[Mechanism of daunorubicin interaction with DNA]

The kinetics of binding of rubomycin and its aglycon (daunomycinon) with DNA was studied with the stopped flow method. It was shown that the reaction of formation of the complex of daunorubicin with DNA involved two stages. At the first stage the antibiotic aglycon intercalated between the pairs of DNA bases and at the second stage the resulting complex was additionally stabilized due to interaction of the positively charged amino sugar residue of the antibiotic with the negatively charged DNA phosphates. The reaction of formation of the complex of daunomycinon with DNA involved one stage. Estimation of the constants characterizing the above reactions is presented.