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Kim Y, Xu QZ, Zhao KH, Gärtner W, Matysik J, Song C. Lyophilization Reveals a Multitude of Structural Conformations in the Chromophore of a Cph2-like Phytochrome. J Phys Chem B 2020; 124:7115-7127. [PMID: 32693592 DOI: 10.1021/acs.jpcb.0c03431] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cyanobacteria sense and respond to various colors of light employing a large number of bilin-based phytochrome-like photoreceptors. All2699 from Nostoc 7120 has three consecutive GAF domains with GAF1 and GAF3 binding a phycocyanobilin chromophore. GAF1, even when expressed independently, can be photoconverted between red-absorbing Pr and far-red-absorbing Pfr states, while the nonphotosensory GAF2 domain is structurally and functionally homologous to the PHY domains in canonical and Cph2-like phytochromes. Here, we characterize possible bilin chromophore conformers using solid-state NMR spectroscopy on the two lyophilized All2699 samples (GAF1-only and GAF1-PHY constructs). On the basis of complete 1H, 13C, and 15N assignments for the chromophore obtained on the two Pr lyophilizates, multiple static conformations of the chromophore in both cases are identified. Moreover, most atoms of the chromophore in the bidomain sample show only subtle changes in the mean chemical shifts relative to those in frozen solution (FS), indicating an optimized interaction of the GAF2 domain with the GAF1-bound chromophore. Our results confirm the conservation of key chromophore-protein interactions and the photoreversibility in both All2699 lyophilizates, offering the possibility to investigate conformational distributions of the heterogeneous chromophore and its functional consequences in phytochromes and other bilin-dependent photoreceptors intractable by the solid-state NMR technique as FSs.
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Affiliation(s)
- Yunmi Kim
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, 04103 Leipzig, Germany
| | - Qian-Zhao Xu
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, 04103 Leipzig, Germany.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Kai-Hong Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Wolfgang Gärtner
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, 04103 Leipzig, Germany
| | - Jörg Matysik
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, 04103 Leipzig, Germany
| | - Chen Song
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, 04103 Leipzig, Germany
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2
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Thompson HN, Thompson CE, Andrade Caceres R, Dardenne LE, Netz PA, Stassen H. Prion protein conversion triggered by acidic condition: a molecular dynamics study through different force fields. J Comput Chem 2018; 39:2000-2011. [DOI: 10.1002/jcc.25380] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 05/15/2018] [Accepted: 05/26/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Helen Nathalia Thompson
- Departamento de Físico-Química, Instituto de Química; Universidade Federal do Rio Grande do Sul; 91501-970 Porto Alegre Rio Grande do Sul Brazil
| | - Claudia Elizabeth Thompson
- Departamento de Farmacociências; Universidade Federal de Ciências da Saúde de Porto Alegre; 90050-170 Porto Alegre Rio Grande do Sul Brazil
| | - Rafael Andrade Caceres
- Departamento de Farmacociências; Universidade Federal de Ciências da Saúde de Porto Alegre; 90050-170 Porto Alegre Rio Grande do Sul Brazil
| | | | - Paulo Augusto Netz
- Departamento de Físico-Química, Instituto de Química; Universidade Federal do Rio Grande do Sul; 91501-970 Porto Alegre Rio Grande do Sul Brazil
| | - Hubert Stassen
- Departamento de Físico-Química, Instituto de Química; Universidade Federal do Rio Grande do Sul; 91501-970 Porto Alegre Rio Grande do Sul Brazil
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3
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Li L, Zhu Y, Zhou S, An X, Zhang Y, Bai Q, He YX, Liu H, Yao X. Experimental and Theoretical Insights into the Inhibition Mechanism of Prion Fibrillation by Resveratrol and its Derivatives. ACS Chem Neurosci 2017; 8:2698-2707. [PMID: 28817252 DOI: 10.1021/acschemneuro.7b00240] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Resveratrol and its derivatives have been shown to display beneficial effects to neurodegenerative diseases. However, the molecular mechanism of resveratrol and its derivatives on prion conformational conversion is poorly understood. In this work, the interaction mechanism between prion and resveratrol as well as its derivatives was investigated using steady-state fluorescence quenching, Thioflavin T binding assay, Western blotting, and molecular dynamics simulation. Protein fluorescence quenching method and Thioflavin T assay revealed that resveratrol and its derivatives could interact with prion and interrupt prion fibril formation. Molecular dynamics simulation results indicated that resveratrol can stabilize the PrP127-147 peptide mainly through π-π stacking interactions between resveratrol and Tyr128. The hydrogen bonds interactions between resveratrol and the PrP127-147 peptide could further reduce the flexibility and the propensity to aggregate. The results of this study not only can provide useful information about the interaction mechanism between resveratrol and prion, but also can provide useful clues for further design of new inhibitors inhibiting prion aggregation.
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Affiliation(s)
- Lanlan Li
- State
Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, P. R. China
| | - Yongchang Zhu
- School
of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Shuangyan Zhou
- State
Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, P. R. China
- School
of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Xiaoli An
- State
Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, P. R. China
| | - Yan Zhang
- State
Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, P. R. China
- School
of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Qifeng Bai
- State
Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, P. R. China
| | - Yong-Xing He
- School
of Life Sciences, Lanzhou University, Lanzhou 730000, P. R. China
| | - Huanxiang Liu
- School
of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China
| | - Xiaojun Yao
- State
Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou 730000, P. R. China
- State
Key Laboratory of Quality Research in Chinese Medicine, Macau Institute
for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau, P. R. China
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4
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Mihaliuk E, Gullion T. Adding a lens Improves spinning speed characterization. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 72:4-8. [PMID: 26382300 DOI: 10.1016/j.ssnmr.2015.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 09/02/2015] [Accepted: 09/03/2015] [Indexed: 06/05/2023]
Abstract
Highly stable sample rotation is important in many solid-state NMR experiments. Whether the necessary stability is achieved is not always clear. Typically only an average frequency over some time interval (often relatively long and unknown) is available from the spinning speed controller readout, which is not representative of the short-term variations of instantaneous rotation frequency. The necessity of the relatively slow measurement of spinning speed is a consequence of phase noise in the tachometer, which prevents speed measurement to be both rapid and precise at the same time. We show that adding a lens to the tachometer, without any other changes in the probe, reduces phase noise by nearly an order of magnitude and allows improved measurement of the spinning speed.
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Affiliation(s)
- Eugene Mihaliuk
- West Virginia University, Morgantown, WV 26506, United States
| | - Terry Gullion
- West Virginia University, Morgantown, WV 26506, United States.
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ATR-FTIR: A “rejuvenated” tool to investigate amyloid proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2328-38. [DOI: 10.1016/j.bbamem.2013.04.012] [Citation(s) in RCA: 263] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 02/20/2013] [Accepted: 04/02/2013] [Indexed: 12/24/2022]
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7
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Singh J, Udgaonkar JB. Dissection of Conformational Conversion Events during Prion Amyloid Fibril Formation Using Hydrogen Exchange and Mass Spectrometry. J Mol Biol 2013; 425:3510-21. [DOI: 10.1016/j.jmb.2013.06.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 06/10/2013] [Accepted: 06/12/2013] [Indexed: 10/26/2022]
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GhattyVenkataKrishna PK, Uberbacher EC, Cheng X. Effect of the amyloid β hairpin's structure on the handedness of helices formed by its aggregates. FEBS Lett 2013; 587:2649-55. [PMID: 23845280 DOI: 10.1016/j.febslet.2013.06.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 05/16/2013] [Accepted: 06/21/2013] [Indexed: 11/16/2022]
Abstract
Various structural models for amyloid β fibrils have been derived from a variety of experimental techniques. However, these models cannot differentiate between the relative position of the two arms of the β hairpin called the stagger. Amyloid fibrils of various hierarchical levels form left-handed helices composed of β sheets. However it is unclear if positive, negative and zero staggers all form the macroscopic left-handed helices. To address this issue we have conducted extensive molecular dynamics simulations of amyloid β sheets of various staggers and shown that only negative staggers lead to the experimentally observed left-handed helices while positive staggers generate the incorrect right-handed helices. This result suggests that the negative staggers are physiologically relevant structure of the amyloid β fibrils.
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9
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Emwas AHM, Al-Talla ZA, Guo X, Al-Ghamdi S, Al-Masri HT. Utilizing NMR and EPR spectroscopy to probe the role of copper in prion diseases. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2013; 51:255-268. [PMID: 23436479 DOI: 10.1002/mrc.3936] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 12/19/2012] [Accepted: 01/11/2013] [Indexed: 06/01/2023]
Abstract
Copper is an essential nutrient for the normal development of the brain and nervous system, although the hallmark of several neurological diseases is a change in copper concentrations in the brain and central nervous system. Prion protein (PrP) is a copper-binding, cell-surface glycoprotein that exists in two alternatively folded conformations: a normal isoform (PrP(C)) and a disease-associated isoform (PrP(Sc)). Prion diseases are a group of lethal neurodegenerative disorders that develop as a result of conformational conversion of PrP(C) into PrP(Sc). The pathogenic mechanism that triggers this conformational transformation with the subsequent development of prion diseases remains unclear. It has, however, been shown repeatedly that copper plays a significant functional role in the conformational conversion of prion proteins. In this review, we focus on current research that seeks to clarify the conformational changes associated with prion diseases and the role of copper in this mechanism, with emphasis on the latest applications of NMR and EPR spectroscopy to probe the interactions of copper with prion proteins.
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Affiliation(s)
- Abdul-Hamid M Emwas
- NMR Core Lab, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.
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10
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Kleinjung J, Fraternali F. Urea-Water Solvation Forces on Prion Structures. J Chem Theory Comput 2012; 8:3977-3984. [PMID: 23066353 PMCID: PMC3466777 DOI: 10.1021/ct300264w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Indexed: 01/28/2023]
Abstract
Solvation forces are crucial determinants in the equilibrium between the folded and unfolded state of proteins. Particularly interesting are the solvent forces of denaturing solvent mixtures on folded and misfolded states of proteins involved in neurodegeneration. The C-terminal globular domain of the ovine prion protein (1UW3) and its analogue H2H3 in the α-rich and β-rich conformation were used as model structures to study the solvation forces in 4 M aqueous urea using molecular dynamics. The model structures display very different secondary structures and solvent exposures. Most protein atoms favor interactions with urea over interactions with water. The force difference between protein-urea and protein-water interactions correlates with hydrophobicity; i.e., urea interacts preferentially with hydrophobic atoms, in agreement with results from solvent transfer experiments. Solvent Shannon entropy maps illustrate the mobility gradient of the urea-water mixture from the first solvation shell to the bulk. Single urea molecules replace water in the first solvation shell preferably at locations of relatively high solvent entropy.
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Affiliation(s)
- Jens Kleinjung
- Division of Mathematical Biology,
MRC National Institute for Medical Research, The Ridgeway, Mill Hill,
London NW7 1AA, United Kingdom
| | - Franca Fraternali
- Randall Division of Cell and
Molecular Biophysics, King’s College London, New Hunt’s
House, London SE1 1UL, United Kingdom
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11
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Cao Z, Liu L, Wang J. Why the OPLS-AA Force Field Cannot Produce the β-Hairpin Structure of H1 Peptide in Solution When Comparing with the GROMOS 43A1 Force Field? J Biomol Struct Dyn 2011; 29:527-39. [DOI: 10.1080/07391102.2011.10507403] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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12
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Dias CL, Karttunen M, Chan HS. Hydrophobic interactions in the formation of secondary structures in small peptides. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:041931. [PMID: 22181199 DOI: 10.1103/physreve.84.041931] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Indexed: 05/31/2023]
Abstract
Effects of the attractive and repulsive parts of hydrophobic interactions on α helices and β sheets in small peptides are investigated using a simple atomic potential. Typically, a physical spatial range of attraction tends to favor β sheets, but α helices would be favored if the attractive range were more extended. We also found that desolvation barriers favor β sheets in collapsed conformations of polyalanine, polyvaline, polyleucine, and three fragments of amyloid peptides tested in this study. Our results provide insight into the multifaceted role of hydrophobicity in secondary structure formation, including the α to β transitions in certain amyloid peptides.
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Affiliation(s)
- Cristiano L Dias
- Department of Biochemistry and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
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13
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Critical nucleus size for disease-related polyglutamine aggregation is repeat-length dependent. Nat Struct Mol Biol 2011; 18:328-36. [PMID: 21317897 PMCID: PMC3075957 DOI: 10.1038/nsmb.1992] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 11/24/2010] [Indexed: 01/29/2023]
Abstract
Since polyglutamine (polyQ) aggregate formation has been implicated as playing an important role in expanded CAG repeat diseases, it is important to understand the biophysics underlying the initiation of aggregation. Previously we showed that relatively long polyQ peptides aggregate by nucleated growth polymerization and a monomeric critical nucleus. We show here that, over a short repeat length range from Q26 to Q23, the size of the critical nucleus for aggregation increases from monomeric to dimeric to tetrameric. This variation in nucleus size suggests a common duplex anti-parallel β-sheet framework for the nucleus, and further supports the feasibility of an organized monomeric aggregation nucleus for longer polyQ repeat peptides. The data also suggest that a change in aggregation nucleus size may play a role in the pathogenicity of polyQ expansion in this series of familial neurodegenerative diseases.
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14
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Adrover M, Pauwels K, Prigent S, de Chiara C, Xu Z, Chapuis C, Pastore A, Rezaei H. Prion fibrillization is mediated by a native structural element that comprises helices H2 and H3. J Biol Chem 2010; 285:21004-12. [PMID: 20375014 PMCID: PMC2898372 DOI: 10.1074/jbc.m110.111815] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2010] [Revised: 03/21/2010] [Indexed: 11/06/2022] Open
Abstract
Aggregation and misfolding of the prion protein (PrP) are thought to be the cause of a family of lethal neurodegenerative diseases affecting humans and other animals. Although the structures of PrP from several species have been solved, still little is known about the mechanisms that lead to the misfolded species. Here, we show that the region of PrP comprising the hairpin formed by the helices H2 and H3 is a stable independently folded unit able to retain its secondary and tertiary structure also in the absence of the rest of the sequence. We also prove that the isolated H2H3 is highly fibrillogenic and forms amyloid fibers morphologically similar to those obtained for the full-length protein. Fibrillization of H2H3 but not of full-length PrP is concomitant with formation of aggregates. These observations suggest a "banana-peeling" mechanism for misfolding of PrP in which H2H3 is the aggregation seed that needs to be first exposed to promote conversion from a helical to a beta-rich structure.
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Affiliation(s)
- Miquel Adrover
- From the MRC National Institute for Medical Research, The Ridgeway, London NW7 1AA, United Kingdom
- the Departament de Química, Universitat de les Illes Balears, Palma de Mallorca E-07122, Spain
| | - Kris Pauwels
- From the MRC National Institute for Medical Research, The Ridgeway, London NW7 1AA, United Kingdom
| | - Stephanie Prigent
- the Institut National de la Recherche Agronomique, Jouy-en-Josas F-78352, France, and
| | - Cesira de Chiara
- From the MRC National Institute for Medical Research, The Ridgeway, London NW7 1AA, United Kingdom
| | - Zhou Xu
- the Institut National de la Recherche Agronomique, Jouy-en-Josas F-78352, France, and
- the Commissariat à l'Énergie Atomique, Fontenay-aux-Roses F-92265, France
| | - Céline Chapuis
- the Institut National de la Recherche Agronomique, Jouy-en-Josas F-78352, France, and
| | - Annalisa Pastore
- From the MRC National Institute for Medical Research, The Ridgeway, London NW7 1AA, United Kingdom
- the Institut National de la Recherche Agronomique, Jouy-en-Josas F-78352, France, and
| | - Human Rezaei
- the Institut National de la Recherche Agronomique, Jouy-en-Josas F-78352, France, and
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15
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CAO ZX, WANG JH. A Comparative Study of Different Temperatures on Computed Structural Character of H1 Peptide via Temperature Replica Exchange Molecular Dynamics Simulations*. PROG BIOCHEM BIOPHYS 2010. [DOI: 10.3724/sp.j.1206.2009.00616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Molecular Structure of Amyloid Fibrils Formed by Residues 127 to 147 of the Human Prion Protein. Chemistry 2010; 16:5492-9. [DOI: 10.1002/chem.200903290] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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17
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Abstract
The crucial event in the development of transmissible spongiform encephalopathies (TSEs) is the conformational change of a host-encoded membrane protein - the cellular PrPC - into a disease associated, fibril-forming isoform PrPSc. This conformational transition from the α-helix-rich cellular form into the mainly β-sheet containing counterpart initiates an ‘autocatalytic’ reaction which leads to the accumulation of amyloid fibrils in the central nervous system (CNS) and to neurodegeneration, a hallmark of TSEs. The exact molecular mechanisms which lead to the conformational change are still unknown. It also remains to be brought to light how a polypeptide chain can adopt at least two stable conformations. This review focuses on structural aspects of the prion protein with regard to protein-protein interactions and the initiation of prion protein misfolding. It therefore highlights parts of the protein which might play a notable role in the conformational transition from PrPC to PrPSc and consequently in inducing a fatal chain reaction of protein misfolding. Furthermore, features of different proteins, which are able to adopt insoluble fibrillar states under certain circumstances, are compared to PrP in an attempt to understand the unique characteristics of prion diseases.
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Affiliation(s)
- L Kupfer
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
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Oztug Durer ZA, Cohlberg JA, Dinh P, Padua S, Ehrenclou K, Downes S, Tan JK, Nakano Y, Bowman CJ, Hoskins JL, Kwon C, Mason AZ, Rodriguez JA, Doucette PA, Shaw BF, Valentine JS. Loss of metal ions, disulfide reduction and mutations related to familial ALS promote formation of amyloid-like aggregates from superoxide dismutase. PLoS One 2009; 4:e5004. [PMID: 19325915 PMCID: PMC2659422 DOI: 10.1371/journal.pone.0005004] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 03/03/2009] [Indexed: 12/18/2022] Open
Abstract
Mutations in the gene encoding Cu-Zn superoxide dismutase (SOD1) are one of the causes of familial amyotrophic lateral sclerosis (FALS). Fibrillar inclusions containing SOD1 and SOD1 inclusions that bind the amyloid-specific dye thioflavin S have been found in neurons of transgenic mice expressing mutant SOD1. Therefore, the formation of amyloid fibrils from human SOD1 was investigated. When agitated at acidic pH in the presence of low concentrations of guanidine or acetonitrile, metalated SOD1 formed fibrillar material which bound both thioflavin T and Congo red and had circular dichroism and infrared spectra characteristic of amyloid. While metalated SOD1 did not form amyloid-like aggregates at neutral pH, either removing metals from SOD1 with its intramolecular disulfide bond intact or reducing the intramolecular disulfide bond of metalated SOD1 was sufficient to promote formation of these aggregates. SOD1 formed amyloid-like aggregates both with and without intermolecular disulfide bonds, depending on the incubation conditions, and a mutant SOD1 lacking free sulfhydryl groups (AS-SOD1) formed amyloid-like aggregates at neutral pH under reducing conditions. ALS mutations enhanced the ability of disulfide-reduced SOD1 to form amyloid-like aggregates, and apo-AS-SOD1 formed amyloid-like aggregates at pH 7 only when an ALS mutation was also present. These results indicate that some mutations related to ALS promote formation of amyloid-like aggregates by facilitating the loss of metals and/or by making the intramolecular disulfide bond more susceptible to reduction, thus allowing the conversion of SOD1 to a form that aggregates to form resembling amyloid. Furthermore, the occurrence of amyloid-like aggregates per se does not depend on forming intermolecular disulfide bonds, and multiple forms of such aggregates can be produced from SOD1.
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Affiliation(s)
- Zeynep A. Oztug Durer
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Jeffrey A. Cohlberg
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
- * E-mail:
| | - Phong Dinh
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Shelby Padua
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Krista Ehrenclou
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Sean Downes
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - James K. Tan
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Yoko Nakano
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Christopher J. Bowman
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Jessica L. Hoskins
- Department of Physics and Astronomy, California State University Long Beach, Long Beach, California, United States of America
| | - Chuhee Kwon
- Department of Physics and Astronomy, California State University Long Beach, Long Beach, California, United States of America
| | - Andrew Z. Mason
- Department of Biological Sciences, California State University Long Beach, Long Beach, California, United States of America
| | - Jorge A. Rodriguez
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Peter A. Doucette
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Bryan F. Shaw
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Joan Selverstone Valentine
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
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19
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Correlating DWI MRI With Pathologic and Other Features of Jakob-Creutzfeldt Disease. Alzheimer Dis Assoc Disord 2009; 23:82-87. [DOI: 10.1097/wad.0b013e31818323ef] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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20
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21
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Ulmschneider JP, Ulmschneider MB, Di Nola A. Monte Carlo vs molecular dynamics for all-atom polypeptide folding simulations. J Phys Chem B 2007; 110:16733-42. [PMID: 16913813 DOI: 10.1021/jp061619b] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An efficient Monte Carlo (MC) algorithm including concerted rotations is directly compared to molecular dynamics (MD) in all-atom statistical mechanics folding simulations of small polypeptides. The previously reported algorithm "concerted rotations with flexible bond angles" (CRA) has been shown to successfully locate the native state of small polypeptides. In this study, the folding of three small polypeptides (trpzip2/H1/Trp-cage) is investigated using MC and MD, for a combined sampling time of approximately 10(11) MC configurations and 8 micros, respectively. Both methods successfully locate the experimentally determined native states of the three systems, but they do so at different speed, with 2-2.5 times faster folding of the MC runs. The comparison reveals that thermodynamic and dynamic properties can reliably be obtained by both and that results from folding simulations do not depend on the algorithm used. Similar to previous comparisons of MC and MD, it is found that one MD integration step of 2 fs corresponds to one MC scan, revealing the good sampling of MC. The simplicity and efficiency of the MC method will enable its future use in folding studies involving larger systems and the combination with replica exchange algorithms.
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22
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Petkova AT, Yau WM, Tycko R. Experimental constraints on quaternary structure in Alzheimer's beta-amyloid fibrils. Biochemistry 2006; 45:498-512. [PMID: 16401079 PMCID: PMC1435828 DOI: 10.1021/bi051952q] [Citation(s) in RCA: 898] [Impact Index Per Article: 49.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We describe solid-state nuclear magnetic resonance (NMR) measurements on fibrils formed by the 40-residue beta-amyloid peptide associated with Alzheimer's disease (Abeta(1-40)) that place constraints on the identity and symmetry of contacts between in-register, parallel beta-sheets in the fibrils. We refer to these contacts as internal and external quaternary contacts, depending on whether they are within a single molecular layer or between molecular layers. The data include (1) two-dimensional 13C-13C NMR spectra that indicate internal quaternary contacts between side chains of L17 and F19 and side chains of I32, L34, and V36, as well as external quaternary contacts between side chains of I31 and G37; (2) two-dimensional 15N-13C NMR spectra that indicate external quaternary contacts between the side chain of M35 and the peptide backbone at G33; (3) measurements of magnetic dipole-dipole couplings between the side chain carboxylate group of D23 and the side chain amine group of K28 that indicate salt bridge interactions. Isotopic dilution experiments allow us to make distinctions between intramolecular and intermolecular contacts. On the basis of these data and previously determined structural constraints from solid-state NMR and electron microscopy, we construct full molecular models using restrained molecular dynamics simulations and restrained energy minimization. These models apply to Abeta(1-40) fibrils grown with gentle agitation. We also present evidence for different internal quaternary contacts in Abeta(1-40) fibrils grown without agitation, which are morphologically distinct.
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Affiliation(s)
- Aneta T Petkova
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA
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23
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Tycko R. Characterization of amyloid structures at the molecular level by solid state nuclear magnetic resonance spectroscopy. Methods Enzymol 2006; 413:103-22. [PMID: 17046393 PMCID: PMC1633711 DOI: 10.1016/s0076-6879(06)13006-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Solid state nuclear magnetic resonance (NMR) spectroscopy is particularly useful in structural studies of amyloid fibrils because solid state NMR techniques have unique capabilities as site-specific, molecular-level structural probes of noncrystalline materials. These techniques provide experimental data that strongly constrain the secondary, tertiary, and quaternary structures of amyloid fibrils, permitting the development of experimentally based structural models. Examples of techniques that are applicable to amyloid samples prepared with isotopic labeling of specific sites and to samples prepared with uniform isotopic labeling of selected residues are presented, illustrating the utility of the various techniques and labeling schemes. Information regarding the preparation of amyloid samples for solid state NMR measurements is also included.
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Affiliation(s)
- Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 5, Room 112, Bethesda, Maryland 20892-0520, e-mail: , phone: 301-402-8272, fax: 301-496-0825
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24
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O'Nuallain B, Thakur AK, Williams AD, Bhattacharyya AM, Chen S, Thiagarajan G, Wetzel R. Kinetics and Thermodynamics of Amyloid Assembly Using a High‐Performance Liquid Chromatography–Based Sedimentation Assay. Methods Enzymol 2006; 413:34-74. [PMID: 17046390 DOI: 10.1016/s0076-6879(06)13003-7] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Nonnative protein aggregation has been classically treated as an amorphous process occurring by colloidal coagulation kinetics and proceeding to an essentially irreversible endpoint often ascribed to a chaotic tangle of unfolded chains. However, some nonnative aggregates, particularly amyloid fibrils, exhibit ordered structures that appear to assemble according to ordered mechanisms. Some of these fibrils, as illustrated here with the Alzheimer's plaque peptide amyloid beta, assemble to an endpoint that is a dynamic equilibrium between monomers and fibrils exhibiting a characteristic equilibrium constant with an associated free energy of formation. Some fibrils, as illustrated here with the polyglutamine repeat sequences associated with Huntington's disease, assemble via highly regular mechanisms exhibiting nucleated growth polymerization kinetics. Here, we describe a series of linked methods for quantitative analysis of such aggregation kinetics and thermodynamics, focusing on a robust high-performance liquid chromatography (HPLC)-based sedimentation assay. An integrated group of protocols is provided for peptide disaggregation, setting up the HPLC sedimentation assay, the preparation of fibril seed stocks and determination of the average functional molecular weight of the fibrils, elongation and nucleation kinetics analysis, and the determination of the critical concentration describing the thermodynamic endpoint of fibril elongation.
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Affiliation(s)
- Brian O'Nuallain
- University of Tennessee Medical Center, Graduate School of Medicine, Knoxville, TN, USA
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25
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Siemer AB, Ritter C, Ernst M, Riek R, Meier BH. High-Resolution Solid-State NMR Spectroscopy of the Prion Protein HET-s in Its Amyloid Conformation. Angew Chem Int Ed Engl 2005; 44:2441-4. [PMID: 15770629 DOI: 10.1002/anie.200462952] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ansgar B Siemer
- Laboratory of Physical Chemistry, ETH Zurich, ETH-Hönggerberg, Switzerland
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26
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Daidone I, Amadei A, Di Nola A. Thermodynamic and kinetic characterization of a β-hairpin peptide in solution: An extended phase space sampling by molecular dynamics simulations in explicit water. Proteins 2005; 59:510-8. [PMID: 15789436 DOI: 10.1002/prot.20427] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The folding of the amyloidogenic H1 peptide MKHMAGAAAAGAVV taken from the syrian hamster prion protein is explored in explicit aqueous solution at 300 K using long time scale all-atom molecular dynamics simulations for a total simulation time of 1.1 mus. The system, initially modeled as an alpha-helix, preferentially adopts a beta-hairpin structure and several unfolding/refolding events are observed, yielding a very short average beta-hairpin folding time of approximately 200 ns. The long time scale accessed by our simulations and the reversibility of the folding allow to properly explore the configurational space of the peptide in solution. The free energy profile, as a function of the principal components (essential eigenvectors) of motion, describing the main conformational transitions, shows the characteristic features of a funneled landscape, with a downhill surface toward the beta-hairpin folded basin. However, the analysis of the peptide thermodynamic stability, reveals that the beta-hairpin in solution is rather unstable. These results are in good agreement with several experimental evidences, according to which the isolated H1 peptide adopts very rapidly in water beta-sheet structure, leading to amyloid fibril precipitates [Nguyen et al., Biochemistry 1995;34:4186-4192; Inouye et al., J Struct Biol 1998;122:247-255]. Moreover, in this article we also characterize the diffusion behavior in conformational space, investigating its relations with folding/unfolding conditions.
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Affiliation(s)
- Isabella Daidone
- Department of Chemistry, University of Rome La Sapienza,Rome, Italy
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27
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Siemer AB, Ritter C, Ernst M, Riek R, Meier BH. Hochauflösende Festkörper-NMR-Spektroskopie am Prionprotein HET-s in seiner amyloiden Form. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200462952] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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28
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Megy S, Bertho G, Kozin SA, Debey P, Hoa GHB, Girault JP. Possible role of region 152-156 in the structural duality of a peptide fragment from sheep prion protein. Protein Sci 2004; 13:3151-60. [PMID: 15537751 PMCID: PMC2287313 DOI: 10.1110/ps.04745004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The conformational conversion of the nonpathogenic "cellular" prion isoform into a pathogenic "scrapie" protease-resistant isoform is a fundamental event in the onset of transmissible spongiform encephalopathies (TSE). During this pathogenic conversion, helix H1 and its two flanking loops of the normal prion protein are thought to undergo a conformational transition into a beta-like structure. A peptide spanning helix H1 and beta-strand S2 (residues 142-166 in human numbering) was studied by circular dichroism and nuclear magnetic resonance spectroscopies. This peptide in aqueous solution, in contrast to many prion fragments studied earlier (1) is highly soluble and (2) does not aggregate until the millimolar concentration range, and (3) exhibits an intrinsic propensity to a beta-hairpin-like conformation at neutral pH. We found that this peptide can also fold into a helix H1 conformation when dissolved in a TFE/PB mixture. The structures of the peptide calculated by MD showed solvent-dependent internal stabilizing forces of the structures and evidenced a higher mobility of the residues following the end of helix H1. These data suggest that the molecular rearrangement of this peptide in region 152-156, particularly in position 155, could be associated with the pathogenic conversion of the prion protein.
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Affiliation(s)
- Simon Megy
- Université René Descartes-Paris V, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques (Unité Mixte de Recherche 8601 Centre National de Recherche Scientifique), 75270 Paris 06, France
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29
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Daidone I, Simona F, Roccatano D, Broglia RA, Tiana G, Colombo G, Di Nola A. β-Hairpin conformation of fibrillogenic peptides: Structure and α-β transition mechanism revealed by molecular dynamics simulations. Proteins 2004; 57:198-204. [PMID: 15326604 DOI: 10.1002/prot.20178] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Understanding the conformational transitions that trigger the aggregation and amyloidogenesis of otherwise soluble peptides at atomic resolution is of fundamental relevance for the design of effective therapeutic agents against amyloid-related disorders. In the present study the transition from ideal alpha-helical to beta-hairpin conformations is revealed by long timescale molecular dynamics simulations in explicit water solvent, for two well-known amyloidogenic peptides: the H1 peptide from prion protein and the Abeta(12-28) fragment from the Abeta(1-42) peptide responsible for Alzheimer's disease. The simulations highlight the unfolding of alpha-helices, followed by the formation of bent conformations and a final convergence to ordered in register beta-hairpin conformations. The beta-hairpins observed, despite different sequences, exhibit a common dynamic behavior and the presence of a peculiar pattern of the hydrophobic side-chains, in particular in the region of the turns. These observations hint at a possible common aggregation mechanism for the onset of different amyloid diseases and a common mechanism in the transition to the beta-hairpin structures. Furthermore the simulations presented herein evidence the stabilization of the alpha-helical conformations induced by the presence of an organic fluorinated cosolvent. The results of MD simulation in 2,2,2-trifluoroethanol (TFE)/water mixture provide further evidence that the peptide coating effect of TFE molecules is responsible for the stabilization of the soluble helical conformation.
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Affiliation(s)
- Isabella Daidone
- Department of Chemistry, University of Rome La Sapienza, Rome, Italy
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30
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DeMarco ML, Daggett V. From conversion to aggregation: protofibril formation of the prion protein. Proc Natl Acad Sci U S A 2004; 101:2293-8. [PMID: 14983003 PMCID: PMC356944 DOI: 10.1073/pnas.0307178101] [Citation(s) in RCA: 265] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2003] [Indexed: 01/08/2023] Open
Abstract
The ability to diagnose and treat prion diseases is limited by our current understanding of the conversion process of the protein from healthy to harmful isoform. Whereas the monomeric, benign species is well characterized, the misfolded conformations responsible for infectivity and neurodegeneration remain elusive. There is mounting evidence that fibrillization intermediates, or protofibrils, but not mature fibrils or plaques, are the pathogenic species in amyloid diseases. Here, we use molecular dynamics to simulate the conversion of the prion protein. Molecular dynamics simulation produces a scrapie prion protein-like conformation enriched in beta-structure that is in good agreement with available experimental data. The converted conformation was then used to model a protofibril by means of the docking of hydrophobic patches of the template structure to form hydrogen-bonded sheets spanning adjacent subunits. The resulting protofibril model provides a non-branching aggregate with a 3(1) axis of symmetry that is in good agreement with a wide variety of experimental data; importantly, it was derived from realistic simulation of the conversion process.
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Affiliation(s)
- Mari L DeMarco
- Biomolecular Structure and Design Program, Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195-7610, USA
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31
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Jaroniec CP, MacPhee CE, Bajaj VS, McMahon MT, Dobson CM, Griffin RG. High-resolution molecular structure of a peptide in an amyloid fibril determined by magic angle spinning NMR spectroscopy. Proc Natl Acad Sci U S A 2004; 101:711-6. [PMID: 14715898 PMCID: PMC321745 DOI: 10.1073/pnas.0304849101] [Citation(s) in RCA: 386] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Amyloid fibrils are self-assembled filamentous structures associated with protein deposition conditions including Alzheimer's disease and the transmissible spongiform encephalopathies. Despite the immense medical importance of amyloid fibrils, no atomic-resolution structures are available for these materials, because the intact fibrils are insoluble and do not form diffraction-quality 3D crystals. Here we report the high-resolution structure of a peptide fragment of the amyloidogenic protein transthyretin, TTR(105-115), in its fibrillar form, determined by magic angle spinning NMR spectroscopy. The structure resolves not only the backbone fold but also the precise conformation of the side chains. Nearly complete (13)C and (15)N resonance assignments for TTR(105-115) formed the basis for the extraction of a set of distance and dihedral angle restraints. A total of 76 self-consistent experimental measurements, including 41 restraints on 19 backbone dihedral angles and 35 (13)C-(15)N distances between 3 and 6 A were obtained from 2D and 3D NMR spectra recorded on three fibril samples uniformly (13)C, (15)N-labeled in consecutive stretches of four amino acids and used to calculate an ensemble of peptide structures. Our results indicate that TTR(105-115) adopts an extended beta-strand conformation in the amyloid fibrils such that both the main- and side-chain torsion angles are close to their optimal values. Moreover, the structure of this peptide in the fibrillar form has a degree of long-range order that is generally associated only with crystalline materials. These findings provide an explanation of the unusual stability and characteristic properties of this form of polypeptide assembly.
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Affiliation(s)
- Christopher P Jaroniec
- Department of Chemistry and Center for Magnetic Resonance, Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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32
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Tcherkasskaya O, Sanders W, Chynwat V, Davidson EA, Orser CS. The Role of Hydrophobic Interactions in Amyloidogenesis: Example of Prion-Related Polypeptides. J Biomol Struct Dyn 2003; 21:353-65. [PMID: 14616031 DOI: 10.1080/07391102.2003.10506931] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Conversion of the non-infectious, cellular form of the prion protein (PrP(C)) to the infectious form (PrP(Sc)) is thought to be driven by an alpha-helical to beta-sheet conformational transition. To reveal the sequence determinants which encourage the transition to beta-fold, we study the synthetic peptides associated with hydrophobic conserved fragments of the N-terminal region of the prion protein. The structure of peptides in solution was probed under various thermodynamic conditions employing circular dichroism and steady state fluorescence spectroscopy as well as dye binding assays. The fluorescence methods utilized pyrene residues covalently attached to the end of the model peptides. In aqueous solutions, the structure assessments indicate the formation of metastable peptide aggregates; the molecular conformations within the peptide micelles are largely coiled. This stage in molecular assembly exists without significant beta-strand formation, i.e., before the appearance of any ordered secondary structure detectable by circular dichroism. At moderate concentrations of trifluoroethanol and/or acetonitrile, the conformational ensemble shifts towards beta-strand formation, and the population of the amorphous aggregates decreases significantly. Overall, the present data indicate that hydrophobic interactions between side chains of the peptide variants prevent, in fact, the formation of the rigid beta-sheet structures. Encouragement of beta-folds requires the destabilization of local interactions in the peptide chain, which in vivo might be possible within cell membranes as well as within partly folded molecular forms.
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Affiliation(s)
- Olga Tcherkasskaya
- Department of Biochemistry & Molecular Biology, Georgetown University School of Medicine, Washington DC, USA.
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33
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Jaroniec CP, MacPhee CE, Astrof NS, Dobson CM, Griffin RG. Molecular conformation of a peptide fragment of transthyretin in an amyloid fibril. Proc Natl Acad Sci U S A 2002; 99:16748-53. [PMID: 12481032 PMCID: PMC139215 DOI: 10.1073/pnas.252625999] [Citation(s) in RCA: 192] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The molecular conformation of peptide fragment 105-115 of transthyretin, TTR(105-115), previously shown to form amyloid fibrils in vitro, has been determined by magic-angle spinning solid-state NMR spectroscopy. 13C and 15N linewidth measurements indicate that TTR(105-115) forms a highly ordered structure with each amino acid in a unique environment. 2D 13C-13C and 15N-13C-13C chemical shift correlation experiments, performed on three fibril samples uniformly 13C,15N-labeled in consecutive stretches of 4 aa, allowed the complete sequence-specific backbone and side-chain 13C and 15N resonance assignments to be obtained for residues 105-114. Analysis of the 15N, 13CO, 13Calpha, and 13Cbeta chemical shifts allowed quantitative predictions to be made for the backbone torsion angles phi and psi. Furthermore, four backbone 13C-15N distances were determined in two selectively 13C,15N-labeled fibril samples by using rotational-echo double-resonance NMR. The results show that TTR(105-115) adopts an extended beta-strand conformation that is similar to that found in the native protein except for substantial differences in the vicinity of the proline residue.
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Affiliation(s)
- Christopher P Jaroniec
- Department of Chemistry and Center for Magnetic Resonance, Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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34
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Tagliavini F, Forloni G, D'Ursi P, Bugiani O, Salmona M. Studies on peptide fragments of prion proteins. ADVANCES IN PROTEIN CHEMISTRY 2002; 57:171-201. [PMID: 11447690 DOI: 10.1016/s0065-3233(01)57022-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- F Tagliavini
- Istituto Nazionale Neurologico Carlo Besta, Milano, Italy
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35
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Wüthrich K, Riek R. Three-dimensional structures of prion proteins. ADVANCES IN PROTEIN CHEMISTRY 2002; 57:55-82. [PMID: 11447697 DOI: 10.1016/s0065-3233(01)57018-7] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- K Wüthrich
- Institut für Molekularbiologie und Biophysik, Eldgenössische Technische Hochschule Zürich, CH-8093 Zürich-Hönggerberg, Switzerland
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36
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Kozin SA, Bertho G, Mazur AK, Rabesona H, Girault JP, Haertlé T, Takahashi M, Debey P, Hoa GH. Sheep prion protein synthetic peptide spanning helix 1 and beta-strand 2 (residues 142-166) shows beta-hairpin structure in solution. J Biol Chem 2001; 276:46364-70. [PMID: 11577109 DOI: 10.1074/jbc.m108014200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
According to the "protein only" hypothesis, a conformational conversion of the non-pathogenic "cellular" prion isoform into a pathogenic "scrapie" isoform is the fundamental event in the onset of prion diseases. During this pathogenic conversion, helix H1 and two adjacent surface loops L2 and L3 of the normal prion protein are thought to undergo a conformational transition into an extended beta-like structure, which is prompted by interactions with the pre-existing beta-sheet. To get more insight into the interaction between the helix and one of the beta-strands in the partially unfolded prion protein, the solution structure of a synthetic linear peptide spanning helix H1 and beta-strand S2 (residues 142-166 in human numbering) was studied by circular dichroism and nuclear magnetic resonance spectroscopies. We found that, in contrast to many prion fragments studied earlier, this peptide (i) is highly soluble and does not aggregate up to a millimolar concentration range in aqueous medium and (ii) exhibits an intrinsic propensity to a beta-hairpin like conformation at neutral pH. This beta-propensity can be one of the internal driving forces of the molecular rearrangement responsible for the pathogenic conversion of the prion protein.
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Affiliation(s)
- S A Kozin
- Institut National de la Recherche Agronomique 806, Muséum National d'Histoire Naturelle (EA 2703), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
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37
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Levy Y, Hanan E, Solomon B, Becker OM. Helix-coil transition of PrP106-126: molecular dynamic study. Proteins 2001; 45:382-96. [PMID: 11746686 DOI: 10.1002/prot.1157] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A set of 34 molecular dynamic (MD) simulations totaling 305 ns of simulation time of the prion protein-derived peptide PrP106-126 was performed with both explicit and implicit solvent models. The objective of these simulations is to investigate the relative stability of the alpha-helical conformation of the peptide and the mechanism for conversion from the helix to a random-coil structure. At neutral pH, the wild-type peptide was found to lose its initial helical structure very fast, within a few nanoseconds (ns) from the beginning of the simulations. The helix breaks up in the middle and then unwinds to the termini. The spontaneous transition into the random coil structure is governed by the hydrophobic interaction between His(111) and Val(122). The A117V mutation, which is linked to GSS disease, was found to destabilize the helix conformation of the peptide significantly, leading to a complete loss of helicity approximately 1 ns faster than in the wild-type. Furthermore, the A117V mutant exhibits a different mechanism for helix-coil conversion, wherein the helix begins to break up at the C-terminus and then gradually to unwind towards the N-terminus. In most simulations, the mutation was found to speed up the conversion through an additional hydrophobic interaction between Met(112) and the mutated residue Val(117), an interaction that did not exist in the wild-type peptide. Finally, the beta-sheet conformation of the wild-type peptide was found to be less stable at acidic pH due to a destabilization of the His(111)-Val(122), since at acidic pH this histidine is protonated and is unlikely to participate in hydrophobic interaction.
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Affiliation(s)
- Y Levy
- Department of Chemical Physics, School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel.
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38
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Laws DD, Bitter HM, Liu K, Ball HL, Kaneko K, Wille H, Cohen FE, Prusiner SB, Pines A, Wemmer DE. Solid-state NMR studies of the secondary structure of a mutant prion protein fragment of 55 residues that induces neurodegeneration. Proc Natl Acad Sci U S A 2001; 98:11686-90. [PMID: 11562491 PMCID: PMC58790 DOI: 10.1073/pnas.201404298] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The secondary structure of a 55-residue fragment of the mouse prion protein, MoPrP(89-143), was studied in randomly aggregated (dried from water) and fibrillar (precipitated from water/acetonitrile) forms by (13)C solid-state NMR. Recent studies have shown that the fibrillar form of the P101L mutant of MoPrP(89-143) is capable of inducing prion disease in transgenic mice, whereas unaggregated or randomly aggregated samples do not provoke disease. Through analysis of (13)C chemical shifts, we have determined that both wild-type and mutant sequence MoPrP(89-143) form a mixture of beta-sheet and alpha-helical conformations in the randomly aggregated state although the beta-sheet content in MoPrP(89-143, P101L) is significantly higher than in the wild-type peptide. In a fibrillar state, MoPrP(89-143, P101L) is completely converted into beta-sheet, suggesting that the formation of a specific beta-sheet structure may be required for the peptide to induce disease. Studies of an analogous peptide from Syrian hamster PrP verify that sequence alterations in residues 101-117 affect the conformation of aggregated forms of the peptides.
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Affiliation(s)
- D D Laws
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
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39
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Luca S, Filippov DV, van Boom JH, Oschkinat H, de Groot HJ, Baldus M. Secondary chemical shifts in immobilized peptides and proteins: a qualitative basis for structure refinement under magic angle spinning. JOURNAL OF BIOMOLECULAR NMR 2001; 20:325-331. [PMID: 11563556 DOI: 10.1023/a:1011278317489] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Resonance assignments recently obtained on immobilized polypeptides and a membrane protein aggregate under Magic Angle Spinning are compared to random coil values in the liquid state. The resulting chemical shift differences (secondary chemical shifts) are evaluated in light of the backbone torsion angle psi previously reported using X-ray crystallography. In all cases, a remarkable correlation is found suggesting that the concept of secondary chemical shifts, well established in the liquid state, can be of similar importance in the context of multiple-labelled polypeptides studied under MAS conditions.
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Affiliation(s)
- S Luca
- Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
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40
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Antzutkin ON, Levitt MH. Coherence transfer signals in the rotational resonance NMR of a spinning single crystal. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2000; 147:147-151. [PMID: 11042058 DOI: 10.1006/jmre.2000.2169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A recent analysis of rotational resonance lineshapes (M. Helmle et al., J. Magn. Reson. 140, 379-403, 1999) predicted the existence of coherence transfer signals, which are generated by mechanically induced coherence transfer during the detection process. These signals correspond to the generation of observable coherences at spin sites that have no magnetization at the beginning of the observation interval but which acquire coherence while the detection is underway. The coherence transfer signals disappear for powder samples in conventional magic-angle-spinning solid-state NMR experiments. In this Communication, we report the successful detection of coherence transfer signals in rotor-synchronized experiments performed on a single crystal of [1,2-(13)C(2)]glycine. Copyright 2000 Academic Press.
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Affiliation(s)
- ON Antzutkin
- Division of Inorganic Chemistry, Lulea University of Technology, Lulea, S-971 87, Sweden
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41
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Abstract
Amyloid fibrils are intrinsically noncrystalline, insoluble, high-molecular-weight aggregates of peptides and proteins, with considerable biomedical and biophysical significance. Solid-state NMR techniques are uniquely capable of providing high-resolution, site-specific structural constraints for amyloid fibrils, at the level of specific interatomic distances and torsion angles. So far, a relatively small number of solid-state NMR studies of amyloid fibrils have been reported. These have addressed issues about the supramolecular organization of beta-sheets in the fibrils and the peptide conformation in the fibrils, and have concentrated on the beta-amyloid peptide of Alzheimer's disease. Many additional applications of solid-state NMR to amyloid fibrils from a variety of sources are anticipated in the near future, as these systems are ideally suited for the technique and are of widespread current interest.
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Affiliation(s)
- R Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA.
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42
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Abstract
Solid-state nmr spectroscopy provides a robust method for investigating polypeptides that have been prepared by chemical synthesis and that are immobilized by strong interactions with solid surfaces or large macroscopic complexes. Solid-state nmr spectroscopy has been widely used to investigate membrane polypeptides or peptide aggregates such as amyloid fibrils. Whereas magic angle spinning solid-state nmr spectroscopy allows one to measure distances and dihedral angles with high accuracy, static membrane samples that are aligned with respect to the magnetic field direction allow one to determine the secondary structure of bound polypeptides and their orientation with respect to the bilayer normal. Peptide dynamics and the effect of polypeptides on the macroscopic phase preference of phospholipid membranes have been investigated in nonoriented samples. Investigations of the structure and topology of membrane channels, peptide antibiotics, signal sequences as well as model systems that allow one to dissect the interaction contributions in phospholipid membranes will be presented in greater detail.
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Affiliation(s)
- B Bechinger
- Max-Planck-Institute for Biochemistry, Am Klopferspitz 18A, 82152 Marinsried, Germany.
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43
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Inouye H, Bond J, Baldwin MA, Ball HL, Prusiner SB, Kirschner DA. Structural changes in a hydrophobic domain of the prion protein induced by hydration and by ala-->Val and pro-->Leu substitutions. J Mol Biol 2000; 300:1283-96. [PMID: 10903869 DOI: 10.1006/jmbi.2000.3926] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
X-ray diffraction was used to study the structure of assemblies formed by synthetic peptide fragments of the prion protein (PrP) that include the hydrophobic domain implicated in the Gerstmann-Sträussler-Scheinker (GSS) mutation (P102L). The effects of hydration on polypeptide assembly and of Ala-->Val substitutions in the hydrophobic domain were characterized. Synthetic peptides included: (i) Syrian hamster (SHa) hydrophobic core, SHa106-122 (KTNMKHMAGAAAAGAVV); (ii) SHa104-122(3A-V), with A-->V mutations at 113, 115 and 118 (KPKTNMKHMVGVAAVGAVV); (iii) mouse (Mo) wild-type sequence of the N-terminal hydrophobic domain, Mo89-143WT; and (iv) the same mouse sequence with leucine substitution for proline at residue number 101, Mo89-143(P101L). Samples of SHa106-122 that formed assemblies while drying under ambient conditions showed X-ray patterns indicative of 33 A thick slab-like structures having extensive H-bonding and intersheet stacking. By contrast, lyophilized peptide that was equilibrated against 100 % relative humidity showed assemblies with only a few layers of beta-sheets. The Ala-->Val substitutions in SHa104-122 and Mo89-143(P101L) resulted in the formation of 40 A wide, cross-beta fibrils. Observation of similar size beta-sheet fibrils formed by peptides SHa104-122(3A-V) and the longer Mo89-143(P101L) supports the notion that the hydrophobic sequence forms a template or core that promotes the beta-folding of the longer peptide. The substitution of amino acids in the mutants, e.g. 3A-->V and P101L, enhances the folding of the peptide into compact structural units, significantly enhancing the formation of the extensive beta-sheet fibrils.
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Affiliation(s)
- H Inouye
- Department of Biology, Boston College, Chestnut Hill, MA 02467-3811, USA.
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44
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Abstract
Improved understanding of amyloidogenic peptides and proteins such as prion proteins and Alzheimer's beta peptides has attracted much attention to the elucidation of the molecular mechanisms of such amyloidogenesis. As a representative, in the prion protein, the conformational transitions from alpha-helix to beta-structure undergo along with the amyloidogenesis in a self-catalytic manner. Moreover, recent studies by the de novo design of peptides and proteins as well as the amyloidogenesis of peptides and proteins including pathogenic protein mutants have provided insight into the conformational changes essential to amyloidogenesis and correct folding.
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Affiliation(s)
- H Mihara
- Department of Bioengineering, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
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45
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Lynn DG, Meredith SC. Review: model peptides and the physicochemical approach to beta-amyloids. J Struct Biol 2000; 130:153-73. [PMID: 10940223 DOI: 10.1006/jsbi.2000.4287] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
beta-Amyloid peptides are the main protein components of neuritic plaques and may be important in the pathogenesis of Alzheimer's Disease. The determination of the structure of beta-amyloid fibrils poses a challenge because of the limited solubility of beta-amyloid peptides and the noncrystalline nature of fibrils formed from these peptides. In this paper, we describe several physicochemical approaches which have been used to examine fibrils and the fibrillogenesis of peptide models of beta-amyloid. Recent advances in solid state NMR, such as the DRAWS pulse sequence, have made this approach a particularly attractive one for peptides such as beta-amyloid, which are not yet amenable to high-resolution solution phase NMR and crystallography. The application of solid state NMR techniques has yielded information on a model peptide comprising residues 10-35 of human beta-amyloid and indicates that in fibrils, this peptide assumes a parallel beta-strand conformation, with all residues in exact register. In addition, we discuss the use of block copolymers of Abeta peptides and polyethylene glycol as probes for the pathways of fibrillogenesis. These methods can be combined with other new methods, such as high-resolution synchrotron X-ray diffraction and small angle neutron and X-ray scattering, to yield structural data of relevance not only to disease, but to the broader question of protein folding and self-assembly.
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Affiliation(s)
- D G Lynn
- Department of Chemistry, The University of Chicago, 5735 S. Ellis Avenue, Chicago, Illinois, 60637-1403, USA
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46
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Shaw WJ, Long JR, Dindot JL, Campbell AA, Stayton PS, Drobny GP. Determination of Statherin N-Terminal Peptide Conformation on Hydroxyapatite Crystals. J Am Chem Soc 2000. [DOI: 10.1021/ja9842823] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Wendy J. Shaw
- Contribution from the Department of Bioengineering and Department of Chemistry, University of Washington, Seattle, Washington 98195, and Pacific Northwest National Laboratory, Richland, Washington 99352
| | - Joanna R. Long
- Contribution from the Department of Bioengineering and Department of Chemistry, University of Washington, Seattle, Washington 98195, and Pacific Northwest National Laboratory, Richland, Washington 99352
| | - John L. Dindot
- Contribution from the Department of Bioengineering and Department of Chemistry, University of Washington, Seattle, Washington 98195, and Pacific Northwest National Laboratory, Richland, Washington 99352
| | - Allison A. Campbell
- Contribution from the Department of Bioengineering and Department of Chemistry, University of Washington, Seattle, Washington 98195, and Pacific Northwest National Laboratory, Richland, Washington 99352
| | - Patrick S. Stayton
- Contribution from the Department of Bioengineering and Department of Chemistry, University of Washington, Seattle, Washington 98195, and Pacific Northwest National Laboratory, Richland, Washington 99352
| | - Gary P. Drobny
- Contribution from the Department of Bioengineering and Department of Chemistry, University of Washington, Seattle, Washington 98195, and Pacific Northwest National Laboratory, Richland, Washington 99352
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48
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Affiliation(s)
- M A Baldwin
- Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446, USA
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49
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Affiliation(s)
- D Wemmer
- Department of Chemistry, University of California, Berkeley 94720, USA
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50
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Helmle M, Lee YK, Verdegem PJ, Feng X, Karlsson T, Lugtenburg J, de Groot HJ, Levitt MH. Anomalous rotational resonance spectra in magic-angle spinning NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1999; 140:379-403. [PMID: 10497046 DOI: 10.1006/jmre.1999.1843] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Magic-angle spinning NMR spectra of samples containing dilute spin-1/2 pairs display broadenings or splittings when a rotational resonance condition is satisfied, meaning that a small integer multiple of the spinning frequency matches the difference in the two isotropic shift frequencies. We show experimental rotational resonance NMR spectra of a 13C2-labeled retinal which are in qualitative disagreement with existing theory. We propose an explanation of these anomalous rotational spectra involving residual heteronuclear couplings between the 13C nuclei and the neighboring 1H nuclei. These couplings strongly influence the rotational resonance 13C spectrum, despite the presence of a strong radiofrequency decoupling field at the 1H Larmor frequency. We model the residual heteronuclear couplings by differential transverse relaxation of the 13C single-quantum coherences. We present a superoperator theory of the phenomenon and describe a numerical algorithm for rapid Liouville space simulations in periodic systems. Good agreement with experimental results is obtained by using a biexponential transverse relaxation model for each spin site.
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Affiliation(s)
- M Helmle
- Arrhenius Laboratory, Stockholm University, Stockholm, S-10691, Sweden
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