Nanoscale Characterization of Parallel and Antiparallel -Sheet Amyloid Beta 1-42 Aggregates. Academic Article uri icon

abstract

  • Abrupt aggregation of amyloid beta (A) peptide is strongly associated with Alzheimer's disease. In this study, we used atomic force microscopy-infrared (AFM-IR) spectroscopy to characterize the secondary structure of A oligomers, protofibrils and fibrils formed at the early (4 h), middle (24 h), and late (72 h) stages of protein aggregation. This innovative spectroscopic approach allows for label-free nanoscale structural characterization of individual protein aggregates. Using AFM-IR, we found that at the early stage of protein aggregation, oligomers with parallel -sheet dominated. However, these species exhibited slower rates of fibril formation compared to the oligomers with antiparallel -sheet, which first appeared in the middle stage. These antiparallel -sheet oligomers rapidly propagated into fibrils that were simultaneously observed together with parallel -sheet fibrils at the late stage of protein aggregation. Our findings showed that aggregation of A is a complex process that yields several distinctly different aggregates with dissimilar toxicities.

published proceedings

  • ACS Chem Neurosci

altmetric score

  • 11.6

author list (cited authors)

  • Zhaliazka, K., & Kurouski, D.

citation count

  • 7

publication date

  • October 2022