Backbone 1H, 13C, and 15N assignments of the extracellular region of human Fcγ receptor IIIb

Fc gamma receptor (Fc gamma R) promotes various immune responses through interactions with the Fc portion of immunoglobulin G (IgG). Fc gamma RIIIb is a glycosylphosphatidylinositol-linked protein expressed on neutrophils and triggers degranulation and opsonic phagocytosis. The extracellular region of Fc gamma R is composed of two Ig-fold domains and can be cleaved as a soluble form (sFc gamma RIIIb), which is also reactive with complement receptor type 3. Although structure and Fc interaction of sFc gamma RIIIb have been characterized by X-ray crystallography, little has been known about its structure in solution. We herein report the backbone NMR assignments of human sFc gamma RIIIb to gain basic understanding of functional IgG-Fc gamma RIII interactions of immunological and biopharmaceutical interest regarding the structural investigation.