G-Quadruplex DNA (g-quadruplex + dna)

Distribution by Scientific Domains


Selected Abstracts


Conformational Switching of G-Quadruplex DNA by Photoregulation,

ANGEWANDTE CHEMIE, Issue 31 2010
Xiaolin Wang
Beugen , und strecken: Ein Azobenzol-Derivat wurde genutzt, um die reversible Streckung und Faltung von G-Quadruplex-DNA bei Lichteinstrahlung auszulösen (siehe Bild). Der G-Quadruplex, der in Gegenwart des trans -Isomers gebildet wird, dissoziiert unter UV-Bestrahlung, und das entstehende offene Oligomer faltet unter Bestrahlung mit sichtbarem Licht in einen G-Quadruplex zurück. Diese Nanofunktionseinheit wandelt also Licht direkt in mechanische Arbeit um. [source]


Stabilization of G-Quadruplex DNA with Platinum(II) Schiff Base Complexes: Luminescent Probe and Down-Regulation of c- myc Oncogene Expression

CHEMISTRY - A EUROPEAN JOURNAL, Issue 47 2009
Peng Wu Dr.
Abstract The interactions of a series of platinum(II) Schiff base complexes with c- myc G-quadruplex DNA were studied. Complex [PtL1a] (1,a; H2L1a=N,N,-bis(salicylidene)-4,5-methoxy-1,2-phenylenediamine) can moderately inhibit c- myc gene promoter activity in a cell-free system through stabilizing the G-quadruplex structure and can inhibit c- myc oncogene expression in cultured cells. The interaction between 1,a and G-quadruplex DNA has been examined by 1H NMR spectroscopy. By using computer-aided structure-based drug design for hit-to-lead optimization, an in silico G-quadruplex DNA model has been constructed for docking-based virtual screening to develop new platinum(II) Schiff base complexes with improved inhibitory activities. Complex [PtL3] (3; H2L3=N,N,-bis{4-[1-(2-propylpiperidine)oxy]salicylidene}-4,5-methoxy-1,2-phenylenediamine) has been identified with a top score in the virtual screening. This complex was subsequently prepared and experimentally tested in vitro for its ability to stabilize or induce the formation of the c -myc G-quadruplex. The inhibitory activity of 3 (IC50=4.4,,M) is tenfold more than that of 1,a. The interaction between 1,a or 3 with c- myc G-quadruplex DNA has been examined by absorption titration, emission titration, molecular modeling, and NMR titration experiments, thus revealing that both 1,a and 3 bind c- myc G-quadruplex DNA through an external end-stacking mode at the 3' terminal face of the G-quadruplex. Such binding of G-quadruplex DNA with 3 is accompanied by up to an eightfold increase in the intensity of photoluminescence at ,max=652,nm. Complex 3 also effectively down-regulated the expression of c- myc in human hepatocarcinoma cells. [source]