• Purity

  >95%, 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 the ability of the immobilized protein to support the adhesion of human pancreatic cancer cells. When 5 x 10    ⁴ cells/well are added to Recombinant Human Semaphorin 5B Fc Chimera coated plates, cell adhesion is enhanced in a dose dependent manner after 1 hour at 37 °C. The ED    ₅₀ for this effect is 0.7‑2.8 μg/mL.

• Source

  Chinese Hamster Ovary cell line, CHO-derived

  Human Semaphorin 5B (Val78 - Thr834) Accession # NP_001026872	IEGRMD	Human IgG1 (Pro100 - Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Val78

• Predicted Molecular Mass

  110.3 kDa (monomer)

• SDS-PAGE

  130-140 kDa, reducing conditions

Background: Semaphorin 5B

Semaphorin 5B (Sema5B, previously called SemG) is a ~150 kDa protein of the semaphorin family of axon guidance molecules (1, 2). Class 5 semaphorins are 1-pass transmembrane glycoproteins with an N-terminal Sema domain and multiple juxtamembrane type 1 thrombospondin (TSP) repeats within their extracellular domains (1, 2). Sema5B is expressed developmentally in the neuroepithelium along the anterior-posterior axis in a complimentary pattern with Sema5A (2, 3). It has been identified in oligodendrocytes and their precursors, neurons, dental mesenchyme and pre‑osteoblasts (1 ‑ 6). Sema5B expression may be up‑regulated in cancer cells such as renal carcinoma clear cells, where blocking Sema5B expression attenuates viability (7). The human Sema5B cDNA encodes a 1151 amino acid (aa) type III transmembrane protein with a 1036 aa extracellular domain (ECD), a 21 aa transmembrane sequence and a 94 aa cytoplasmic portion. Within aa 78 ‑ 834, which includes the sema domain and two of the five TSP repeats, human Sema5B shares 94 ‑ 95% aa identity with corresponding mouse, rat, equine and bovine sequences. An alternate start site at aa 59 and two splicing variations in the cytoplasmic domain may create isoforms of 1093, 1092 or 1130 aa, respectively (7, 8). In the hippocampus, either full-length or proteolytically created secreted Sema5B mediates neuronal synapse elimination (6). In the cortex, Sema5B appears to be inhibitory to cortical axons, but not to dorsal thalamic axons, indicating a role in corticothalamic axon guidance during development (3). Sema5B promotes the influx of extracellular calcium, which is necessary to induce neuronal growth cone collapse (9). Semaphorins typically transduce signals through transmembrane plexins, but additional molecules, such as heparin sulfate or chondroitin sulfate proteoglycans which bind TSP repeats on the class 5 family member Sema5A, can mediate midbrain axon attraction or repulsion (10).

• References:

1. Yazdani, U. and J.R. Terman (2006) Genome Biol. 7:211.

2. Adams, R.H. et al. (1996) Mech. Dev. 57:33.

3. Lett, R.L.M. et al. (2009) Cerebral Cortex 19:1408.

4. Goldberg, J.L. et al. (2004) J. Neurosci. 24:4989.

5. Cohen, R.I. et al. (2003) J. Neurochem. 85:1262.

6. O’Connor, T.P. et al. (2009) Neural Dev. 4:18.

7. Hirota, E. et al. (2006) Int. J. Oncol. 29:799.

8. Swiss-Prot Accession # Q9P283

9. To, K.C.W. et al. (2007) Mol. Cell. Neurosci. 36:425.

10. Kantor, D.B. et al. (2004) Neuron 44:961.

• Entrez Gene IDs:

  54437 (Human)

• Alternate Names:

  FLJ10372; KIAA1445; sema domain, seven thrombospondin repeats (type 1 and type 1-like), transmembrane domain (TM) and short cytoplasmic domain, (semaphorin) 5B; SEMA5B; SEMAG; Semaphorin 5B; SEMG