title: Preparation, crystallization and preliminary X-ray diffraction studies of the glycosylated form of human interleukin-23.
abstract: Interleukin-23 (IL-23), a member of the IL-12 family, is a heterodimeric cytokine composed of p19 and p40 subunits. IL-23 plays crucial roles in the activation, proliferation and survival of IL-17-producing helper T cells which induce various autoimmune diseases. Human p19 and p40 subunits were cloned and coexpressed in N-acetylglucosaminyltransferase I-negative 293S cells, which produce high-mannose-type glycosylated proteins in order to diminish the heterogeneity of modified N-linked glycans. The glycosylated human IL-23 was purified and crystallized by the hanging-drop vapour-diffusion method. X-ray diffraction data were then collected to 2.6 Å resolution. The crystal belonged to space group P6(1) or P6(5), with unit-cell parameters a = b = 108.94, c = 83.79 Å, γ = 120°. Assuming that the crystal contains one molecule per asymmetric unit, the calculated Matthews coefficient was 2.69 Å(3) Da(-1), with a solvent content of 54.2%. The structure was determined by the molecular-replacement method, with an initial R factor of 52.6%. After subsequent rigid-body and positional refinement, the R(work) and R(free) values decreased to 31.4% and 38.7%, respectively.
authors.affiliation: Division of Structural Biology, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kummoto 862-0973, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Shirouzono
authors.forename: Mami
authors.initials: M
authors.lastname: Chirifu
authors.forename: Chiharu
authors.initials: C
authors.lastname: Nakamura
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Yamagata
authors.forename: Shinji
authors.initials: S
authors.lastname: Ikemizu
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D006031:Glycosylation; D006801:Humans; D053759:Interleukin-23 / Q000737:chemistry*; D008958:Models, Molecular; D017434:Protein Structure, Tertiary
chemical_list: D053759:Interleukin-23