摘要: The goal of this project was to develop new spectroscopic techniques and to adapt existing methods for studies of the interactions of polycyclic aromatic mutagens and carcinogens with nucleic acids. A highly sensitive, computer-in... 展开 The goal of this project was to develop new spectroscopic techniques and to adapt existing methods for studies of the interactions of polycyclic aromatic mutagens and carcinogens with nucleic acids. A highly sensitive, computer-interfaced linear dichroism system was constructed to allow for studies of the conformations of carcinogen-DNA non-covalent complexes and covalent adducts. Fluorescence techniques were adapted for studies of the heterogeneities of carcinogen-DNA adducts utilizing fluorescence emission spectra, and detailed comparisons between excitation and absorption spectra acquired with digital instrumentation. Detailed fluorescence quenching studies, together with accurate determinations of fluorescence decay profiles utilizing the National Synchrotron Light Source at the Brookhaven National Laboratory, allowed for a determination of the solvent exposure of the polycyclic aromatic moieties in covalent carcinogen-DNA adducts. Finally, a detailed study of the base-sequence dependence of non-covalent intercalation complex formation and chemical reactivity of polycyclic aromatic diol epoxide with synthetic polynucleotides was performed. These studies provided insight into the detailed mechanisms of interaction of benzo(a)pyrene trans-7,8-dihydrodiol-9,10-epoxide with DNA. 收起