R&D Systems Recombinant Human LDL R
The low density lipoprotein receptor (LDLR) is the founding member of the LDLR family of scavenger receptors. This family contains transmembrane molecules that are characterized by the presence of EGF repeats, complement-like repeats, and YWTD motifs that form β-propellers.
Specifications and Use for R&D LDL R
Source of R&D LDL R
• A DNA sequence encoding the signal peptide from human CD33 was fused to the C-terminal
polyhistidine tagged extracellular domain of human LDL Receptor (LDL R) (Ala 22 - Arg 788)
(Yamamoto, T. et al., 1984, Cell 39:27 - 38). The protein was expressed in a mouse myeloma
cell line, NS0.
• The recombinant polyhistidine tagged human LDL R, generated by proteolytic removal of the
signal peptide region, is a monomeric protein. Based on N-terminal sequencing, the mature
recombinant human LDL R protein begins with Ala 22 and has a calculated molecular mass of
85.5 kDa. As a result of glycosylation, the recombinant protein migrates as an approximately 110
- 140 kDa protein in SDS-PAGE under reducing conditions.
• > 90%, as determined by SDS-PAGE and visualized by silver stain.
• < 1.0 EU per 1 μg of the cytokine as determined by the LAL method.
Activity of R&D LDL R
• Measured by its ability to bind human LDL in a functional ELISA.
• Immobilized humna LDL at 2 μg/mL (100 μL/well) can bind rhLDL R with a linear range of
3 - 200 ng/mL (100 μL/well).
• Lyophilized from a 0.2 μm filtered solution in PBS containing 50 μg of bovine serum albumin per
1 μg of cytokine.
Reconstitution of of R&D LDL R
♦ It is recommended that sterile PBS containing at least 0.1% human serum albumin or bovine
serum albumin be added to the vial to prepare a stock solution of no less than 10 μg/mL.
Storage of R&D LDL R
• Lyophilized samples are stable for up to twelve months from date of receipt at -20° C to -70° C.
• Upon reconstitution, this cytokine can be stored under sterile conditions at 2° - 8° C for one
month or at -20° C to -70° C in a manual defrost freezer for three months without detectable
loss of activity.
• Avoid repeated freeze-thaw cycles.