Fig. 5.

Compound 10 binds to DNA. Fluorescence emission of Compound 10 (50 nM) alone or in the presence of the indicated oligonucleotides. The emission peak of Compound 10 bound to DNA is at ∼370 nm. Excitation wavelength, 310 nm or 320 nm. FLU, fluorescence units. Results are representative of at least two independent experiments. (A) Compound 10 binds to the murine ARRE-2 oligonucleotide in a concentration-dependent manner. Excitation was at 320 nm for this experiment, and the sharp early peak at 360 nm in these scans is the expected Raman peak due to scattering from water. In the remaining figure panels, excitation was at 310 nm, and therefore the Raman peak was observed just below 350 nm. (B) Titration of Compound 10 (50 nM) with increasing concentrations of the murine ARRE-2 oligo. DNA concentrations: 0, 10, 50, 100, 500 nM; 1 and 5 μM, respectively. Fluorescence emission was read at 377 nm. (C) Compound 10 binds to the murine and human ARRE-2 oligonucleotides, but not to the AP-1 consensus, TNF κ3 element and GM-330 site from GM-CSF enhancer, used for EMSA assays. All oligonucleotides were present at 500 nM. (D) A single A > C substitution that interrupts a stretch of adenines and thymines abrogates binding of Compound 10 to the mouse and human ARRE-2 oligonucleotides (500 nM).