Highly Disordered Amyloid-β Monomer Probed by Single-Molecule FRET and MD Simulation.

ABSTRACT: Monomers of amyloid-β (Aβ) protein are known to be disordered, but there is considerable controversy over the existence of residual or transient conformations that can potentially promote oligomerization and fibril formation. We employed single-molecule Förster resonance energy transfer (FRET) spectroscopy with site-specific dye labeling using an unnatural amino acid and molecular dynamics simulations to investigate conformations and dynamics of Aβ isoforms with 40 (Aβ40) and 42 residues (Aβ42). The FRET efficiency distributions of both proteins measured in phosphate-buffered saline at room temperature show a single peak with very similar FRET efficiencies, indicating there is apparently only one state. 2D FRET efficiency-donor lifetime analysis reveals, however, that there is a broad dist

SUBMITTER: Meng F 

PROVIDER: S-EPMC5984999 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature