FIGURE 1.

Kinetics of insulin amyloid fibrillation in the presence of KR7 by ThT assay. All experiments were performed using 2 mg/ml insulin at 335 K in 50 mm citrate phosphate buffer with 100 mm NaCl at pH 2.6. A, kinetics of insulin fibrillation in the presence of varying ratios of KR7 peptide. KR7 decreases the rate of fiber formation with little effect on the lag time before fiber formation. AU, atomic units, B, bar plot of the normalized final ThT fluorescence from A. KR7 reduces the total amount of amyloid formed after the reaction has reached completion. C, effect of KR7 addition at different time points. KR7 arrests fiber formation immediately after the addition, but breakdown of fibers is minor. This pattern is consistent with KR7 stopping the fiber elongation step.