TABLE 2.
Examples of structurally characterized amyloid-forming proteins
aa, amino acids.
| Protein/peptide | Pathology/function linked to amyloid | Structural information |
|---|---|---|
| α-Synuclein (aa 1–140) | Parkinson disease | Five β-strands within fibril core comprising residues 35–96 (92); parallel in-register β-sheet core region from residues 36–98 (19) |
| Aβ1–40 | Alzheimer disease | Parallel in-register β-sheet (16); two fibril morphologies (twisted and striated ribbons) with 2- and 3-fold symmetry; both are parallel β-sheets, using almost same β-strand segments (8, 24) |
| Aβ1–40 seeded with diseased brain | Alzheimer disease | Parallel in-register β-sheet (75) |
| Aβ1–40(D23N) | Familial Alzheimer disease | Two species: antiparallel (major) and parallel in-register (minor) β-sheets (51) |
| Aβ1–42 | Alzheimer disease | Parallel in-register β-sheet (93); molecules form steric zipper (94) |
| Amylin (aa 1–37) | Type 2 diabetes | Four layers of parallel β-sheets (25) |
| β2-Microglobulin (aa 1–99) | Dialysis-related amyloidosis | Parallel in-register β-sheet (20); fibril core comprising 60–70 residues (95) |
| Curli (CsgA and CsgB) | Proteins secreted by E. coli; biofilm formation, surface colonization | Not parallel in-register, likely β-helix (55) |
| HET-s (aa 218–289) | Regulation of heterokaryon formation in P. anserina | Left-handed β-helix structure (14) |
| Htau40 | Tauopathies | Parallel in-register β-sheet (96, 97) |
| Rnq1 (aa 153–405) | Prion of S. cerevisiae; increased frequency of generation of [URE3] and [PSI+] prions | Parallel in-register β-sheet (36) |
| Sup35 (aa 1–253) | Prion of S. cerevisiae; reduction in fidelity of translation termination | Parallel in-register β-sheet (35); multiple variants employ same basic architecture (34) |
| Ure2 (aa 1–89) | Prion of S. cerevisiae; inappropriate derepression of nitrogen catabolism genes | Parallel in-register β-sheet (98) |