Product Specifications for Recombinant Human LDLR (High Purity) Protein, CF
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
<0.10 EU per 1 μg of the protein by the LAL method.
N-terminal sequence Analysis
Predicted Molecular Mass
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
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our
Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant
protein to be stored at a more dilute concentration.
The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or
as an ELISA standard.
In contrast, the carrier free protein is recommended for applications, in which the presence of BSA
Lyophilized from a 0.2 μm filtered solution in PBS.
Reconstitute at 100 μg/mL in PBS.
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.
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).
Go, G.W. and A. Mani (2012) Yale J. Biol. Med. 85:19.
Ren, G. et al. (2010) Proc. Natl. Acad. Sci. USA 107:1059.
Bujo, H. and Y. Saito (2006) Arterioscler. Thromb. Vasc. Biol. 26:1246.
Gent, J. and I. Braakman (2004) Cell. Mol. Life Sci. 61:2461.
Yamamoto, T. et al. (1984) Cell 39:27.
Begg, M.J. et al. (2004) Eur. J. Biochem. 271:524.
Fischer, D.G. et al. (1993) Science 262:250.
Stolt, P.C. and H.H. Bock (2006) Cell. Signal. 18:1560.
Defesche, J.C. (2004) Semin. Vasc. Med. 4:5.
De Castro-Oros, I. et al. (2010) Appl. Clin Genet. 3:53.
Zhang, D.W. et al. (2008) Proc. Natl. Acad. Sci. USA 105:13045.
Tavori, H. et al. (2013) Circulation 127:2403.
Low Density Lipoprotein Receptor
Entrez Gene IDs
3949 (Human); 16835 (Mouse); 300438 (Rat)
FH, FHC, LDL R, LDL receptor, LDLCQ2, LDLR, low density lipoprotein receptor, low-density lipoprotein receptor, low-density lipoprotein receptor class A domain-containing protein 3
Citations for Recombinant Human LDLR (High Purity) Protein, CF
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Product Documents for Recombinant Human LDLR (High Purity) Protein, CF
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