Abstract:

The interactions of water-soluble metal porphyrins Cu(NECN) and Ni(NEAE) with calf thymus ds DNA and ss DNA have been investigated by microcalarimetry and UV spectroscopy. The results demonstrat that the reaction of Cu(NACN) with ds DNA is endothermic with the binding enthalpy △H=9.2 kJ•mol-1 for Cu(NACN), its saturated binding number is 4~5 base pairs, the reaction of Ni(NEAE) with ds DNA is exothermal with the binding enthalpy △H=-7.6 kJ•mol-1 for Ni(NEAE), its saturated binding number is 5-6 base pairs, the difference of their binding modes are mainly attributed to their metal ionic properties in porphyrine molecules which are studied in this paper. Watersoluble porphyrins, Cu(NACN) and Ni(NEAE) interact with ss DNA more intensive.

Key words: Watr-soluble metal porphyrin, DNA, Microcalorimetry