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Detergent shock proteins in Escherichia coli as examined by two-dimensional gel electrophoresis
Abstract
At least 22 proteins in Escherichia coliW3110 were found to increase a minimum of 2-fold after cells were shocked with 0.5% sodium dodecyl sulfate (SDS). Among these 22 proteins, 5 were not observed during normal growth, they were only synthesized during SDS stress thus making them unique. These 22 proteins were also found to follow a time-dependent pattern in their synthesis, with various proteins being synthesized at their peak levels within 10 minutes of SDS shock. Other proteins did not appear in elevated quantities until 1 hour after SDS shock. The SDS shock proteins did not show significant overlap with any of the established shock stimulons, however the DnaK chaperonin protein and the Universal Shock Protein have been tentatively identified as being SDS shock proteins. The SDS resistant phenotype could be at least partially eliminated by transposon mutagenesis to create a mutant strain of Escherichia coli which grew poorly after SDS shock. This mutant strain also failed to show a wild-type pattern of protein synthesis after SDS shock. Only 3 of the 22 SDS shock proteins showed significant increases in synthesis after SDS shock, all of the others increased very little or not at all. The synthesis of proteins, including the SDS shock proteins, was not found to be required for survival of E. coli after SDS shock. Cultures treated with chloramphenicol, which halted protein synthesis, showed no decrease in viability after 4 hours of SDS shock. This result may indicate that SDS resistance is a constitutive property of enteric bacteria and that the SDS shock proteins may serve to facilitate growth in an SDS containing environment, but are not essential for short term survival when cells are exposed to detergents.
Subject Area
Microbiology
Recommended Citation
Adamowicz, Michael Stephen, "Detergent shock proteins in Escherichia coli as examined by two-dimensional gel electrophoresis" (1993). ETD collection for University of Nebraska-Lincoln. AAI9406073.
https://digitalcommons.unl.edu/dissertations/AAI9406073