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.