INFLUENCE OF CATIONIC PORPHYRINS ON MELTING PARAMETERS OF CALF THYMUS DNA

Abstract

The influence of water soluble cationic 3N- and 4N-pyridyl porphyrins with different peripheral substituents on melting parameters of Calf Thymus DNA has been studied. It was shown, that the presence of porphyrin changes the shape and parameters of DNA melting curve. The decrease of T in the presence of 3N-porphyrins is observed. Because of the intercalation binding mechanism occurs in GC-rich regions of DNA, which is the reason for the decrease melting interval. While even at the low relative concentration for 4N-porphyrins already the external binding mechanism “turns on” and as a result the change in the melting parameters of DNA upon complexation with these porphyrins is not observed.