NEAR-UV-INDUCED BREAKS IN PHAGE DNA: SENSITIZATION BY HYDROGEN PEROXIDE (A TRYPTOPHAN PHOTOPRODUCT) |
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| Authors: | H N Ananthaswamy A Eisenstark |
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| Institution: | Division of Biological Sciences, University of Missouri, Columbia, MO 65201, U.S.A. |
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| Abstract: | Abstract— Near-UV irradiation of l -tryptophan yields a large number of photoproducts. When this mixture is added to recombinationless ( rec ) mutants of bacteria, the cells are killed. The most toxic component of tryptophan photoproducts has been identified as hydrogen peroxide (H2O2). We now report that both tryptophan photoproducts and H2O2 sensitize phage DNA to near-UV radiation resulting in enhanced killing as well as enhanced DNA breakages. We conclude that the in situ production of H2O2 via tryptophan photolysis may be an important biological event. |
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