Lipid membrane-mediated assembly of the functional amyloid-forming peptide Somatostatin-14.

Autor: Prasath V; School of Science, STEM College, RMIT University, Melbourne, Australia., Zhai J; School of Science, STEM College, RMIT University, Melbourne, Australia., Dyett BP; School of Science, STEM College, RMIT University, Melbourne, Australia., Yu H; School of Science, STEM College, RMIT University, Melbourne, Australia., Hoffmann SV; ISA, Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark., Jones NC; ISA, Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark., Reynolds NP; Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Australia. Electronic address: nicholas.reynolds@latrobe.edu.au., Valéry C; School of Health and Biomedical Sciences, STEM College, RMIT University, Bundoora, Australia. Electronic address: celine.valery@rmit.edu.au., Drummond CJ; School of Science, STEM College, RMIT University, Melbourne, Australia., Conn CE; School of Science, STEM College, RMIT University, Melbourne, Australia. Electronic address: charlotte.conn@rmit.edu.au.
Jazyk: angličtina
Zdroj: Biophysical chemistry [Biophys Chem] 2022 Aug; Vol. 287, pp. 106830. Date of Electronic Publication: 2022 May 21.
DOI: 10.1016/j.bpc.2022.106830
Abstrakt: Membrane-mediated assembly has been well characterised for toxic amyloid species such as the amyloid-β peptide implicated in Alzheimer's disease. However, little is known about the membrane-mediated assembly of functional-amyloid forming peptides, recently identified as a natural storage state for neuropeptide hormones in vivo. Here, we study the aggregation of somatostatin-14 (SST-14) co-incubated with model lipid membranes. Atomic force microscopy (AFM) studies confirmed that nanofibrils formed in the presence of various lipid membranes display reduced fibrillogenesis and promote the formation of non-fibrillar oligomers. Both circular dichroism (CD) and intrinsic tryptophan fluorescence studies confirmed interaction between the peptide and the lipid bilayer; this interaction appears to drive changes in membrane-mediated aggregation kinetics. We show that both the surface charge of the membrane and chain packing drive changes in the electrostatic and hydrophobic interactions between the peptide and the membrane, and hence the rate of assembly. The similarities in the effect of the lipid membrane on aggregation of functional amyloids and the more well studied toxic amyloids suggest strong aggregation modifying lipid bilayer interactions are a ubiquitous feature of all amyloid fibrils and highlight the need for further investigation as to why this leads to toxicity in some systems and not others.
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Databáze: MEDLINE
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