• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.1 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. When rhLRP-1C2/Fc Chimera is immobilized at 50 ng/mL (100 µL/well), the concentration of rhLRPAP (Catalog # 4296-LR) that produces 50% of the optimal binding response is found to be approximately 0.5-2.5 ng/mL.

• Source

  Mouse myeloma cell line, NS0-derived

  Human LRP-1C2 (Arg786 - Leu1165) Accession # Q07954	IEGRMD	Human IgG1 (Pro100 - Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Arg786

• Structure / Form

  Disulfide-linked homodimer    
   

• Predicted Molecular Mass

  68.1 kDa

• SDS-PAGE

  90-100 kDa, reducing conditions    
   

Background: LRP-1 Cluster II

LDL receptor-related protein 1 (LRP-1), also known as CD91 and the alpha 2-macroglobulin receptor, is a type I transmembrane protein in the LDL receptor superfamily. It is expressed on neurons, hepatocytes, adipocytes, vascular smooth muscle cells, fibroblasts, keratinocytes, macrophages, and megakaryocytes. LRP-1 is important for the clearance of a large number of circulating molecules involved in fatty acid metabolism and the inhibition of serine proteases (1 - 4). LRP-1 also associates, or through intracellular scaffold proteins, with other membrane associated proteins on the same cell. This allows LRP-1 to modulate the activity or internalization of PDGF R beta, NMDA receptor subunits, TGF-beta receptors, Frizzled-1, various integrins, and the prion protein PrP^C (1, 5 - 10). Human LRP 1 is N glycosylated and sialylated, and cleaved in the Golgi to produce an 85 kDa transmembrane beta chain, and a 515 kDa alpha chain. Both associate noncovalently, with the beta chain remaining completely extracellular (11, 12). The alpha chain of LRP 1 contains 31 LDLR class A repeats, 34 LDLR class B repeats, and 22 EGF-like repeats (13). The LDLR domains are clustered in four regions throughout the protein (13). Cluster II (aa 786 - 1165) contains one EGF-like and eight LDLR class A repeats (14, 15). Cluster II contains binding sites for Apolipoprotein E, LPL, LRPAP/RAP, alpha 2 Macroglobulin, Coagulation Factor VIII light chain, Lactoferrin, PAI-1, tPA-PAI-1 complexes, Pro-uPA, and TFPI (14, 15). Within this region, human LRP-1 shares 99% aa sequence identity with mouse and rat LRP-1. A shed soluble form of LRP-1 circulates in the serum and retains ligand binding properties (16).

• References:

1. Lillis, A.P. et al. (2008) Physiol. Rev. 88:887.

2. Galliano, M.-F. et al. (2008) PLoS ONE 3:e2729.

3. Bouchard, B.A. et al. (2007) J. Thromb. Haemost. 6:638.

4. Sendra, J. et al. (2008) Cardiovasc. Res. 78:581.

5. Takayama, Y. et al. (2005) J. Biol. Chem. 280:18504.

6. Martin, A.M. et al. (2008) J. Biol. Chem. 283:12004.

7. Cabello-Verugio, C. and E. Brandan (2007) J. Biol. Chem. 282:18842.

8. Zilberberg, A. et al. (2004) J. Biol. Chem. 279:17535.

9. Taylor, D.R. and N.M. Hooper (2007) Biochem. J. 402:17.

10. Parkyn, C.J. et al. (2007) J. Cell Sci. 121:773.

11. Herz, J. et al. (1990) EMBO J. 9:1769.

12. Strickland, D.K. et al. (1990) J. Biol. Chem. 265:17401.

13. Herz, J. et al. (1988) EMBO J. 7:4119.

14. Horn, I.R. et al. (1997) J. Biol. Chem. 272:13608.

15. Neels, J.G. et al. (1999) J. Biol. Chem. 274:31305.

16. Quinn, K.A. et al. (1999) Exp. Cell Res. 251:433.

• Long Name:

  LDL Receptor-related Protein 1, Cluster II

• Entrez Gene IDs:

  4035 (Human); 16971 (Mouse); 299858 (Rat)

• Alternate Names:

  A2MR; Alpha-2-Macroglobulin Receptor; APOER; APR; CD91; LRP1 Cluster II; LRP-1 Cluster II; LRP1; TGFBR5