• Purity

  >90%, by SDS-PAGE with silver staining.

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to induce adhesion of ATDC5 mouse chondrogenic cells. The ED    ₅₀ for this effect is 0.3-1.5 μg/mL.

• Source

  Human embryonic kidney cell, HEK293-derived Ser22-Val956 with a C-terminal 10-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Ser22

• Structure / Form

  Disulfide-linked oligomer

• Predicted Molecular Mass

  103 kDa

• SDS-PAGE

  100-145 kDa, reducing conditions

Background: Thrombospondin-3

Thrombospondin-3 (TSP-3) is a 140-150 kDa heparin-binding protein in the thrombospondin family of matricellular adhesion proteins. Within this family, TSP-3, TSP-4, and TSP-5/COMP are secreted as pentamers, while TSP-1 and TSP-2 are homotrimeric (1). TSP-3 contains an N-terminal Laminin G-like globular domain, a flexible linker region, multiple tandem EGF-like repeats, multiple tandem TSP type-3 repeats, and a globular TSP C-terminal domain (2). Alternative splicing of human TSP-3 generates a short isoform with a deletion of approximately half of the Laminin-like domain and a portion of the linker. Mature human TSP-3 shares 98% and 97% amino acid sequence identity with mouse and rat TSP-3, respectively. In the disulfide-linked TSP-3 pentamer, the Laminin-like domains are clustered while the C-terminal globular domains are extended (3). TSP-3 is expressed during mouse embryogenesis in the brain, dorsal root ganglia, cartilage, lung, and gut (4, 5). In postnatal mice it is most highly expressed in the lung (6). TSP-3 is involved in the columnar organization of chondrocytes in developing growth plates of long bones (7). It is up-regulated in metastatic osteosarcoma and in the corneal stroma during wound healing (8, 9).

• References:

1. Murphy-Ullrich, J.E. and R.V. Iozzo (2012) Matrix Biol. 31:152.

2. Adolph, K.W. et al. (1995) Genomics 27:329.

3. Qabar, A. et al. (1995) J. Biol. Chem. 270:12725.

4. Iruela-Arispe, M.L. et al. (1993) Dev. Dyn. 197:40.

5. Qabar, A. et al. (1994) J. Biol. Chem. 269:1262.

6. Vos, H.L. et al. (1992) J. Biol. Chem. 267:12192.

7. Posey, K.L. et al. (2008) Am. J. Pathol. 172:1664.

8. Dalla-Torre, C.A. et al. (2006) BMC Cancer 6:237.

9. Armstrong, D.J. et al. (2002) Int. J. Biochem. Cell Biol. 34:588.

• Entrez Gene IDs:

  7059 (Human); 21827 (Mouse); 681309 (Rat)

• Alternate Names:

  MGC119565; THBS3; thrombospondin 3; Thrombospondin3; Thrombospondin-3; TSP3; TSP3MGC119564