Fig. 1.

Identification of pharmacophore. A. FRET assay results for AI-4-57, AI-10-104, and AI-14-91. Cerulean-Runt domain and Venus-CBFβ concentration was 100 nM. X-axis indicates compound concentration and y-axis is ratio between the emission intensities at 525 and 474 nm. Experiments were performed in duplicate. Error bars represent average ± standard deviation. The average data points were fit using Origin. B. Schemes 1–3 illustrate the targets of modifications to AI-4-57 as well as compounds synthesized and assayed to delineate the active pharmacophore. C. Results of STD NMR experiment with AI-4-57 (2 mM) and CBFβ (200 μM). Bottom panel shows 1D NMR spectrum of AI-4-57. Upper 2 panels show STD difference spectra (off-resonance (70 ppm) saturation spectrum minus on-resonance (0.4 ppm) CBFβ saturation spectrum) with saturation times of 500 and 2000 ms.