FcRn (FCGRT & B2M)

FcRn is a heterodimer comprising a β2-microglobulin (β2m) light chain and a major histocompatibility complex class I-like heavy chain. It is widely accepted that the interaction of IgGs with the Fc FcRn plays a critical role in regulating IgG homeostasis in vivo. FcRn interacts with the CH2-CH3 portion of the Fc domain of IgGs in a tightly regulated pH-dependent manner with high affinity binding occurring at an acidic (pH 6.0) and weak to no binding interactions as the pH is raised to neutral (pH 7.4). FcRn is responsible for the extended serum half-life of IgG and also serum albumin, and for the transport across endothelial and epithelial barriers, increasing the overall bioavailability of IgG and serum albumin. The binding affinity between FcRn and IgG are commonly used to characterize the metabolic levels of antibody drugs.
The Human FcRn Binding Kit (TR-FRET) takes advantage of binding of Europium-chelate labeled FcRn (donor) and FA labeled Human IgG1 antibody (acceptor) in a homogeneous (no wash) TR-FRET (Time-Resolved Fluorescence Resonance Energy Transfer) competition assay to measure the interaction between human FcRn and antibody drug candidates or FcRn inhibitors. It is designed to facilitate the half-life evaluation of antibody drug candidates, and also high-throughput screening of FcRn inhibitors within 0.5-1 hours. It is highly sensitive, has a short detection time and easy to use.