Extended Data Fig. 8. Boron cluster-induced enhancement of biological activity.
a, Dose–response experiment for dBET1 binding to the CRBN E3 Ubiquitin ligase, quantified with the CRBN NanoBRET target engagement assay, in the presence of 0, 25 and 50 μM B12Br122−. In this assay, HEK293 cells are transfected with a plasmid expressing a CRBN-NanoLuc fusion protein for 24 h and subsequently incubated with a labelled tracer molecule (0.5 µM) and the test compounds. dBET1 acts as a competitive inhibitor and decreases the NanoBRET signal between CRBN-NanoLuc and the tracer. Solid points indicate mean ± s.d. of three technical replicates. Values were normalized to the controls without dBET1, as indicated in the Methods section. b, Corresponding IC50 values calculated with the CRBN Target Engagement assay. Cross-bars indicate mean ± s.d. of three independent experiments (two with technical triplicates, one with technical duplicates); values obtained in each experiment are represented by different shapes. c, Viability of HeLa cells after incubation with different doses of MMAF in the presence of 0, 5 and 10 μM B12Br122−. Solid points indicate mean ± s.d. of three technical replicates. d, Corresponding IC50 values of MMAF. Cross-bars indicate mean ± s.d. of four independent experiments, each with technical triplicates; each experiment is represented by a different shape. e, E. coli Top10 viability in the presence of different concentrations of kanamycin A monosulphate (0–3.5 μg/mL) and B12Br122− (0–1,000 μM) in LB broth at 37 °C; data are mean ± s.d. of triplicate measurements.