Altering prion replication for therapy and diagnosis of transmissible spongiform encephalopathies

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.

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

Biomolecular NMR Assignments ◽

10.1007/s12104-021-10005-y ◽

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.

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Efficient Conversion of Normal Prion Protein (PrP) by Abnormal Hamster PrP Is Determined by Homology at Amino Acid Residue 155

Journal of Virology ◽

10.1128/jvi.75.10.4673-4680.2001 ◽

2001 ◽

Vol 75 (10) ◽

pp. 4673-4680 ◽

Cited By ~ 49

Author(s):

Suzette A. Priola ◽

Joëlle Chabry ◽

Kaman Chan

Keyword(s):

Amino Acid ◽

Prion Protein ◽

Amino Acid Residue ◽

Animal Species ◽

Alpha Helix ◽

Proteinase K ◽

Transmissible Spongiform Encephalopathies ◽

Spongiform Encephalopathies ◽

A Cell ◽

Resistant Product

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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A case–control study of scrapie Nor98 in Norwegian sheep flocks

Journal of General Virology ◽

10.1099/vir.0.81951-0 ◽

2006 ◽

Vol 87 (12) ◽

pp. 3729-3736 ◽

Cited By ~ 24

Author(s):

Petter Hopp ◽

Mohamed K. Omer ◽

Berit T. Heier

Keyword(s):

Prion Protein ◽

Case Control Study ◽

Demographic Data ◽

Case Control ◽

Classical Scrapie ◽

Transmissible Spongiform Encephalopathies ◽

Indirect Contact ◽

Spongiform Encephalopathies ◽

Animal Contact ◽

Control Study

Scrapie is a fatal, neurological disease of sheep and goats and belongs to the transmissible spongiform encephalopathies. In 1998, a new type of scrapie, designated scrapie Nor98, was detected in Norway. Scrapie Nor98 differs from classical scrapie in the distribution of pathological changes and of the scrapie prion protein, the Western blot profile of the prion protein, and with isolated cases usually being observed in the case flocks. In 2004, a case–control study was conducted on scrapie Nor98 with 28 cases and 102 randomly selected controls. The questionnaire included questions on demographic data, animal contact between sheep flocks, indirect contact with equipment, use of concentrate feed and supplemental feeds, and use of medicines and vaccines. The data were analysed by using logistic regression with the sheep flock as the statistical unit. In the final model, the detection of scrapie Nor98 was related to the practice of not removing all afterbirths, the use of vitamin and mineral feed supplements, the absence of concentrate feed of swine or poultry on the farm and the presence of dogs on the farm. The results show that the epidemiology of scrapie Nor98 differs from that of classical scrapie in that no risk factors that indicate transmission of scrapie Nor98 between flocks by movement or direct contact between animals were found. Furthermore, the association between scrapie Nor98 and mineral intake shown herein should be explored further. Although the possibility that scrapie Nor98 has a low transmissibility between animals under natural conditions cannot be ruled out, the results would also be in accordance with a spontaneous aetiology.

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COMPARING FOLDING MECHANISMS OF DIFFERENT PRION PROTEINS BY Gō MODEL

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633613410046 ◽

2013 ◽

Vol 12 (08) ◽

pp. 1341004

Author(s):

XUE WU ◽

TING FU ◽

ZHI-LONG XIU ◽

LIU YIN ◽

JIN-GUANG WANG ◽

...

Keyword(s):

Free Energy ◽

Prion Protein ◽

Energy Barrier ◽

Prion Proteins ◽

Coarse Grained ◽

Transmissible Spongiform Encephalopathies ◽

Free Energy Barrier ◽

Spongiform Encephalopathies ◽

Go Model ◽

Folding Free Energy

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.

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

10.1101/2021.12.12.472308 ◽

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.

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

Scientific Reports ◽

10.1038/s41598-021-00495-0 ◽

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.

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Self-Replication of Prion Protein Fragment 89-230 Amyloid Fibrils Accelerated by Prion Protein Fragment 107-143 Aggregates

International Journal of Molecular Sciences ◽

10.3390/ijms21197410 ◽

2020 ◽

Vol 21 (19) ◽

pp. 7410

Author(s):

Tomas Sneideris ◽

Mantas Ziaunys ◽

Brett K.-Y. Chu ◽

Rita P.-Y. Chen ◽

Vytautas Smirnovas

Keyword(s):

Prion Protein ◽

Disease Transmission ◽

Amyloid Fibrils ◽

The Self ◽

Transmissible Spongiform Encephalopathies ◽

Protein Fragment ◽

Spongiform Encephalopathies ◽

Amyloid Fibril Formation ◽

Amyloid Aggregates ◽

Self Replication

Prion protein amyloid aggregates are associated with infectious neurodegenerative diseases, known as transmissible spongiform encephalopathies. Self-replication of amyloid structures by refolding of native protein molecules is the probable mechanism of disease transmission. Amyloid fibril formation and self-replication can be affected by many different factors, including other amyloid proteins and peptides. Mouse prion protein fragments 107-143 (PrP(107-143)) and 89-230 (PrP(89-230)) can form amyloid fibrils. β-sheet core in PrP(89-230) amyloid fibrils is limited to residues ∼160–220 with unstructured N-terminus. We employed chemical kinetics tools, atomic force microscopy and Fourier-transform infrared spectroscopy, to investigate the effects of mouse prion protein fragment 107-143 fibrils on the aggregation of PrP(89-230). The data suggest that amyloid aggregates of a short prion-derived peptide are not able to seed PrP(89-230) aggregation; however, they accelerate the self-replication of PrP(89-230) amyloid fibrils. We conclude that PrP(107-143) fibrils could facilitate the self-replication of PrP(89-230) amyloid fibrils in several possible ways, and that this process deserves more attention as it may play an important role in amyloid propagation.

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Do Bovine Lymphocytes Express a Peculiar Prion Protein?

Developmental Immunology ◽

10.1080/10446670310001593550 ◽

2002 ◽

Vol 9 (4) ◽

pp. 245-252 ◽

Cited By ~ 2

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.

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