The IL-6 receptor system consists of two chains, IL-6R alpha and gp130. The IL-6R alpha is the binding component specific to the IL-6,
but does not transduce a signal alone. On the contrary, gp130 transmits signals not only of IL-6, but also IL-6 related cytokines, i.e.
LIF, OSM, CNTF, IL-11 and CT-1. The low affinity binding sites for IL-6, is composed of IL-6R alpha alone. At low concentrations, soluble
IL-6R alpha acts as an agonist of IL-6 activity. SBH Sciences' recombinant human sIL-6R alpha is a 37.6 kDa protein, consisting of the extra
cellular domain of the sIL-6R alpha chain (338 amino acids).