Mechanism of DNA Intercalation by Chloroquine Provides Insights into Toxicity.

Chloroquine has been used as a potent antimalarial, anticancer drug, and prophylactic. While chloroquine is known to interact with DNA, the details of DNA-ligand interactions have remained unclear. Here we characterize chloroquine-double-stranded DNA binding with four complementary approaches, including optical tweezers, atomic force microscopy, duplex DNA melting measurements, and isothermal titration calorimetry.