Figure 2.

Steric zipper hypothesis of amyloid fibril structure. Amyloid proteins often contain two or more amyloidogenic segments (steric zippers). The homo or hetero association of zipper segments results in five types of β-sheet architecture, giving rise to a large variety of possible assemblies of amyloid molecules. (A,B) The homotypic association between identical zipper segments in parallel (A) and antiparallel (B) arrangement. (C,D) The hetero association between different zipper segments in parallel (C) and antiparallel (D) arrangement. (E) “Hetero” interaction is built from the parallel stacking of different segments in the right-hand β-helix or solenoid.