Features of distamycin preferential binding sites on natural DNA predicted using differential scanning calorimetry

The interaction of distamycin with ColE1 DNA was examined by using differential scanning calorimetry (DSC) taking the helix-coil transition theory of DNA into consideration. Our results here strongly indicate that the affinity of distamycin to DNA, at a low distamycin concentration, depends highly on the DNA sequence, and preferential binding occurs to the sites of four to six successive A-T pairs having two or more successive G-C pairs on both their ends.