Spectroscopic studies on the interaction of Rebeccamycin with calf thymus DNA in the absence and presence of Histone H1

The interaction of Rebeccamycin with calf thymus DNA (ct DNA) in the absence and presence of Histone H1 was investigated by employing multi spectroscopic techniques. In the presence of H1, ct DNA- Rebeccamycin complex revealed intercalator and groove binding modes with dominant of intercalator role. The impression of ionic strength, such as Sodium Chloride and Potassium iodide on ct DNA-Rebeccamycin complex provided further evidence that their interaction modes were dependent on substituted groups. One of the strong indication for the reciprocal of molecules into the helix is obtaining by DNA melting studies. In this experiment the melting curve of ct DNA –Rebeccamycin complex has revealed that the binding mode is intercalative, however in presence of H1, the results indicated that there were a few changes.