TA 102 and the in vivo nicking of plasmids derived from this strain. In vivo DNA strand scission requires all the components essential for the in vitro activity: 1,10-phenanthroline, cupric ion, thiol and hydrogen peroxide. Although 60Co gamma radiation potentiates the nuclease activity of 1,10-phenanthroline-copper ion in vitro via a superoxide dependent pathway, it does not promote significant mutagenesis in vivo at exposure levels below cytotoxicity.