• 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. Immobilized rhAcLDL at 2 µg/mL (100 µL/well) can bind rhSREC-II/Fc Chimera with a linear range of 30-2000 ng/mL.

• Source

  Mouse myeloma cell line, NS0-derived

  Human SREC-II (Gln44 - Gly442) Accession # Q96GP6	IEGRMD	Human IgG1 (Pro100 - Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  No results obtained: Gln44 predicted

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  69.8 kDa (monomer)

• SDS-PAGE

  86-95 kDa, reducing conditions

Background: SREC-II/SCARF2

The scavenger receptor (SR) family comprises a group of functionally defined membrane receptors that share a common ability to bind and internalize modified forms of low density lipoproteins (LDL) such as acetylated LDL (AcLDL) and oxidized LDL(OxLDL) (1 - 3). Family members are classified alphabetically. In general, they play important roles in lipid metabolism, in host defence and in the regulation of acquired immunity (2, 4). Scavenger receptor expressed by endothelial cells-I (SREC-I) and SREC-II are two proteins that belong to the F type scavenger receptor group (SR-F1 and SR-F2). Unlike SREC-I, SREC-II is somewhat unique in that it doesn’t show expected binding to modified LDL (5). The full length cDNA for human SREC-II encodes an 870 amino acid (aa) type I transmembrane protein which contains a 43 aa signal peptide, a 398 aa extracellular region, a 21 aa transmembrane segment, and a 408 aa cytoplasmic domain (5, 6). Depending upon the reference, the extracellular region contains 7 - 10 EGF-like repeats, with a cytoplasmic domain that is rich in serine and proline in its N-terminal half and glycine in its C-terminal segment (5, 6). There is at least one alternate splice variant that shows a 5 aa deletion in the juxtamembrane region of the cytoplasmic domain (6, 7). The deletion does not change the reading frame as the distal 390 amino acids are identical in the two isoforms. The Genbank suggests another variant is possible involving amino acids 750 - 768 of the precursor. Again, this doesn’t seem to change the reading frame as amino acids downstream of this are unchanged (6, 8). SREC-II is expressed by endothelial cells and vascular smooth muscle cells (5, 9). In the extracellular region human SREC-II is 95% aa identical to mouse SREC-II. The extracellular regions of human SREC-II and SREC-I are 53% aa identical. Notably, more than serving as a scavenger receptor, SREC-II would seem to form heterophilic interactions with SREC-I during cell-to-cell aggregation (5).

• References:

1. Horiuchi, S. et al. (2003) Amino Acids 25:283.

2. Greaves, D.R. and S. Gordon (2005) J. Lipid Res. 46:11.

3. Platt, N. and S. Gordon (1998) Chem. Biol. 5:R193.

4. Platt, N. and S. Gordon (2001) J. Clin. Invest. 108:649. 

5. Ishii, J. et al. (2002) J. Biol. Chem. 277:39696.

6. GenBank Accession # Q96GP6.

7. GenBank Accession # NP_699165.

8. GenBank Accession # NP_878315.

9. Sukhanov, S. et al. (2003) Biochem. Biophys. Res. Commun. 306:443.

• Long Name:

  Scavenger Receptor Expressed by Endothelial Cells 2

• Entrez Gene IDs:

  91179 (Human)

• Alternate Names:

  HUMZD58C02; SCARF2; scavenger receptor class F, member 2; Scavenger receptor expressed by endothelial cells 2 protein; SREC2NSR1; SRECII; SREC-II; SREC-IIscavenger receptor class F member 2; SRECRP-1; SREPCR