Differentiating Alzheimer's Aβ Isoforms Coaggregated in Cerebrospinal Fluid via Single-Particle Imaging.

ABSTRACT: Amyloid polymorphism can reflect Alzheimer's disease (AD) stages. This paper demonstrates that amyloid β (Aβ) peptides, primarily Aβ-40 and Aβ-42 (implicated in AD pathology), present in cerebrospinal fluid (CSF), can be differentiated, and their morphology studied in detail using fluorescence-based super-resolution and atomic force microscopy (AFM). An inhibitory effect of Aβ-40 on Aβ-42 protein aggregation, marked by Aβ-40 oligomers colocalizing along the Aβ-42 fibril backbone, was resolved at the single-particle level. Molecular dynamics simulations revealed that coaggregation is modulated by the ionic environment in CSF, where calcium ions form bridges between Glu residues of Aβ-40 and Aβ-42, known to stabilize the fibril structure. This ion-mediated tethering compacts Aβ-40 and kineti

SUBMITTER: Henry L 

PROVIDER: S-EPMC12879737 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature