title: Purification, crystallization and preliminary X-ray crystallographic analysis of human IL-18 and its extracellular complexes.
abstract: Interleukin-18 (IL-18), a pro-inflammatory cytokine belonging to the interleukin-1 (IL-1) family, is involved in the pathogenesis of autoimmune/autoinflammatory and allergic diseases such as juvenile idiopathic arthritis and bronchial asthma. IL-18 forms a signalling complex with the IL-18 receptor α (IL-18Rα) and β (IL-18Rβ) chains; however, the detailed activation mechanism remains unclear. Here, the IL-18-IL-18Rα binary and IL-18-IL-18Rα-IL-18Rβ ternary complexes were purified and crystallized as well as IL-18 alone. An X-ray diffraction data set for IL-18 was collected to 2.33 Å resolution from a crystal belonging to space group P21, with unit-cell parameters a = 68.15, b = 79.51, c = 73.46 Å, β = 100.97°. Crystals of both the IL-18 binary and ternary complexes belonging to the orthorhombic space groups P21212 and P212121, respectively, diffracted to 3.10 Å resolution. Unit-cell parameters were determined as a = 135.49, b = 174.81, c = 183.40 Å for the binary complex and a = 72.56, b = 111.56, c = 134.57 Å for the ternary complex.
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Naotaka
authors.initials: N
authors.lastname: Tsutsumi
authors.affiliation: Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho,Tsurumi-ku, Yokohama, Japan.
authors.forename: Kyohei
authors.initials: K
authors.lastname: Arita
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Ariyoshi
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ohnishi
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Kondo
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shirakawa
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan.
authors.forename: Zenichiro
authors.initials: Z
authors.lastname: Kato
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Hidehito
authors.initials: H
authors.lastname: Tochio
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002850:Chromatography, Gel; D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D020382:Interleukin-18 / Q000737:chemistry* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D011485:Protein Binding; D053724:Receptors, Interleukin-18 / Q000737:chemistry* / Q000302:isolation & purification; D061987:Sf9 Cells; D018411:Spodoptera
chemical_list: C000589760:IL18 protein, human; D020382:Interleukin-18; D053724:Receptors, Interleukin-18
keywords: IL-1 superfamily; allergy; autoimmunity; immunity; inflammation; interleukin-18; interleukin-18 receptor α; interleukin-18 receptor β