Fig 7. In vitro assays to evaluate the CUG-binding potential of compounds 1–3 and 2–5.

Fluorescence polarization assays with the indicated concentrations of (A) four substituted pyrido[2,3-d]pyrimidines (compound family 1) and (B) four pentamidine-like compounds (compound family 2). Data were normalized to 100 μM pentamidine as a positive control (marked as a red line). Steady-state fluorescence emission profile for CUG^exp-TO (red line) and changes in the emission intensity after addition of increasing amounts of (C) 1–3 and (D) 2–5 recorded in buffered NaCAC 50mM aqueous solution (pH = 7.4) at 298.1 ± 0.1 K. [TO] = 0.5 μM, [RNA] = 0.25 μM, [Ligand] = 0.1 mM.λ_exc = 485 nm. (E) Ligand-CUG^exp binding constants determined by displacement assays with TO. ^aValues in parenthesis are standard deviations in the last significant figure.