DNA-Interactions and Photocatalytic Strand Cleavage by Artificial Nucleases based on Water-Soluble Gold(III) Porphyrins
Sprache des Titels:
The novel gold porphyrin complex (5,10,15-Tris-(N-methylpyridinium-4-yl)-20-(1-pyrenyl)porphyrinato)gold(III) chloride, [AuIII(TMPy3Pyr1P)](Cl)4 was prepared and characterized by optical spectroscopy, high resolution nuclear magnetic resonance (NMR) and electrospray mass spectrometry (ESI-MS). This cationic multichromophore compound exhibits excellent water solubility and does not form aggregates under physiological conditions. Binding interactions of this complex and related model componds with nucleic acid substrates have been studied and characterized by NMR- and CD-spectroscopy. The photoreactivity of [AuIII(TMPy3Pyr1P)](Cl)4 was investigated under anaerobic and aerobic conditions in the presence of an excess of purine nucleoside, guanosine and plasmid DNA. Photocatalytic oxidative degradation of guanosine and the change from supercoiled to circular plasmid DNA upon monochromatic irradiation and polychromatic blue-light exposure with a maximum at 420 nm was explored. The potential of the novel water-soluble cationic metallo-intercalator complex [AuIII(TMPy3Pyr1P)](Cl)4 to serve as a catalytic photonuclease for the sequence specific cleavage of DNA has been demonstrated.