>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
<0.10 EU per 1 μg of the protein by the LAL method.
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 0.2-1.2 μg/mL.
Human embryonic kidney cell, HEK293-derived Ala22-Arg788 (Asp193Ala), with a C-terminal 6-His tag
When Human LDL is immobilized at 1 μg/mL (100 μL/well),Recombinant Human LDL R (Catalog # 9177-LD) inhibits the binding between HumanLDL and Biotinylated Recombinant Human LDL R. The ED50 for this effect is0.2-1.2 μg/mL.
Background: LDL R
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 receptor; LDLCQ2; LDLR; low density lipoprotein receptor; low-density lipoprotein receptor class A domain-containing protein 3; low-density lipoprotein receptor
The reconstitution calculator allows you to quickly calculate the volume of a reagent to reconstitute your vial. Simply enter the mass of reagent and the target concentration and the calculator will determine the rest.