title: New studies on the interaction between 8-methoxypsoralen and DNA in vitro.
abstract: Some aspects of the interactions between DNA and 8-methoxypsoralen (8-MOP) in its ground state (complex formation) or in its excited state (photobinding) have been investigated. 8-MOP shows a low affinity towards DNA in the complex formation; this fact minimizes the possible biological consequences deriving from this interaction, when it occurs in vivo. In covalent photobinding to DNA, 8-MOP forms mainly monofunctional adducts, and to a lesser extent bifunctional adducts, showing a behavior similar to that of other linearly condensed furocoumarins (psoralens); the ratio between mono- and bifunctional adducts was found to be 9:1. The covalent photobinding to DNA does not occur at random along the macromolecule, but preferentially at the level of specific receptor sites. The regions having an alternate sequence of A-T seem to be the best receptor sites for the formation of monoadducts while the regions containing an alternate sequence of A-T and C-G appeared to be the preferential sites for the cross-linkage formation.
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000378:metabolism* / Q000528:radiation effects; D005363:Ficusin / Q000378:metabolism / Q000528:radiation effects; D008730:Methoxsalen / Q000378:metabolism* / Q000528:radiation effects; D008954:Models, Biological; D011089:Polydeoxyribonucleotides / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D014466:Ultraviolet Rays
chemical_list: D011089:Polydeoxyribonucleotides; D004247:DNA; D005363:Ficusin; D008730:Methoxsalen