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INDUCTION OF DNA–PROTEIN CROSS‐LINKING IN CHINESE HAMSTER CELLS BY MONOCHROMATIC 365 AND 405 NM ULTRAVIOLET LIGHT
Author(s) -
HAN A.,
PEAK M. J.,
PEAK J. G.
Publication year - 1984
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.1751-1097.1984.tb08188.x
Subject(s) - endonuclease , chinese hamster , dna , monochromatic color , microbiology and biotechnology , biology , irradiation , pyrimidine dimer , chemistry , biophysics , dna repair , biochemistry , physics , botany , nuclear physics
— The survival, the induction of DNA‐protein cross‐linking, and the number of T4‐endonuclease sensitive sites were measured in Chinese hamster cells that had been irradiated with 365 and 405 nm monochromatic light. The survival measurements show that cells are somewhat less sensitive to 405 nm light than to 365 nm light. The difference is expressed predominantly in the shoulder widths of the survival curves, whereas the slopes of the two curves are about the same. Induction of pyrimidine dimers, as indicated by the number of endonuclease‐sensitive sites, after exposures that produce about 10% survival is very low at 365 nm (˜ 4 endonuclease sites per 2 × 10 8 daltons), while no dimers are detected at 405 nm. In contrast, DNA‐protein cross‐links are induced rather effectively at either wavelength even after exposures that result in a relatively high survival (60‐20%). Our measurements support the conclusion that lethality in mammalian cells after irradiations with 365 or 405 nm light is caused by a nondimer damage, possibly DNA‐protein cross‐links.