Physico-Chemical Methods for the Study of Polycyclic Aromatic Hydrocarbon - DNA Interactions. Progress Report, October 1, 1985-September 30, 1986

摘要

Previous linear dichroism measurements suggested that the (-)BPDE-DNA adducts are characterized by considerable interactions between the pyrene residue and the DNA bases. Such a conformation is consistent with intercalation, or partial intercalation. With the pyrene residue thus protected from the solvent environment, one might expect a low degree of accessibility to acrylamide quencher molecules. Since the fluorescence of these (-)BPDE-DNA adducts is indeed insensitive to acrylamide, the quenching results reported here are consistent with such a conformation. The covalent adducts derived from the binding of (+)BPDE to DNA appear to be 70% accessible to acrylamide, suggesting that a majority of these adducts reside at external binding sites, or in a locally disordered region of the DNA double helix. Again, these conclusions derived from the fluorescence quenching data are consistent with our previous linear dichroism results. 3 refs., 3 figs. (ERA citation 12:002012)