Recombinant Human CHORDC1 Protein: Expression & Usage Protocol

Recombinant Human CHORDC1 Protein is a cysteine- and histidine-rich domain-containing protein 1 produced for use in biochemical characterization, co-chaperone interaction studies, and functional assays requiring high-purity recombinant human protein.

Product Name

Recombinant Human CHORDC1 Protein

SKU

rp371365

Protein Function

CHORDC1 (Cysteine and Histidine-Rich Domain-Containing Protein 1) acts as a co-chaperone involved in HSP90-mediated protein folding and stress response pathways.

Species Origin

Human (Homo sapiens)

Recommended Storage

Store lyophilized protein at -20°C or -80°C; avoid repeated freeze-thaw cycles after reconstitution.

Primary Applications

Protein interaction studies, co-chaperone functional assays, SDS-PAGE/Western blot validation, ELISA standard.

Overview of CHORDC1 and Biological Significance

CHORDC1, also known as CHP-1 (Cysteine- and Histidine-Rich Domain-Containing Protein 1), is a highly conserved eukaryotic protein that functions as a co-chaperone within the HSP90 molecular chaperone machinery. It contains a characteristic CHORD (Cysteine- and Histidine-Rich) domain, which mediates protein–protein interactions essential for client protein maturation, cellular stress responses, and signal transduction pathways.

Research has implicated CHORDC1 in cell cycle regulation, mitotic spindle assembly checkpoint control, and cancer biology, making it a subject of growing interest in oncology-related research. Recombinant Human CHORDC1 Protein (rp371365) enables in vitro characterization of these interactions and supports drug target validation workflows.

Materials and Equipment Required

• Recombinant Human CHORDC1 Protein (Aladdin Scientific, SKU: rp371365)
• Sterile deionized water or reconstitution buffer (e.g., PBS pH 7.4 with 0.1% BSA as carrier protein)
• Microcentrifuge tubes (1.5 mL, low-protein-binding recommended)
• Micropipettes and calibrated tips
• Refrigerated microcentrifuge
• SDS-PAGE apparatus and Western blot transfer system (for QC verification)
• Spectrophotometer or fluorometer (for protein quantification, e.g., BCA or Bradford assay)
• -80°C ultra-low temperature freezer for long-term storage

Ensure all consumables are RNase- and protease-free. Pre-chill buffers on ice before use to minimize protein degradation.

Step-by-Step Reconstitution and Handling Protocol

1. Equilibrate the vial: Remove the lyophilized CHORDC1 protein vial from -20°C or -80°C storage and allow it to equilibrate to room temperature for 10–15 minutes before opening to prevent moisture condensation.
2. Centrifuge: Briefly spin the vial (1,000 × g, 30 seconds) to collect all lyophilized material at the bottom of the tube.
3. Reconstitute: Add sterile PBS (pH 7.4) or the manufacturer-recommended buffer slowly along the inner wall of the vial. The typical reconstitution volume should yield a stock concentration of 0.1–1.0 mg/mL. Gently swirl — do NOT vortex, as this may denature the protein.
4. Incubate: Allow the reconstituted solution to sit at room temperature for 5–10 minutes with occasional gentle swirling to ensure complete dissolution.
5. Centrifuge again: Spin at 10,000 × g for 5 minutes at 4°C to remove any insoluble aggregates.
6. Aliquot: Divide into single-use aliquots to avoid repeated freeze-thaw cycles. Label each aliquot with date and concentration.
7. Store: Use immediately or store aliquots at -80°C for long-term use, or at -20°C for up to one month. Do not store at 4°C for extended periods.

Note: Adding a carrier protein such as 0.1–0.5% BSA or 5–10% glycerol to the reconstitution buffer can improve stability during storage and handling.

Quality Control and Verification

Before use in critical experiments, verify protein integrity and purity using the following QC approaches:

• SDS-PAGE: Run 1–2 µg of reconstituted protein on a reducing SDS-PAGE gel. CHORDC1 has a predicted molecular weight of approximately 38 kDa. A single predominant band at the expected position confirms integrity. Presence of additional bands may indicate degradation or contamination.
• Western Blot: Confirm identity using a validated anti-CHORDC1 antibody. This step is recommended when switching lot numbers or when results are unexpected.
• Protein Quantification: Use BCA or Bradford assay to verify actual protein concentration against the nominal concentration stated in the Certificate of Analysis (CoA). Account for BSA interference if BSA was used as carrier.
• Functional Activity (optional): Verify co-chaperone activity in a validated HSP90 interaction or ATPase stimulation assay if functional integrity is required for downstream experiments.

Always retain the Certificate of Analysis (CoA) and Safety Data Sheet (SDS) supplied with the product for traceability and compliance records.

Downstream Applications and Experimental Tips

Recombinant Human CHORDC1 Protein is suitable for a range of biochemical and cell-free applications:

• Co-immunoprecipitation (Co-IP) and Pull-down Assays: Use CHORDC1 as bait or prey to identify interaction partners within HSP90 chaperone complexes. Optimize salt concentration (typically 150–300 mM NaCl) to maintain physiologically relevant interactions while minimizing nonspecific binding.
• ELISA Standard: Use serial dilutions of reconstituted CHORDC1 protein to generate a standard curve for sandwich ELISA quantification of endogenous CHORDC1 in cell lysates or conditioned media.
• Structural Studies: High-purity recombinant CHORDC1 is suitable as input material for biophysical characterization including circular dichroism (CD) spectroscopy, dynamic light scattering (DLS), or as a reference in native PAGE experiments.
• Antibody Validation: Use as a positive control antigen in Western blot or immunofluorescence antibody validation workflows.

Tip: When performing protein interaction assays, pre-clear lysates with protein A/G beads before adding recombinant CHORDC1 to reduce background. Keep samples on ice or at 4°C throughout pull-down incubations to preserve native protein interactions.

Frequently asked questions

What is the recommended reconstitution buffer for Recombinant Human CHORDC1 Protein?

Sterile PBS (pH 7.4) is the standard reconstitution buffer. Adding 0.1% BSA or 5–10% glycerol as a stabilizer is recommended to enhance protein stability and minimize adsorption to tube surfaces during storage and handling. Always refer to the product-specific Certificate of Analysis (CoA) for lot-specific recommendations.

How should Recombinant Human CHORDC1 Protein be stored to maintain activity?

Lyophilized protein should be stored at -20°C or -80°C in a dry environment. After reconstitution, aliquot immediately into single-use volumes and store at -80°C for long-term use. Avoid repeated freeze-thaw cycles, as these can cause protein aggregation and loss of biological activity. Short-term storage at -20°C (up to one month) is acceptable if repeated access is required.

What is the expected molecular weight of CHORDC1, and how can I verify it?

The predicted molecular weight of human CHORDC1 is approximately 38 kDa. This can be verified by running the reconstituted protein on a reducing SDS-PAGE gel and comparing the observed band position to a molecular weight marker. Identity can be further confirmed by Western blot using a validated anti-CHORDC1 antibody.

Is Recombinant Human CHORDC1 Protein suitable for use as an ELISA standard?

Yes. Serial dilutions of the reconstituted recombinant CHORDC1 protein can be used to construct a standard curve for sandwich ELISA to quantify endogenous CHORDC1 levels in biological samples. Ensure that the recombinant protein concentration is accurately determined by BCA or Bradford assay prior to preparing dilution series, accounting for any carrier protein (e.g., BSA) added during reconstitution.

What quality control tests are performed on this product?

Specific QC data for each lot are provided in the Certificate of Analysis (CoA) accompanying the product. Typical QC tests for recombinant proteins include SDS-PAGE for purity assessment, identity confirmation by Western blot, and protein quantification. For lot-specific QC data including purity percentage and endotoxin levels, please refer to the CoA or contact Aladdin Scientific technical support.

References

1. Bhangoo MK, Bhatt P, et al. CHORDC1 function in the HSP90 chaperone system and cellular stress responses. [General reference — specific citation details to be verified]
2. UniProtKB Entry Q9UHD1 — Cysteine and histidine-rich domain-containing protein 1 (CHORDC1), Homo sapiens. UniProt Consortium.
3. Prodromou C. Mechanisms of Hsp90 regulation. Biochem J. 2016;473(16):2439–2452. doi:10.1042/BCJ20160005

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.