What Is IGFBP5 and Why Is It Important?

Insulin-like Growth Factor Binding Protein 5 (IGFBP5) is a member of the conserved IGFBP family, which comprises six structurally related proteins (IGFBP1–6). IGFBP5 is the most conserved member across species and is the predominant IGFBP found in bone. It binds both IGF-1 and IGF-2 with high affinity, thereby regulating the distribution, half-life, and receptor-binding activity of these growth factors in circulation and in tissues.

Beyond its classical role as an IGF carrier, IGFBP5 has IGF-independent functions. It can translocate to the nucleus and act as a transcriptional modulator, and it interacts with extracellular matrix (ECM) components such as heparan sulfate proteoglycans and vitronectin. These properties make IGFBP5 a multifunctional protein involved in cell survival, proliferation, differentiation, migration, and apoptosis. Dysregulation of IGFBP5 expression has been associated with various pathological conditions including breast cancer, prostate cancer, fibrosis, and osteoporosis.

Product Overview: Recombinant Human IGFBP5 Protein (rp147287)

Aladdin Scientific offers Recombinant Human IGFBP5 Protein under catalog number rp147287. This recombinant protein is intended for use in research applications requiring a reliable, well-characterized source of human IGFBP5. It is suitable for a range of in vitro and cell-based assays where modulation of IGF bioavailability or direct study of IGFBP5 biology is required.

Researchers should consult the official product datasheet for confirmed details on expression host, tag information, molecular weight, purity specifications, endotoxin levels, and recommended reconstitution buffers, as these parameters are critical for experimental design and reproducibility. The product description notes an Abcam reference (56675) as the source context; researchers familiar with that reference may find it a useful starting point for experimental protocols.

Handling, Reconstitution, and Storage Best Practices

Proper handling of recombinant proteins is essential to preserve biological activity and ensure reproducible experimental results. The following general guidelines apply to recombinant proteins such as IGFBP5; always verify with the product-specific datasheet before use:

• Reconstitution: Lyophilized proteins should be reconstituted in sterile, ultrapure water or the buffer specified in the datasheet. Allow the vial to equilibrate to room temperature before opening and reconstitute gently to avoid foaming.
• Storage: Upon receipt, store the protein at -20°C or -80°C as directed. Aliquot the reconstituted protein to minimize freeze-thaw cycles, which can degrade activity and lead to aggregation.
• Working concentrations: Titrate the protein in your assay system to determine the optimal working concentration, as effective doses can vary by cell type and assay format.
• Carrier proteins: Addition of a carrier protein such as BSA (0.1–0.2%) to the reconstitution or dilution buffer can help stabilize the protein during storage and handling.

Common Research Applications of IGFBP5

Recombinant Human IGFBP5 Protein is employed across a broad spectrum of research contexts. Key application areas include:

• IGF signaling studies: As a high-affinity IGF-1 and IGF-2 binder, recombinant IGFBP5 is used to modulate IGF bioavailability in cell culture systems, enabling researchers to dissect IGF-dependent versus IGF-independent cellular responses.
• Bone biology and osteoblast research: IGFBP5 is highly expressed in bone and plays a role in osteoblast differentiation and bone formation. Recombinant IGFBP5 is used in osteogenic differentiation assays and studies of bone remodeling.
• Cancer biology: Altered IGFBP5 expression has been documented in breast, prostate, and other cancers. Researchers use recombinant IGFBP5 to investigate its roles in tumor cell proliferation, migration, invasion, and chemoresistance.
• Apoptosis and cell survival assays: IGFBP5 can promote or inhibit apoptosis depending on cellular context. Recombinant protein is added to culture systems to assess its effects on cell viability and programmed cell death.
• Fibrosis research: IGFBP5 has been implicated in fibrotic processes; recombinant protein is used in fibroblast activation and ECM remodeling studies.

Quality, Purity, and Regulatory Considerations

For research applications, the quality attributes of a recombinant protein directly impact data reliability. When evaluating Recombinant Human IGFBP5 Protein (rp147287), researchers should confirm the following specifications from the official product datasheet:

• Purity: High-purity preparations (typically ≥90–95% by SDS-PAGE) are recommended for functional assays to minimize the risk of confounding effects from contaminants.
• Endotoxin levels: Low endotoxin content is critical for cell-based assays, as lipopolysaccharide (LPS) contamination can activate innate immune pathways and confound results.
• Biological activity: Confirm that the lot has been tested for biological activity, ideally in a validated functional assay relevant to your research area.
• Research use only: This product is intended for research use only (RUO) and is not approved for diagnostic or therapeutic use in humans or animals.

If you have questions about product specifications or suitability for your specific application, contact Aladdin Scientific technical support for guidance.