Fig. 1: Comparison of the stability of the Ac-WT and Ac-E46K α-syn fibrils.

a Cold denaturation of 20 μM Ac-WT (blue) and Ac-E46K (red) α-syn fibrils. CD spectra monitored at 0 °C at different incubation time are shown on the left. CD signals at 218 nm are analyzed on the right. b Freeze-thaw denaturation of Ac-WT (blue) and Ac-E46K (red) fibrils. CD spectra obtained at different freeze-thaw cycles are shown on the left. CD signals at 218 nm are analyzed on the right. Data are shown as mean ± s.d., n = 3 biologically independent samples for both panels (a) and (b). Exact p values of the unpaired, two-tailed Student’s t test are shown. c Negative-staining TEM (left) and AFM (right) images of 5 μM Ac-WT and Ac-E46K α-syn PFFs after sonication. d Size distribution of sonicated Ac-WT and Ac-E46K PFFs. The lengths of the sonicated PFFs are measured by AFM. 300 fibrils were measured for each fibril sample. e ThT kinetic assay of the Ac-WT and Ac-E46K fibril formation with or without seeding. Mole percent of added PFF seeds are indicated. Data shown are mean ± s.d., n = 3. f PK digestion of the Ac-WT and Ac-E46K fibrils. The fibrils were incubated with indicated concentrations of PK at 37 °C for 30 min (left). Intensities of the total protein bands of each lane on SDS-PAGE are analyzed on the right. Data shown are mean ± s.d., n = 3 biologically independent samples. Source data are provided as a Source Data file.