Binding mode of Co(en)(3)(3+) with calf thymus DNA

The binding mode of Co(en)(3)(3+) (en = ethylenediamine) to calf thymus DNA is investigated using electrochemical and spectroscopic methods. Binding c onstant value (K = 2.284 x 10(3) L/mol) is found to be the same by the two methods. Both isomers show the same CV behavior associated with binding to B-form DNA. CD spectra results show no enantoselectivety for both isomers b inding to DNA. All of this evidence suggests that the Co(en)(3)(3 divided b y)complex binds to DNA by an electrostatic mode. (C) 1999 John Wiley & Sons , Inc.