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

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.

2019 ◽  
Author(s):  
Pardis Tabaee Damavandi

Prion 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.


2021 ◽  
Vol 15 (1) ◽  
pp. 193-196
Author(s):  
Máximo Sanz-Hernández ◽  
Alfonso De Simone

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.


2013 ◽  
Vol 12 (08) ◽  
pp. 1341004
Author(s):  
XUE WU ◽  
TING FU ◽  
ZHI-LONG XIU ◽  
LIU YIN ◽  
JIN-GUANG WANG ◽  
...  

Prions are associated with neurodegenerative diseases induced by transmissible spongiform encephalopathies. The infectious scrapie form is referred to as PrP Sc , which has conformational change from normal prion with predominant α-helical conformation to the abnormal PrP Sc that is rich in β-sheet content. Neurodegenerative diseases have been found from both human and bovine sources, but there are no reports about infected by transmissible spongiform encephalopathies from rabbit, canine and horse sources. Here we used coarse-grained Gō model to compare the difference among human, bovine, rabbit, canine, and horse normal (cellular) prion proteins. The denatured state of normal prion has relation with the conversion from normal to abnormal prion protein, so we used all-atom Gō model to investigate the folding pathway and energy landscape for human prion protein. Through using coarse-grained Gō model, the cooperativity of the five prion proteins was characterized in terms of calorimetric criterion, sigmoidal transition, and free-energy profile. The rabbit and horse prion proteins have higher folding free-energy barrier and cooperativity, and canine prion protein has slightly higher folding free-energy barrier comparing with human and bovine prion proteins. The results from all-atom Gō model confirmed the validity of C α-Gō model. The correlations of our results with previous experimental and theoretical researches were discussed.


1998 ◽  
Vol 335 (2) ◽  
pp. 369-374 ◽  
Author(s):  
Mar PÉREZ ◽  
Francisco WANDOSELL ◽  
Camilo COLAÇO ◽  
Jesús AVILA

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.


2012 ◽  
Vol 93 (7) ◽  
pp. 1624-1629 ◽  
Author(s):  
Rona Wilson ◽  
Chris Plinston ◽  
Nora Hunter ◽  
Cristina Casalone ◽  
Cristiano Corona ◽  
...  

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.


2021 ◽  
Vol 118 (12) ◽  
pp. e2019631118
Author(s):  
Máximo Sanz-Hernández ◽  
Joseph D. Barritt ◽  
Jens Sobek ◽  
Simone Hornemann ◽  
Adriano Aguzzi ◽  
...  

The misfolding and aggregation of the human prion protein (PrP) is associated with transmissible spongiform encephalopathies (TSEs). Intermediate conformations forming during the conversion of the cellular form of PrP into its pathological scrapie conformation are key drivers of the misfolding process. Here, we analyzed the properties of the C-terminal domain of the human PrP (huPrP) and its T183A variant, which is associated with familial forms of TSEs. We show that the mutation significantly enhances the aggregation propensity of huPrP, such as to uniquely induce amyloid formation under physiological conditions by the sole C-terminal domain of the protein. Using NMR spectroscopy, biophysics, and metadynamics simulations, we identified the structural characteristics of the misfolded intermediate promoting the aggregation of T183A huPrP and the nature of the interactions that prevent this species to be populated in the wild-type protein. In support of these conclusions, POM antibodies targeting the regions that promote PrP misfolding were shown to potently suppress the aggregation of this amyloidogenic mutant.


2016 ◽  
Vol 474 (1) ◽  
pp. 123-147 ◽  
Author(s):  
Ankit Srivastava ◽  
Sakshi Sharma ◽  
Sandhya Sadanandan ◽  
Sakshi Gupta ◽  
Jasdeep Singh ◽  
...  

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.


2004 ◽  
Vol 71 ◽  
pp. 193-202 ◽  
Author(s):  
David R Brown

Prion diseases, also referred to as transmissible spongiform encephalopathies, are characterized by the deposition of an abnormal isoform of the prion protein in the brain. However, this aggregated, fibrillar, amyloid protein, termed PrPSc, is an altered conformer of a normal brain glycoprotein, PrPc. Understanding the nature of the normal cellular isoform of the prion protein is considered essential to understanding the conversion process that generates PrPSc. To this end much work has focused on elucidation of the normal function and activity of PrPc. Substantial evidence supports the notion that PrPc is a copper-binding protein. In conversion to the abnormal isoform, this Cu-binding activity is lost. Instead, there are some suggestions that the protein might bind other metals such as Mn or Zn. PrPc functions currently under investigation include the possibility that the protein is involved in signal transduction, cell adhesion, Cu transport and resistance to oxidative stress. Of these possibilities, only a role in Cu transport and its action as an antioxidant take into consideration PrPc's Cu-binding capacity. There are also more published data supporting these two functions. There is strong evidence that during the course of prion disease, there is a loss of function of the prion protein. This manifests as a change in metal balance in the brain and other organs and substantial oxidative damage throughout the brain. Thus prions and metals have become tightly linked in the quest to understand the nature of transmissible spongiform encephalopathies.


2013 ◽  
Vol 94 (12) ◽  
pp. 2819-2827 ◽  
Author(s):  
Rona Wilson ◽  
Karen Dobie ◽  
Nora Hunter ◽  
Cristina Casalone ◽  
Thierry Baron ◽  
...  

The transmission of bovine spongiform encephalopathy (BSE) to humans, leading to variant Creutzfeldt–Jakob disease has demonstrated that cattle transmissible spongiform encephalopathies (TSEs) can pose a risk to human health. Until recently, TSE disease in cattle was thought to be caused by a single agent strain, BSE, also known as classical BSE, or BSE-C. However, due to the initiation of a large-scale surveillance programme throughout Europe, two atypical BSE strains, bovine amyloidotic spongiform encephalopathy (BASE, also named BSE-L) and BSE-H have since been discovered. To model the risk to human health, we previously inoculated these two forms of atypical BSE (BASE and BSE-H) into gene-targeted transgenic (Tg) mice expressing the human prion protein (PrP) (HuTg) but were unable to detect any signs of TSE pathology in these mice. However, despite the absence of TSE pathology, upon subpassage of some BASE-challenged HuTg mice, a TSE was observed in recipient gene-targeted bovine PrP Tg (Bov6) mice but not in HuTg mice. Disease transmission from apparently healthy individuals indicates the presence of subclinical BASE infection in mice expressing human PrP that cannot be identified by current diagnostic methods. However, due to the lack of transmission to HuTg mice on subpassage, the efficiency of mouse-to-mouse transmission of BASE appears to be low when mice express human rather than bovine PrP.


2001 ◽  
Vol 75 (10) ◽  
pp. 4673-4680 ◽  
Author(s):  
Suzette A. Priola ◽  
Joëlle Chabry ◽  
Kaman Chan

ABSTRACT In the transmissible spongiform encephalopathies, disease is closely associated with the conversion of the normal proteinase K-sensitive host prion protein (PrP-sen) to the abnormal proteinase K-resistant form (PrP-res). Amino acid sequence homology between PrP-res and PrP-sen is important in the formation of new PrP-res and thus in the efficient transmission of infectivity across species barriers. It was previously shown that the generation of mouse PrP-res was strongly influenced by homology between PrP-sen and PrP-res at amino acid residue 138, a residue located in a region of loop structure common to PrP molecules from many different species. In order to determine if homology at residue 138 also affected the formation of PrP-res in a different animal species, we assayed the ability of hamster PrP-res to convert a panel of recombinant PrP-sen molecules to protease-resistant PrP in a cell-free conversion system. Homology at amino acid residue 138 was not critical for the formation of protease-resistant hamster PrP. Rather, homology between PrP-sen and hamster PrP-res at amino acid residue 155 determined the efficiency of formation of a protease-resistant product induced by hamster PrP-res. Structurally, residue 155 resides in a turn at the end of the first alpha helix in hamster PrP-sen; this feature is not present in mouse PrP-sen. Thus, our data suggest that PrP-res molecules isolated from scrapie-infected brains of different animal species have different PrP-sen structural requirements for the efficient formation of protease-resistant PrP.


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