Unique cooperative binding interaction observed between a minor groove binding Pt antitumor agent and Hoechst dye 33258.

@article{Harris2005UniqueCB,
  title={Unique cooperative binding interaction observed between a minor groove binding Pt antitumor agent and Hoechst dye 33258.},
  author={Amanda L Harris and Yongzhu Qu and Nicholas Farrell},
  journal={Inorganic chemistry},
  year={2005},
  volume={44 5},
  pages={
          1196-8
        }
}
The trinuclear compound [{Pt(NH3)3}2mu-{trans-Pt(NH3)2(H2N(CH2)6NH2)}2(6+) (0,0,0/t,t,t) binds to DNA only through noncovalent hydrogen bonding and electrostatic interactions. The presence of this 6+ cation allows discrimination of binding modes for common DNA ligands: binding of minor-groove agents such as Hoechst 33258 is cooperative, and dye-DNA interaction is enhanced whereas intercalation as exemplified by ethidium bromide is competitively inhibited.