Purification, crystallization and preliminary X-ray crystallographic analysis of human IL-18 and its extracellular complexes

IL-18 and its two receptors, IL-18Rα and IL-18Rβ, were purified for crystallization and biochemical analysis. IL-18 was crystallized in free, IL-18Rα-bound and IL-18Rα/IL-18Rβ-bound states and complete X-ray data sets suitable for further structural analysis were obtained from each crystal.