Development of viscometric methods for studying the interaction of various porphyrins with DNA. Part IV: Meso-tetra-(4N-allylpyridyl) porphyrin and its Cu-, Co- and Zn-containing derivatives

Abstract

The influence of water soluble cationic meso-tetra-(4N-allylpyridyl) porphyrin (H2TAlPyP4) and its metal complexes with Cu, Co and Zn on hydrodynamic and spectral behavior of DNA solutions has been studied by viscometry, CD and UV-vis spectroscopy methods. The results were compared with the results of previously conducted similar studies on meso-tetra-(3N-allylpyridyl) porphyrin (H2TAllPyP3). It has been shown that the change in position of peripheral radicals on the pyridylic ring has absolutely no effect on the rules of interaction of investigated porphyrins with DNA in the case of outside binders CoTAllPyP4 and ZnTAllPyP4. Planar porphyrin H2TAllPyP4 interacts with DNA predominantly by the intercalation mode at low relative concentrations of [Formula: see text] ([Formula: see text] [Porphyrin]/[DNA]) and by external binding mode at high values of [Formula: see text]. CuTAllPyP4 shows unusual behavior by interacting with DNA via a non-classical (partial) intercalation binding mode. It was shown that H[Formula: see text]TAllPyP3 and its metal complexes bind to DNA much more intensely than H2TAllPyP4 and its metal complexes.