1
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Jaklin M, Hritz J, Hribar-Lee B. A new fibrillization mechanism of β-lactoglobulin in glycine solutions. Int J Biol Macromol 2022; 216:414-425. [PMID: 35803407 PMCID: PMC10039397 DOI: 10.1016/j.ijbiomac.2022.06.182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/15/2022] [Accepted: 06/27/2022] [Indexed: 11/26/2022]
Abstract
Even though amyloid aggregates were discovered many years ago the mechanism of their formation is still a mystery. Because of their connection to many of untreatable neurodegenerative diseases the motivation for finding a common aggregation path is high. We report a new high heat induced fibrillization path of a model protein β-lactoglobulin (BLG) when incubated in glycine instead of water at pH 2. By combining atomic force microscopy (AFM), transmission emission microscopy (TEM), dynamic light scattering (DLS) and circular dichroism (CD) we predict that the basic building blocks of fibrils made in glycine are not peptides, but rather spheroid oligomers of different height that form by stacking of ring-like structures. Spheroid oligomers linearly align to form fibrils by opening up and combining. We suspect that glycine acts as an hydrolysation inhibitor which consequently promotes a different fibrillization path. By combining the known data on fibrillization in water with our experimental conclusions we come up with a new fibrillization scheme for BLG. We show that by changing the fibrillization conditions just by small changes in buffer composition can dramatically change the aggregation pathway and the effect of buffer shouldn't be neglected. Fibrils seen in our study are also gaining more and more attention because of their pore-like structure and a possible cytotoxic mechanism by forming pernicious ion-channels. By preparing them in a simple model system as BLG we opened a new way to study their formation.
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Affiliation(s)
- Matej Jaklin
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, Ljubljana SI-1000, Slovenia
| | - Jozef Hritz
- CEITEC Masaryk University Kamenice 5, Brno 625 00, Czech Republic; Department of Chemistry, Faculty of Science, Masaryk University Kamenice 5, Brno 625 00, Czech Republic
| | - Barbara Hribar-Lee
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, Ljubljana SI-1000, Slovenia.
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2
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Zhou DH, Wang J, Xiao K, Wu YZ, Maimaitiming A, Hu C, Gao LP, Chen J, Gao C, Chen C, Shi Q, Dong XP. Stilbene Compounds Inhibit the Replications of Various Strains of Prions in the Levels of Cell Culture, PMCA, and RT-QuIC Possibly via Molecular Binding. ACS Chem Neurosci 2020; 11:2117-2128. [PMID: 32511904 DOI: 10.1021/acschemneuro.0c00218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Resveratrol shows the ability to block prion replication in a scrapie-infected cell line, SMB-S15, and remove the infectivity of the treated cell lysates in an experimental bioassay. In this study, we compared the effectiveness of three stilbene compounds, resveratrol (Res), pterostilbene (Pte), and piceatannol (Pic), on inhibiting prion propagations in the levels of cell culture, PMCA, and RT-QuIC. All three chemicals showed active suppressions on PrPSc replication in SMB-S15 cells, in which Res seemed to be the most active one, followed by Pic and Pte. Mouse PrP-based PMCA tests using the lysates of SMB-S15 cells and brain homogenates of scrapie agents S15-, 139A-, or ME7-infected mice verified that Res, Pte, and Pic inhibited the amplifications of PK-resistant signals. Res was also the most effective one. Mouse PrP-based RT-QuIC using the above seeds demonstrated that three stilbenes efficiently inhibited the fibril formation. However, Pic was the most effective one, followed by Res and Pte. Furthermore, the inhibition activities of the three stilbenes on the brain-derived prion from a 263K-infected hamster were tested with hamster PrP-based PMCA and RT-QuIC. The results indicated that Pic was the most effective one apparently, followed by Res and Pte. According to the results of Biacore, Res showed binding affinities much stronger than those of Pte, whereas both revealed markedly stronger binding affinities with mouse PrP. Our data here indicate that different stilbenes have the ability to block PrPSc replication in vitro with different prion species. The suppressive effects of stilbene compounds are likely associated with their molecular binding activities with PrPs.
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Affiliation(s)
- Dong-Hua Zhou
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Jing Wang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Kang Xiao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Yue-Zhang Wu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Adalaiti Maimaitiming
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Chao Hu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Li-Ping Gao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Jia Chen
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Chen Gao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
- Chinese Center for Disease Control and Prevention, Wuhan Institute of Virology, Chinese Academy of Sciences Joint Research Center for Emerging Infectious Diseases and Biosafety, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan 430071, China
| | - Cao Chen
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
| | - Qi Shi
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
- China Academy of Chinese Medical Sciences, Beijing 100050, China
| | - Xiao-Ping Dong
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases (Zhejiang University), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
- Center for Global Public Health, Chinese Center for Disease Control and Prevention, Chang-Bai Road 155, Beijing 102206, China
- Chinese Center for Disease Control and Prevention, Wuhan Institute of Virology, Chinese Academy of Sciences Joint Research Center for Emerging Infectious Diseases and Biosafety, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan 430071, China
- China Academy of Chinese Medical Sciences, Beijing 100050, China
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3
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Sengupta I, Udgaonkar JB. Expression and purification of single cysteine-containing mutant variants of the mouse prion protein by oxidative refolding. Protein Expr Purif 2017; 140:1-7. [PMID: 28736314 DOI: 10.1016/j.pep.2017.07.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 07/19/2017] [Accepted: 07/19/2017] [Indexed: 11/16/2022]
Abstract
The folding and aggregation of proteins has been studied extensively, using multiple probes. To facilitate such experiments, introduction of spectroscopically-active moieties in to the protein of interest is often necessary. This is commonly achieved by specifically labelling cysteine residues in the protein, which are either present naturally or introduced artificially by site-directed mutagenesis. In the case of the recombinant prion protein, which is normally expressed in inclusion bodies, the presence of the native disulfide bond complicates the correct refolding of single cysteine-containing mutant variants of the protein. To overcome this major bottleneck, a simple purification strategy for single tryptophan, single cysteine-containing mutant variants of the mouse prion protein is presented, with yields comparable to that of the wild type protein. The protein(s) obtained by this method are correctly folded, with a single reduced cysteine, and the native disulfide bond between residues C178 and C213 intact. The β-sheet rich oligomers formed from these mutant variant protein(s) are identical to the wild type protein oligomer. The current strategy facilitates sample preparation for a number of high resolution spectroscopic measurements for the prion protein, which specifically require thiol labelling.
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Affiliation(s)
- Ishita Sengupta
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India.
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4
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Sengupta I, Bhate SH, Das R, Udgaonkar JB. Salt-Mediated Oligomerization of the Mouse Prion Protein Monitored by Real-Time NMR. J Mol Biol 2017; 429:1852-1872. [DOI: 10.1016/j.jmb.2017.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/05/2017] [Accepted: 05/07/2017] [Indexed: 12/11/2022]
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5
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Moulick R, Das R, Udgaonkar JB. Partially Unfolded Forms of the Prion Protein Populated under Misfolding-promoting Conditions: CHARACTERIZATION BY HYDROGEN EXCHANGE MASS SPECTROMETRY AND NMR. J Biol Chem 2015; 290:25227-40. [PMID: 26306043 DOI: 10.1074/jbc.m115.677575] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Indexed: 12/16/2022] Open
Abstract
The susceptibility of the cellular prion protein (PrP(C)) to convert to an alternative misfolded conformation (PrP(Sc)), which is the key event in the pathogenesis of prion diseases, is indicative of a conformationally flexible native (N) state. In the present study, hydrogen-deuterium exchange (HDX) in conjunction with mass spectrometry and nuclear magnetic resonance spectroscopy were used for the structural and energetic characterization of the N state of the full-length mouse prion protein, moPrP(23-231), under conditions that favor misfolding. The kinetics of HDX of 34 backbone amide hydrogens in the N state were determined at pH 4. In contrast to the results of previous HDX studies on the human and Syrian hamster prion proteins at a higher pH, various segments of moPrP were found to undergo different extents of subglobal unfolding events at pH 4, a pH at which the protein is known to be primed to misfold to a β-rich conformation. No residual structure around the disulfide bond was observed for the unfolded state at pH 4. The N state of the prion protein was observed to be at equilibrium with at least two partially unfolded forms (PUFs). These PUFs, which are accessed by stochastic fluctuations of the N state, have altered surface area exposure relative to the N state. One of these PUFs resembles a conformation previously implicated to be an initial intermediate in the conversion of monomeric protein into misfolded oligomer at pH 4.
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Affiliation(s)
- Roumita Moulick
- From the National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Ranabir Das
- From the National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- From the National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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6
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Singh J, Udgaonkar JB. Molecular Mechanism of the Misfolding and Oligomerization of the Prion Protein: Current Understanding and Its Implications. Biochemistry 2015; 54:4431-42. [PMID: 26171558 DOI: 10.1021/acs.biochem.5b00605] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Prion diseases, also known as transmissible spongiform encephalopathies, make up a group of fatal neurodegenerative disorders linked with the misfolding and aggregation of the prion protein (PrP). Although it is not yet understood how the misfolding of PrP induces neurodegeneration, it is widely accepted that the formation of misfolded prion protein (termed PrP(Sc)) is both the triggering event in the disease and the main component of the infectious agent responsible for disease transmission. Despite the clear involvement of PrP(Sc) in prion diseases, the exact composition of PrP(Sc) is not yet well-known. Recent studies show that misfolded oligomers of PrP could, however, be responsible for neurotoxicity and/or infectivity in the prion diseases. Hence, understanding the molecular mechanism of formation of the misfolded oligomers of PrP is critical for developing an understanding about the prion diseases and for developing anti-prion therapeutics. This review discusses recent advances in understanding the molecular mechanism of misfolded oligomer formation by PrP and its implications for the development of anti-prion therapeutics.
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Affiliation(s)
- Jogender Singh
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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7
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Hoop CL, Lin HK, Kar K, Hou Z, Poirier MA, Wetzel R, van der Wel PCA. Polyglutamine amyloid core boundaries and flanking domain dynamics in huntingtin fragment fibrils determined by solid-state nuclear magnetic resonance. Biochemistry 2014; 53:6653-66. [PMID: 25280367 PMCID: PMC4211650 DOI: 10.1021/bi501010q] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
In Huntington’s disease, expansion
of a polyglutamine (polyQ)
domain in the huntingtin (htt) protein leads to misfolding and aggregation.
There is much interest in the molecular features that distinguish
monomeric, oligomeric, and fibrillar species that populate the aggregation
pathway and likely differ in cytotoxicity. The mechanism and rate
of aggregation are greatly affected by the domains flanking the polyQ
segment within exon 1 of htt. A “protective” C-terminal
proline-rich flanking domain inhibits aggregation by inducing polyproline
II structure (PPII) within an extended portion of polyQ. The N-terminal
flanking segment (httNT) adopts an α-helical structure
as it drives aggregation, helps stabilize oligomers and fibrils, and
is seemingly integral to their supramolecular assembly. Via solid-state
nuclear magnetic resonance (ssNMR), we probe how, in the mature fibrils,
the htt flanking domains impact the polyQ domain and in particular
the localization of the β-structured amyloid core. Using residue-specific
and uniformly labeled samples, we find that the amyloid core occupies
most of the polyQ domain but ends just prior to the prolines. We probe
the structural and dynamical features of the remarkably abrupt β-sheet
to PPII transition and discuss the potential connections to certain
htt-binding proteins. We also examine the httNT α-helix
outside the polyQ amyloid core. Despite its presumed structural and
demonstrated stabilizing roles in the fibrils, quantitative ssNMR
measurements of residue-specific dynamics show that it undergoes distinct
solvent-coupled motion. This dynamical feature seems reminiscent of
molten-globule-like α-helix-rich features attributed to the
nonfibrillar oligomeric species of various amyloidogenic proteins.
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Affiliation(s)
- Cody L Hoop
- Department of Structural Biology, University of Pittsburgh School of Medicine , Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15260, United States
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8
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Moulick R, Udgaonkar JB. Thermodynamic characterization of the unfolding of the prion protein. Biophys J 2014; 106:410-20. [PMID: 24461016 DOI: 10.1016/j.bpj.2013.11.4491] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 11/15/2013] [Accepted: 11/27/2013] [Indexed: 12/16/2022] Open
Abstract
The prion protein appears to be unusually susceptible to conformational change, and unlike nearly all other proteins, it can easily be made to convert to alternative misfolded conformations. To understand the basis of this structural plasticity, a detailed thermodynamic characterization of two variants of the mouse prion protein (moPrP), the full-length moPrP (23-231) and the structured C-terminal domain, moPrP (121-231), has been carried out. All thermodynamic parameters governing unfolding, including the changes in enthalpy, entropy, free energy, and heat capacity, were found to be identical for the two protein variants. The N-terminal domain remains unstructured and does not interact with the C-terminal domain in the full-length protein at pH 4. Moreover, the enthalpy and entropy of unfolding of moPrP (121-231) are similar in magnitude to values reported for other proteins of similar size. However, the protein has an unusually high native-state heat capacity, and consequently, the change in heat capacity upon unfolding is much lower than that expected for a protein of similar size. It appears, therefore, that the native state of the prion protein undergoes substantial fluctuations in enthalpy and hence, in structure.
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Affiliation(s)
- Roumita Moulick
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.
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9
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Trevitt CR, Hosszu LLP, Batchelor M, Panico S, Terry C, Nicoll AJ, Risse E, Taylor WA, Sandberg MK, Al-Doujaily H, Linehan JM, Saibil HR, Scott DJ, Collinge J, Waltho JP, Clarke AR. N-terminal domain of prion protein directs its oligomeric association. J Biol Chem 2014; 289:25497-508. [PMID: 25074940 PMCID: PMC4162156 DOI: 10.1074/jbc.m114.566588] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The self-association of prion protein (PrP) is a critical step in the pathology of prion diseases. It is increasingly recognized that small non-fibrillar β-sheet-rich oligomers of PrP may be of crucial importance in the prion disease process. Here, we characterize the structure of a well defined β-sheet-rich oligomer, containing ∼12 PrP molecules, and often enclosing a central cavity, formed using full-length recombinant PrP. The N-terminal region of prion protein (residues 23-90) is required for the formation of this distinct oligomer; a truncated form comprising residues 91-231 forms a broad distribution of aggregated species. No infectivity or toxicity was found using cell and animal model systems. This study demonstrates that examination of the full repertoire of conformers and assembly states that can be accessed by PrP under specific experimental conditions should ideally be done using the full-length protein.
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Affiliation(s)
- Clare R Trevitt
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Laszlo L P Hosszu
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Mark Batchelor
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Silvia Panico
- the Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX
| | - Cassandra Terry
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Andrew J Nicoll
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Emmanuel Risse
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - William A Taylor
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Malin K Sandberg
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Huda Al-Doujaily
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Jacqueline M Linehan
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Helen R Saibil
- the Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX
| | - David J Scott
- the National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, the ISIS Spallation Neutron and Muon Source and Research Complex at Harwell, Rutherford Appleton Laboratory, Oxfordshire, OX11 0FA, and
| | - John Collinge
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG
| | - Jonathan P Waltho
- the Department of Molecular Biology and Biotechnology, Krebs Institute for Biomolecular Research, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Anthony R Clarke
- From the Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, Queen Square, London WC1N 3BG,
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10
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Larda ST, Simonetti K, Al-Abdul-Wahid MS, Sharpe S, Prosser RS. Dynamic Equilibria between Monomeric and Oligomeric Misfolded States of the Mammalian Prion Protein Measured by 19F NMR. J Am Chem Soc 2013; 135:10533-41. [DOI: 10.1021/ja404584s] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Sacha Thierry Larda
- Department of Chemistry, University of Toronto, Toronto, Ontario,
Canada M5S 3H6
| | - Karen Simonetti
- Molecular
Structure and Function
Program, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | | | - Simon Sharpe
- Molecular
Structure and Function
Program, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
- Department of Biochemistry, University of Toronto, Toronto, Ontario,
Canada M5S 1A8
| | - R. Scott Prosser
- Department of Chemistry, University of Toronto, Toronto, Ontario,
Canada M5S 3H6
- Department of Biochemistry, University of Toronto, Toronto, Ontario,
Canada M5S 1A8
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11
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Pires RH, Karsai Á, Saraiva MJ, Damas AM, Kellermayer MSZ. Distinct annular oligomers captured along the assembly and disassembly pathways of transthyretin amyloid protofibrils. PLoS One 2012; 7:e44992. [PMID: 22984597 PMCID: PMC3440338 DOI: 10.1371/journal.pone.0044992] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 08/15/2012] [Indexed: 11/20/2022] Open
Abstract
Background Defects in protein folding may lead to severe degenerative diseases characterized by the appearance of amyloid fibril deposits. Cytotoxicity in amyloidoses has been linked to poration of the cell membrane that may involve interactions with amyloid intermediates of annular shape. Although annular oligomers have been detected in many amyloidogenic systems, their universality, function and molecular mechanisms of appearance are debated. Methodology/Principal Findings We investigated with high-resolution in situ atomic force microscopy the assembly and disassembly of transthyretin (TTR) amyloid protofibrils formed of the native protein by pH shift. Annular oligomers were the first morphologically distinct intermediates observed in the TTR aggregation pathway. Morphological analysis suggests that they can assemble into a double-stack of octameric rings with a 16±2 nm diameter, and displaying the tendency to form linear structures. According to light scattering data coupled to AFM imaging, annular oligomers appeared to undergo a collapse type of structural transition into spheroid oligomers containing 8–16 monomers. Disassembly of TTR amyloid protofibrils also resulted in the rapid appearance of annular oligomers but with a morphology quite distinct from that observed in the assembly pathway. Conclusions/Significance Our observations indicate that annular oligomers are key dynamic intermediates not only in the assembly but also in the disassembly of TTR protofibrils. The balance between annular and more compact forms of aggregation could be relevant for cytotoxicity in amyloidogenic disorders.
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Affiliation(s)
- Ricardo H. Pires
- Department of Biophysics and Radiation Biology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
- * E-mail: (RHP); (AMD); (MSZK)
| | - Árpád Karsai
- Department of Biophysics, University of Pécs, Pécs, Hungary
| | - Maria J. Saraiva
- Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Porto, Portugal
| | - Ana M. Damas
- Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Porto, Portugal
- * E-mail: (RHP); (AMD); (MSZK)
| | - Miklós S. Z. Kellermayer
- Department of Biophysics and Radiation Biology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- * E-mail: (RHP); (AMD); (MSZK)
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12
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Jain S, Udgaonkar JB. Defining the Pathway of Worm-like Amyloid Fibril Formation by the Mouse Prion Protein by Delineation of the Productive and Unproductive Oligomerization Reactions. Biochemistry 2011; 50:1153-61. [DOI: 10.1021/bi101757x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Shweta Jain
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Jayant B. Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
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13
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Abstract
The prion protein is well known because of its association with prion diseases. These diseases, which include variant CJD, are unusual because they are neurodegenerative diseases that can be transferred between individuals experimentally. The prion protein is also widely known as a copper binding protein. The binding of copper to the prion protein is possibly necessary for its normal cellular function. The prion protein has also been suggested to bind other metals, and among these, manganese. Despite over ten years of research on manganese and prion disease, this interaction has often been dismissed or at best seen as a poor cousin to the involvement of copper. However, recent data has shown that manganese could stabilise prions in the environment and that chelation therapy specifically aimed at manganese can extend the life of animals with prion disease. This article reviews the evidence for a link between prions and manganese.
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Affiliation(s)
- David R Brown
- Department of Biology and Biochemistry, University of Bath, Bath, UKBA2 7AY.
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14
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Erlich P, Dumestre-Pérard C, Ling WL, Lemaire-Vieille C, Schoehn G, Arlaud GJ, Thielens NM, Gagnon J, Cesbron JY. Complement protein C1q forms a complex with cytotoxic prion protein oligomers. J Biol Chem 2010; 285:19267-76. [PMID: 20410306 DOI: 10.1074/jbc.m109.071860] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
A growing number of studies have investigated the interaction between C1q and PrP, but the oligomeric form of PrP involved in this interaction remains to be determined. Aggregation of recombinant full-length murine PrP in the presence of 100 mm NaCl allowed us to isolate three different types of oligomers by size-exclusion chromatography. In contrast to PrP monomers and fibrils, these oligomers activate the classical complement pathway, the smallest species containing 8-15 PrP protomers being the most efficient. We used Thioflavine T fluorescence to monitor PrP aggregation and showed that, when added to the reaction, C1q has a cooperative effect on PrP aggregation and leads to the formation of C1q-PrP complexes. In these complexes, C1q interacts through its globular domains preferentially with the smallest oligomers, as shown by electron microscopy, and retains the ability to activate the classical complement pathway. Using two cell lines, we also provide evidence that C1q inhibits the cytotoxicity induced by the smallest PrP oligomers. The cooperative interaction between C1q and PrP could represent an early step in the disease, where it prevents elimination of the prion seed, leading to further aggregation.
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Affiliation(s)
- Paul Erlich
- Laboratoire Adaptation et Pathogénie des Micro-organismes, Université Joseph Fourier, 38042 Grenoble cedex 9, France
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15
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Stefani M. Protein aggregation diseases: toxicity of soluble prefibrillar aggregates and their clinical significance. Methods Mol Biol 2010; 648:25-41. [PMID: 20700703 DOI: 10.1007/978-1-60761-756-3_2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Amyloid diseases, the most clinically relevant protein misfolding pathologies due to the high prevalence of some of them in the population, are characterized by the presence, in specific tissues and organs, of fibrillar deposits of specific peptides or proteins. Increasing efforts are presently dedicated at investigating the structural features and the structure-toxicity relation of the soluble oligomeric precursors arising in the path of fibril formation. In fact, it is increasingly recognised that these unstable, dynamic assemblies are remarkably toxic to cells thus featuring these as the main factor responsible for cell impairment in amyloid diseases. This chapter will review shortly the data presently available on the structural and biochemical features of these assemblies, as well as on their biological and clinical significance.
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16
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Role of Different Pre-Treatments on Composition and Rheology of Synovial Fluids. Polymers (Basel) 2009. [DOI: 10.3390/polym1010016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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17
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Rheologic behavior of osteoarthritic synovial fluid after addition of hyaluronic acid: a pilot study. Clin Orthop Relat Res 2009; 467:3002-9. [PMID: 19418104 PMCID: PMC2758976 DOI: 10.1007/s11999-009-0867-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 04/15/2009] [Indexed: 01/31/2023]
Abstract
Viscosupplementation is a symptomatic treatment of osteoarthritis (OA) intended to restore rheologic homeostasis of the synovial fluid by injecting hyaluronic acid intraarticularly. Despite the long history of this therapy, little is known about its mechanisms of action and differences between commercial preparations. We investigated the rheologic behavior of OA synovial fluid with time, when stored at 4 degrees C, before and after the addition of two hyaluronic acid commercial preparations (linear and cross-linked). Thirteen OA synovial fluids were stored at 4 degrees C and assayed using steric exclusion chromatography, which allows hyaluronic acid to be separated from the remaining pool of proteins and its molecular weight and concentration to be determined without any pretreatment and calibration. The synovial fluid rheology also was studied in vitro, before and after addition of two viscosupplements, over 6 weeks. The non-Newtonian behavior of synovial fluid throughout followup appears to be the result of loose interactions between proteins and hyaluronic acid. When mixed with the linear hyaluronic acid, synovial fluid becomes less non-Newtonian whereas the non-Newtonian behavior was reinforced when mixed with the cross-linked hyaluronic acid. The rheology was nearly unchanged for all synovial fluids over 6 weeks. Our preliminary trial shows it is possible to study synovial fluid, stored at 4 degrees C, over a long time and suggests the enzymatic degradation of hyaluronic acid is negligible under these experimental conditions.
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18
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Jain S, Udgaonkar JB. Evidence for Stepwise Formation of Amyloid Fibrils by the Mouse Prion Protein. J Mol Biol 2008; 382:1228-41. [DOI: 10.1016/j.jmb.2008.07.052] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Revised: 06/28/2008] [Accepted: 07/21/2008] [Indexed: 11/16/2022]
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19
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Leclerc E, Vetter S. Conformational changes and development of proteinase K resistance in surface-immobilized PrP. Arch Virol 2008; 153:683-91. [DOI: 10.1007/s00705-008-0049-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Accepted: 01/09/2008] [Indexed: 12/25/2022]
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20
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Dumestre-Pérard C, Osmundson J, Lemaire-Vieille C, Thielens N, Grives A, Favier B, Csopaki F, Jamin M, Gagnon J, Cesbron JY. Activation of classical pathway of complement cascade by soluble oligomers of prion. Cell Microbiol 2008; 9:2870-9. [PMID: 17991046 DOI: 10.1111/j.1462-5822.2007.01002.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mice defective for C1q complement factor show enhanced resistance to peripheral prion inoculation, and previous work demonstrated a direct interaction between C1q and conformationally modified PrP. However, the nature and physiological consequences of this interaction remain uncharacterized. PrP amino acids 141-159 has been identified as a potential C1q binding site; we show, by both surface plasmon resonance (SPR) spectroscopy and ELISA, that C1q and its globular region bind to PrP mutagenized in the region of interest with comparable efficiency to that of wild-type protein. To test PrP's ability to activate complement, soluble oligomers of the PrP constructs were made. Only PrP and mutagenized PrP oligomers activate the classical complement cascade while PrP monomer and the C-terminal domain, both in oligomeric and in monomeric form, failed to induce activation. This suggests that a conformational change in PrP, which occurs both when PrP is bound to an SPR sensor chip and when it undergoes oligomerization, is requisite for PrP/C1q interaction and activation of the complement cascade. We propose that C1q may act as a natural sensor for prions, leading to activation of the classical complement cascade, which could result in local inflammation and subsequent recruitment of the immune cells that prions initially infect.
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Affiliation(s)
- Chantal Dumestre-Pérard
- Laboratoire d'Adaptation et Pathogenèse des Microorganismes, UMR5163 CNRS-UJF, Institut Jean Roget, BP170, 38042 Grenoble cedex 9, France
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21
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Stefani M. Generic cell dysfunction in neurodegenerative disorders: role of surfaces in early protein misfolding, aggregation, and aggregate cytotoxicity. Neuroscientist 2007; 13:519-31. [PMID: 17901260 DOI: 10.1177/1073858407303428] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Recent knowledge supports the idea that early protein aggregates share basic structural features and are responsible for cytotoxicity underlying neurodegeneration; in most cases, early aggregate cytotoxicity apparently proceeds through similar molecular mechanisms and results in similar biochemical modifications. Data suggest that aggregate cytotoxicity may be considered a generic property of the oligomers preceding fibril appearance. Oligomers can interact with cell membranes, impairing their structural organization and destroying their selective ion permeability, eventually culminating with cell death. This process can be influenced by the physicochemical features and aggregation state of amyloids as well as by the physical and biochemical features of cell surfaces. The roles of synthetic and biological surfaces in affecting protein folding and misfolding, in speeding up aggregate nucleation, and as targets of aggregate toxicity is gaining consideration. Recent research has highlighted the involvement of surfaces as protein-misfolding chaperones and aggregation catalysts and their effects in these phenomena.
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Affiliation(s)
- Massimo Stefani
- Department of Biochemical Sciences and Research Centre on the Molecular Basis of Neurodegeneration, University of Florence, Florence, Italy.
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22
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Kaiser-Schulz G, Heit A, Quintanilla-Martinez L, Hammerschmidt F, Hess S, Jennen L, Rezaei H, Wagner H, Schätzl HM. Polylactide-coglycolide microspheres co-encapsulating recombinant tandem prion protein with CpG-oligonucleotide break self-tolerance to prion protein in wild-type mice and induce CD4 and CD8 T cell responses. THE JOURNAL OF IMMUNOLOGY 2007; 179:2797-807. [PMID: 17709493 DOI: 10.4049/jimmunol.179.5.2797] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prion diseases are fatal neurodegenerative diseases that are characterized by the conformational conversion of the normal, mainly alpha-helical cellular prion protein (PrP) into the abnormal beta-sheet-rich infectious isoform (PrP(Sc)). The immune system neither shows reaction against cellular PrP nor PrP(Sc), most likely due to profound self-tolerance. In previous studies, we were able to partly overcome self-tolerance using recombinantly expressed dimeric PrP (tandem PrP (tPrP)), in association with different adjuvants. Proof of principle for antiprion efficacy was obtained in vitro and in vivo. In this study, we demonstrate the induction of a specific Th1 T cell response in wild-type mice immunized with tPrP and CpG-oligonucleotide (ODN). Biochemical influences such as refolding conditions, ionic strength, pH, and interaction with CpG-ODN affected antigenic structure and thus improved immunogenicity. Furthermore, s.c. immunization with tPrP and CpG-ODN co-encapsulated in biodegradable polylactide-coglycolide microspheres (PLGA-MS) enhanced CD4 T cell responses and, more prominent, the induction of CD8 T cells. In this vaccination protocol, PLGA-MS function as endosomal delivery device of Ag plus CpG-ODN to macrophages and dendritic cells. In contrast, PLGA-MS-based DNA vaccination approaches with a tPrP construct generated poor humoral and T cell responses. Our data show that prophylactic and therapeutic immunization approaches against prion infections might be feasible using tPrP Ag and CpG-ODN adjuvant without detectable side effects.
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Affiliation(s)
- Gunnar Kaiser-Schulz
- Institute of Virology, Prion Research Group, Technical University of Munich, Trogerstrasse 30, 81675 Munich, Germany
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23
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Erlich P, Cesbron JY, Lemaire-Vieille C, Curt A, Andrieu JP, Schoehn G, Jamin M, Gagnon J. PrP N-terminal domain triggers PrP(Sc)-like aggregation of Dpl. Biochem Biophys Res Commun 2007; 365:478-83. [PMID: 17997980 DOI: 10.1016/j.bbrc.2007.10.202] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Accepted: 10/31/2007] [Indexed: 12/19/2022]
Abstract
Transmissible spongiform encephalopathies are fatal neurodegenerative disorders thought to be transmitted by self-perpetuating conformational conversion of a neuronal membrane glycoprotein (PrP(C), for "cellular prion protein") into an abnormal state (PrP(Sc), for "scrapie prion protein"). Doppel (Dpl) is a protein that shares significant biochemical and structural homology with PrP(C). In contrast to its homologue PrP(C), Dpl is unable to participate in prion disease progression or to achieve an abnormal PrP(Sc)-like state. We have constructed a chimeric mouse protein, composed of the N-terminal domain of PrP(C) (residues 23-125) and the C-terminal part of Dpl (residues 58-157). This chimeric protein displays PrP-like biochemical and structural features; when incubated in presence of NaCl, the alpha-helical monomer forms soluble beta-sheet-rich oligomers which acquire partial resistance to pepsin proteolysis in vitro, as do PrP oligomers. Moreover, the presence of aggregates akin to protofibrils is observed in soluble oligomeric species by electron microscopy.
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Affiliation(s)
- Paul Erlich
- Laboratoire Adaptation et Pathogénie des Micro-organismes, Université Joseph Fourier, BP 170, 38042 Grenoble Cedex 9, France
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24
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Lennon CW, Cox HD, Hennelly SP, Chelmo SJ, McGuirl MA. Probing structural differences in prion protein isoforms by tyrosine nitration. Biochemistry 2007; 46:4850-60. [PMID: 17397138 PMCID: PMC2562509 DOI: 10.1021/bi0617254] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two conformational isomers of recombinant hamster prion protein (residues 90-232) have been probed by reaction with two tyrosine nitration reagents, peroxynitrite and tetranitromethane. Two conserved tyrosine residues (tyrosines 149 and 150) are not labeled by either reagent in the normal cellular form of the prion protein. These residues become reactive after the protein has been converted to the beta-oligomeric isoform, which is used as a model of the fibrillar form that causes disease. After conversion, a decrease in reactivity is noted for two other conserved residues, tyrosine 225 and tyrosine 226, whereas little to no effect was observed for other tyrosines. Thus, tyrosine nitration has identified two specific regions of the normal prion protein isoform that undergo a change in chemical environment upon conversion to a structure that is enriched in beta-sheet.
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Affiliation(s)
- Christopher W. Lennon
- Division of Biological Sciences and the Biomolecular Structure and Dynamics Program, The University of Montana, Missoula, MT 59812 USA
| | | | - Scott P. Hennelly
- Division of Biological Sciences and the Biomolecular Structure and Dynamics Program, The University of Montana, Missoula, MT 59812 USA
| | | | - Michele A. McGuirl
- Division of Biological Sciences and the Biomolecular Structure and Dynamics Program, The University of Montana, Missoula, MT 59812 USA
- Corresponding author information: Michele A. McGuirl, Clapp Building 204, Division of Biological Sciences, 32 Campus Drive The University of Montana, Missoula, MT 59812, , (406) 243-4404 phone, (406) 243-4304 fax
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25
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O'Sullivan D, Jones C, Abdelraheim S, Thompsett A, Brazier M, Toms H, Brown D, Viles J. NMR characterization of the pH 4 beta-intermediate of the prion protein: the N-terminal half of the protein remains unstructured and retains a high degree of flexibility. Biochem J 2007; 401:533-40. [PMID: 16958619 PMCID: PMC1820806 DOI: 10.1042/bj20060668] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Prion diseases are associated with the misfolding of the PrP (prion protein) from a largely alpha-helical isoform to a beta-sheet-rich oligomer. CD has shown that lowering the pH to 4 under mildly denaturing conditions causes recombinant PrP to convert from an alpha-helical protein into one that contains a high proportion of beta-sheet-like conformation. In the present study, we characterize this soluble pH 4 folding intermediate using NMR. (15)N-HSQC (heteronuclear single-quantum correlation) studies with mPrP (mouse PrP)-(23-231) show that a total of 150 dispersed amide signals are resolved in the native form, whereas only 65 amide signals with little chemical shift dispersion are observable in the pH 4 form. Three-dimensional (15)N-HSQC-TOCSY and NOESY spectra indicate that the observable residues are all assigned to amino acids in the N-terminus: residues 23-118. (15)N transverse relaxation measurements indicate that these N-terminal residues are highly flexible with additional fast motions. These observations are confirmed via the use of truncated mPrP-(112-231), which shows only 16 (15)N-HSQC amide peaks at pH 4. The loss of signals from the C-terminus can be attributed to line broadening due to an increase in the molecular size of the oligomer or exchange broadening in a molten-globule state.
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Affiliation(s)
- Denis B. D. O'Sullivan
- *School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, U.K
| | - Christopher E. Jones
- *School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, U.K
| | | | - Andrew R. Thompsett
- †Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, U.K
| | - Marcus W. Brazier
- †Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, U.K
| | - Harold Toms
- *School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, U.K
| | - David R. Brown
- †Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, U.K
| | - John H. Viles
- *School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, U.K
- To whom correspondence should be addressed (email )
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26
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Murphy RM. Kinetics of amyloid formation and membrane interaction with amyloidogenic proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:1923-34. [PMID: 17292851 DOI: 10.1016/j.bbamem.2006.12.014] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 12/22/2006] [Accepted: 12/27/2006] [Indexed: 11/19/2022]
Abstract
Interest in amyloidogenesis has exploded in recent years, as scientists recognize the role of amyloid protein aggregates in degenerative diseases such as Alzheimer's and Parkinson's disease. Assembly of proteins or peptides into mature amyloid fibrils is a multistep process initiated by conformational changes, during which intermediate aggregation states such as oligomers, protofibrils, and filaments are sampled. Although once it was assumed that the mature fibril was the biologically toxic species, more recently it has been widely speculated that soluble intermediates are the most damaging. Because of its relevance to mechanism of disease, the paths traversed during fibrillogenesis, and the kinetics of the process, are of considerable interest. In this review we discuss various kinetic models used to describe amyloidogenesis. Although significant advances have been made, construction of rigorous, detailed, and experimentally validated quantitative models remains a work in progress. We briefly review recent literature that illustrates the interplay between kinetics and amyloid-membrane interactions: how do different intermediates interact with lipid bilayers, and how does the lipid bilayer affect kinetics of amyloidogenesis?
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Affiliation(s)
- Regina M Murphy
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
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27
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Tahiri-Alaoui A, Sim VL, Caughey B, James W. Molecular heterosis of prion protein beta-oligomers. A potential mechanism of human resistance to disease. J Biol Chem 2006; 281:34171-8. [PMID: 16980300 DOI: 10.1074/jbc.m606606200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The gene encoding prion protein is polymorphic in human populations, with over 40% of native Europeans, for example, being heterozygous for the Met-129 and Val-129 alleles. The polymorphism affects both the incidence and the clinical presentation of a range of prion diseases, with heterozygotes generally showing the highest levels of resistance. It has been suggested that an earlier epidemic of prion diseases exerted balancing selection on the two alleles, and we have previously demonstrated that the two encoded proteins have potentially compensating tendencies to form amyloid and soluble beta-oligomers, respectively, in vitro. More strikingly, here we demonstrate that mixed oligomers, composed of both allelic forms, show an extreme sluggishness in converting to amyloid in comparison with oligomers homogenous for either allele. It may be that this example of molecular heterosis in vitro provides the basis for maintenance of the polymorphism in the population and that beta-oligomers represent a form of PrP sequestered from pathogenic amyloid formation in vivo.
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Affiliation(s)
- Abdessamad Tahiri-Alaoui
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom.
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28
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Vasan S, Mong PY, Grossman A. Interaction of Prion Protein with Small Highly Structured RNAs: Detection and Characterization of PrP-Oligomers. Neurochem Res 2006; 31:629-37. [PMID: 16770734 DOI: 10.1007/s11064-006-9063-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Accepted: 02/23/2006] [Indexed: 01/28/2023]
Abstract
Conformational modification of normal prion protein (PrP(c)) to protease-resistant, beta-sheet rich, aggregates (PrP(sc)) is commonly accepted cause for prion diseases. On the other hand, several studies in recent years implicate soluble, protease-sensitive, oligomers of PrP(c) in neuronal damage. Previously, our group has shown that small, highly structured RNAs (shsRNAs), in conjunction with a serum factor, facilitated the conversion of hrPrP to a protease resistant, high molecular weight isoform. In the current study we demonstrate that shsRNAs, in the absence of the serum factor, generate soluble, protease-sensitive, and potentially toxic oligomers of ovrPrP. We have isolated a 500 kD oligomer by size exclusion chromatography of the reaction mixture and identified the accessible epitopes. The soluble PrP-oligomers were present in enhanced amounts in scrapie infected sheep brain and treating extracts of normal sheep brain with shsRNA resulted in oligomerization of endogenous PrP. Isolation, characterization of PrP-oligomers and their possible implication in prion diseases is discussed.
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Affiliation(s)
- Sara Vasan
- Q-RNA, Inc.,, 3960 Broadway, New York, NY 10032, USA
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