FIGURE 1.

Effects of salt concentration on the heat-induced spontaneous fibrillation reaction of insulin amyloid fibrils. A–C, ThT fluorescence intensity measured before and after the 1st, 2nd, and 3rd cycles of the periodic heat treatment with a linear gradient of temperature from 25 to 90 °C at a rate of 2 °C/min. The results of NaCl concentrations of 0 m (A), 0.1 m (B), and 1.0 m (C) are shown. All measurements were performed three times and the error bars depict the S.D. ± mean. D–G, AFM images of insulin fibrils formed by heat-induced fibrillation. The amyloid fibrils formed at 0.1 and 1.0 m NaCl were sampled after the 1st and 2nd cycles of heat treatment in the presence of 0.1 m (D, 1st; E, 2nd) and 1.0 m (F, 1st; G, 2nd) NaCl. The scale bars represent 500 nm.