Although much has been learned about the fibrillization kinetics, structure and toxicity of amyloid proteins, the properties of amyloid fibrils beyond the saturation phase are often perceived as chemically and biologically inert, despite evidence suggesting otherwise. To fill this knowledge gap, we examined the physical and biological characteristics of human islet amyloid polypeptide (IAPP) fibrils that were aged up to two months. Not only did aging decrease the toxicity of IAPP fibrils, but the fibrils also sequestered fresh IAPP and suppressed their toxicity in an embryonic zebrafish model. The mechanical properties of IAPP fibrils in different aging stages were probed by atomic force microscopy and sonication, which displayed comparable stiffness but age-dependent fragmentation, followed by self-assembly of such fragments into the largest lamellar amyloid structures reported to date. The dynamic structural and toxicity profiles of amyloid fibrils and plaques suggest that they play active, long-term roles in cell degeneration and may be a therapeutic target for amyloid diseases.
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http://dx.doi.org/10.1016/j.scib.2018.11.012 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Technische Universität München, Division of Peptide Biochemistry, Emil-Erlenmeyer-Forum 5, 85354, Freising, GERMANY.
Amyloid self-assembly of α-synuclein (αSyn) is linked to the pathogenesis of Parkinson's disease (PD). Type 2 diabetes (T2D) has recently emerged as a risk factor for PD. Cross-interactions between their amyloidogenic proteins may act as molecular links.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Key Laboratory of Marine Drugs, Ministry of Education; School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
Amyloidosis of the human islet amyloid polypeptide (hIAPP) is closely related to the pathogenesis of type 2 diabetes (T2D) and serves as both a diagnostic hallmark and a key therapeutic target for T2D. In this study, we discovered that oritavancin (Ori), a glycopeptide antibiotic primarily prescribed for Gram-positive bacterial infections, can dose-dependently inhibit recombinant hIAPP (rhIAPP) amyloid formation. Ori specifically inhibited rhIAPP amyloid formation at the initial nucleation stage but didn't affect mature rhIAPP fibrils.
View Article and Find Full Text PDFJ Phys Chem Lett
December 2024
Department of Chemistry and Biochemistry, The University of Alabama, 1007E Shelby Hall, Tuscaloosa, Alabama 35487, United States.
Amyloid aggregates are hallmarks of the pathology of a wide range of diseases, including type 2 diabetes (T2D) and Alzheimer's disease (AD). Much epidemiological and pathological evidence points to significant overlap between AD and T2D. Individuals with T2D have a higher likelihood of developing AD; moreover, colocalized aggregates of amyloid β (Aβ) and the islet amyloid polypeptide (IAPP), the two main peptides implicated in the formation of toxic amyloid aggregates in AD and T2D, have also been identified in the brain.
View Article and Find Full Text PDFJ Biol Chem
November 2024
Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States; Department of Biomedical Engineering, Texas A&M University, College Station, Texas, United States. Electronic address:
The onset and progression of type 2 diabetes is linked to the accumulation and aggregation of human islet amyloid polypeptide (hIAPP) in the pancreas. Amyloid oligomers and fibrils formed as a result of such aggregation exert high cytotoxicity. Although some pieces of evidence suggest that lipids could alter the rate of hIAPP aggregation, the effect of lipids on the aggregation properties of this peptide remains unclear.
View Article and Find Full Text PDFACS Chem Neurosci
December 2024
PhD Programs in Chemistry and Biochemistry, the Graduate Center of the City University of New York, New York, New York 10016, United States.
Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the onset of COVID-19 have been linked to an increased risk of developing type 2 diabetes. While a variety of mechanisms may ultimately be responsible for the onset of type 2 diabetes under these circumstances, one mechanism that has been postulated involves the increased aggregation of human islet amyloid polypeptide (hIAPP) through direct interaction with SARS-CoV-2 viral proteins. Previous computational studies investigating this possibility revealed that a nine-residue peptide fragment known as SK9 (SFYVYSRVK) from the SARS-CoV-2 envelope protein can stabilize the native conformation of hIAPP by interacting with the N-terminal region of amylin.
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