The Measurement of Protein Degradation in Response to Oxidative Stress
Many elegant techniques have been developed to measure free radical/ oxidant production and toxicity. Such studies can now be conducted with model systems; in cell lysates, extracts, and organelles; and (in some cases) in intact cells, organs, or organisms. One way to find out if a radical/oxidant has altered a cell is to isolate damaged cellular constituents. The most popular index of free radical damage thus far has been the measurement of lipid peroxidation. The effects of radicals on lipids are clearly important; however, mounting evidence suggests that DNA, RNA, carbohydrates, and proteins are also suceptible to oxidative damage. This paper will focus on the measurement of protein degradation following oxidative stress. Recent studies in this laboratory1–10 and by other groups11–14 have demonstrated that proteins which have been damaged by radicals or oxidants become excellent substrates for intracellular proteolytic systems and are rapidly degraded.
KeywordsFree Amino Acid Protein Degradation Proteolytic System Amino Acid Pool Radiolabeled Amino Acid
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