• Purity

  >90%, 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 by its binding ability in a functional ELISA. When Recombinant Human EphB2 Fc Chimera is coated at 2 μg/mL, Recombinant Human Ephrin-B2 Fc Chimera (Catalog # ) binds with an apparent K    _d <0.1 nM.  

• Source

  Mouse myeloma cell line, NS0-derived

  Human EphB2 (Val19-Leu543) Accession # P29323	IEGRMD	Human IgG1 (Pro100-Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Val19

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  84.7 kDa (monomer)

• SDS-PAGE

  103-108 kDa, reducing conditions

Background: EphB2

EphB2, also known as Cek5, Nuk, Erk, Qek5, Tyro5, Sek3, Hek5, and Drt, is a 125 kDa member of the transmembrane Eph receptor tyrosine kinase family that binds members of the Ephrin family on adjacent cells. The interaction triggers forward signaling in the receptor-expressing cells through the Eph receptor and reverse signaling in the ligand-expressing cells through Ephrin (1, 2). Human EphB2 cDNA encodes a 1055 amino acid (aa) precursor, which includes an 18 aa signal sequence, a 525 aa extracellar domain (ECD), a 21 aa transmembrane segment, and a 491 aa cytoplamic domain. The ECD contains a cysteine-rich region followed by two fibronectin type III domains. The cytoplasmic domain contains the tyrosine kinase domain, a sterile alpha motif (SAM), and a PDZ binding motif (3). Human EphB2 shares 99% aa sequence identity with mouse and rat EphB2 within the ECD region. A short isoform that lacks 70 aa at the C-terminus has also been reported (4). Hippocampal neurons can release vesicles containing full length EphB2, and these are taken up by neighboring glial cells (5). EphB2 is expressed on both sides of the neuronal synapse. It controls axon guidance across the embryonic midline, promotes a neuronal fate from neural precursors, and regulates NMDA receptor activity  
(6-10). EphB2 interaction with Ephrin-A5 promotes axonal growth cone collapse, while its interaction with Ephrin-B ligands is required for inner ear, renal, urorectal, and vascular development (6, 11-15). Signaling in Ephrin expressing cells through EphB2-Ephrin complex requires proteolytic cleavage of EphB2 that releases its extracellular domain (16). Following the shedding of the extracellular domain of EphB2, the cytoplasmic domain of EphB2 is released from the plasma membrane by the presenilin-dependent gamma -secretase activity to initiate a signaling cascade in the EphB2 expressing cells (16). Aberrant EphB2 expression and activity are implicated in the progression of several cancers (17).

• References:

1. Pasquale, E.B. (2008) Cell 133:38.

2. Merlos-Suarez, A. and E. Batlle (2008) Curr. Opin. Cell Biol. 20:194.

3. Fox, G.M. et al. (1995) Oncogene 10:897.

4. Tang, X.X. et al. (1998) Oncogene, 17:521.

5. Lauterbach, J. and R. Klein (2006) J. Neurosci.         26:11575.

6. Cowan C.A. et al. (2000) Neuron 26:417.

7. Bouvier, D. et al. (2008) J. Neurochem. 106:682.

8. Cramer, K.S. et al. (2006) Dev. Biol. 295:76.

9. Katakowski, M. et al. (2005) Neurosci. Lett. 385:204.

10. Henderson, J.T. et al. (2001) Neuron 32:1041.

11. Himanen, J.-P. et al. (2004) Nat. Neurosci. 7:501.

12. Dravis, C. et al. (2007) Hear. Res. 223:93.

13. Dravis, C. et al. (2004) Dev. Biol. 271:272.

14. Ogawa, K. et al. (2006) J. Cell Sci. 119:559.

15. Salvucci, O. et al. (2006) Blood 108:2914.

16. Litterst, C. et al. (2007) J. Biol. Chem. 282:16155.

17. Castano, J. et al. (2008) Histol. Histopathol. 23:1011.

• Long Name:

  Eph Receptor B2

• Entrez Gene IDs:

  2048 (Human); 13844 (Mouse)

• Alternate Names:

  CAPB; Cek5; Drt; DRTEphB2; EC 2.7.10; EC 2.7.10.1; EK5; elk-related tyrosine kinase; EPH receptor B2; eph tyrosine kinase 3; EphB2; EPH-like kinase 5; ephrin type-B receptor 2; EPHT3MGC87492; EPTH3; Erk; ERKHek5; Hek5; Nuk; PCBC; protein-tyrosine kinase HEK5; Qek2; Renal carcinoma antigen NY-REN-47; Sek3; Tyro5; Tyrosine-protein kinase receptor EPH-3; Tyrosine-protein kinase TYRO5