Mouse CD32b Protein - Biotin (ICH3026B)

Please refer to the specific buffer information in the hardcopy of datasheet or the lot-specific COA.

This is a recombinant Mouse CD32b (FcgammaRIIb) protein, expressed in human embryonic kidney (HEK) 293 cells and corresponding to UniProt entry P08101. Mammalian HEK293 expression supports native-like folding and post-translational modification, including glycosylation, which helps preserve the conformational integrity of the extracellular Ig-like domains that mediate Fc engagement. The protein is validated for binding and biophysical applications such as surface plasmon resonance (SPR), bio-layer interferometry (BLI), and ELISA, making it well suited to characterizing antibody Fc-FcgammaR interactions, ranking Fc variants, and studying inhibitory receptor engagement in vitro. It is manufactured to an ultra-low endotoxin specification, which minimizes confounding innate-immune activation in cell-based assays and other endotoxin-sensitive systems. Supplied for research use only (RUO) and available in bulk quantities, it is intended as a reagent-grade protein for functional and structural studies rather than as a therapeutic or in-vivo dosing agent. No clone or isotype applies, as this is a recombinant protein and not an antibody. Mouse CD32b (FcgammaRIIb, encoded by Fcgr2b) is the only inhibitory Fcgamma receptor in the mouse and a key negative regulator of humoral and innate immune responses. It is a low-affinity receptor for the Fc region of aggregated IgG (IgG1, IgG2a, IgG2b) and signals through a cytoplasmic immunoreceptor tyrosine-based inhibitory motif (ITIM). On B cells, co-ligation of CD32b with the B-cell receptor raises the threshold for activation and dampens antibody production, contributing to peripheral tolerance. On myeloid cells such as macrophages and dendritic cells, CD32b restrains activating FcgammaR signaling, phagocytosis, and inflammatory cytokine release. The balance between CD32b and activating receptors (CD16, CD32a-equivalents, CD64) sets the threshold for antibody effector function, making CD32b central to studies of immune-complex handling, antibody engineering, and Fc-dependent therapeutic mechanisms.