Figure 3

The interaction of EGCG and hIAPP. hIAPP fibril formation was studied for 12–13 hours in the absence or presence of EGCG. (A) Aggregation kinetics of hIAPP in the absence (black line) or presence (green line) of EGCG using 1D-NMR. Relative resonance intensities were plotted as a function of time. (B) hIAPP fibril formation was studied using transmission electron microscope in the absence (left panel) and presence (right panel) of EGCG. The white bar represents 200 nm. (A,B) The molar ratio of hIAPP:EGCG was 1:20. (C) Chemical shift perturbations extracted from 2D-NMR experiments. The numbers denote the molar ratio of hIAPP:EGCG. Black bars under the diagram represent the regions of hIAPP, which show the largest changes in chemical shifts upon binding of EGCG. (D) Best ranking binding model of hIAPP monomer-EGCG proposed by molecular docking. Various colors represent various binding mode of EGCG obtained by docking. (E) hIAPP-EGCG interactions from the HADDOCK docking simulations. The interactions are shown as lines between receptor residues and ligand atoms, the solvent accessible surface of an interacting residue is represented by a halo around the residue. The diameter of the circle is proportional to the solvent accessible surface.