Polymeric immunoglobulin receptor, also known as PIGR, is a member of the immunoglobulin superfamily and a Fc receptor. The ectodomain of this receptor consists of five units with homology to the variable units of immunoglobulins and a transmembrane region, which also has some homology to certain immunoglobulin variable regions. PIGR is expressed on several glandular epithelia including those of liver and breast. The deduced amino-acid sequence has a length of 764 residues and shows an overall similarity of 56% and 64% with the rabbit and rat counterpart. PIGR mediates transcellular transport of polymeric immunoglobulin molecules, and thus facilitates the secretion of IgA and IgM. During this process, a cleavage occurs that separates the extracellular (known as the secretory component) from the transmembrane segment of PIGR.
Measured by its binding ability in a functional ELISA.Immobilized rhhuman IgM at 2 µg/ml (100 ?l/well) can bind biotinylated PIGR with a linear range of 0.94-15 ng/ml.2. When human human IgM is immobilized at 2 µg/ml (100 ?l/well), PIGR inhibits 50% binding of biotinylated PIGR (0.062 µg/ml) at the concentration range of 0.03-20 µg/ml.
Endotoxin:
<1.0 EU per µg of the protein as determined by the LAL method.
Protein Construction:
A DNA sequence encoding the extracellular domain (Met 1-Arg 638, 365 Ser/Gly) of human PIGR (NP_002635.2) was expressed with a C-terminal polyhistidine tag.
Purity:
> 97 % as determined by reducing SDS-PAGE.
Mol Mass:
69 kDa
Formulation:
Lyophilized from sterile PBS, pH 7.4
Shipping:
This product is provided as lyophilized powder which is shipped with ice packs.
Stability and Storage:
Lyophilized proteins are stable for up to 12 months when stored at -20 to -80°C. Reconstituted protein solution can be stored at 4-8°C for 2-7 days. Aliquots of reconstituted samples are stable at < -20°C for 3 months.
