title: G quadruplex-based FRET probes with the thrombin-binding aptamer (TBA) sequence designed for the efficient fluorometric detection of the potassium ion.
abstract: The dual-labeled oligonucleotide derivative, FAT-0, carrying 6- carboxyfluorescein (FAM) and 6-carboxytetramethylrhodamine (TAMRA) labels at the 5' and 3' termini of the thrombin-binding aptamer (TBA) sequence 5'-GGT TGG TGT GGT TGG-3', and its derivatives, FAT-n (n=3, 5, and 7) with a spacer at the 5'-end of a TBA sequence of T(m)A (m=2, 4, and 6) have been designed and synthesized. These fluorescent probes were developed for monitoring K(+) concentrations in living organisms. Circular dichroism, UV-visible absorption, and fluorescence studies revealed that all FAT-n probes could form intramolecular tetraplex structures after binding K(+). Fluorescence resonance energy transfer and quenching results are discussed taking into account dye-dye contact interactions. The relationship between the fluorescence behavior of the probes and the spacer length in FAT-n was studied in detail and is discussed.
authors.affiliation: Department of Applied Chemistry, Kyushu University, Motooka, 819-0395, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Nagatoishi
authors.forename: Takahiko
authors.initials: T
authors.lastname: Nojima
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Galezowska
authors.forename: Bernard
authors.initials: B
authors.lastname: Juskowiak
authors.forename: Shigeori
authors.initials: S
authors.lastname: Takenaka
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001483:Base Sequence; D031541:Fluorescence Resonance Energy Transfer; D005470:Fluorometry; D007477:Ions / Q000737:chemistry; D011188:Potassium / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D052157:Aptamers, Nucleotide; D007477:Ions; C081676:thrombin aptamer; D011188:Potassium