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DsbG, a protein disulfide isomerase with chaperone activity
1Department of Biology, Program in Biomedical Sciences, University of Michigan, Ann Arbor, Michigan 48109-1048, USA.
The Journal of Biological Chemistry
|May 2, 2000
Summary
Escherichia coli DsbG, a protein disulfide isomerase, acts as a molecular chaperone. It prevents thermal aggregation of proteins like citrate synthase and luciferase, enhancing its isomerase function.
Area of Science:
- Biochemistry
- Molecular Biology
- Protein Folding
Background:
- DsbG is a protein disulfide isomerase located in the periplasm of Escherichia coli.
- Molecular chaperones assist protein folding and prevent aggregation.
- The general chaperone activity of periplasmic proteins is not well-established.
Purpose of the Study:
- To investigate the molecular chaperone activity of DsbG.
- To determine if DsbG can prevent protein aggregation.
- To understand the interaction of DsbG with protein folding intermediates.
Main Methods:
- Assessing the ability of DsbG to prevent thermal aggregation of citrate synthase and luciferase.
- Studying the interaction of DsbG with chemically denatured citrate synthase.
- Analyzing citrate synthase reactivation in the presence of DsbG.
Main Results:
- DsbG effectively prevented the thermal aggregation of citrate synthase and luciferase.
- DsbG interacted with refolding intermediates of denatured citrate synthase, inhibiting aggregation in vitro.
- DsbG demonstrated high-affinity binding to early, unstructured protein folding intermediates.
Conclusions:
- DsbG exhibits significant molecular chaperone activity.
- This chaperone function likely enhances DsbG's role as a protein disulfide isomerase.
- DsbG is among the first identified periplasmic proteins with general chaperone capabilities.
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