Product Specifications for Recombinant Human pIgR Protein, CF
Mouse myeloma cell line, NS0-derived human pIgR protein Lys19-Arg638, with a C-terminal 6-His tag
>97%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
<0.01 EU per 1 μg of the protein by the LAL method.
N-terminal sequence Analysis
Predicted Molecular Mass
90-95 kDa, reducing conditions
Measured by its binding ability in a functional ELISA. When Recombinant Human plgR is immobilized at 2 μg/mL (100 μL/well), the concentration of human IgM that produces 50% of the optimal binding response is found to be approximately 20-100 ng/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 sterile 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 human polymeric immunoglobulin receptor (pIgR; also known as membrane secretory component) is a 100 kDa type I transmembrane glycoprotein that is synthesized as a 764 amino acid (aa) precursor. It includes a signal sequence (aa 1-18), an extracellular region (aa 19-638), a transmembrane segment (aa 639-661), and a cytoplasmic domain (aa 662-764) (1-3). The extracellular region consists of five Ig-like domains and a sixth non-Ig domain that connects to the membrane region. pIgR is expressed on secretory epithelial cells of exocrine tissues. Immunoglobulin isotypes consist of two heavy (H) and two light (L) chains. For IgA and IgM, this H2L2 monomer can form larger polymers through association with a joining chain (J chain). The Fc regions of IgA and IgM have a carboxy-terminal extension called a secretory tailpiece that binds the J chain (4). pIgR functions as a carrier that transports IgA and IgM across epithelium (5). On the basolateral surface of epithelial cells, the receptor initially binds non-covalently to IgA via a docking site on the J chain. This initiates a rearrangement in which a disulfide bond forms between pIgR and an IgA heavy chain (2). The complexes are then internalized and transcytosed to the apical surface. A soluble covalent complex called secretory IgA (SIgA) is now generated by proteolytic cleavage of the sixth extracellular domain of pIgR and released into the lumen (6). This IgA-bound and proteolytically generated pIgR fragment is referred to as secretory component (SC). Notably, human pIgR transcytoses constitutively, with or without ligand, creating both bound and free, 78 kDa SC following cleavage (3). The extracellular region of pIgR is 64%, 65% and 70% aa identical to the equivalent region in rat, mouse and porcine, respectively. The receptor component of the complex anchors the SIgA molecule to mucous (7). SIgA is a crucial component of the mucosal immune system serving to protect the large expanse of mucous membranes that form a barrier between the interior of the body and the external environment (8).
Krajci, P. et al. (1989) Biochem. Biophys. Res. Commun. 158:783.
Piskurich, J. et al. (1995) J. Immunol. 154:1735.
Brandtzaeg, P. and F-E. Johansen (2001) Trends Immunol. 22:545.
Braathen, R. et al. (2002) J. Biol. Chem. 277:42755.
Ben-Hur, H. et al. (2004) Int. J. Mol. Med. 14:35.
Asano, M. et al. (2004) Immunology 112:583.
Phalipon, A. and B. Corthesy (2003) Trends Immunol. 24:55.
Uren, T. et al. (2003) J. Immunol. 170:2531.
Polymeric Immunoglobulin Receptor
Entrez Gene IDs
5284 (Human); 18703 (Mouse)
FLJ22667, Hepatocellular carcinoma-associated protein TB6, MGC125361, MGC125362, Poly-Ig receptor, hepatocellular carcinoma associated protein TB6, pIgR, polymeric immunoglobulin receptor
Which Brands are Currently Available on bio‑techne.com? R&D Systems, Tocris Bioscience and ProteinSimple branded products are available to purchase through bio‑techne.com. ProteinSimple branded instruments are available to quote. ACD branded products will be available on bio‑techne.com in the near future. Novus Biologicals branded products are not currently available on bio‑techne.com and can be found at novusbio.com.
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