Growth Factors & Cytokines

The IL-2 receptor system consists of three non-covalently linked subunits termed IL-2Rα, IL-2Rβ, and IL-2Rγ.  The IL-2Rα is a type I transmembrane protein consisting of a 219 amino acid extracellular domain, a 19 amino acid transmembrane domain and a 13 amino acid intracellular domain, which is not involved in the transduction of IL-2 signals.  Proteolytic processing of IL-2Rα releases the entire extracellular domain of IL-2Rα, thereby generating a 219 amino acid soluble protein called soluble IL-2Rα (sIL-2Rα).  The homodimeric form binds IL-2 (KD=10mM) and facilitates IL-2 signaling.  The secreted sIL-2Rα is expressed on leukemia cells, lymphoma cells, and newly activated T and B cells, as well as on approximately 10% of NK cells.  Recombinant Human sIL-2 Receptor α is a 24.8 kDa protein containing 219 amino acid residues consisting of only the extracellular domain of IL-2Rα. As a result of glycosylation, Recombinant Human sIL-2 Receptor α migrates with an apparent molecular mass of approximately 40-50 kDa by SDS-PAGE gel, under reducing and non-reducing conditions.