Method for Efficient Refolding and Purification of Chemoreceptor Ligand Binding Domain
December 12th, 2017
17.9K views
A procedure is presented for the refolding of the dCACHE periplasmic ligand binding domain of Campylobacter jejuni chemoreceptor Tlp3 from inclusion bodies and the purification to yield milligram quantities of protein.
Overview
This article presents a procedure for refolding the dCACHE periplasmic ligand binding domain of the Campylobacter jejuni chemoreceptor Tlp3 from inclusion bodies. The method allows for the purification of milligram quantities of functional protein for further studies.
Key Study Components
Area of Science
- Biochemistry
- Structural Biology
- Microbiology
Background
- Bacterial chemoreceptors play a crucial role in signal transduction.
- Expression of ligand binding domains in E. coli often leads to inclusion body formation.
- Isolated ligand binding domains can be used for structural and functional studies.
- Recovery of functional proteins from inclusion bodies is essential for research.
Purpose of Study
- To refold and purify the Tlp3 ligand binding domain from inclusion bodies.
- To enable structural studies and ligand screening.
- To provide a reliable method for obtaining functional protein.
Methods Used
- Inoculation of LB broth with transformed BL21-CodonPlus RIPL cells.
- Incubation at 200 RPM and 37 degrees Celsius overnight.
- Refolding of the protein from inclusion bodies.
- Purification of the refolded protein for further analysis.
Main Results
- Successful recovery of milligram quantities of functional Tlp3-LBD.
- Demonstration of the refolding process from inclusion bodies.
- Potential for use in ligand screening and structural studies.
- Establishment of a reliable protocol for protein purification.
Conclusions
- The procedure effectively recovers functional protein from inclusion bodies.
- This method can facilitate further research on bacterial chemoreceptors.
- Future studies can utilize the purified protein for various applications.
Frequently Asked Questions
What is the significance of the Tlp3 ligand binding domain?
The Tlp3 ligand binding domain is important for understanding bacterial signal transduction mechanisms.
How does the refolding process work?
The refolding process involves solubilizing inclusion bodies and allowing the protein to regain its functional conformation.
What applications can the purified protein be used for?
The purified protein can be used for structural studies and screening against small molecule libraries.
Why do proteins form inclusion bodies in E. coli?
Proteins often form inclusion bodies due to misfolding or aggregation during overexpression in E. coli.
What are the benefits of using this purification method?
This method allows for the recovery of functional proteins in a straightforward and efficient manner.
Executive Industry Relevance
Recovering functional ligand binding domains from inclusion bodies enables target validation and structural studies for bacterial chemoreceptors, supporting early discovery of antimicrobial targets. This refolding and purification method provides milligram quantities of pure, folded protein suitable for ligand screening and crystallization, reducing mechanistic uncertainty in target de-risking. The approach enhances portfolio triage by delivering reproducible, soluble protein for downstream biophysical and functional assays.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of therapeutic hypotheses by providing purified ligand binding domains for structural and functional analysis.
- Operational Value: Supports biological de-risking through recovery of milligram amounts of folded protein from inclusion bodies.
- Predictive Value: Facilitates target confidence by yielding soluble, crystallizable protein for ligand specificity studies.
Screening & Assay Development
- Scientific Value: Prepares validated biological systems for screening against small molecule libraries to identify ligand specificity.
- Operational Value: Ensures assay standardization and reproducibility via consistent production of pure, folded protein.
- Scalability: Enables platform reuse for other bacterial chemoreceptor ligand binding domains with similar protocols.
Translational & Preclinical Research
- Translational Continuity: Supports progression from discovery to preclinical validation by providing protein for structural studies that inform ligand-receptor interactions.
- Mechanistic De-risking: Reduces ambiguity in target function through confirmed secondary structure via circular dichroism spectroscopy.
- Predictive Confidence: Enables risk-adjusted advancement decisions by delivering protein suitable for crystallographic and binding studies.
Pipeline & Workflow Integration
The method integrates into the discovery continuum from target identification through lead identification, providing purified protein for structural and functional characterization essential for early-stage antimicrobial target validation.
- Discovery Biology: Supports hypothesis testing and pathway clarification by enabling structural studies of ligand binding domains.
- Screening: Delivers assay readiness through production of pure, soluble protein suitable for ligand screening applications.
- Analytics: Provides quantitative outputs via circular dichroism spectroscopy to confirm folded state and secondary structure content.
- Translational Research: Connects discovery to preclinical work by enabling crystallization and structural determination of ligand-bound states.
- Enterprise Reuse: Establishes a reusable capability for producing milligram amounts of folded ligand binding domains across multiple bacterial chemoreceptor targets.
Operational & Enterprise Impact
- Scientific Value: Predictive confidence in target validation through recovery of functional protein with confirmed secondary structure.
- Operational Value: Standardization, reproducibility, and scalability of refolding and purification workflows.
- Strategic Value: Improved go/no-go decisions via reduced biological risk in early target assessment.
- Portfolio Impact: Risk-adjusted prioritization of targets based on structural and ligand-binding data.
Implementation Considerations
- Requires expertise in protein expression, inclusion body isolation, and refolding optimization.
- Needs instrumentation for high-pressure homogenization, centrifugation, chromatography, and circular dichroism spectroscopy.
- Demands cross-team standardization of buffer compositions and dialysis protocols for consistent results.
- Involves adaptation considerations for different ligand binding domains based on denaturing and refolding buffer optimization.
- Includes practical limitations such as the need for optimization of denaturing and refolding conditions for each new target.
Biopharma FAQs
Why does refolding from inclusion bodies matter for target validation?
Refolding enables recovery of functional ligand binding domains that would otherwise remain insoluble, providing material for structural and functional studies essential to validate targets in antimicrobial discovery.
How does isolation of inclusion bodies support the discovery pipeline?
Isolating inclusion bodies allows recovery of overexpressed protein that can be solubilized and refolded, enabling access to target material for downstream screening and structural analysis.
What quantitative measurements confirm successful refolding of the ligand binding domain?
Circular dichroism spectroscopy measures secondary structure content, providing quantitative data on alpha-helix and beta-sheet composition to confirm the folded state relative to predicted values.
Why are replication requirements important for cross-functional collaboration?
Reproducible refolding and purification across batches ensure consistent protein quality, enabling reliable data sharing between structural biology, screening, and medicinal chemistry teams.
What statistical analysis capabilities are required before implementing this refolding method?
Implementation requires assessment of yield consistency and purity metrics across runs, supported by SDS-PAGE and concentration measurements to ensure process reliability for production planning.
Chapters in this video
0:05
Title
0:46
Expression of His6-TIp3-LBD in E. coli
2:29
Isolation and Denaturation of Inclusion Bodies
5:34
Protein Refolding
7:39
Purification of His6-tagged Protein Using Immobilized Metal Ion Affinity Chromatogrphy
8:49
His6-tag Removal Using TEV Protease and Size-excluson Chromatography of Tlp3-LBD
11:06
Results: Expression, Refolding, and Purification of Tlp3-LBD
12:41
Conclusion
