Purity
>97%, by SDS-PAGE under reducing conditions and visualized by silver stain
Endotoxin Level
<0.10 EU per 1 μg of the protein by the LAL method.
Activity
Measured in a cell proliferation assay using MO7e human megakaryocytic leukemic cells. Avanzi, G. et al. (1988) Br. J. Haematol. 69:359. The ED 50 for this effect is 0.4-2.4 ng/mL.
Source
Mouse myeloma cell line, NS0-derived Ser22-Thr356
Accession #
N-terminal Sequence
AnalysisSer22
Predicted Molecular Mass
35 kDa
SDS-PAGE
80-90 kDa, reducing conditions
Carrier Free
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.
488-TO |
| 488-TO/CF |
Formulation Lyophilized from a 0.2 μm filtered solution in PBS with BSA as a carrier protein. | Formulation Lyophilized from a 0.2 μm filtered solution in PBS. | |
Reconstitution Reconstitute at 50 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin. | Reconstitution Reconstitute at 50 μg/mL in sterile PBS. | |
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. | Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. | |
Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
| Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
|
Data Images
Bioactivity
| Recombinant Mouse Thrombopoietin/Tpo (Catalog # 488-TO) stimulates cell proliferation in the MO7e human megakaryocytic leukemic cell line. The ED50 for this effect is 0.4-2.4 ng/mL. |
SDS-PAGE
| 1 μg/lane of Recombinant Mouse Thrombopoietin/Tpo was resolved with SDS-PAGE under reducing (R) conditions and visualized by silver staining, showing a band at 80-90 kDa. |
Background: Thrombopoietin/Tpo
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 356 amino acid (aa) mouse Tpo precursor is cleaved to yield the 335 aa mature protein. Mature mouse Tpo shares 71% and 81% aa sequence homology with human and rat Tpo, respectively. 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 mouse 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). Full length Tpo and shorter forms circulate in the plasma (4, 5). 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 (15, 16).
References:
Deutsch, V.R. and A. Tomer (2006)J. Haematol. 134:453.
Kaushansky, K. (2005) J. Clin. Invest. 115:3339.
Li, J. et al. (1999)J. Haematol. 106:345.
Bartley, T.D. et al. (1994) Cell 77:1117.
de Sauvage, F.J. et al. (1994) Nature 369:533.
Marcucci, R. and M. Romano (2008) Biochim. Biophys. Acta 1782:427.
Kaushansky, K. et al. (1994) Nature 369:568.
Kaushansky, K. et al. (1995) Proc. Natl. Acad. Sci. 92:3234.
Broudy, V.C. et al. (1995) Blood 85:1719.
Lok, S.I. et al. (1994) Nature 369:565.
Chen, J. et al. (1995) Blood 86:4054.
Oda, A. et al. (1996) Blood 87:4664.
Van Os, E. et al. (2003) Br. J. Haematol. 121:482.
Kato, T. et al. (1997) Proc. Natl. Acad. Sci. 94:4669.
Ehrenreich, H. et al. (2005) Proc. Natl. Acad. Sci. 102:862.
Samoylenko, A. et al. (2008) Cell. Signal. 20:154.
Entrez Gene IDs:
7066 (Human); 21832 (Mouse); 81811 (Rat)
Alternate Names:
Megakaryocyte colony-stimulating factor; Megakaryocyte growth and development factor; megakaryocyte stimulating factor; MGDF; MGDFC-mpl ligand; MK-CSF; ML; MPL ligand; MPLLGMGC163194; Myeloproliferative leukemia virus oncogene ligand; THPO; thrombopoietin nirs variant 1; Thrombopoietin; Tpo; TPOMKCSF
