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This is a preview of subscription content, log in to check access. Review: history of the amyloid fibril. J Struct Biol ; — Protofibrillar islet amyloid polypeptide permeabilizes synthetic vesicles by a pore-like mechanism that may be relevant to type II diabetes. Biochemistry ; — Hirakura Y, Kagan BL. Pore formation by betamicroglobulin: a mechanism for the pathogenesis of dialysis associated amyloidosis.
Amyloid ; — PubMed Google Scholar. Sipe JD. Serum amyloid A: from fibril to function. Current status. Properties and modulation of alpha human atrial natriuretic peptide alpha-hANP -formed ion channels. Can J Physiol Pharmacol ; — Polyglutamine-induced ion channels: a possible mechanism for the neurotoxicity of huntington and other CAG repeat diseases.
Structure-Property Relationship of Amyloidogenic Prion Nanofibrils
J Neurosci Res, ; — Ion channels with different selectivity formed by transthyretin. Biophys J ; a. Google Scholar. Ion channels formed by a fragment of alpha-synucleain NAC in lipid membranes. Biophs J ; a. Channel formation by serum amyloid A: a potential mechanism for amyloid pathogenesis and host defense. Channel formation by salmon and human calcitonin in black lipid membranes.
Direct Evidence for Self-Propagation of Different Amyloid-β Fibril Conformations
Biophys J ; — Amyloid protofilaments from the calcium-binding protein equine lysozyme: formation of ring and linear structures depends on pH and metal ion concentration. J Mol Biol ; — Channels formed with a mutant prion protein PrP — homologous to a 7-kDa fragment in diseased brain of GSS patients. Amyloid ion channels: a common structural link for protein-misfolding disease. Synthetic lipid vesicles recruit native-like aggregates and affect the aggregation process of the prion Ure2p: Insights on vesicle permeabilization and charge selectivity.
Natively folded HypF-N and its early amyloid aggregates interact with phospholipid monolayers and destabilize supported phospholipid bilayers. Size and morphology of toxic oligomers of amyloidogenic proteins: a case study of human stefin B. Scintigraphic quantification and serial monitoring of human visceral amyloid deposits provide evidence for turnover and regression.
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Pathways of Peptide Assembly
J Neurosci ; — Ann Rev of Biochem ; — Membrane perturbation by the neurotoxic Alzheimer amyloid fragment beta requires aggregation and beta-sheet formation. Biochem Mol Biol Int ; — A specific amyloid-beta protein assembly in the brain impairs memory. Naturally secreted oligomers of amyloid beta protein potently inhibit hippocampal long-term potentiation in vivo. Lin H, Bhatia R et al. Faseb J ; — Janson J, Ashley RH, Harrison D et al The mechanism of islet amyloid polypeptide toxicity is membrane disruption by intermediate-sized toxic amyloid particles.
Diabetes ; — Common structure of soluble amyloid oligomers implies common mechanism of pathogenesis.
Effect of Surfaces on Amyloid Fibril Formation
Science ; — Amyloid peptide channels. J Membr Biol ; — Amyloid beta ion channels in artificial lipid bilayer and neuronal cells. The key point of this mechanism is that one block monomer of amyloid proteins can be regarded as a template for other block monomers, even if the blocks have different physiochemical characteristics and are constructed with different conformations and compositions [ 22 — 25 ].
The cross-seeding mechanism can explain the formation of heterogeneous-composed amyloid fibrils and polymorphic fibrils, and these models offered better insight into amyloid accumulation processes. Experimental studies showed that seeding with amyloid-like fibrils made from short synthetic peptides from other amyloid proteins or fibrils of a completely different nature; for example, bacterial curli or Sup35 from Saccharomyces may function through other interactions [ 26 ]. In addition, Yan et al. Recently, computational studies were performed to overcome the limitation of experimental studies, which are unable to determine molecular structures in detail.
For several decades, many studies have evaluated the mechanical properties and behaviors of amyloid fibrils [ 27 — 32 ], providing insight into the amyloid fibril formation mechanism. Most studies examined homologous amyloid fibrils. Experimentally, it was revealed that heterogeneous interactions enabled different amyloid monomers to aggregate with each other.
Recent studies revealed the structural and interaction features of cross-seeded amyloid oligomers and proto-fibrils. In addition, Miller et al.
They studied the interactions between heterologous monomers. Furthermore, Choi et al. They found that different binding directions showed different structural stabilities.
follow link It was observed that amyloid beta monomers and other monomers could act as templates for seeding processes. Experimental result for heterogeneous amyloid fibrils left panel  and schematic constraint for simulation of heterogeneous amyloid fibrils right panel . Many computational studies showed that not only structural similarity but also specific interactions between residues of amyloid proteins play a major role in seeding processes. Elongation of amyloid fibrils along the fibril axis is related to the binding features of the seed amyloids and their structural stabilities.
The binding sites on monomers enable the attachment of other monomers [ 39 ]. It was revealed that the structural stabilities of intra-layers were affected by steric-zipper-like interactions [ 40 — 42 ] and salt-bridge interactions [ 37 ]. Intra-structural stabilities are dominantly affected by specific interactions. Hydrophobic residues in interior regions of amyloid fibrils form steric-zipper-like structures and help maintain cross-sectional structures. Although heterologous monomers contain different residues, hydrophobic residues commonly construct dry-regions and affect structural stabilities.
In addition, charged residues such as lysine K and aspartic acid D form salt-bridge regions and affect intra-stabilities. The stabilities of inter-layers are also affected by hydrogen-bonding networks and nonbonding interaction energies, such as Van der Waals and electrostatic energy induced by interactions between residues of layers that face each other.
Interactions between single layers are dominantly affected by electrostatic and Van der Waals energies.
However, as the number of layers is increased, the effect of electrostatic energies becomes dominant. In the fibril formation processes of heterologous amyloids, binding between monomers is affected by electrostatic energies Figure 5. In the previous section, we described the general aggregation and seeding mechanism of amyloid-like prion fibrils based on homogeneous and heterogeneous structures. During the aggregation of prion fibrils in the seeding mechanism, the external environment affects growth of prion-like amyloid fibrils.
Here, the effect of the external environment is referred to as the physiological conditions, which have been shown to affect molecular conformational variation in the fibrillary growth of PrP C , HET-s, and Sup35, in detail.
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First, the development of prion proteins is caused by the conversion of native prion protein monomeric PrP C as misfolded and denatured PrP Sc because of external conditions such as partial mutation, internal flow, pH, ionic strength, and temperature variations. This PrP C protein is glycosylated and functions similar to components of the extracellular surface of neurons, which play a significant role in signal transduction.
This native PrP C is converted to monomeric PrP Sc , which gradually aggregates to form oligomeric, fibrillar, and plaque structures. These converted monomeric PrP Sc act as seeds at specific concentrations with a lag phase, which induce the aggregation of fibrillar and plaque prions. Prion proteins. The other type of prion proteins is the HET-s prion protein. According to Govaerts et al.
In contrast, right-handed prion proteins are not toxic based on combined experimental and computational studies. In , Wasmer et al. Lateral thickness composition of Sup 35 prion proteins. Fibrillar and plaque forms of PrP Sc prion proteins are frequently observed because of their considerable infectivity ability. These fibrillar and plaque types of prion proteins can be generated through repetitive fragmentation and elongation mechanisms. The prion proteins grow by adding monomers or attracting other fragmented prion segments.
Colby et al. Through the repetitive process of fragmentation and elongation mechanism, neuro-toxic prion oligomers could be generated. In this aggregation, after conversion from PrP C to PrP Sc , prion proteins showed toxic characteristics and affected intercellular processes. Similarly, for the fragmentation and elongation mechanisms of HET-s prion proteins, Mizuno et al. Fragmentation and addition of prion seeds generated different types of fibrillar HET-s near pH 2 and 3, while lattice-like HET-s was observed under neutral physiological conditions.
To discuss the structural characteristics of plaque and fibrillar prions from converted PrP Sc , in this section, we described the conversion mechanism of PrP C from PrP Sc prion proteins at the atomic scale based on computational results. In , Daggett et al.