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Recombinant Human LDLR (High Purity) Protein, CF

Catalog # 2148-HP | R&D Systems, Inc. a Bio-Techne Brand
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Key Product Details

Accession #







Product Specifications


Mouse myeloma cell line, NS0-derived human LDL R protein
Ala22-Arg788, with a C-terminal 6-His tag


>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.

N-terminal Sequence Analysis


Predicted Molecular Mass

86 kDa


120-145 kDa, reducing conditions


Measured in a competitive binding assay.
When human LDL is immobilized at 1 μg/mL (100 μL/well), Recombinant Human LDL R inhibits 50% binding of biotinylated recombinant human LDL R (0.5 μg/mL) at the concentration range of 0.3-1.5 μg/mL

Formulation, Preparation and Storage

Formulation Lyophilized from a 0.2 μm filtered solution in PBS.
Reconstitute at 100 μg/mL in PBS.

Reconstitution Buffer Available:
Size / Price
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: LDLR

The low density lipoprotein receptor (LDL R) is the founding member of the LDL R family of widely expressed cell surface scavenger receptors (1-5). Members of the family are endocytic receptors, but can also co-regulate adjacent cell-surface signaling molecules (3, 4). Many proteins in the LDL R family are cleaved by extracellular proteases to release soluble forms to the circulation, and many of these soluble forms are active (1, 6). Mature LDL R is a 120-160 kDa (depending on glycosylation) type I transmembrane glycoprotein that contains cysteine-rich complement-like repeats (class A LDL domains), calcium-binding EGF repeats, and beta‑propeller structures (class B LDL repeats) in the extracellular domain (ECD) (1-7). A membrane-proximal Ser/Thr-rich region shows extensive O-linked glycosylation (4, 8). A cytoplasmic NPxY motif links the LDL R to clathrin pits for endocytosis, and binds to select adaptor proteins (1, 4, 8). The human LDL R ECD shares 78%, 76%, 81% and 82% aa sequence identity with mouse, rat, bovine, and porcine LDL R, respectively. LDL R is constitutively and widely expressed. Its class A LDL domains near the N-terminus bind apoB and apoE, the apolipoproteins of low- and very low-density lipoproteins (LDL and VLDL), respectively (1, 2, 4, 9). Hepatocyte LDL R is responsible for endocytosis and clearing of most plasma LDL cholesterol (2, 9). At the low pH of the endocytic vesicle, it dissociates, allowing degradation of LDL and recycling of LDL R to the cell surface (1, 4). Lack of LDL R expression or function causes familial hypercholesterolemia (FH) (4, 9, 10). The protease PCSK9 (proprotein convertase subtilisin/kexin type 9) can also cause increased plasma cholesterol by promoting LDL R degradation rather than recycling to the cell surface (10-12). Soluble forms of approximately 140 kDa and 28 kDa are reported to be released by phorbol esters or interferons, respectively (6, 7).


  1. Go, G.W. and A. Mani (2012) Yale J. Biol. Med. 85:19.
  2. Ren, G. et al. (2010) Proc. Natl. Acad. Sci. USA 107:1059.
  3. Bujo, H. and Y. Saito (2006) Arterioscler. Thromb. Vasc. Biol. 26:1246.
  4. Gent, J. and I. Braakman (2004) Cell. Mol. Life Sci. 61:2461.
  5. Yamamoto, T. et al. (1984) Cell 39:27.
  6. Begg, M.J. et al. (2004) Eur. J. Biochem. 271:524.
  7. Fischer, D.G. et al. (1993) Science 262:250.
  8. Stolt, P.C. and H.H. Bock (2006) Cell. Signal. 18:1560.
  9. Defesche, J.C. (2004) Semin. Vasc. Med. 4:5.
  10. De Castro-Oros, I. et al. (2010) Appl. Clin Genet. 3:53.
  11. Zhang, D.W. et al. (2008) Proc. Natl. Acad. Sci. USA 105:13045.
  12. Tavori, H. et al. (2013) Circulation 127:2403.

Long Name

Low Density Lipoprotein Receptor

Alternate Names


Entrez Gene IDs

3949 (Human); 16835 (Mouse); 300438 (Rat); 396801 (Porcine); 102127361 (Cynomolgus Monkey)

Gene Symbol



Product Documents for Recombinant Human LDLR (High Purity) Protein, CF

Certificate of Analysis

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Product Specific Notices for Recombinant Human LDLR (High Purity) Protein, CF

For research use only

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