Chaperone-substrate interactions monitored via a robust TEM-1 β-lactamase fragment complementation assay.

Area of Science:

• Biochemistry
• Molecular Biology
• Microbiology

Background:

• Protein folding is crucial for cellular function.
• Chaperone proteins assist in proper protein folding.
• Weak and unstable interactions are challenging to study.

Purpose of the Study:

• To apply the TEM-1 beta-lactamase protein fragment complementation assay (PCA) for detecting weak protein-protein interactions.
• To investigate chaperone-assisted protein folding in Escherichia coli periplasm.

Main Methods:

• Utilized the TEM-1 beta-lactamase PCA system.
• Analyzed interactions between chaperone and substrate pairs.
• Quantified interaction strength via penicillin resistance levels.
• Performed assays under 0.5% butanol stress conditions.

Main Results:

• Successfully detected interactions for three chaperone-substrate pairs.
• Demonstrated quantitative analysis of interaction strength.
• Showed assay viability under physiologically relevant stress.

Conclusions:

• The TEM-1 beta-lactamase PCA system accurately reports chaperone-substrate interactions.
• This assay can map protein homeostasis networks in fluctuating environments.