• Species Reactivity

  Human

• Specificity

  Detects human SPARC/Osteonectin in direct ELISAs and Western blots. In direct ELISAs and Western blots, no cross-reactivity with recombinant mouse SPARC/Osteonectin is observed.

• Source

  Monoclonal Mouse IgG    ₁ Clone # 122511

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human SPARC    
  Ala18-Ile303    
  Accession # P09486

• Formulation

  Supplied in a saline solution containing BSA and Sodium Azide.

• Label

  Phycoerythrin

Applications

• 
  

  Recommended    
  Concentration

  Sample

• Intracellular Staining by Flow Cytometry

  10 µL/10    ⁶ cells

  See below

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Data Examples

Preparation and Storage

• Shipping

  The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

• Stability & Storage

  Protect from light.    Do not freeze.    

• 12 months from date of receipt, 2 to 8 °C as supplied.

Background: SPARC

SPARC, an acronym for “secreted protein, acidic and rich in cysteine”, is also known as osteonectin or BM-40 (1-5). It is the founding member of a family of secreted matricellular proteins with similar domain structure. The 286 amino acid (aa), 43 kDa protein contains an N-terminal acidic region that binds calcium, a follistatin domain that contains Kazal-like sequences, and a C-terminal extracellular calcium (EC) binding domain with two EF-hand motifs (1-5). Crystal structure modeling shows that residues implicated in cell binding, inhibition of cell spreading, and disassembly of focal adhesions cluster on one face of SPARC, while a collagen binding epitope and an N-glycosylation site are opposite this face (6). SPARC is produced by fibroblasts, capillary endothelial cells, platelets and macrophages, especially in areas of tissue morphogenesis and remodeling (3, 7). SPARC shows context-specific effects, but generally inhibits adhesion, spreading and proliferation, and promotes collagen matrix formation (3-5). For endothelial cells, SPARC disrupts focal adhesions and binds and sequesters PDGF and VEGF (3-5). SPARC is abundantly expressed in bone, where it promotes osteoblast differentiation and inhibits adipogenesis (5, 8). SPARC is potentially cleaved by metalloproteinases, producing an angiogenic peptide that includes the copper-binding sequence KGHK (7). Paradoxically, SPARC is highly expressed in many tumor types undergoing an endothelial to mesenchymal transition; its expression, however, mainly decreases the likelihood of metastasis and confers sensitivity to chemotherapy and radiation (4, 9-11). Stabilin-1, which is expressed on alternately activated macrophages, is the first SPARC receptor to be identified. It binds the SPARC EC domain and mediates endocytosis for degradation (12). Mature human SPARC shows 92%, 92%, 97%, 99%, 96% and 85% aa identity with mouse, rat, canine, bovine, porcine and chick SPARC, respectively.

• References:

1. Lankat-Buttgereit, B. et al. (1988) FEBS Lett. 236:352.

2. Sweetwyne, M. T. et al. (2004) J. Histochem. Cytochem. 52:723.

3. Sage, H. et al. (1989) J. Cell Biol. 109:341.

4. Framson, P. E. and E. H. Sage (2004) J. Cell. Biochem. 92:679.

5. Alford, A. I. and K. D. Hankenson (2006) Bone 38:749.

6. Hohenester, E et al. (1997) EMBO J. 16:3778.

7. Sage, E. H. et al. (2003) J. Biol. Chem. 278:37849.

8. Delany, A. M. et al. (2003) Endocrinology 144:2588.

9. Robert, G. et al. (2006) Cancer Res. 66:7516.

10. Koblinski, J. E. et al. (2005) Cancer Res. 65:7370.

11. Tai, I. T. et al. (2005) J. Clin. Invest. 115:1492.

12. Kzhyshkowska, J. et al. (2006) J. Immunol. 176:5825.

• Long Name:

  Secreted Protein Acidic and Rich in Cysteine

• Entrez Gene IDs:

  6678 (Human); 20692 (Mouse)

• Alternate Names:

  Basement-membrane protein 40; BM-40; ONcysteine-rich protein; Osteonectin; Secreted protein acidic and rich in cysteine; secreted protein, acidic, cysteine-rich (osteonectin); SPARC