Acidic pH Promotes Refolding and Macroscopic Assembly of Amyloid β (16-22) Peptides at the Air-Water Interface.

ABSTRACT: Assembly by amyloid-beta (Aβ) peptides is vital for various neurodegenerative diseases. The process can be accelerated by hydrophobic interfaces such as the cell membrane interface and the air-water interface. Elucidating the assembly mechanism for Aβ peptides at hydrophobic interface requires knowledge of the microscopic structure of interfacial peptides. Here we combine scanning force microscopy, sum-frequency generation spectroscopy, and metadynamics simulations to probe the structure of the central fragment of Aβ peptides at the air-water interface. We find that the structure of interfacial peptides depends on pH: at neutral pH, the peptides adopt a less folded, bending motif by forming intra-hydrogen bonds; at acidic pH, the peptides refold into extended β-strand fibril conformation,

SUBMITTER: Lu H 

PROVIDER: S-EPMC9340808 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature