Recombinant Human Osteopontin/OPN-a His-tag Protein, CF

Recombinant Human Osteopontin/OPN-a His-tag Protein (Catalog # 11437-OP) supports the adhesion of HEK293 human embryonic kidney cells. The ED50 for this effect is 0.100‑1.20 µg/mL.

2 μg/lane of Recombinant Human Osteopontin/OPN-a His-tag Protein (Catalog # 11437-OP) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 60‑66 kDa, under reducing conditions.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human Osteopontin/OPN-a His-tag Protein, CF Summary

• Details of Functionality: Measured by the ability of the immobilized protein to support the adhesion of HEK293 human embryonic kidney cells. The ED₅₀ for this effect is 0.100-1.20 µg/mL.
• Source: Human embryonic kidney cell, HEK293-derived human Osteopontin/OPN protein
  Ile17-Asn314 with a C-terminal 6-His tag
• Accession #: P10451.1
• N-terminal Sequence: Ile17
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 35 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 60-66 kDa, under reducing conditions.

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 500 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human Osteopontin/OPN-a His-tag Protein, CF

• BNSP
• Bone sialoprotein 1
• Eta-1
• MGC110940
• Nephropontin
• OPN
• Osteopontin
• secreted phosphoprotein 1bone sialoprotein I, early T-lymphocyteactivation 1)
• secreted phosphoprotein-1 (osteopontin, bone sialoprotein)
• Spp1
• SPP-1
• SPP1/CALPHA1 fusion
• Urinary stone protein
• uropontin

Background

Osteopontin (OPN), previously called SPP1 (secreted phosphoprotein 1), Eta-1 (early T lymphocyte activation 1) or BSP (bone sialoprotein), is a secreted molecule in the SIBLING (small integrin-binding ligand N-linked glycoprotein) family of non-collagenous matricellular proteins (1-3). Human OPN is synthesized as a 317 amino acid (aa) precursor protein with a 16 aa signal peptide and a 301 aa mature protein (3). At the transcript level, at least five isoforms are generated: OPNa (full‐length), OPNb (lacking exon 5), OPNc (lacking exon 4), OPN4 (lacking exons 4 and 5), and OPN5 (alternative N‐terminus upstream of exon 4). Besides these variants, four additional isoforms have been described for OPN5 (OPN5b, OPN5c, OPN5d, and OPN5e) (4). Mature human OPN shares 64% and 62% aa sequence identity with mouse and rat OPN, respectively. OPN is highly acidic and has 26 potential Ser/Thr phosphorylation sites and a C-terminal CD44 binding site (1-5). Depending on tissue-specific modification by O- and N-glycosylation, sulfation, phosphorylation and transglutamination, OPN can be detected at 45-75 kDa (6, 7). The central region of OPN contains RGD and non-RGD binding sites for multiple integrins (3, 5). OPN receptors include alpha v ( beta 1, beta 3, or beta 5) and ( alpha 4, alpha 5, alpha 8, or alpha 9) beta 1‐integrins, receptor CD44, and epidermal growth factor receptor (12). Adjacent to the RGD motif is the sequence SVVYGLR (SLAYGLR in mouse) which serves as a cryptic binding site for additional integrins: it is masked in full length OPN but is exposed following OPN cleavage by thrombin in tumors and sites of tissue injury (8-10). OPN can also be cleaved by MMP-3, -7, -9, and -12 within the SVVYGLR motif and at sites closer to the C-terminus (9, 10). OPN is widely expressed and is prominent in mineralized tissues. It inhibits bone mineralization and kidney stone formation and promotes inflammation, cell adhesion and migration (1, 2, 5, 7). Its expression is upregulated during inflammation, obesity, atherosclerosis, cancer, and tissue damage, and contributes to the pathophysiology of these conditions (1, 2, 7, 10, 11). Osteopontin occurs in many healthy tissues and secretions as well, but the highest concentrations are found in milk. Its concentration in bovine milk is 0.018–0.022 g/L and ~0.138 g/L in human milk (13).

1. Scatena, M. et al. (2007) Arterioscler. Thromb. Vasc. Biol. 27:2302.
2. Rangaswami, H. et al. (2006) Trends Cell Biol. 16:79.
3. Young, M.F. et al. (1990) Genomics 7:491.
4. Briones-Orta, M.A. et al. (2017) Biochim Biophys Acta Rev Cancer. 1868(1):93-108.A.
5. Weber, G.F. et al. (2002) J. Leukoc. Biol. 72:752.
6. Keykhosravani, M. et al. (2005) Biochemistry 44:6990.
7. Kazanecki, C.C. et al. (2007) J. Cell. Biochem. 102:912.
8. Senger, D.R. et al. (1994) Mol. Biol. Cell 5:565.
9. Yokosaki, Y. et al. (2005) Matrix Biol. 24:418.
10. Takafuji, V. et al. (2007) Oncogene 26:6361.
11. Kiefer, F.W. et al. (2010) Diabetes 59:935.
12. Koroknai, V. et al. (2024) Clin Transl Sci. 17(1): e13694.
13. Hall, B.K. (2015) Bones and Cartilage (Second Edition).

Bioinformatics

• Uniprot:
  • P10451.1()