Human CD16b (NA1) Protein (In Vivo Grade, Ultra-Low Endotoxin) (ICH3016)

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

This is a recombinant Human CD16b (FcgammaRIIIb) protein carrying the NA1 allotype, expressed in HEK293 cells to preserve native mammalian folding and glycosylation (UniProt O75015). It is a soluble antigen/reagent protein rather than an antibody, supplied at research-grade purity with ultra-low endotoxin (<0.5 EU/mg) and offered in bulk mg-g quantities for RUO applications. HEK293 expression makes it well suited to biophysical and functional in-vitro work where correct conformation and post-translational modification matter: measuring Fc-CD16b engagement, screening antibody Fc variants or glyco-engineered candidates, and characterizing FcgammaRIIIb-directed binders. Validated for SPR, BLI, and ELISA, it serves as an immobilized ligand or soluble analyte for kinetic and affinity ranking. The low-endotoxin, bulk format supports assay-intensive campaigns and reagent-heavy screening pipelines. Note that this is a protein reagent, not an in-vivo therapeutic antibody, so the low-endotoxin specification here primarily benefits cell-based functional assays rather than animal dosing. CD16b, encoded by FCGR3B, is a low-affinity IgG Fc receptor (FcgammaRIIIb) expressed almost exclusively on human neutrophils (and eosinophils under some conditions). Unlike its close relative CD16a (FcgammaRIIIa), CD16b is a GPI-anchored receptor lacking a transmembrane and cytoplasmic signaling domain, so it signals through lateral association with other receptors rather than directly. It contributes to neutrophil-mediated immune-complex clearance, degranulation, and the capture of opsonized targets. FCGR3B is highly polymorphic, giving rise to the neutrophil antigen allotypes NA1 and NA2, which differ in glycosylation and IgG-subclass binding; these polymorphisms are clinically relevant in neonatal alloimmune neutropenia and autoimmune neutropenia. Copy-number variation at the FCGR3B locus also modulates neutrophil FcgammaR density and is associated with susceptibility to autoimmune conditions such as systemic lupus erythematosus.