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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

beta-sheet assembly in amyloidogenic glutamic acid nanostructures: Insights from X-ray scattering and infrared nanospectroscopy

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Author(s):
Mello, Lucas R. [1] ; Hamley, Ian W. [2] ; Miranda, Antonio [1] ; Alves, Wendel A. [3] ; Silva, Emerson R. [1]
Total Authors: 5
Affiliation:
[1] Univ Fed Sao Paulo, Dept Biofis, BR-04044020 Sao Paulo, SP - Brazil
[2] Univ Reading, Dept Chem, Reading, Berks - England
[3] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Santo Andre - Brazil
Total Affiliations: 3
Document type: Journal article
Source: JOURNAL OF PEPTIDE SCIENCE; v. 25, n. 6 JUN 2019.
Web of Science Citations: 1
Abstract

Glutamic acid-rich peptides are crucial to a variety of biological processes, including glutamatergic neurotransmission and immunological defense. Glutamic acid sequences often exhibit unusual organization into beta(2)-type sheets, where bifurcated H bonds formed between glutamic acid side chains and NH in amide bonds on adjacent beta-strands play a paramount role for stabilizing the molecular assembly. Herein, we investigate the self-assembly and supramolecular structure of simplified models consisting of alternating glutamic acid/phenylalanine residues. Small-angle X-ray scattering and atomic force microscopy show that the aggregation pathway is characterized by the formation of small oligomers, followed by coalescence into nanofibrils and nanotapes. Amyloidogenic features are further demonstrated through fiber X-ray diffraction, which reveal molecular packing according to cross-beta patterns, where beta-strands appear perpendicularly oriented to the long axis of nanofibrils and nanotapes. Nanoscale infrared spectroscopy from individual nanoparticles on dried samples shows a remarkable decrease of beta(2)-sheet content, accompanied by growth of standard beta-sheet fractions, indicating a beta(2)-to-beta(1) transition as a consequence of the release of solvent from the interstices of peptide assemblies. Our findings highlight the key role played by water molecules in mediating H-bond formation in beta(2)-sheets commonly found in amyloidogenic glutamic acid-rich aggregates. (AU)

FAPESP's process: 15/24018-1 - Polymer-Peptide Conjugates for hydrogel formulation and its usage in detection
Grantee:Wendel Andrade Alves
Support Opportunities: Regular Research Grants
FAPESP's process: 14/50867-3 - INCT 2014: National Institute of Science and Technology in Bioanalysis
Grantee:Marco Aurelio Zezzi Arruda
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
Grantee:Adalberto Fazzio
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 16/24409-3 - Cell-Penetrating Peptides for Transport of Plasmid DNA and microRNA: from Nanoscopic Structure to Gene Delivery.
Grantee:Emerson Rodrigo da Silva
Support Opportunities: Regular Research Grants