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INDUCTION OF SLOWLY DEVELOPING ALKALI‐LABILE SITES IN HUMAN P3 CELL DNA BY UVA AND BLUE‐ AND GREEN‐LIGHT PHOTONS: ACTION SPECTRUM
Author(s) -
Peak Jennifer G.,
Peak Meyrick. J.
Publication year - 1995
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1995.tb02349.x
Subject(s) - action spectrum , chromophore , photochemistry , wavelength , flavin group , visible spectrum , chemistry , photosensitizer , photon , dna , spectral line , absorption (acoustics) , alkali metal , absorption spectroscopy , porphyrin , optoelectronics , optics , materials science , physics , biochemistry , enzyme , organic chemistry , astronomy
Action spectra (365–520nm) for the formation of DNA single‐strand breaks (SSB) and slowly developing alkali‐labile sites (SDALS) in human teratocarcinoma P3 cells in culture were determined. Induction of SDALS results from the absorption of blue‐ and green‐light photons. The spectrum has a broad peak that is maximal between 400 nm to 500 nm and declines sharply above and below these wavelength regions. Negligible yields of SDALS were produced by photons at wavelengths of 365 nm or shorter and at 520 nm or longer, whereas for SSB, the action increases with shorter wavelength throughout the whole spectral range studied. The configuration of the SDALS action spectrum suggests that the primary chromophore, and therefore possibly the photosensitizer, is a mixture of porphyrin and flavin residues.