No abstract

Trihydroxyphenyl porphyrin (POH3) was designed to specifically bind with a triplex DNA by a resultant turn-on fluorescence response. This ensemble can be developed into a catalytic triplex DNAzyme towards porphyrin...

Switching of G-quadruplex (G4) structures between variant types of folding has been proved to be a versatile tool for regulation of genomic expression and development of nucleic acid-based constructs. Various specific ligands have been developed to target G4s in K+ solution with therapeutic prospects. Although G4 structures have been reported to be converted by sequence modification or a unimolecular ligand binding event in K+-deficient conditions, switching G4s towards non-G4 folding continues to be a great challenge due to the stability of G4 in physiological K+ conditions. Herein, we first observed the G4 switching towards parallel-stranded duplex (psDNA) by multimolecular ligand binding (namely ligand clustering) to overcome the switching barrier in K+. Purine-rich sequences (e.g. those from the KRAS promoter region) can be converted from G4 structures to dimeric psDNAs using molecular rotors (e.g. thioflavin T and thiazole orange) as initiators. The formed psDNAs provided multiple binding sites for molecular rotor clustering to favor subsequent structures with stability higher than the corresponding G4 folding. Our finding provides a clue to designing ligands with the competency of molecular rotor clustering to implement an efficient G4 switching.

The heptad-interfaced G-quadruplexes (G4s), formed with GGA repeats locating in the nuclear proto-oncogene c-myb promoter, can be selectively targeted by a prenylated flavonol of sophoflavescenol (Sop) with restriction of molecular...

DNA-tuned dye assemblies have received considerable attention in developing variant devices. Owing to easy conformation implementation, G-quadruplexes (G4s) have been extensively used as initiators to grow dye assemblies with controllable...