Temporary exposure to hydrogen peroxide increases intracellular protein degradation in E. coli

A brief exposure of Escherichia coli cells to hydrogen peroxide doubled the rate of intracellular protein degradation. The enhanced protein degradation was energy-dependent. The treatment with hydrogen peroxide caused a transient decrease in the cellular ATP level, but it seems unlikely that the increased rate of proteolysis was caused by starvation or by energy depletion. The findings suggest that a protective mechanism which prevents accumulation of damaged proteins in E. coli cells plays a role in cellular response to oxidative stress.