The research on the G-quadruplex DNAs has received much attention in recent years and numerous reports appeared probing its detection, structure, stability, reactivity and selectivity, aimed mainly for the chemical intervention of specific biological activity or sensor applications. Our study has demonstrated the use of a fluorogenic dye, Thioflavin T, to stabilize the telomeric DNA strand into...

Understanding the nature of the interaction between small molecules and G-quadruplex DNA is crucial for the development of novel anticancer drugs. In this paper, we present the first data on time-resolved fluorescence anisotropy study on the interaction between a water-soluble cationic porphyrin H(2)TMPyP4 and four distinct G-quadruplex DNAs, that is, AG(3)(T(2)AG(3))(3), thrombin-binding aptam...

Replacement of deoxyguanosine (dG) nucleobases within G-tetrads of G-quadruplex folding oligonucleotides with donor (D)/acceptor (A) fluorescent 8aryldG residues provides diagnostic FRET signalling for G-quadruplex detection.

The G-quadruplex is a non-canonical DNA structure biologically significant in DNA replication, transcription and telomere stability. To date, only G4s with all guanines originating from the same strand of DNA have been considered in the context of the human nuclear genome. Here, I discuss interstrand topological configurations of G-quadruplex DNA, consisting of guanines from both strands of gen...

We have used both adaptive biasing force (ABF) and regular molecular dynamics (MD) simulations to investigate the asymmetrical NH(4)(+) ion movement inside of a bimolecular G-quadruplex DNA structure [d(G(3)T(4)G(4))](2). The free-energy landscapes obtained from ABF MD simulations suggest that the NH(4)(+) ion exiting the [d(G(3)T(4)G(4))](2) G-quadruplex stem in the direction toward the edge-t...

This is a correction to the following paper: General peroxidase activity of a parallel G-quadruplex-hemin DNAzyme formed by Pu39WT a mixed G-quadruplex forming sequence in the Bcl-2 P1 promoter, Bo Liu, Da Li* and Hong Shang*, Chemistry Central Journal 2014, 8:43 (1 July 2014). CorrectionThis is a correction to the following paper: Generalperoxidase activity of a parallel G-quadruplex-h...

We describe a general multinuclear (1H, 23Na, 87Rb) NMR approach for direct detection of alkali metal ions bound to G-quadruplex DNA. This study is motivated by our recent discovery that alkali metal ions (Na+, K+, Rb+) tightly bound to G-quadruplex DNA are actually "NMR visible" in solution (Wong, A.; Ida, R.; Wu, G. Biochem. Biophys. Res. Commun. 2005, 337, 363). Here solution and solid-state...

The double helix is a conformation that genomic DNA usually assumes; under certain conditions, however, guanine-rich DNA sequences can form a four-stranded structure, G-quadruplex, which is found to play a role in regulating gene expression. Indeed, it has been demonstrated that the G-quadruplex formed in the c-MYC promoter suppresses its transcriptional activity. Recent studies suggest that G-...

The present work is devoted to the analysis of the G-quadruplex DNA structure using the bioinformatics method. The interest towards quadruplex DNAs is determined by their involvement in the functioning of telomeres and onco-promoters as well as by the possibility to create on their basis aptamers and nanostructures. Here, we present an algorithm for a general analysis of the polymorphism of the...

The human oncogene c-myc is regulated by G-quadruplex formation within the nuclease hypersensitive element (NHE III(I)) in the c-myc promoter, making the quadruplex a strong anti-cancer target. With respect to this, the competing equilibrium between intramolecular quadruplex folding and bimolecular duplex formation is poorly understood and very few techniques have addressed this problem. We pre...