Thrombopoietin from mouse 

The biological activity was measured in a cell proliferation assay using MO7e cells.

Lyophilized from a 0.2 μm filtered solution in phosphate buffered saline containing 0.25 mg bovine serum albumin

Thrombopoeitin (TPO), also known as the ligand for the c-mpl proto-oncogene (Mpl-L) and as megakaryocyte colony stimulating factor (Meg-CSF), is a primary regulatory factor for megakaryocytopoiesis and thrombopoiesis.^1,2,3,4 Produced mainly by hepatocytes but also by kidney cells, TPO is a humoral glycoprotein that stimulates growth and maturation of megakaryocytes and megakaryocytic colonies from bone marrow cultures. TPO binds and activates an 68-78 kDa glycoprotein receptor belonging to the GH family of cytokine receptors, a family that includes receptors to growth hormone (GH), erythropoietin (EPO) and prolactin (PRL).^5,6 Like GH and EPO, TPO may bind to its receptor at two distinct sites, initiating receptor dimerization and activation.⁷ Analysis of mRNA indicates also the existence of a novel truncated and potentially soluble form of TPO receptor. The viral oncogene v-mlp of the myeloproliferative leukemia virus (MPLV) contains the gene sequence for the entire cytoplasmic and transmembrane domains and a portion of the extracellular domain of c-mlp (TPO receptor). TPO receptors are found on megakaryocytes and their precursors and on platelets. The mature form of TPO is a highly conserved glycoprotein, showing approximately 70% sequence homology among various mammals. Human TPO contains 332 amino acids (mouse 335) including two internal disulfide bonds and 6 N-linked glycosylation sites (mouse 7). The N-terminal 153 amino acid region of TPO shows structural and amino acid sequence homology to erythropoietin and a pair of arginines (potential cleavage site) separating it from the highly glycosylated carboxyterminal domain.

expressed in NSO cells

>97% (SDS-PAGE)

lyophilized powder

mol wt ~75 kDa by SDS-PAGE (as a result of glycosylation)

predicted mol wt 35 kDa

Endotoxin, tested

cell culture tested

mouse ... Thpo(21832)

−20°C

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