Nanoscale Hyperspectral Imaging of Amyloid Secondary Structures in Liquid. Issue 9 (7th January 2021)

• Record Type: Journal Article
• Authors: Lipiec, Ewelina; Kaderli, Janina; Kobierski, Jan; Riek, Roland; Skirlińska‐Nosek, Katarzyna; Sofińska, Kamila; Szymoński, Marek; Zenobi, Renato
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 9(2021)
• Page Start: 4545
• Page End: 4550
• Publication Date: 2021-01-07
• Subjects: aggregation pathways -- Alzheimer's disease -- amyloid-β -- tip-enhanced Raman spectroscopy (TERS); Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202010331
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Abnormal aggregation of amyloid‐β is a very complex and heterogeneous process. Owing to methodological limitations, the aggregation pathway is still not fully understood. Herein a new approach is presented in which the secondary structure of single amyloid‐β aggregates is investigated with tip‐enhanced Raman spectroscopy (TERS) in a liquid environment. Clearly resolved TERS signatures of the amide I and amide III bands enabled a detailed analysis of the molecular structure of single aggregates at each phase of the primary aggregation of amyloid‐β and also of small species on the surface of fibrils attributed to secondary nucleation. Notably, a β‐sheet rearrangement from antiparallel in protofibrils to parallel in fibrils is observed. This study allows better understanding of Alzheimer's disease etiology and the methodology can be applied in studies of other neurodegenerative disorders. Abstract : Tip‐enhanced Raman spectroscopic (TERS) mapping in liquid is shown to be an efficient tool to investigate the secondary structure of the neurodegenerative peptide amyloid‐β. The high heat capacity of liquid increased the capability of TERS, allowing an observation of the conformational transition from the antiparallel arrangement of β‐sheets in protofibrils to parallel in fibrils, at the single aggregates level.