Receptors for the Fc region of IgG (Fc?R) are members of the Ig superfamily that function in the activation or inhibition of immune responses. Human Fc?Rs are divided into three classes designated Fc?RI (CD64); Fc?RII (CD32); and Fc?RIII (CD16); which generate multiple isoforms; are recognized. The activating- type receptor either has or associates non-covalently with an accessory subunit that has an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic domain. Fc?RI binds IgG with high affinity and functions during early immune responses; whereas Fc?RII and RIII are low affinity receptors that recognize IgG as aggregates surrounding multivalent antigens during late immune responses. Three genes for human Fc?RII (A; B; and C) and one for mouse (Fc?RIIB); encoding type I transmembrane proteins with ITAM motifs (Fc?RII A and C) or ITIM motifs (Fc?RIIB) in their cytoplasmic domains; have been identified. Human CD32; also known as Low affinity immunoglobulin ? Fc region receptor II-a (IgG Fc receptor II-a); Fc?RII A or FCGR2A Protein; is expressed on cells of both myeloid and lymphoid lineages as well as on cells of non-hematopoietic origin. Associated with an ITAM-bearing adapter subunit; FcR?; CD32a (Fc?RII A) delivers an activating signal upon ligand binding; and results in the initiation of inflammatory responses including cytolysis; phagocytosis; degranulation; and cytokine production. The responses can be modulated by signals from the co-expressed inhibitory receptors such as Fc? RII B; and the strength of the signal is dependent on the ratio of expression of the activating and inhibitory receptors.
Product Name:
Human CD32a/FCGR2A Recombinant Protein (RPES0287)
Product Code:
RPES0287
Size:
20µg
Species:
Human
Expressed Host:
HEK293 Cells
Synonyms:
Low affinity immunoglobulin gamma Fc region receptor II-a, IgG Fc receptor II-a, CDw32, Fc-gamma RII-a, Fc-gamma-RIIa, FcRII-a, CD32, FCGR2A, FCG2, FCGR2A1,IGFR2,CD32A,CDw32,Fc gamma RIIA,FCG2,FcGR,FCGR2
Accession:
P12318-1
Sequence:
Met 1-Met 210
Fusion tag:
C-His & AVI
Activity:
1. Measured by its binding ability in a functional ELISA. Immobilized human IgG2 at 10 µg/ml (100 ?l/well) can bind biotinylated human CD32 with a linear ranger of 0.16-0.8 µg/ml.2. Using the Octet RED System; the affinity constant (Kd) of CD32a-AVI-His + BirA bound to human IgG was 12nM.3. Labeling ratio of biotin to protein: 0.1-0.6.
Endotoxin:
<1.0 EU per µg as determined by the LAL method.
Protein Construction:
A DNA sequence encoding the extracellular domain (Met 1-Met 210) of human CD32a (P12318-1) was fused with a c-terminal polyhistidine tagged AVI tag at the C-terminus. The expressed protein was biotinylated in vivo by the Biotin-Protein ligase (BirA enzyme) which is co-expressed. It is identical to FCGR2A131H/R in the reference.
Purity:
> 95 % as determined by reducing SDS-PAGE.
Mol Mass:
23.6 kDa
AP Mol Mass:
33 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.
