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Determination of the proteins induced in mutant forms of Deinococcus radiodurans after exposure to hydrogen peroxide

EMSL Project ID


The extraordinary repair mechansims of D. radiodurans allow the organism to survive even after exposure to extremely large doses of ionizing radiation. Although it is clear that the DNA is fragmented after exposure to radiation, it remains unclear how the organism is able to repair and reform its DNA in such a way for its continued survival. Two proteins that are implicated as playing key roles in the radiation resistance are catalase and superoxide dismutase. The former enzyme has been shown to increase in abundance in cells exposed to hydrogen peroxide and mutations in either enzyme renders the organism sensitive to radiation. By using the database of proteins expressed in Deinococcus that was created during a pilot project designed at defining the proteome of the organism, it will be possible to determine what mechanisms are present in the organism to overcome the mutations in the enzymes. The mutant forms of Deinococcus will be treated with either ionizing radiation or hydrogen peroxide and then mixed with an equal number of cells grown on isotopically labeled media. This creates the possibility of doing differential display experiments with the mass spectrometer to determine which proteins are over expressed or under expressed after treatment. These experiments will yield potential DNA repair targets for further study.

Project Details

Project type
Exploratory Research
Start Date
End Date


Principal Investigator

Kwong Kwok Wong
Pacific Northwest National Laboratory

Team Members

Mary Lipton
Environmental Molecular Sciences Laboratory