Modulation of prion polymerization and toxicity by rationally designed peptidomimetics

2016 ◽  
Vol 474 (1) ◽  
pp. 123-147 ◽  
Author(s):  
Ankit Srivastava ◽  
Sakshi Sharma ◽  
Sandhya Sadanandan ◽  
Sakshi Gupta ◽  
Jasdeep Singh ◽  
...  
Keyword(s):  
Prion Protein ◽  
Self Assembly ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Limited Information ◽  
Spongiform Encephalopathies ◽  
Daunting Task ◽  
Human Prion Protein ◽  
The Stability ◽  
Dynamics Simulations

Misfolding and aggregation of cellular prion protein is associated with a large array of neurological disorders commonly called the transmissible spongiform encephalopathies. Designing inhibitors against prions has remained a daunting task owing to limited information about mechanism(s) of their pathogenic self-assembly. Here, we explore the anti-prion properties of a combinatorial library of bispidine-based peptidomimetics (BPMs) that conjugate amino acids with hydrophobic and aromatic side chains. Keeping the bispidine unit unaltered, a series of structurally diverse BPMs were synthesized and tested for their prion-modulating properties. Administration of Leu- and Trp-BPMs delayed and completely inhibited the amyloidogenic conversion of human prion protein (HuPrP), respectively. We found that each BPM induced the HuPrP to form unique oligomeric nanostructures differing in their biophysical properties, cellular toxicities and response to conformation-specific antibodies. While Leu-BPMs were found to stabilize the oligomers, Trp-BPMs effected transient oligomerization, resulting in the formation of non-toxic, non-fibrillar aggregates. Yet another aromatic residue, Phe, however, accelerated the aggregation process in HuPrP. Molecular insights obtained through MD (molecular dynamics) simulations suggested that each BPM differently engages a conserved Tyr 169 residue at the α2–β2 loop of HuPrP and affects the stability of α2 and α3 helices. Our results demonstrate that this new class of molecules having chemical scaffolds conjugating hydrophobic/aromatic residues could effectively modulate prion aggregation and toxicity.

scholarly journals Zn(II) binding causes interdomain changes in the structure and flexibility of the human prion protein

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maciej Gielnik ◽  
Michał Taube ◽  
Lilia Zhukova ◽  
Igor Zhukov ◽  
Sebastian K. T. S. Wärmländer ◽  
...  
Keyword(s):  
Prion Protein ◽  
Metal Ion ◽  
Structural Transition ◽  
Cellular Prion Protein ◽  
Zinc Homeostasis ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathies ◽  
Structural Conversion ◽  
Protein Size ◽  
Dynamics Simulations

AbstractThe cellular prion protein (PrPC) is a mainly α-helical 208-residue protein located in the pre- and postsynaptic membranes. For unknown reasons, PrPC can undergo a structural transition into a toxic, β-sheet rich scrapie isoform (PrPSc) that is responsible for transmissible spongiform encephalopathies (TSEs). Metal ions seem to play an important role in the structural conversion. PrPC binds Zn(II) ions and may be involved in metal ion transport and zinc homeostasis. Here, we use multiple biophysical techniques including optical and NMR spectroscopy, molecular dynamics simulations, and small angle X-ray scattering to characterize interactions between human PrPC and Zn(II) ions. Binding of a single Zn(II) ion to the PrPC N-terminal domain via four His residues from the octarepeat region induces a structural transition in the C-terminal α-helices 2 and 3, promotes interaction between the N-terminal and C-terminal domains, reduces the folded protein size, and modifies the internal structural dynamics. As our results suggest that PrPC can bind Zn(II) under physiological conditions, these effects could be important for the physiological function of PrPC.

scholarly journals Backbone NMR assignments of the C-terminal domain of the human prion protein and its disease‐associated T183A variant

2021 ◽  
Vol 15 (1) ◽  
pp. 193-196
Author(s):  
Máximo Sanz-Hernández ◽  
Alfonso De Simone
Keyword(s):  
Prion Protein ◽  
Nmr Assignments ◽  
Chemical Shifts ◽  
Prion Diseases ◽  
Random Coil ◽  
Transmissible Spongiform Encephalopathies ◽  
Globular Domain ◽  
Structural Elements ◽  
Spongiform Encephalopathies ◽  
Human Prion Protein

AbstractTransmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative disorders associated with the misfolding and aggregation of the human prion protein (huPrP). Despite efforts into investigating the process of huPrP aggregation, the mechanisms triggering its misfolding remain elusive. A number of TSE-associated mutations of huPrP have been identified, but their role at the onset and progression of prion diseases is unclear. Here we report the NMR assignments of the C-terminal globular domain of the wild type huPrP and the pathological mutant T183A. The differences in chemical shifts between the two variants reveal conformational alterations in some structural elements of the mutant, whereas the analyses of secondary shifts and random coil index provide indications on the putative mechanisms of misfolding of T183A huPrP.

scholarly journals The Prion Protein Octarepeat Domain Forms Transient β-sheet Structures Upon Residue-Specific Cu(II) and Zn(II) Binding

2021 ◽  
Author(s):  
Maciej Gielnik ◽  
Aneta Szymanska ◽  
Xiaolin Dong ◽  
Jyri Jarvet ◽  
Zeljko M. Svedruzic ◽  
...  
Keyword(s):  
Metal Ions ◽  
Prion Protein ◽  
Metal Binding ◽  
Cd Spectroscopy ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Amyloid Formation ◽  
Spectroscopy Data ◽  
Spongiform Encephalopathies ◽  
Β Sheet

Misfolding of the cellular prion protein (PrPC) is associated with the development of fatal neurodegenerative diseases called transmissible spongiform encephalopathies (TSEs). Metal ions appear to play a crucial role in the protein misfolding, and metal imbalance may be part of TSE pathologies. PrPC is a combined Cu(II) and Zn(II) metal binding protein, where the main metal binding site is located in the octarepeat (OR) region. Here, we used biophysical methods to characterize Cu(II) and Zn(II) binding to the isolated OR region. Circular dichroism (CD) spectroscopy data suggest that the OR domain binds up to four Cu(II) ions or two Zn(II) ions. Upon metal binding, the OR region seems to adopt a transient antiparallel β-sheet hairpin structure. Fluorescence spectroscopy data indicates that under neutral conditions, the OR region can bind both Cu(II) and Zn(II) ions, whereas under acidic conditions it binds only Cu(II) ions. Molecular dynamics simulations suggest that binding of both metal ions to the OR region results in formation of β-hairpin structures. As formation of β-sheet structures is a first step towards amyloid formation, we propose that high concentrations of either Cu(II) or Zn(II) ions may have a pro-amyloid effect in TSEs.

scholarly journals Do Bovine Lymphocytes Express a Peculiar Prion Protein?

2002 ◽  
Vol 9 (4) ◽  
pp. 245-252 ◽  
Author(s):  
France Mélot ◽  
Caroline Thielen ◽  
Thouraya Labiet ◽  
Sabine Eisher ◽  
Olivier Jolois ◽  
...  
Keyword(s):  
Prion Protein ◽  
Immune Cells ◽  
Surface Protein ◽  
In Vitro Study ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Lymphoid Tissues ◽  
Spongiform Encephalopathies ◽  
Bovine Lymphocytes

The cellular prion protein (PrPc) is a glycolipid-anchored cell surface protein that usually exhibits three glycosylation states. Its post-translationally modified isoform, PrPsc, is involved in the pathogenesis of various transmissible spongiform encephalopathies (TSEs). In bovine species, BSE infectivity appears to be restricted to the central nervous system; few or no detectable infectivity is found in lymphoid tissues in contrast to scrapie or variant CJD. Since expression of PrPc is a prerequisite for prion replication, we have investigated PrPc expression by bovine immune cells. Lymphocytes from blood and five different lymph organs were isolated from the same animal to assess intra- and interindividual variability of PrPc expression, considering six individuals. As shown by flow cytometry, this expression is absent or weak on granulocytes but is measurable on monocytes, B and T cells from blood and lymph organs. The activation of the bovine cells produces an upregulation of PrPc. The results of our in vitro study of PrPc biosynthesis are consistent with previous studies in other species. Interestingly, western blotting experiments showed only one form of the protein, the diglycosylated band. We propose that the glycosylation state could explain the lack of infectivity of the bovine immune cells.

scholarly journals Sulphated glycosaminoglycans prevent the neurotoxicity of a human prion protein fragment

1998 ◽  
Vol 335 (2) ◽  
pp. 369-374 ◽  
Author(s):  
Mar PÉREZ ◽  
Francisco WANDOSELL ◽  
Camilo COLAÇO ◽  
Jesús AVILA
Keyword(s):  
Prion Protein ◽  
Amyloid Fibrils ◽  
Transmissible Spongiform Encephalopathies ◽  
Therapeutic Effects ◽  
Protein Fragment ◽  
Spongiform Encephalopathies ◽  
Sulphated Polysaccharides ◽  
Human Prion Protein ◽  
Sulphated Glycosaminoglycans

Although a number of features distinguish the disease isoform of the prion protein (PrPSc) from its normal cellular counterpart (PrPC) in the transmissible spongiform encephalopathies (TSEs), the neuropathogenesis of these diseases remains an enigma. The amyloid fibrils formed by fragments of human PrP have, however, been shown to be directly neurotoxic in vitro. We show here that sulphated polysaccharides (heparin, keratan and chondroitin) inhibit the neurotoxicity of these amyloid fibrils and this appears to be mediated via inhibition of the polymerization of the PrP peptide into fibrils. This provides a rationale for the therapeutic effects of sulphated polysaccharides and suggests a rapid in vitro functional screen for TSE therapeutics.

scholarly journals Prion Diseases and the Gastrointestinal Tract

2006 ◽  
Vol 20 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Gwynivere A Davies ◽  
Adam R Bryant ◽  
John D Reynolds ◽  
Frank R Jirik ◽  
Keith A Sharkey
Keyword(s):  
Nervous System ◽  
Dendritic Cells ◽  
Enteric Nervous System ◽  
Prion Protein ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Gi Tract ◽  
Spongiform Encephalopathies ◽  
The Brain

The gastrointestinal (GI) tract plays a central role in the pathogenesis of transmissible spongiform encephalopathies. These are human and animal diseases that include bovine spongiform encephalopathy, scrapie and Creutzfeldt-Jakob disease. They are uniformly fatal neurological diseases, which are characterized by ataxia and vacuolation in the central nervous system. Alhough they are known to be caused by the conversion of normal cellular prion protein to its infectious conformational isoform (PrPsc) the process by which this isoform is propagated and transported to the brain remains poorly understood. M cells, dendritic cells and possibly enteroendocrine cells are important in the movement of infectious prions across the GI epithelium. From there, PrPscpropagation requires B lymphocytes, dendritic cells and follicular dendritic cells of Peyer’s patches. The early accumulation of the disease-causing agent in the plexuses of the enteric nervous system supports the contention that the autonomic nervous system is important in disease transmission. This is further supported by the presence of PrPscin the ganglia of the parasympathetic and sympathetic nerves that innervate the GI tract. Additionally, the lymphoreticular system has been implicated as the route of transmission from the gut to the brain. Although normal cellular prion protein is found in the enteric nervous system, its role has not been characterized. Further research is required to understand how the cellular components of the gut wall interact to propagate and transmit infectious prions to develop potential therapies that may prevent the progression of transmissible spongiform encephalopathies.

scholarly journals A Promising Antiprion Trimethoxychalcone Binds to the Globular Domain of the Cellular Prion Protein and Changes Its Cellular Location

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
N. C. Ferreira ◽  
L. M. Ascari ◽  
A. G. Hughson ◽  
G. R. Cavalheiro ◽  
C. F. Góes ◽  
...  
Keyword(s):  
Cell Surface ◽  
Real Time ◽  
Prion Protein ◽  
Molecular Mechanisms ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Globular Domain ◽  
Mrna Levels ◽  
Spongiform Encephalopathies

ABSTRACTThe search for antiprion compounds has been encouraged by the fact that transmissible spongiform encephalopathies (TSEs) share molecular mechanisms with more prevalent neurodegenerative pathologies, such as Parkinson's and Alzheimer's diseases. Cellular prion protein (PrPC) conversion into protease-resistant forms (protease-resistant PrP [PrPRes] or the scrapie form of PrP [PrPSc]) is a critical step in the development of TSEs and is thus one of the main targets in the screening for antiprion compounds. In this work, three trimethoxychalcones (compounds J1, J8, and J20) and one oxadiazole (compound Y17), previously identifiedin vitroto be potential antiprion compounds, were evaluated through different approaches in order to gain inferences about their mechanisms of action. None of them changed PrPCmRNA levels in N2a cells, as shown by reverse transcription-quantitative real-time PCR. Among them, J8 and Y17 were effective in real-time quaking-induced conversion reactions using rodent recombinant PrP (rPrP) from residues 23 to 231 (rPrP23–231) as the substrate and PrPScseeds from hamster and human brain. However, when rPrP from residues 90 to 231 (rPrP90–231), which lacks the N-terminal domain, was used as the substrate, only J8 remained effective, indicating that this region is important for Y17 activity, while J8 seems to interact with the PrPCglobular domain. J8 also reduced the fibrillation of mouse rPrP23–231seeded within vitro-produced fibrils. Furthermore, most of the compounds decreased the amount of PrPCon the N2a cell surface by trapping this protein in the endoplasmic reticulum. On the basis of these results, we hypothesize that J8, a nontoxic compound previously shown to be a promising antiprion agent, may act by different mechanisms, since its efficacy is attributable not only to PrP conversion inhibition but also to a reduction of the PrPCcontent on the cell surface.

scholarly journals Chronic wasting disease and atypical forms of bovine spongiform encephalopathy and scrapie are not transmissible to mice expressing wild-type levels of human prion protein

2012 ◽  
Vol 93 (7) ◽  
pp. 1624-1629 ◽  
Author(s):  
Rona Wilson ◽  
Chris Plinston ◽  
Nora Hunter ◽  
Cristina Casalone ◽  
Cristiano Corona ◽  
...  
Keyword(s):  
Bovine Spongiform Encephalopathy ◽  
Prion Protein ◽  
Chronic Wasting Disease ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Wild Type ◽  
Wasting Disease ◽  
Spongiform Encephalopathies ◽  
Jakob Disease ◽  
Human Prion Protein

The association between bovine spongiform encephalopathy (BSE) and variant Creutzfeldt–Jakob disease (vCJD) has demonstrated that cattle transmissible spongiform encephalopathies (TSEs) can pose a risk to human health and raises the possibility that other ruminant TSEs may be transmissible to humans. In recent years, several novel TSEs in sheep, cattle and deer have been described and the risk posed to humans by these agents is currently unknown. In this study, we inoculated two forms of atypical BSE (BASE and H-type BSE), a chronic wasting disease (CWD) isolate and seven isolates of atypical scrapie into gene-targeted transgenic (Tg) mice expressing the human prion protein (PrP). Upon challenge with these ruminant TSEs, gene-targeted Tg mice expressing human PrP did not show any signs of disease pathology. These data strongly suggest the presence of a substantial transmission barrier between these recently identified ruminant TSEs and humans.

scholarly journals Structure analysis of human Prion protein involved in Sporadic Fatal Insomnia

2018 ◽  
Author(s):  
Philip J Camp ◽  
Pardis Tabaee Damavandi ◽  
Richard W Pickersgill ◽  
Martin T Dove
Keyword(s):  
Prion Protein ◽  
Prion Proteins ◽  
Transmissible Spongiform Encephalopathies ◽  
Human Form ◽  
Native Form ◽  
Spongiform Encephalopathies ◽  
Root Cause ◽  
Progressive Neurodegeneration ◽  
Human Prion Protein ◽  
Key Residues

AbstractPrion disorders are the root cause of Transmissible Spongiform Encephalopathies (TSE), a group of lethal diseases portrayed by progressive neurodegeneration and spongiosis. In recent years, researchers have come to understand that it is not the endogenous presence of Prions itself that causes neurodegeneration, but the amount of prion proteins that accumulates in the nervous tissue, leading them to exert neurotoxicity. More specifically, the cause of these disorders is mapped to several mutations that can bring the prion protein structure to a disordered permanent misfolded state. Our research is focused on Sporadic Fatal Insomnia (sFI), a rare TSE characterized by severe and chronic insomnia, leading to a life expectancy estimation of about two and a half years, from the onset of the first symptoms. The goal of this work was to analyze through computational studies the structure of the native human Prion Protein (PrPnat) and compare it with the toxic form (FI-Prion) which causes disease. Our findings show that the structure of the human mutant FI-Prion, responsible for Sporadic Fatal Insomnia is more flexible than the native human form PrPnat. Specific regions of the mutant seem to fluctuate more freely than the corresponding loops in the native form. We also identified amino acids Tyr128 and Met129 to be the key residues playing a major role in the manifestation of the disease. Therefore, we’ve learnt that the FI-Prion is more flexible than PrPnat. In addition, we also confirmed that sporadic fatal insomnia is undoubtedly an infectious disease.

scholarly journals Prion protein β2–α2 loop conformational landscape

2017 ◽  
Vol 114 (36) ◽  
pp. 9617-9622 ◽  
Author(s):  
Enrico Caldarulo ◽  
Alessandro Barducci ◽  
Kurt Wüthrich ◽  
Michele Parrinello
Keyword(s):  
Prion Protein ◽  
Mammalian Species ◽  
Wild Type Mouse ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Free Energy Surface ◽  
Spongiform Encephalopathies ◽  
New Information ◽  
Amyloid Aggregates ◽  
Wide Range

In transmissible spongiform encephalopathies (TSEs), which are lethal neurodegenerative diseases that affect humans and a wide range of other mammalian species, the normal “cellular” prion protein (PrPC) is transformed into amyloid aggregates representing the “scrapie form” of the protein (PrPSc). Continued research on this system is of keen interest, since new information on the physiological function of PrPC in healthy organisms is emerging, as well as new data on the mechanism of the transformation of PrPC to PrPSc. In this paper we used two different approaches: a combination of the well-tempered ensemble (WTE) and parallel tempering (PT) schemes and metadynamics (MetaD) to characterize the conformational free-energy surface of PrPC. The focus of the data analysis was on an 11-residue polypeptide segment in mouse PrPC(121–231) that includes the β2–α2 loop of residues 167–170, for which a correlation between structure and susceptibility to prion disease has previously been described. This study includes wild-type mouse PrPC and a variant with the single-residue replacement Y169A. The resulting detailed conformational landscapes complement in an integrative manner the available experimental data on PrPC, providing quantitative insights into the nature of the structural transition-related function of the β2–α2 loop.

Sign in / Sign up

Export Citation Format

Share Document