Tie2, Fc Chimera, Recombinant, Rat (Tunica Internal Endothelial Cell Kinase, Angiopoietin1 Receptor, p140 Tek, Tyrosine Protein Kinase Receptor)

Tie-2, also known as Tek, is a 145 kD, type I transmembrane glycoprotein receptor tyrosine kinase that is a receptor for angiopoietins. 1 The 1120 amino acid (aa) rat Tie-2 precursor contains an 18 aa signal sequence, a 723 aa extracellular domain (ECD), a 25 aa transmembrane segment, and a 354 aa cytoplasmic tail. 2 The ECD contains two C2 Ig-like domains, three EGF-like motifs, and three fibronectin type III repeats. The cytoplasmic region has a split tyrosine kinase domain and presumably autophosphorylates as a ligand-induced homodimer. 3 Rat Tie-2 ECD shares 96%, 90% and 89% aa identity with mouse, human and bovine Tie-2, respectively, and 47% aa identity with rat Tie-1 ECD. Cells known to express Tie-2 include embryonic and adult endothelial cells, hematopoietic stem cells and a circulating population of proangiogenic Tie-2 expressing monocytes (TEM). 4-7 A soluble form of Tie-2, most likely the result of proteolytic cleavage, is found in serum. 8 The four angiopoietins are ligands of Tie-2. Ang-1 and Ang-4 are Tie-2 activators, while Ang-2 and Ang-3 can be activators or inhibitors, depending on context. 1, 9 Tie-2 is said to be important for maintaining vascular integrity. It mediates endothelial cell-smooth muscle cell communication, and inhibits endothelial cell apoptosis, thus maintaining endothelial cell survival. 10-12 It is also absolutely required for embryonic development of the endocardium. 3, 10, 13 While not essential for embryonic hematopoiesis, Ang-1 production by osteoblasts promotes quiescence of Tie-2-expressing bone marrow stem cells. This quiescence is critical for maintaining an ongoing hematopoietic capability. 12, 14, 15\n\nSource: Human CD33 signal peptide (Met 1-Ala 16), Rat Tie-2 (Ala 60-Leu 780), IEGRMD, Human IgG1 (Pro 100-Lys 330); A DNA sequence encoding the signal peptide from human CD33 joined with the extracellular domain of rat Tie-2 (Ala 60-Leu 780; Accession # XP_342864) was fused to the Fc region of human IgG1 via a peptide linker. The chimeric protein was expressed in a mouse myeloma cell line, NS0.\n\nMolecular Mass: The recombinant mature rat Tie-2/Fc chimera, generated by proteolytic removal of the signal peptide, is a disulfide-linked homodimer. Based on N-terminal amino acid sequencing, the recombinant rat Tie-2 protein starts at Ala 60. The predicted molecular mass of the monomer is approximately 107.3 kD. As a result of glycosylation, the recombinant protein migrates as an approximately 120-140 kD protein in SDS-PAGE under reducing conditions. A small amount of free Fc and free rat Tie-2 may be present in the preparation.\n\nEndotoxin Level: < 1.0 EU per 1 microg of the protein as determined by the LAL method.\n\nActivity: Measured in a functional ELISA assay. When rrTIE-2/Fc is immobilized at 4microg/mL (100 microL/well), it binds rhAngiopoietin-2 with a linear range of 0.8-50 ng/mL.\n\nReconstitution: It is recommended that sterile PBS be added to the vial to prepare a working stock solution of no less than 100ug/ml. The carrier-free protein should be used immediately upon reconstitution to avoid losses in activity due to non-specific binding to the inside surface of the vial. For long term storage as a dilute solution, a carrier protein (e.g. 0.1% HSA or BSA) should be added to the vial.\n\nStorage and Stability: Lyophilized samples are stable for up to twelve months from date of receipt at -20 degrees C. Upon reconstitution, this protein, in the presence of a carrier protein, can be stored under sterile conditions at 2 degrees -8 degrees C for one month or at -20 degrees C in a manual defrost freezer for three months without detectable loss of activity. Avoid repeated freeze-thaw cycles.

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SPECIFICATIONS

Catalog Number

T5498-70F

Size

100ug

Form

Supplied as a lyophilized powder from a 0.2um filtered solution in PBS.

Purity

(same/more than) 90%, as determined by SDS-PAGE and visualized by silver stain.

References

1. Eklund, L and B. R. Olsen, 2006, Exp. Cell Res. 312:630. \n2. Maisonpierre, P.C. et al., 1993, Oncogene 8:1631. \n3. Vikkula, M. et al., 1996, Cell 87:1181. \n4. Asahara, T. et al., 1997 Science 275:964. \n5. Dallabrida, S.M. et al., 2003, Biochem. Biophys. Res. Commun. 311:563. \n6. Takakura, N. et al., 1998, Immunity 9:677. \n7. DePalma, M. et al., 2005, Cancer Cell 8:211-226. \n8. Reusch, P. et al., 2001, Angiogenesis 4:123. \n9. Lee, H.J. et al., 2004, FASEB J. 18:1200. \n10. Jones, N. et al., 2001, EMBO Rep. 2:438. \n11. Wong, A. L. et al., 1997, Circ. Res. 81:567. \n12. Hamaguchi, I. et al., 2006, Blood 107:1207. \n13. Puri, M.C. et al., 1999, Development 126:4569. \n14. Puri, M.C. and A. Bernstein, 2003, Proc. Natl. Acad. Sci. USA 100:12753. \n15. Arai, F. et al., 2004, Cell 118:149.