title: Competitive binding of abasic site-binding ligands and masking ligands to DNA duplexes for the analysis of single-base mutation.
abstract: We describe a competitive binding assay for the analysis of single-base mutation by using abasic site (AP site)-specific binding fluorescent ligands and masking ligands bound to the AP site in DNA duplexes.  2-Amino-5,6,7-trimethyl-1,8-naphthyridine (ATMND) can strongly bind to not only cytosine (C), but also thymine (T) opposite an AP site in the DNA duplexes (K(11)/10(7) M(-1): C, 15; T, 7.0).  By contrast, in the presence of lumichrome (Lch) as a masking ligand, ATMND shows a clear binding selectivity for C over T (K(11)/10(7) M(-1): C, 7.0; T, 0.57), which is ascribed to the effective masking effect of Lch to the ATMND-T interaction in the AP site-containing DNA duplexes.  It was shown that the competitive binding of ATMND and Lch to the AP site allowed the highly selective detection of C-related single-base mutation in DNAs amplified by polymerase chain reaction.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Aoba, Sendai, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sato
authors.forename: Tomoe
authors.initials: T
authors.lastname: Kageyama
authors.forename: Seiichi
authors.initials: S
authors.lastname: Nishizawa
authors.forename: Norio
authors.initials: N
authors.lastname: Teramae
mesh_terms: D001667:Binding, Competitive; D003596:Cytosine / Q000737:chemistry; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D004252:DNA Mutational Analysis / Q000379:methods*; D005415:Flavins / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D009287:Naphthyridines / Q000737:chemistry*; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D013050:Spectrometry, Fluorescence; D013941:Thymine / Q000737:chemistry
chemical_list: C528376:2-amino-5,6,7-trimethyl-1,8-naphthyridine; D005415:Flavins; D008024:Ligands; D009287:Naphthyridines; C001559:7,8-dimethylalloxazine; D003596:Cytosine; D004247:DNA; D013941:Thymine