Escherichia coli small heat shock proteins IbpA/B enhance activity of enzymes sequestered in inclusion bodies.
Escherichia coli small heat shock proteins, IbpA/B, function as molecular chaperones and protect misfolded proteins against irreversible aggregation. IbpA/B are induced during overproduction of recombinant proteins and bind to inclusion bodies in E. coli cells. We investigated the effect of DeltaibpA/B mutation on formation of inclusion bodies and biological activity of enzymes sequestered in the aggregates in E. coli cells. Using three different recombinant proteins: Cro-beta-galactosidase, beta-lactamase and rat rHtrA1 we demonstrated that deletion of the ibpA/B operon did not affect the level of produced inclusion bodies. However, in aggregates containing IbpA/B a higher enzymatic activity was detected than in the IbpA/B-deficient inclusion bodies. These results confirm that IbpA/B protect misfolded proteins from inactivation in vivo.
Kuczyńska-Wiśnik
Dorota
D
Department of Biochemistry, University of Gdańsk, Gdańsk, Poland.
Zurawa-Janicka
Dorota
D
Narkiewicz
Joanna
J
Kwiatkowska
Joanna
J
Lipińska
Barbara
B
Laskowska
Ewa
E
D000818:Animals; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000502:physiology*; D002479:Inclusion Bodies / Q000201:enzymology* / Q000378:metabolism; D009154:Mutation; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; C097578:IbpA protein, E coli; C097579:IbpB protein, E coli; D011994:Recombinant Proteins