Overview of Recombinant Human LCOR Protein

LCOR (Ligand-Dependent Nuclear Receptor Corepressor) is a transcriptional corepressor that interacts with nuclear receptors in a ligand-dependent manner. It plays critical roles in modulating gene expression programs involved in differentiation, development, and cellular homeostasis. The Recombinant Human LCOR Protein (SKU: rp369077) is produced for research applications requiring a well-characterized corepressor component, enabling in vitro biochemical and cell-free transcription studies.

This protein is relevant to researchers investigating nuclear receptor signaling pathways, chromatin remodeling, and epigenetic silencing mechanisms. Its availability in recombinant form ensures batch-to-batch consistency essential for reproducible experimental outcomes.

Materials Required

Before beginning, ensure the following materials are available:

• Recombinant Human LCOR Protein (rp369077, Aladdin Scientific)
• Sterile ultrapure water or manufacturer-recommended reconstitution buffer
• Low-protein-binding microcentrifuge tubes (1.5 mL)
• Ice bucket and wet ice
• Micropipettes and sterile tips (10 µL, 200 µL)
• Microcentrifuge
• Appropriate assay buffer compatible with downstream application (e.g., EMSA buffer, pull-down lysis buffer)
• Protein quantification reagents (e.g., BCA or Bradford assay kit)
• SDS-PAGE reagents for quality verification (optional but recommended)

Step-by-Step Protocol: Reconstitution and Handling

Step 1 – Thawing: Remove the vial from -20°C or -80°C storage and allow it to thaw slowly on ice for 10–15 minutes. Do not thaw at room temperature rapidly, as this may compromise protein integrity.

Step 2 – Brief Centrifugation: Briefly centrifuge the vial (1,000–2,000 × g, 30 seconds) to collect any material from the walls and cap before opening.

Step 3 – Reconstitution: If the protein is supplied lyophilized, add the volume of sterile ultrapure water or reconstitution buffer specified in the product datasheet to achieve the recommended working concentration. Gently pipette to mix; do not vortex. Allow the solution to stand for 5 minutes on ice to ensure complete dissolution.

Step 4 – Protein Quantification: Determine the protein concentration using a BCA or Bradford assay with BSA as a standard. Compare with the stated concentration on the Certificate of Analysis.

Step 5 – Quality Check (Optional): Run an aliquot on SDS-PAGE to confirm the expected molecular weight band and assess purity.

Step 6 – Aliquoting: Divide the reconstituted protein into single-use aliquots in low-protein-binding tubes to avoid repeated freeze-thaw cycles, which degrade activity.

Step 7 – Storage: Store aliquots at -80°C for long-term use or at -20°C for use within one month. For immediate use, keep on ice and use within the same working session.

Experimental Applications and Tips

Recombinant Human LCOR Protein is suitable for a range of in vitro applications, including:

• Protein–Protein Interaction Studies: Use in co-immunoprecipitation (Co-IP) or GST pull-down assays to characterize interactions between LCOR and nuclear receptor ligand-binding domains or other corepressor complex components.
• Electrophoretic Mobility Shift Assays (EMSA): Assess LCOR involvement in multi-protein–DNA complexes at target gene promoters.
• In Vitro Transcription Assays: Incorporate LCOR protein into cell-free transcription systems to evaluate its repressive effect on nuclear receptor-driven gene expression.
• Enzyme-Linked Immunosorbent Assay (ELISA) Standards: Use as a positive control or quantification standard in LCOR-specific ELISA formats.

Practical Tips:

• Always keep the protein on ice during experimental setup to maintain stability.
• Use carrier protein (e.g., 0.1% BSA) in dilution buffers if working at very low protein concentrations to prevent adsorption to tube surfaces.
• Consult the product Certificate of Analysis for lot-specific concentration, purity, and endotoxin data before use.

Troubleshooting

The following table summarizes common issues encountered when working with Recombinant Human LCOR Protein and suggested remedies:

• Problem: Protein precipitates upon reconstitution.
  Possible cause: Incorrect buffer or overly rapid reconstitution. Solution: Use the buffer recommended in the datasheet; dissolve slowly on ice with gentle pipetting.
• Problem: Lower-than-expected biological activity.
  Possible cause: Repeated freeze-thaw cycles or prolonged storage at -20°C. Solution: Use freshly thawed single-use aliquots; store long-term at -80°C.
• Problem: Unexpected bands on SDS-PAGE.
  Possible cause: Protein degradation or contamination. Solution: Verify storage conditions; confirm the vial was not previously opened; contact Aladdin Scientific technical support with the lot number.
• Problem: Inconsistent results between experiments.
  Possible cause: Variation in protein concentration due to adsorption to tube surfaces. Solution: Add carrier protein (0.1% BSA) to working dilutions; use low-protein-binding plasticware.