AMYLOID-LIKE PROPERTIES OF A SYNTHETIC PEPTIDE CORRESPONDING TO THE CARBOXY TERMINUS OF BETA-AMYLOID PROTEIN-PRECURSOR

A synthetic peptide whose sequence corresponds to the 20 carboxy-terminal amino acids of β-amyloid protein precursor (APP) was found to form fibrils in vitro. These fibrils showed birefringence in polarized light when stained with Congo red, fluoresced when bound with thioflavin S, were resistant to proteases, and had a crossβ conformation. By contrast, peptides with other sequences from the intracellular domain of APP and a peptide corresponding to this entire domain did not exhibit the full range of β-amyloid properties. These results suggest that a fragment from the C-terminus of the β-amyloid protein precursor could bind to intraneuronal paired helical filaments and account for some of its amyloid-like properties. © 1992.