title: Strong positive cooperativity in binding to the A3T3 repeat by Hoechst 33258 derivatives attaching the quinoline units at the end of a branched linker.
abstract: Hoechst 33258 derivatives with additional interacting moieties attached at the ends of branched linkers were synthesized, and their DNA binding properties were investigated with regard to the A3T3 repeat by measuring fluorescence spectra. The binding property of the ligand was investigated by fluorescence titration, and the titration data were analyzed using the McGhee-von Hippel method. Ligand 6Q with the quinolin-6-yloxyacetyl group and Ligand IQ with isoquinolin-6-yloxyacetyl group at the ends of the branched linkers exhibit highly positive cooperativity for the DNA having 5 A3T3 sites with 3 base-insertions between them with sequence selectivity. The strategy developed in this study may be generally applicable for designing ligands for repetitive DNA sequences.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Koda
authors.affiliation: School of Pharmacy, University of Reading, Chemistry Building, Whiteknights, PO Box 224, Reading RG6 6AD, UK.
authors.forename: John Alan
authors.initials: JA
authors.lastname: Brazier
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Ippei
authors.initials: I
authors.lastname: Onishi
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: sasaki@phar.kyushu-u.ac.jp.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Sasaki
mesh_terms: D006690:Bisbenzimidazole / Q000737:chemistry*; D011804:Quinolines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011804:Quinolines; D006690:Bisbenzimidazole
keywords: Cooperative binding; DNA repeat; Fluorescence titration; Hoechst; McGhee–von Hippel equation