Recombinant Human Thrombopoietin His (HEK-293) Protein, CF

Recombinant Human Thrombopoietin (Catalog # 288-TPH) has a molecular weight (MW) of 23.3 kDa as analyzed by SEC-MALS, suggesting that this protein is a monomer. MW may differ from predicted MW due to post-translational modifications (PTMs) present (i.e. Glycosylation).

Recombinant Human Thrombopoietin/Tpo His-tag Protein (HEK-293-expressed) (Catalog # 288-TPH) stimulates proliferation in the MO7e human megakaryocytic leukemic cell line. The ED50 for this effect is 0.0500‑0.500 ng/mL.

2 μg/lane of Recombinant Human Thrombopoietin/Tpo His-tag (HEK-293-expressed) Protein (Catalog # 288-TPH) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 26-30 kDa.

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

Recombinant Human Thrombopoietin His (HEK-293) Protein, CF Summary

• Additional Information: Analyzed by SEC-MALS. His-tag (HEK-293-expressed)
• Details of Functionality: Measured in a cell proliferation assay using MO7e human megakaryocytic leukemic cells. Avanzi, G. et al. (1988) Br. J. Haematol. 69:359. The ED₅₀ for this effect is 0.0500-0.500 ng/mL.
• Source: Human embryonic kidney cell, HEK293-derived human Thrombopoietin/Tpo protein
  Ser22-Leu195, with a C-terminal 6-His tag
• Accession #: P40225.1
• N-terminal Sequence: Ser22
• 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: 19 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: 26-30 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 the 10 μg size at 100 μg/mL in PBS. Reconstitute all other sizes 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 Thrombopoietin His (HEK-293) Protein, CF

• Megakaryocyte colony-stimulating factor
• Megakaryocyte growth and development factor
• megakaryocyte stimulating factor
• MGDF
• MGDFC-mpl ligand
• MKCSF
• MK-CSF
• ML
• MPL ligand
• MPLLG
• MPLLGMGC163194
• Myeloproliferative leukemia virus oncogene ligand
• THCYT1
• THPO
• thrombopoietin nirs variant 1
• Thrombopoietin
• Tpo
• TPOMKCSF

Background

Thrombopoietin (Tpo), is a key regulator of megakaryocytopoiesis and thrombopoiesis. It is principally produced in the liver and is bound and internalized by the receptor Tpo R/c-mpl. Defects in the Tpo-Tpo R signaling pathway are associated with a variety of platelet disorders (1-3). The 353 amino acid (aa) human Tpo precursor is cleaved to yield the 332 aa mature protein. Mature human Tpo shares approximately 70% aa sequence homology with mouse and rat Tpo. It is an 80‑85 kDa protein that consists of an N‑terminal domain with homology to Erythropoietin (Epo) and a C‑terminal domain that contains multiple N‑linked and O-linked glycosylation sites (4, 5). Tissue specific alternate splicing of human Tpo generates multiple isoforms with internal deletions, insertions, and/or C‑terminal substitutions (6). Tpo promotes the differentiation, proliferation, and maturation of MK and their progenitors (4, 5, 7). Several other cytokines can promote these functions as well but only in cooperation with Tpo (8, 9). Notably, IL-3 independently induces MK development, although its effects are restricted to early in the MK lineage (8, 9). Tpo additionally promotes platelet production, aggregation, ECM adhesion, and activation (10-13). It is cleaved by platelet-derived thrombin following Arg191 within the C‑terminal domain and subsequently at other sites upon extended digestion (14). Both full length Tpo and shorter forms circulate in the plasma, with the shorter, N‑terminal EPO-like domain forms showing significantly increased specific activity (4, 5, 15). The C‑terminal domain is not required for binding to Tpo R or inducing MK growth and differentiation (5). Aside from its hematopoietic effects, Tpo is expressed in the brain where it promotes the apoptosis of hypoxia-sensitized neurons and inhibits neuronal differentiation by blocking NGF induced signaling (16, 17).

1. Deutsch, V.R. and A. Tomer (2006) Br. J. Haematol. 134:453.
2. Kaushansky, K. (2005) J. Clin. Invest. 115:3339.
3. Li, J. et al. (1999) Br. J. Haematol. 106:345.
4. Bartley, T.D. et al. (1994) Cell 77:1117.
5. de Sauvage, F.J. et al. (1994) Nature 369:533.
6. Marcucci, R. and M. Romano (2008) Biochim. Biophys. Acta 1782:427.
7. Kaushansky, K. et al. (1994) Nature 369:568.
8. Kaushansky, K. et al. (1995) Proc. Natl. Acad. Sci. 92:3234.
9. Broudy, V.C. et al. (1995) Blood 85:1719.
10. Lok, S.I. et al. (1994) Nature 369:565.
11. Chen, J. et al. (1995) Blood 86:4054.
12. Oda, A. et al. (1996) Blood 87:4664.
13. Van Os, E. et al. (2003) Br. J. Haematol. 121:482.
14. Kato, T. et al. (1997) Proc. Natl. Acad. Sci. 94:4669.
15. Foster, D. & Hunt, P. (1997) Thrombopoiesis and Thrombopoietins 13:203.
16. Ehrenreich, H. et al. (2005) Proc. Natl. Acad. Sci. 102:862.
17. Samoylenko, A. et al. (2008) Cell. Signal. 20:154.

Bioinformatics

• Uniprot:
  • P40225.1()