Figure 4.

Hematoxylin inhibits IGF1R activity in vitro and binds directly to IGF1R-CD. (A) Inhibitory activity of hematoxylin on IGF1R detected by ELISA assay. Tests were performed three times independently. (B) Hematoxylin binds to IGF1R-CD. SPR assay was performed as described in Materials and methods. (C) The binding mode of hematoxylin to the kinase domain of IGF1R predicted by molecular docking. The ligand (green carbon) and residues (cyan carbon) are represented as sticks and lines, respectively. The yellow dashed lines denote the hydrogen bonds and the oxygen atoms are colored in red. The molecular surface of the binding site was shown as green dots. The structure figure was prepared using PyMol (www.pymol.org). Data shown were mean±SD from three independent experiments.