Header

UZH-Logo

Maintenance Infos

Structure Analysis of Amyloid Aggregates at Lipid Bilayers by Supercritical Angle Raman Microscopy


Dubois, Valentin; Serrano, Diana; Zhang, Xiaotian; Seeger, Stefan (2020). Structure Analysis of Amyloid Aggregates at Lipid Bilayers by Supercritical Angle Raman Microscopy. Analytical Chemistry, 92(7):4963-4970.

Abstract

The amyloid-β peptide is correlated with Alzheimer’s disease and is assumed to cause toxicity by its interaction with the neuron membrane. A custom-made microscope objective based on the supercritical angle technique was developed by our group, which allows investigation of interfacial events by performing surface-sensitive and low-invasive spectroscopy. Applied to Raman spectroscopy, this technique was used to collect information about the structure of polypeptides that interact with a supported lipid bilayer. Notably, the conformation used by amyloid-β(1–40) and amyloid-β(1–42) when interacting directly with or next to the supported lipid bilayer was characterized. We observed two distinct secondary structures, α-helix and β-sheet, which were exhibited by the peptide. These two structures were detected simultaneously. The propensity of the peptide to fold into these structures seemed dependent on both their number of amino acids and their proximity with the supported lipid bilayer. The α-helix structure was observed for amyloid-β(1–42) fragments that were closer to the lipid bilayer. Peptides that were located further away from the bilayer favored the β-sheet structure. Amyloid-β(1–40) was less prone to adopt the α-helix secondary structure.

Abstract

The amyloid-β peptide is correlated with Alzheimer’s disease and is assumed to cause toxicity by its interaction with the neuron membrane. A custom-made microscope objective based on the supercritical angle technique was developed by our group, which allows investigation of interfacial events by performing surface-sensitive and low-invasive spectroscopy. Applied to Raman spectroscopy, this technique was used to collect information about the structure of polypeptides that interact with a supported lipid bilayer. Notably, the conformation used by amyloid-β(1–40) and amyloid-β(1–42) when interacting directly with or next to the supported lipid bilayer was characterized. We observed two distinct secondary structures, α-helix and β-sheet, which were exhibited by the peptide. These two structures were detected simultaneously. The propensity of the peptide to fold into these structures seemed dependent on both their number of amino acids and their proximity with the supported lipid bilayer. The α-helix structure was observed for amyloid-β(1–42) fragments that were closer to the lipid bilayer. Peptides that were located further away from the bilayer favored the β-sheet structure. Amyloid-β(1–40) was less prone to adopt the α-helix secondary structure.

Statistics

Citations

Altmetrics

Downloads

0 downloads since deposited on 29 Jul 2020
0 downloads since 12 months

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Uncontrolled Keywords:Analytical Chemistry
Language:English
Date:7 April 2020
Deposited On:29 Jul 2020 09:54
Last Modified:29 Jul 2020 09:55
Publisher:American Chemical Society (ACS)
ISSN:0003-2700
Additional Information:This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acs.analchem.9b05092
OA Status:Closed
Publisher DOI:https://doi.org/10.1021/acs.analchem.9b05092

Download

Closed Access: Download allowed only for UZH members

Content: Accepted Version
Filetype: PDF - Registered users only until 7 April 2021
Size: 395kB
View at publisher
Embargo till: 2021-04-07