title: X-ray scattering from immunostimulatory tetrapod-shaped DNA in aqueous solution to explore its biological activity-conformation relationship.
abstract: We carried out synchrotron X-ray scattering experiments from four DNA supermolecules designed to form tetrapod shapes; these supermolecules had different sequences but identical numbers of total base pairs, and each contained an immunostimulatory CpG motif. We confirmed that the supermolecules did indeed form the expected tetrapod shape. The sample that had the largest radius of gyration (Rg) induced the most cytokine secretion from cultured immune cells. Structural analysis in combination with a rigid tetrapod model and an atomic scale DNA model revealed that the larger Rg can be ascribed to dissociation of the DNA double strands in the central connecting portion of the DNA tetrapod. This finding suggests that the biological activity is related to the ease with which single DNA strands can be formed.
authors.affiliation: Department of Chemistry and Biochemistry, University of Kitakyushu , 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sanada
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Sakamoto
authors.forename: Tomoki
authors.initials: T
authors.lastname: Shiomi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Okobira
authors.forename: Efstratios
authors.initials: E
authors.lastname: Mylonas
authors.forename: Noboru
authors.initials: N
authors.lastname: Ohta
authors.forename: Naoto
authors.initials: N
authors.lastname: Yagi
authors.forename: Makiya
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Isamu
authors.initials: I
authors.lastname: Akiba
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takakura
authors.forename: Kazuo
authors.initials: K
authors.lastname: Sakurai
mesh_terms: D000818:Animals; D002460:Cell Line; D003198:Computer Simulation; D018899:CpG Islands; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008957:Models, Genetic; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D012542:Scattering, Radiation; D012996:Solutions; D012997:Solvents / Q000737:chemistry*; D017356:Synchrotrons; D044366:Transition Temperature; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014867:Water / Q000737:chemistry*; D014965:X-Rays
chemical_list: D012996:Solutions; D012997:Solvents; D014409:Tumor Necrosis Factor-alpha; D014867:Water; D004247:DNA