Porelike Morphologies in Amyloidogenic Proteins

2021 ◽  
Author(s):  
Matthew J. Voelker
Keyword(s):  
Amyloidogenic Proteins

Proteoglycans and Amyloidogenic Proteins in Peripheral Amyloidosis

2003 ◽  
Vol 3 (4) ◽  
pp. 361-370 ◽  
Author(s):  
Francine Gervais ◽  
Celine Morissette ◽  
Xianqi Kong
Keyword(s):  
Amyloidogenic Proteins

Diffusible amyloid oligomers trigger systemic amyloidosis in mice

2008 ◽  
Vol 415 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Sivanesan Senthilkumar ◽  
Edwin Chang ◽  
Rajadas Jayakumar
Keyword(s):  
Protein A ◽  
Mouse Tissue ◽  
Cytokine Induction ◽  
Amyloidogenic Proteins ◽  
Enhancing Factor ◽  
Amyloid Oligomers ◽  
Apparent Relationship ◽  
Amyloid Enhancing Factor ◽  
Local Accumulation

AA (amyloid protein A) amyloidosis in mice is markedly accelerated when the animals are given, in addition to an inflammatory stimulus, an intravenous injection of protein extracted from AA-laden mouse tissue. Previous findings affirm that AA fibrils can enhance the in vivo amyloidogenic process by a nucleation seeding mechanism. Accumulating evidence suggests that globular aggregates rather than fibrils are the toxic entities responsible for cell death. In the present study we report on structural and morphological features of AEF (amyloid-enhancing factor), a compound extracted and partially purified from amyloid-laden spleen. Surprisingly, the chief amyloidogenic material identified in the active AEF was diffusible globular oligomers. This partially purified active extract triggered amyloid deposition in vital organs when injected intravenously into mice. This implies that such a phenomenon could have been inflicted through the nucleation seeding potential of toxic oligomers in association with altered cytokine induction. In the present study we report an apparent relationship between altered cytokine expression and AA accumulation in systemically inflamed tissues. The prevalence of serum AA monomers and proteolytic oligomers in spleen AEF is consistent to suggest that extrahepatic serum AA processing might lead to local accumulation of amyloidogenic proteins at the serum AA production site.

Unraveling the Pressure Effect on Nucleation Processes of Amyloidogenic Proteins

ChemPhysChem ◽  
2010 ◽  
pp. n/a-n/a
Author(s):  
Stefan Gruzielanek ◽  
Yong Zhai ◽  
Roland Winter
Keyword(s):  
Pressure Effect ◽  
Amyloidogenic Proteins

scholarly journals The role of alpha-helix on the structure-targeting drug design of amyloidogenic proteins

2020 ◽  
Author(s):  
Carmelo Tempra ◽  
Carmelo La Rosa ◽  
Fabio Lolicato
Keyword(s):  
Aqueous Phase ◽  
Membrane Integrity ◽  
Alpha Helix ◽  
Helical Structure ◽  
Lipid Binding ◽  
Fibril Formation ◽  
Hydrophobic Core ◽  
Amyloidogenic Proteins ◽  
Contact Probability ◽  
Free Lipids

AbstractThe most accredited hypothesis links the toxicity of amyloid proteins to their harmful effects on membrane integrity through the formation of prefibrillar-transient oligomers able to disrupt cell membranes. However, damage mechanisms necessarily assume a first step in which the amyloidogenic protein transfers from the aqueous phase to the membrane hydrophobic core. This determinant step is still poorly understood. However, according to our lipid-chaperon hypothesis, free lipids in solution play a crucial role in facilitating this footfall. Free phospholipid concentration in the aqueous phase acts as a switch between ion channel-like pore and fibril formation, so that high free lipid concentration in solution promotes pore and repress fibril formation. Conversely, low free lipids in the solution favor fibril and repress pore formation. This behavior is due to the formation of stable lipid-protein complexes. Here, we hypothesize that the helix propensity is a fundamental requirement to fulfill the lipid-chaperon model. The alpha-helix region seems to be responsible for the binding with amphiphilic molecules fostering the proposed mechanism. Indeed, our results show the dependency of protein-lipid binding from the helical structure presence. When the helix content is substantially lower than the wild type, the contact probability decreases. Instead, if the helix is broadening, the contact probability increases. Our findings open a new perspective for in silico screening of secondary structure-targeting drugs of amyloidogenic proteins.

scholarly journals Catechol-Containing Compounds are a Broad Class of Protein Aggregation Inhibitors: Redox State is a Key Determinant of the Inhibitory Activities

2020 ◽  
Author(s):  
Paul Velander ◽  
Ling Wu ◽  
Sherry B. Hildreth ◽  
Nancy J. Vogelaar ◽  
Biswarup Mukhopadhyay ◽  
...  
Keyword(s):  
Protein Aggregation ◽  
Small Molecule ◽  
Rational Design ◽  
Redox State ◽  
Broad Class ◽  
Intrinsically Disordered ◽  
Amyloidogenic Proteins ◽  
Key Factor ◽  
Inhibitory Activities ◽  
Screening Platform

Abstract Background: A range of neurodegenerative and related aging diseases, such as Alzheimer’s disease, Parkinson’s disease, and type 2 diabetes, are linked to toxic protein aggregation. Yet the mechanisms of protein aggregation inhibition by small molecule inhibitors remain poorly understood, in part because most protein targets of aggregation assembly are partially unfolded or intrinsically disordered, which hinders detailed structural characterization of protein-inhibitor complexes and structural-based mechanistic elucidation. Methods: Herein we employed a small molecule screening approach to identify inhibitors against three prototype amyloidogenic proteins in neurodegeneration and related proteinopathies: amylin, Ab and tau. We further systematically investigated selected class of inhibitors under aerobic and anaerobic conditions to uncover a key determinant of the inhibitory activities.Results: One remarkable class of inhibitors identified from all three parallel screenings against different amyloidogenic proteins was catechol-containing compounds and redox-related quinones/anthraquinones. Further mechanistic studies determined that the redox state of the broad class of catechol-containing compounds is a key determinant of the amyloid inhibitor activities. Conclusion: Our small molecule library screening platform was able to identify a broad class of amyloid inhibitors. Redox was found to be a key factor not only regulating the inhibitory activities but also involving the mechanism of inhibition. The molecular insights we gained not only explain why a large number of catechol-containing natural compounds, often enriched in healthy diet, have anti-neurodegeneration and anti-aging activities, but also could guide the rational design of therapeutic or nutraceutical strategies to target a broad range of neurodegenerative and related aging diseases.

A β-Hairpin-Binding Protein for Three Different Disease-Related Amyloidogenic Proteins

ChemBioChem ◽  
2014 ◽  
Vol 16 (3) ◽  
pp. 411-414 ◽  
Author(s):  
Hamed Shaykhalishahi ◽  
Ewa A. Mirecka ◽  
Aziz Gauhar ◽  
Clara S. R. Grüning ◽  
Dieter Willbold ◽  
...  
Keyword(s):  
Binding Protein ◽  
Amyloidogenic Proteins
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