Figure 1
From: Targeting glioma stem cells in vivo by a G-quadruplex-stabilizing synthetic macrocyclic hexaoxazole
6OTD stabilizes G4 structures. (A) Chemical structures of telomestatin (TMS) and 6OTD. (B) List of oligonucleotides used in the FRET melting assay. All oligonucleotides are dual-labeled with FAM and TAMRA at their 5′ and 3′ ends, respectively. Guanines involved in G4 formation are colored in green. (C) T m values of the oligonucleotides (0.2 μM) determined by the FRET melting assay in the absence or the presence of G4 ligands (1.0 μM) in K+-rich buffer. Each T m value represents the mean of triplicate assays (**P < 0.01). In the presence of TMS, T m values of telo21, bcl-2, and c-myc exceeded 98 °C, which was the highest temperature of this measurement. Error bars, standard deviation (SD). (D) ΔT m values for TMS and 6OTD against each nucleotide. Each value represents the mean ± SD of triplicate assays. (E) CD spectra of the telomeric 5′-d[TTAGGG]4-3′ (telo24) oligonucleotide in the presence of 100 mM KCl at 25 °C. Concentrations of telo24 and 6OTD were 10 μM and 50 μM, respectively. (F) SPR analysis of telo24 and dsDNA with 6OTD. KD value for the telo24-6OTD interaction was 163.7 ± 29.3 nM, determined by three independent experiments. KD value for the dsDNA-6OTD could not be determined due to the low affinity of the molecules.
