Recombinant Human IGF-I R

Recombinant Human IGF-I Receptor (IGF-I R) is used in research applications to study and manipulate the insulin-like growth factor signaling pathway, which is critical for cell growth, differentiation, metabolism, and survival. Its use enables precise investigation of receptor-ligand interactions, downstream signaling, and therapeutic targeting in various biological contexts.

Key scientific applications and advantages include:

• Mechanistic Studies: Recombinant IGF-I R allows researchers to dissect the molecular mechanisms of IGF-I signaling, including receptor activation, phosphorylation events, and cross-talk with other pathways such as insulin signaling.
• Bioassays and Screening: It serves as a standardized reagent in bioassays to quantify IGF-I activity, screen for agonists/antagonists, and evaluate the efficacy of potential therapeutic compounds targeting the IGF-I pathway.
• Structural and Binding Analysis: Recombinant IGF-I R is essential for surface plasmon resonance, ELISA, and other binding assays to characterize ligand-receptor interactions, affinity, and specificity.
• Cancer and Disease Models: IGF-I R is a validated target in oncology and metabolic research. Recombinant receptor proteins are used to model IGF-I R-positive cancers, investigate drug conjugates, and study receptor-mediated effects in vitro and in vivo.
• Cell Line Engineering: Expression of recombinant IGF-I R can be used to engineer cell lines with altered IGF-I responsiveness, facilitating studies on cell proliferation, differentiation, and recombinant protein production.

Best practices for using recombinant IGF-I R in research:

• Select carrier-free or BSA-containing formulations based on your application (e.g., cell culture, ELISA standard).
• Validate receptor activity and specificity in your assay system.
• Use appropriate controls to distinguish IGF-I R-mediated effects from off-target or background signaling.

Summary: Recombinant Human IGF-I R is a versatile tool for investigating IGF-I signaling, developing targeted therapies, and optimizing cell-based assays. Its use is fundamental in studies of growth, metabolism, cancer biology, and protein engineering.

Yes, Recombinant Human IGF-I R (IGF1R) can be used as a standard for quantification or calibration in ELISA assays, but with important considerations.

Key Points:

• Purpose of Standards: In ELISA, a standard curve is generated using known concentrations of the target protein (in this case, IGF-I R/IGF1R) to allow quantification of unknown samples. Recombinant proteins are commonly used for this purpose because they provide a consistent and defined reference.

• Evidence from Literature and Product Datasheets:

  • Multiple ELISA kits and protocols (e.g., R&D Systems, RayBiotech, Sigma-Aldrich) explicitly list recombinant human IGF-I R as the standard for their IGF-I R ELISAs.
  • For example, the R&D Systems Recombinant Human IGF-I R/IGF1R Protein (Catalog # 391-GR) is described as being suitable for use in functional ELISA and as a standard.
  • The RayBiotech Human IGF-1 R ELISA Kit and Sigma IGF-I R ELISA Kit also utilize recombinant IGF-I R as the calibrator.

• Best Practices:

  • Ensure the recombinant protein is highly purified and properly characterized (e.g., correct molecular weight, activity, and lack of contaminants).
  • Use the carrier-free version if BSA or other carrier proteins might interfere with your assay.
  • Prepare the standard curve in a matrix that closely matches your samples (e.g., buffer, serum, or plasma) to minimize matrix effects.
  • Always validate the standard curve for linearity, precision, and accuracy in your specific assay conditions.

• Limitations:

  • Recombinant standards may not perfectly mimic the post-translational modifications or conformation of native proteins in biological samples, which could affect antibody binding and quantification.
  • For absolute quantification, reference standards (e.g., WHO reference materials) are preferred when available.

Conclusion:

You can use Recombinant Human IGF-I R as a standard for ELISA quantification, provided it is suitable for your specific assay format and detection antibodies. Always confirm compatibility with your ELISA kit or protocol and validate the standard curve for accuracy and reproducibility.

Recombinant Human IGF-I Receptor (IGF-I R) has been validated for several key applications in published research, including surface plasmon resonance (SPR), bioassays, ELISA, immunohistochemistry (IHC), and in vivo studies.

Validated Applications:

• Surface Plasmon Resonance (SPR):

  • Used to characterize ligand-receptor interactions, antibody binding, and epitope mapping for IGF-I R.
  • Examples include studies on blood-brain barrier shuttles, single-domain antibody targeting, and integrin binding to IGF1R.

• Bioassays:

  • Employed to assess IGF-I R-mediated signaling, receptor activation, and functional potency of ligands or antibodies.
  • Includes cell proliferation assays and aptamer-based activation studies.

• ELISA (Enzyme-Linked Immunosorbent Assay):

  • Used for quantifying IGF-I R expression and ligand binding in cell and tissue samples.
  • Applied in studies of receptor expression during cell differentiation and in preclinical cancer models.

• Immunohistochemistry (IHC):

  • Validated for detection of IGF-I R in tissue sections to study localization and expression patterns.

• In Vivo Studies:

  • Recombinant IGF-I R has been used in animal models to evaluate therapeutic efficacy, receptor targeting, and pharmacodynamics, particularly in cancer and regenerative medicine research.

Additional Functional Assays:

• Recombinant IGF-I R is also validated for use in apoptosis assays and other functional assays to study cell survival, metabolic regulation, and receptor-mediated signaling.

Research Areas:

• Cancer Biomarkers: IGF-I R is widely studied as a target in cancer biology, especially for antibody-drug conjugates and receptor-targeted therapies.
• Endocrine Regulation & Metabolic Studies: IGF-I R is central to research on glucose homeostasis, lipid metabolism, and endocrine signaling.
• Regenerative Medicine: Recombinant IGF-I R and its ligands are validated in tissue repair and regeneration models, including muscle injury and spinal disc herniation.

Summary Table of Validated Applications

Key Insights:

• SPR and bioassays are the most frequently validated applications for recombinant IGF-I R in mechanistic and therapeutic studies.
• ELISA and IHC are standard for quantifying and localizing IGF-I R in biological samples.
• In vivo validation supports translational research in oncology and regenerative medicine.

These applications are supported by peer-reviewed publications and are widely adopted in both basic and translational research settings.

Reconstitution Protocol

Initial Preparation

Before opening the vial, centrifuge it for 20-30 seconds in a microcentrifuge to consolidate any protein powder that may be adhered to the cap, sides, or bottom of the vial. Allow the lyophilized powder to warm to room temperature before opening to minimize condensation and potential protein degradation.

Reconstitution Procedure

Reconstitute the IGF-I R protein at a concentration of 100 μg/mL in sterile PBS. Gently pipette the reconstitution buffer down the sides of the vial rather than directly onto the powder. Allow the vial to reconstitute for 15-30 minutes at room temperature with gentle agitation. Avoid vigorous shaking or vortexing, as this can cause foaming and protein denaturation.

Storage and Stability

Short-term Storage

After reconstitution, store the protein at 2-8°C for up to 1 month under sterile conditions. Reconstituted protein solutions can typically be stored at 4-8°C for 2-7 days.

Long-term Storage

For extended storage, maintain the reconstituted protein at -20 to -70°C in a manual defrost freezer. The lyophilized product remains stable at -20°C for 12 months from the date of receipt when stored desiccated.

Critical Handling Considerations

Avoid repeated freeze-thaw cycles, as freezing significantly affects the pH of the protein solution and can cause protein denaturation. Use a manual defrost freezer rather than automatic defrost models to minimize unintended thawing cycles.

Verification and Quality Control

After reconstitution, confirm the presence of the protein product by running a small amount on SDS-PAGE. A protein band at the expected molecular weight should be visible with as little as 10 ng of protein loaded on an acrylamide gel.