volume effect and the change in compressibility in intercalation of ethidium bromide and daunomycin in DNA
Kudriashov, E.D., Buckin V.A., Braginskaia F.L, and Marky L.A.
Biofizika, 43(1), pp. 40-45 (1998)
Measurement of density and ultrasound velocity were made to study the binding of ethidium bromide and daunomycin to DNA. Intercalation was attended by a decrease in the DNA apparent molar volume and adiabatic compressibility; the changes were respectively -28 cm3mol-1 and -20 10-4 cm3mol-1bar-1 for ethidium bromide, and -28 cm3mol-1 and -18 10-4 cm3mol-1bar-1 for daunomycin. This is supposed to be due to dehydration of heterocycles, changes in the intrinsic compressibility of DNA-ligand complexes, and hydration of the molecules during complexation.