Human CD16b (NA2) Protein (In Vivo Grade, Ultra-Low Endotoxin) (ICH3017)

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

This is a recombinant Human CD16b (FcgRIIIb) protein carrying the NA2 allotype, expressed in HEK293 cells to preserve mammalian glycosylation and native folding. It corresponds to UniProt O75015 (FCG3B_HUMAN). As a purified soluble ectodomain reagent it is intended for in-vitro binding and biophysical work rather than animal dosing: the listed applications are SPR, BLI and ELISA, all of which rely on well-behaved, correctly folded protein with defined activity. Produced under an in-vivo-grade, ultra-low-endotoxin process (<0.5 EU/mg), it is suited to sensitive functional and cell-based assays where endotoxin would confound results, and to affinity/kinetic studies of Fc-FcgR interactions. It is offered bulk at research scale and is RUO. Because CD16b is a receptor rather than a therapeutic-style blocking or depleting antibody, this item is typically used as an analyte or immobilised ligand to characterise antibody Fc engineering, IgG allotype effects, and FcgRIIIb-directed binders, not as an in-vivo dosing agent. CD16b (FcgRIIIb, encoded by FCGR3B) is a low-affinity receptor for the Fc region of IgG. Unlike its close relative CD16a (FcgRIIIa), it is a GPI-anchored surface protein and is expressed almost exclusively on human neutrophils (and eosinophils under some conditions), making it a neutrophil-restricted marker. It binds aggregated IgG and immune complexes, contributing to neutrophil activation, immune-complex clearance, degranulation and NET formation, though because it lacks a transmembrane/cytoplasmic signalling domain it acts largely in concert with other receptors. FCGR3B carries clinically important allotypes, notably NA1 and NA2 (and SH), which differ in glycosylation and influence IgG binding and neutrophil effector function; these polymorphisms are relevant to autoimmune neutropenia and transfusion-related reactions. Copy-number variation at FCGR3B is linked to autoimmune susceptibility. The NA2 allotype represented here is widely used to study allotype-specific Fc engagement.