The formation of the DNA G-quadruplex is induced by the addition of a novel porphyrin carrying four cationic tethers. Circular dichroism spectroscopy reveals that the porphyrin binds to Tetrahymena telomeric repeat to form G-quadruplex under stabilizing-cation-deficient and no buffer conditions.

The perceived motion of two added sinusoidal gratings of similar amplitude and spatial frequency but different orientations is often coherent. However, when either relative grating contrast or frequency are varied, perception may transform to a motion transparency. For plaids, both multiplicative and additive transparent percepts are reported. To explain perception, several computational models...

A water soluble Zn(II) porphyrazine drives the conformational equilibrium of the G-quadruplex of a human telomeric sequence exclusively towards a parallel conformation upon complexation.

G-quadruplex has attracted considerable attention due to their prevalent distribution in functional genomic regions and transcripts, which can importantly influence biological processes such as regulation of telomere maintenance, gene transcription and gene translation. Artificial receptor study has been developed for accurate identification of G-quadruplex from DNA species, since it is importa...

Telomestatin (TMS: 1) is as a potent and selective telomeric G-quadruplex binder. Two molecules of TMS were suggested to be intercalated to one telomeric G-quadruplex according to docking study. In this paper, we designed and synthesized hexaoxazole TMS derivative (6OTD) dimer, and evaluated its G-quadruplex stabilizing ability.

A non-fluorescent naphthalene diimide (NDI) dimer, conjugating red and blue NDI dyes, becomes red/NIR emitting upon G-quadruplex binding. The fluorescence lifetime which is significantly different for the complexes, the G-quadruplex/dimer and the weakly emitting ds-DNA/dimer is the key feature for the development of new rationally engineered G-quadruplex sensors.

The interactions of a series of platinum(II) Schiff base complexes with c-myc G-quadruplex DNA were studied. Complex [PtL(1a)] (1 a; H(2)L(1a)=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...

Here we report the analysis of dual G-quadruplexes formed in the four repeats of the consensus sequence from the insulin-linked polymorphic region (ACAGGGGTGTGGGG; ILPR(n)(=4)). Mobilities of ILPR(n)(=4) in nondenaturing gel and circular dichroism (CD) studies confirmed the formation of two intramolecular G-quadruplexes in the sequence. Both CD and single molecule studies using optical tweezers...

The ribozyme-sensitive element NHE-III1 in the P1 promoter region of the important proto-oncogene c-myc contains many guanine (G)-rich sequences. Induction and stabilization of the G-quadruplex formed by NHE-III1 can downregulate c-myc expression. In the present study, we found that QPB-15e, a quinazoline derivative designed and synthesized by our laboratory, binds to and stabilizes the c-myc G...

The nuclease hypersensitivity element III(1) upstream of the P1 promoter of c-MYC controls 85-90% of the transcriptional activation of this gene. We have demonstrated that the purine-rich strand of the DNA in this region can form two different intramolecular G-quadruplex structures, only one of which seems to be biologically relevant. This biologically relevant structure is the kinetically favo...