DNA binding and nuclease activity of a water-soluble sulfonated manganese(III) corrole

The interaction of a water-soluble sulfonated Mn(III) corrole Mn(tpfc)(SO3Na)(2) [tpfc = 5,10,15-tris(pentafluorophenyl)corrole] with calf thymus DNA (ct-DNA) has been studied by spectroscopic methods, and the nuclease activity of this complex has also been examined by agarose gel electrophoresis. Mn(tpfc)(SO3Na)(2) exhibits weak aggregation tendency in buffer solution and can bind to ct-DNA via an outside binding mode with a binding constant of 1.25 x 10(4) M-1. The observed increase in Stern-Volmer quenching constant with increasing temperature indicates that the competition of the manganese corrole and ethidium bromide with ct-DNA is a dynamic process. Moreover, the manganese corrole displays good chemical nuclease activity in the presence of hydrogen peroxide via oxidative cleavage of DNA.