Recombinant Human Growth Hormone Receptor

Recombinant Human Growth Hormone Receptor (rhGHR) is a critical tool for research applications involving growth hormone (GH) signaling, receptor-ligand interactions, and downstream biological effects. It enables precise, reproducible studies of GH binding, receptor activation, and pathway modulation in both basic and translational research contexts.

Key scientific applications and advantages include:

• Mechanistic Studies of GH Signaling: rhGHR allows researchers to dissect the molecular mechanisms of GH-induced receptor dimerization and activation of the JAK/STAT signaling cascade, which is central to growth, metabolism, and cell proliferation. Using recombinant receptor ensures consistency and eliminates variability inherent in endogenous receptor expression.

• Bioassays and ELISA Standards: Recombinant rhGHR is commonly used as a capture reagent in ELISA assays to quantify GH or its binding proteins, and in bioassays to measure GH activity or antagonism. This is essential for pharmacological studies, drug screening, and quality control.

• Receptor-Ligand Interaction Analysis: Recombinant rhGHR enables detailed studies of GH binding kinetics, affinity, and specificity, facilitating the development of agonists, antagonists, and therapeutic antibodies targeting the GH-GHR axis.

• Modeling Soluble GH-Binding Proteins (GHBP): The extracellular domain of rhGHR can be used to generate soluble GHBP, which modulates GH signaling by competing with membrane-bound receptors or by altering GH clearance rates. This is valuable for investigating physiological and pathological regulation of GH action.

• Structural and Biophysical Research: Recombinant rhGHR is essential for structural studies (e.g., cryo-EM, X-ray crystallography) to elucidate receptor conformation, ligand-induced changes, and receptor complex formation.

• Cellular and Tissue Culture: Using rhGHR in cell-based assays allows for controlled studies of GH responsiveness, receptor activation, and downstream gene expression, supporting research in endocrinology, metabolism, and growth disorders.

Best practices for using recombinant rhGHR include:

• Selecting the appropriate format: Carrier-free preparations are preferred for bioassays and ELISA, while BSA-containing formulations may be suitable for cell culture applications.
• Validating biological activity: Confirm receptor functionality by assessing its ability to bind GH and modulate cell proliferation or signaling in relevant assays.
• Optimizing experimental conditions: Adjust concentration, incubation time, and detection methods based on the specific application and desired sensitivity.

In summary, recombinant human growth hormone receptor is indispensable for rigorous, reproducible research on GH biology, receptor pharmacology, and therapeutic development, providing a standardized platform for mechanistic, analytical, and translational studies.

Yes, recombinant Human Growth Hormone Receptor (GHR) can be used as a standard for quantification or calibration in ELISA assays designed to measure GHR, provided it matches the form and purity required by your assay protocol.

Essential context and supporting details:

• ELISA Calibration Standards: ELISA kits for GHR quantification typically use recombinant human GHR as the standard to generate a calibration curve, allowing accurate quantification of GHR in biological samples. The standard should be of high purity and well-characterized to ensure traceability and reproducibility.

• Form and Isoform Considerations: Recombinant GHR used as a standard should correspond to the isoform detected by your assay (e.g., full-length extracellular domain, Fc chimera, etc.). Mismatched isoforms or domains may affect assay accuracy due to differences in antibody recognition.

• Preparation and Handling: For use as an ELISA standard, recombinant GHR is often supplied with or without carrier proteins (e.g., BSA). Carrier-free formulations are preferred if BSA or other additives could interfere with your assay. Proper dilution and storage conditions must be followed to maintain protein stability.

• Validation: It is critical to validate that your recombinant GHR standard produces a linear, reproducible standard curve within the assay’s detection range and matches the expected recovery and precision metrics. Most commercial ELISA kits provide detailed protocols for standard preparation and curve generation.

• Application Scope: Recombinant GHR standards are suitable for quantifying GHR in serum, plasma, cell culture supernatants, and other biological fluids, as specified by the assay.

Additional relevant information:

• Not for Growth Hormone (GH) Quantification: Recombinant GHR is not suitable as a standard for assays measuring growth hormone (GH) itself; GH quantification requires recombinant GH standards.

• Best Practices: Always ensure the recombinant standard is compatible with the antibodies and detection system used in your ELISA. Follow manufacturer or protocol guidelines for standard curve preparation, and include appropriate controls to confirm assay specificity and accuracy.

In summary, recombinant human GHR is appropriate as a standard for ELISA quantification of GHR, provided it matches the assay requirements and is properly validated for your specific application.

Recombinant Human Growth Hormone Receptor (rhGHR) has been validated in published research for several key applications, primarily in biochemical and cell-based assays.

The most commonly validated applications include:

• ELISA (Enzyme-Linked Immunosorbent Assay) Capture: Recombinant human GHR is frequently used as a capture reagent in ELISA to detect growth hormone or to study hormone-receptor interactions.
• Bioassays: rhGHR has been used in functional bioassays, such as measuring its ability to inhibit growth hormone-induced proliferation of Nb2-11 rat lymphoma cells, which is a standard assay for assessing GH receptor activity.
• Binding Studies: The recombinant receptor is used to study ligand (GH) binding kinetics, receptor dimerization, and downstream signaling events, such as activation of the JAK/STAT pathway.
• Protein-Protein Interaction Studies: Recombinant GHR is utilized to investigate interactions with growth hormone binding protein (GHBP) and to assess how these interactions modulate GH signaling.
• Structural and Biophysical Analyses: Recombinant forms of the receptor, especially extracellular domains, are used in crystallography, NMR, and other structural studies to elucidate the molecular basis of GH-GHR interaction.

Supporting details:

• The ability of recombinant GHR to inhibit GH-induced cell proliferation is a well-established functional validation, as cited in multiple studies.
• Recombinant GHR is often expressed as a soluble extracellular domain or Fc chimera to facilitate purification and use in in vitro assays.
• These applications are foundational for drug screening, mechanistic studies of GH signaling, and the development of GH receptor agonists or antagonists.

Additional relevant information:

• Recombinant GHR is not typically used for direct therapeutic purposes but is essential for research into GH signaling, receptor pharmacology, and the development of diagnostic assays.
• The use of recombinant GHR in ELISA and bioassays is supported by commercial validation and peer-reviewed publications, ensuring reproducibility and reliability in these applications.

If you require protocols or more technical details for a specific application (e.g., ELISA setup, cell-based assay design), please specify.

Reconstitution Protocol

Reconstitution of recombinant human Growth Hormone Receptor (GHR) protein requires careful attention to buffer composition and handling procedures. The standard reconstitution concentration is 100 µg/mL in sterile PBS. For alternative protocols, some applications may use 10 mM sodium phosphate buffer (pH 8.0) or sterile deionized water at concentrations ranging from 0.1 to 1.0 mg/mL, depending on your specific experimental requirements.

Key reconstitution steps:

1. Pre-reconstitution preparation: Centrifuge the vial at 5,000 × g for 5 minutes prior to opening to consolidate the lyophilized material

2. Buffer addition: Add the appropriate volume of sterile PBS or recommended buffer to achieve your target concentration. For example, to achieve 100 µg/mL, add sterile PBS in a volume that corresponds to 10 times the protein mass in micrograms

3. Solubilization: Allow the protein to solubilize for 30 to 60 minutes at room temperature with occasional gentle mixing. This is critical—avoid vigorous shaking or vortexing, as these can denature the protein and reduce activity

Formulation Considerations

The choice between carrier-containing and carrier-free formulations significantly impacts your experimental design. Carrier-containing formulations include bovine serum albumin (BSA) as a stabilizing agent, which enhances protein stability, extends shelf-life, and permits storage at more dilute concentrations. For cell or tissue culture applications and ELISA standards, the carrier-containing version is generally recommended.

Carrier-free formulations lack BSA and are specifically designed for applications where the presence of carrier protein would interfere with your assay or experimental results. If using a carrier-containing formulation, reconstitute at 100 µg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin.

Storage and Stability

After reconstitution, proper storage is essential for maintaining protein activity. Store reconstituted protein at 4°C for short-term use (2-7 days) and at -18°C or below for long-term storage. Use a manual defrost freezer and avoid repeated freeze-thaw cycles, as these significantly compromise protein integrity and biological activity.

For unopened lyophilized vials, maintain desiccated storage at -20°C to -70°C, where the protein remains stable for six to twelve months.

Pre-Use Recommendations

Before using the reconstituted protein in your cell culture experiments, always consult the Certificate of Analysis (CoA) provided with your specific product lot, as reconstitution protocols may include lot-specific modifications or additional recommendations. Brief centrifugation of the reconstituted solution can help remove any particulates before application to cell cultures.