Figure 3.

EDTA modifies insulin aggregation kinetics. (a) Insulin aggregation kinetics at 60°C and pH 1.8 as probed by ThT fluorescence as a function of EDTA concentration. The color shaded areas indicate the standard deviation for three independent aggregation processes. (b) Transmission electron microscopy (fibrils) and fluorescence microscopy (spherulites, insets) images acquired during the kinetics without EDTA (blue curve in a, blue contoured images in b) and at 5 mM EDTA (light green in a, light green contoured images in b). Micrographs were acquired after 2 (left), 4 (middle), and 6 h (right) of incubation at 60°C and pH 1.8 and showed that fibrils and spherulites were formed roughly at the same time, with more numerous and larger spherulites appearing in the presence of EDTA. To see this figure in color, go online.