Absorption and circular dichroism studies of a gold (I)-DNA complex.

The DNA binding properties of the Au(I)-containing antiarthritic drug Ridaura and related Au(I) complexes have been investigated. Absorption and circular dichroism spectroscopy show that if the gold ion possesses an easily displaced ligand, e.g., Cl- or Br-, Au(I) is capable of interacting, in a nondenaturing fashion, with calf thymus DNA. Absorption studies with the four DNA nucleosides suggest that guanine and cytosine bases are important in the Au(I)DNA interaction.