Electrofluorescence study of polycyclic hydrocarbon diol-epoxide binding to DNA.

By the use of a novel electrofluorescence method, estimates have been made of the geometry of binding to DNA of racemic mixtures of the anti-diol-epoxide derivatives of three polycyclic hydrocarbon carcinogens. These anti-configurations bind in a manner consistent with the planar diol-epoxide ring's being inclined at approximately 50 degrees to the DNA axis. This is true for the derivatives of benzo(a)pyrene, benz(a)anthracene and 3-methylcholanthrene. This binding is thus different from the regular intercalative interaction associated with the native hydrocarbons. As the (+ anti)-diol-epoxides are thought to be the initiatory compounds for carcinogenesis, the common binding characteristics for the three hydrocarbons may be significant in understanding the molecular interactions precursive to cancer.