IL-4:IL-4RA TR-FRET Assay Kit

The IL-4:IL-4RA TR-FRET Assay Kit is designed to measure the binding activity of IL-4RA (interleukin 4 receptor alpha) to IL-4 for screening and profiling applications using TR-FRET (Time-Resolved Fluorescence Resonance Energy Transfer). It utilizes a Terbium-labeled donor and a labeled acceptor to complete the TR-FRET pairing. The IL-4:IL-4RA TR-FRET Assay Kit comes in a convenient 384-well format, with enough recombinant IL-4 (amino acids 25-153), recombinant biotinylated IL-4RA (amino acids 26-232), Tb-Labeled Donor and Dye-Labeled Acceptor and assay buffer for 400 reactions. Figure 1: IL-4:IL-4RA TR-FRET Assay Kit schematic. A sample containing terbium-labeled donor, dye-labeled acceptor, IL-4, IL-4RA, and an inhibitor is incubated for 90 minutes. When IL-4RA binds to IL-4, energy transfer occurs due to the proximity of the donor and acceptor. Disruption of the binding results in a decrease of energy transfer. Fluorescence intensity at lambda=665 nm corresponds directly to the binding of IL-4RA to IL-4. Need us to run inhibitor screens or profile your compounds against IL-4RA binding to IL-4? Check out our Immunotherapy Screening Services. Interleukin-4 is produced mainly by a subpopulation of activated T cells (Th2) that are the biologically most active helper cells for B cells and that also secrete IL-5 and IL-6. The biological activities of IL-4 are mediated by a specific receptor. The extracellular domain of the IL-4 receptor is related to the receptors for EPO (erythropoietin), IL-6, and the beta chain of the IL-2 receptor (CD122). There are two types of receptors for IL-4. Type 1 receptor is a heterodimer consisting of IL-4Ralpha (IL-4Ralpha) and IL-4Rgamma (IL-4Rgammac), mostly present on hematopoietic cells. The type 2 receptor is a heterodimer consisting of IL-4Ralpha and IL-13Ralpha1 (Il-13Ralpha1). IL-4 enhances expression of MHC (major histocompatibility class) 2 antigens on B cells. It can promote their capacity to respond to other B cell stimuli and to present antigens for T cells. Pretreatment of macrophages with IL-4 prevents the production of IL-1, TNFalpha (tumor necrosis factor alpha) and prostaglandins in response to activation of the cells by bacterial endotoxins or IFN-gamma (interferon gamma). IL-4 plays crucial roles in inflammation, fibrosis, allergic reactions, and cancer. The therapeutic exploitation of IL-4 signaling pathways can result in advances in the treatment of auto-immune disorders.