This Mouse LDLR/LDL Receptor overexpression lysate was created in HEK293 Cells and intented for use as a Western blot (WB) positive control. Purification of LDLR/LDL Receptor protein (Cat: 50305-M08H) from the overexpression lysate was verified.
A DNA sequence encoding the extracellular domain of mouse LDLR (NP_034830.2) precursor (Met 1-Arg 790) with substitution of Val 23 and Gly 27 by Ala 23 and Cys 27 respectively was expressed with a C-terminal polyhistidine tag.
The secreted recombinant mouse LDLR comprises 780 amino acids with a predicted molecular mass of 85.7 kDa. As a result of glycosylation, it migarates as approximately 120-130 kDa protein in SDS-PAGE under reducing conditions.
Cell lysate was prepared by homogenization of the over-expressed cells in ice-cold modified RIPA Lysis Buffer with cocktail of protease inhibitors (Sigma). Cell debris was removed by centrifugation. Protein concentration was determined by Bradford assay (Bio-Rad protein assay, Microplate Standard assay). The cell lysate was boiled for 5 min in 1 x SDS loading buffer (50 mM Tris-HCl pH 6.8, 12.5% glycerol, 1% sodium dodecylsulfate, 0.01% bromophenol blue) containing 5% b-mercaptoethanol, and lyophilized.
LDL Receptor, also known as LDLR, is a mosaic protein which belongs to the Low density lipoprotein receptor gene family. The low density lipoprotein receptor (LDLR) gene family consists of cell surface proteins involved in receptor-mediated endocytosis of specific ligands. LDL Receptor consists of 84 amino acids (after removal of signal peptide) and mediates the endocytosis of cholesterol-rich LDL. Low density lipoprotein (LDL) is normally bound at the cell membrane and taken into the cell ending up in lysosomes where the protein is degraded and the cholesterol is made available for repression of microsomal enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate-limiting step in cholesterol synthesis. At the same time, a reciprocal stimulation of cholesterol ester synthesis takes place. LDL Receptor is a cell-surface receptor that recognizes the apoprotein B1 which is embedded in the phospholipid outer layer of LDL particles. The receptor also recognizes the apoE protein found in chylomicron remnants and VLDL remnants.
low density lipoprotein receptor
Yamamoto T, et al. (1984) The human LDL receptor: a cysteine-rich protein with multiple Alu sequences in its mRNA. Cell. 39(1): 27-38.
Mao B, et al. (2001) LDL-receptor-related protein 6 is a receptor for Dickkopf proteins. Nature. 411(6835): 321-5.
Pinson KI, et al. (2000) An LDL-receptor-related protein mediates Wnt signalling in mice. Nature. 407(6803): 535-8.