EFFECTS OF GLYCEROL UPON THE BIOLOGICAL ACTIONS OF NEAR-ULTRAVIOLET LIGHT: SPECTRA AND CONCENTRATION DEPENDENCE FOR TRANSFORMING DNA AND FOR ESCHERICHIA COLI B/r

Authors

  • J. G. Peak,

    1. Mutagenesis Group, Division of Biological and Medical Research, Argonne National Laboratory, Argonne, IL 60439.
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  • M. J. Peak,

    Corresponding author
    1. Mutagenesis Group, Division of Biological and Medical Research, Argonne National Laboratory, Argonne, IL 60439.
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  • C. S. Foote

    1. Mutagenesis Group, Division of Biological and Medical Research, Argonne National Laboratory, Argonne, IL 60439.
    2. Department of Chemistry, University of California, Los Angeles, CA 90024, USA
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*To whom correspondence should be addressed.

Abstract

The concentration dependence for the protection of isolated transforming DNA and Escherichia coli by glycerol against 365-nm monochromatic near-ultraviolet light (UV) was measured. Glycerol protection saturates at a concentration of about 0.1 M for DNA and 1.0 M for E. coli. Action spectra for glycerol protection of transforming DNA (tryptophan and histidine markers) are similar to those obtained previously for diazobicyclo[2.2.2.˜octane (DABCO) protection, with protection reaching a maximum near 350-nm UV and decreasing rapidly at wavelengths above and below 350 nm. However, glycerol protects against near-UV about twice as efficiently as DABCO. The action spectrum for protection of E. coli by glycerol against the lethal effects of near-UV was not the same as the spectrum for DNA since glycerol sensitized the cells, but not the DNA, at wavelengths longer than about 380 nm. A possible role of hydroxyl or other radicals was supported by the observation that benzoate also protected DNA against inactivation by 334-nm UV.

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