Fluorescence detection of cytosine/guanine transversion based on a hydrogen bond forming ligand

Seiichi Nishizawa; Keitaro Yoshimoto; Takehiro Seino; Chun-Yan Xu; Masakazu Minagawa; Hiroyuki Satake; Aijun Tong; Norio Teramae

doi:10.1016/j.talanta.2003.09.027

Fluorescence detection of cytosine/guanine transversion based on a hydrogen bond forming ligand

Talanta. 2004 May 10;63(1):175-9. doi: 10.1016/j.talanta.2003.09.027.

Authors

Seiichi Nishizawa¹, Keitaro Yoshimoto, Takehiro Seino, Chun-Yan Xu, Masakazu Minagawa, Hiroyuki Satake, Aijun Tong, Norio Teramae

Affiliation

¹ Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.

PMID: 18969416
DOI: 10.1016/j.talanta.2003.09.027

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.