PMC

Induced ThT fluorescence on binding to several forms of HET-s(218-289) amyloid. Units of relative fluorescence intensity are arbitrary. The sample for the unbound ThT curve (almost coincident with the axis) contained no protein.

Examples of SDS-PAGE and MS/MS analysis of HET-s(218-289) fibril preparations. (A) SDS-PAGE after high pH fibrillization. (B) SDS-PAGE after low pH fibrillization over 12 months. Numbers indicate the bands analyzed by MS/MS. (C) SDS-PAGE after seeded low pH fibrillization. (D) Secondary structure from ssNMR (), amino acid sequence, and peptides found by MS/MS analysis. Black arrows: β-strands. Solid lines connecting arrows: loops or unordered regions. Heavy solid lines below the sequence correspond to tryptic peptides from SDS-PAGE bands in (B).

Negative stain electron micrographs (top row), and x-ray fiber diffraction patterns (bottom row) of HET-s(218-289). (A and E) High pH fibrillization; (B and F) low pH fibrillization; (C and G) low pH fibrillization resulting in degradation; (D and H) low pH fibrillization, seeded by degraded low pH fibrils. Meridians in the diffraction patterns (axes parallel to the fiber axis) run approximately vertically, whereas equators (axes orthogonal to the meridian) are approximately horizontal. White arrows: 4.7 Å meridional reflections. Black arrows: 9.4 Å meridional reflections. Black arrowheads: ∼10 Å equatorial intensities. Scale bars = 100 nm.