title: Fluorescence detection of cytosine/guanine transversion based on a hydrogen bond forming ligand.
abstract: In combination with abasic site (AP site)-containing oligodeoxynucleotides (ODNs), we demonstrate potential use of a hydrogen bond forming ligand, 2-amino-7-methyl-1,8-naphthyridine (AMND), for the fluorescence detection of the cytosine (C)/guanine (G) mutation sequence of the cancer repression gene p53. Our method is based on construction of the AP site in ODN duplexes, which allows small synthetic ligands to bind to target nucleobases accompanied by fluorescence signaling: an AP site-containing ODN is hybridized with a target ODN so as to place the AP site toward a target nucleobase, by which hydrophobic microenvironments are provided for ligands to recognize target nucleobases through hydrogen-bonding. In 10mM sodium cacodylate buffer solutions (pH, 7.0) containing 100mM NaCl and 1.0mM EDTA, AMND is found to strongly bind to C (K(d)=1.5x10(-6)M) in the target ODN while the binding affinity for G is relatively moderate (K(d)=50x10(-6)M). Significant fluorescence quenching of AMND is observed only when binding to C, making it possible to judge the C/G transversion with the naked eye.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Nishizawa
authors.forename: Keitaro
authors.initials: K
authors.lastname: Yoshimoto
authors.forename: Takehiro
authors.initials: T
authors.lastname: Seino
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Xu
authors.forename: Masakazu
authors.initials: M
authors.lastname: Minagawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Satake
authors.forename: Aijun
authors.initials: A
authors.lastname: Tong
authors.forename: Norio
authors.initials: N
authors.lastname: Teramae