title: Fluorescent bioprobes: structural matching in the docking processes of aggregation-induced emission fluorogens on DNA surfaces.
abstract: Whereas most conventional DNA probes are flat disklike aromatic molecules, we explored the possibility of developing quadruplex sensors with nonplanar conformations, in particular, the propeller-shaped tetraphenylethene (TPE) salts with aggregation-induced emission (AIE) characteristics. 1,1,2,2-Tetrakis[4-(2-triethylammonioethoxy)phenyl]ethene tetrabromide (TPE-1) was found to show a specific affinity to a particular quadruplex structure formed by a human telomeric DNA strand in the presence of K(+) ions, as indicated by the enhanced and bathochromically shifted emission of the AIE fluorogen. Steady-state and time-resolved spectral analyses revealed that the specific binding stems from a structural matching between the AIE fluorogen and the DNA strand in the folding process. Computational modeling suggests that the AIE molecule docks on the grooves of the quadruplex surface with the aid of electrostatic attraction. The binding preference of TPE-1 enables it to serve as a bioprobe for direct monitoring of cation-driven conformational transitions between the quadruplexes of various conformations, a job unachievable by the traditional G-quadruplex biosensors. Methyl thiazolyl tetrazolium (MTT) assays reveal that TPE-1 is cytocompatible, posing no toxicity to living cells.
authors: Department of Chemistry, Nano Science and Technology Program, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China.
authors: Yuning
authors: Y
authors: Hong
authors: Hao
authors: H
authors: Xiong
authors: Jacky Wing Yip
authors: JW
authors: Lam
authors: Matthias
authors: M
authors: Häussler
authors: Jianzhao
authors: J
authors: Liu
authors: Yong
authors: Y
authors: Yu
authors: Yongchun
authors: Y
authors: Zhong
authors: Herman H Y
authors: HH
authors: Sung
authors: Ian D
authors: ID
authors: Williams
authors: Kam Sing
authors: KS
authors: Wong
authors: Ben Zhong
authors: BZ
authors: Tang
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D015374:Biosensing Techniques; D002151:Calorimetry; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D054856:G-Quadruplexes; D006367:HeLa Cells; D006801:Humans; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000633:toxicity; D055672:Static Electricity; D013267:Stilbenes / Q000737:chemistry / Q000633:toxicity; D016615:Telomere / Q000378:metabolism; D013816:Thermodynamics
chemical_list: C531393:1,1,2,2-tetrakis(4-(2-triethylammonioethoxy)phenyl)ethene tetrabromide; D005456:Fluorescent Dyes; D000644:Quaternary Ammonium Compounds; D013267:Stilbenes; D004247:DNA