>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
<0.10 EU per 1 μg of the protein by the LAL method.
Measured by its binding ability in a functional ELISA. When Recombinant Cynomolgus Monkey Fc gamma RIIB/CD32b is immobilized on
a His Tag Antibody coated plate, it binds Biotinylated Human IgG. The
of Biotinylated Human IgG that
produces 50% of the optimal binding response is approximately 0.3-1.5
Human embryonic kidney cell, HEK293-derived Ala46-Pro217, with a C-terminal 6-His tag
When Recombinant Cynomolgus Monkey Fc gamma RIIB/CD32b(Catalog # 9246-CD) is immobilized on a His Tag Antibody coated plate,Biotinylated Human IgG binds with an ED50 of 0.3-1.5 μg/mL.
Background: Fc gamma RIIB/CD32b
Receptors for the Fc region of IgG (Fc gamma Rs) are members of the Ig superfamily that function in the activation or inhibition of immune responses such as degranulation, phagocytosis, ADCC (antibody-dependent cellular toxicity), cytokine release, and B cell proliferation (1). The Fc gamma Rs have been divided into three classes based on close relationships in their extracellular domains; these groups are designated Fc gamma RI/CD64, Fc gamma RII/CD32, and Fc gamma RIII/CD16. CD32 proteins are encoded by three genes in human (Fc gamma RII A, B, and C), two in cynomolgus (Fc gamma RII A and B), and one in mouse (Fc gamma RIIB). Fc gamma RII A and C contain activating cytoplasmic ITAM sequences, while Fc gamma RIIB contains an inhibitory cytoplasmic ITIM sequence. The CD64 proteins are high affinity receptors (~10-8-10-9 M) capable of binding monomeric IgG, whereas the CD16 and CD32 proteins bind IgG with lower affinities (~10-6-10-7 M) and only recognize IgG aggregates surrounding multivalent antigens (1). The approximately 40 kDa mature cynomolgus Fc gamma RIIB consists of a 175 amino acid (aa) extracellular domain (ECD) with two Ig-like domains, a 23 aa transmembrane segment, and a 51 aa cytoplasmic domain. Within the ECD, cynomolgus Fc gamma RIIB shares 90%, 64%, and 61% aa sequence identity with human, mouse, and rat Fc gamma RIIB, respectively. It binds to both cynomolgus and human IgG subclasses 1-4 (2). Fc gamma RIIB is expressed on B cells, monocytes, dendritic cells, neutrophils, mast cells, and basophils (1). Ligation of Fc gamma RIIB triggers signaling that suppresses B cell expansion, plasma cell differentiation, production of autoimmune rheumatoid factors, and down-regulation of TLR4 with reduced LPS responsiveness (3-6).
Nimmerjahn, F. and J.V. Ravetch (2008) Nat. Rev. Immunol. 8:34.
CD32 antigen; CD32b; CD32Fc fragment of IgG, low affinity II, receptor for (CD32); CDw32; Fc fragment of IgG, low affinity IIb, receptor (CD32); Fc fragment of IgG, low affinity IIb, receptor for (CD32); Fc gamma RIIb; Fc gamma RIIB/CD32b; FCG2; Fc-gamma RII-b; fc-gamma-RIIb; FCGR2; FCGR2B; FcgRIIB; FCRIIB; fcRII-b; IGFR2; IgG Fc receptor II-b; low affinity immunoglobulin gamma Fc region receptor II-b