INTERACTION OF DNA WITH ACTINOCIN-BASED AMPHOLITES

Complexes of DNA with actinocin-based ampholites were studied by spect rophotometry, viscosimetry, and dynamic birefringence. The ligand-DNA binding constants as dependent on pH and ionic strength, and changes i n the DNA higher structure resulting from complex formation were deter mined. Models of binding of the ligands to DNA are proposed. It is sho wn that the zwitterionic compounds do not bind to DNA through intercal ation. The transition of a compound into a cationic form enables its i ntercalation into the DNA double helix.