Interactions of mono spermine porphyrin derivative with DNAs.

In this work, we have characterized the interactions of monospermine porphyrin derivative with calf thymus DNA (ct-DNA) and poly (dG-dC)2 in both B and Z conformation. By several spectroscopic techniques (UV-vis, electronic circular dichroism and resonance light scattering), the binding modes of monospermine porphyrin derivative with different DNA sequences have been elucidated. In the presence of ct-DNA, the porphyrin binds along the external double helix as well as in the presence of B conformation of poly (dG-dC)2 . Whilst when the Z form of the poly (dG-dC)2 is induced, a slight intercalation of the porphyrin between the basis has been detected.