Characterization of β-sheet amyloid-like aggregates of Palm1–15.

A) CD spectra at 30 µM peptide Palm1–15 (green) and controls Acetyl1–15 (red) and Aβ1–15 (orange) in 2% HFIP/PBS (v/v). B) Profile of ThT emission with different peptide concentrations in the presence of 24 µM of dye. Fluorescence was measured at 485 nm with excitation at 440 nm. C, D, E) ssNMR of Palm1–15 uniformly labeled at Ala2, Ser8 and Gly9: (13C-13C) 2D PDSD correlation spectra with mixing times of 20 ms (C) and 150 ms (D); 1H-13C FSLG-HETCOR spectra (E) together with chemical shift predictions based on secondary structure [38] (red for random coil, green for β-sheet, blue for α-helix). F) Electron micrographs of negatively stained Palm1–15 aggregates formed over 24 hour incubation in 2% HFIP/PBS (v/v). Samples were negatively stained with 2% Uranyl Acetate in water. Scale bar 0.1 µm. Magnification 22000 x.