title: Light up G-quadruplex DNA with a [2.2.2]heptamethinecyanine dye.
abstract: The interactions of a triangle-shaped [2.2.2]heptamethinecyanine dye 1, namely 1,5,7-tris-[3-methylbenzothiazol-2-yl]-[2.2.2]heptamethindiium, with quadruplex DNA were studied with photometric and fluorimetric titrations, thermal DNA denaturation, CD and (1)H-NMR spectroscopy. The ligand binds to the quadruplex DNA with moderate affinity (K = 8 × 10(5) M(-1)), mainly by terminal π stacking. Remarkably, the ligand 1 exhibits a selectivity for quadruplex DNA relative to duplex DNA. Whereas the cyanine dye is very weakly fluorescent in aqueous solution, the emission intensity increases by a factor of >100 upon association with quadruplex DNA. Thus, it is shown that trinuclear cyanine derivatives may be employed as selective probes for the fluorimetric detection of quadruplex DNA.
authors.affiliation: University of Siegen, Organic Chemistry II, Adolf-Reichwein-Str. 2, D-57068, Siegen, Germany. ihmels@chemie.uni-siegen.de
authors.forename: Heiko
authors.initials: H
authors.lastname: Ihmels
authors.forename: Laura
authors.initials: L
authors.lastname: Thomas
mesh_terms: D052160:Benzothiazoles / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D054856:G-Quadruplexes; D015394:Molecular Structure
chemical_list: C584691:1,5,7-tris-(3-methylbenzothiazol-2-yl)-(2.2.2)heptamethindiium; D052160:Benzothiazoles; D004396:Coloring Agents; D004247:DNA