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Gielnik M, Szymańska A, Dong X, Jarvet J, Svedružić ŽM, Gräslund A, Kozak M, Wärmländer SKTS. Prion Protein Octarepeat Domain Forms Transient β-Sheet Structures upon Residue-Specific Binding to Cu(II) and Zn(II) Ions. Biochemistry 2023. [PMID: 37163663 DOI: 10.1021/acs.biochem.3c00129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Misfolding of the cellular prion protein (PrPC) is associated with the development of fatal neurodegenerative diseases called transmissible spongiform encephalopathies (TSEs). Metal ions appear to play a crucial role in PrPC misfolding. PrPC is a combined Cu(II) and Zn(II) metal-binding protein, where the main metal-binding site is located in the octarepeat (OR) region. Thus, the biological function of PrPC may involve the transport of divalent metal ions across membranes or buffering concentrations of divalent metal ions in the synaptic cleft. Recent studies have shown that an excess of Cu(II) ions can result in PrPC instability, oligomerization, and/or neuroinflammation. Here, we have used biophysical methods to characterize Cu(II) and Zn(II) binding to the isolated OR region of PrPC. Circular dichroism (CD) spectroscopy data suggest that the OR domain binds up to four Cu(II) ions or two Zn(II) ions. Binding of the first metal ion results in a structural transition from the polyproline II helix to the β-turn structure, while the binding of additional metal ions induces the formation of β-sheet structures. Fluorescence spectroscopy data indicate that the OR region can bind both Cu(II) and Zn(II) ions at neutral pH, but under acidic conditions, it binds only Cu(II) ions. Molecular dynamics simulations suggest that binding of either metal ion to the OR region results in the formation of β-hairpin structures. As the formation of β-sheet structures can be a first step toward amyloid formation, we propose that high concentrations of either Cu(II) or Zn(II) ions may have a pro-amyloid effect in TSE diseases.
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Affiliation(s)
- Maciej Gielnik
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, PL 61-614 Poznań, Poland
| | - Aneta Szymańska
- Department of Biomedical Chemistry, Faculty of Chemistry, Gdańsk University, PL 80-308 Gdańsk, Poland
| | - Xiaolin Dong
- Chemistry Section, Stockholm University, 10691 Stockholm, Sweden
| | - Jüri Jarvet
- Chemistry Section, Stockholm University, 10691 Stockholm, Sweden
- The National Institute of Chemical Physics and Biophysics, 12618 Tallinn, Estonia
| | - Željko M Svedružić
- Department of Biotechnology, University of Rijeka, HR 51000 Rijeka, Croatia
| | - Astrid Gräslund
- Chemistry Section, Stockholm University, 10691 Stockholm, Sweden
| | - Maciej Kozak
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, PL 61-614 Poznań, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, PL 30-392 Kraków, Poland
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Nochebuena J, Quintanar L, Vela A, Cisneros GA. Structural and electronic analysis of the octarepeat region of prion protein with four Cu 2+ by polarizable MD and QM/MM simulations. Phys Chem Chem Phys 2021; 23:21568-21578. [PMID: 34550129 PMCID: PMC8497436 DOI: 10.1039/d1cp03187b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Prions have been linked to neurodegenerative diseases that affect various species of mammals including humans. The prion protein, located mainly in neurons, is believed to play the role of metal ion transporter. High levels of copper ions have been related to structural changes. A 32-residue region of the N-terminal domain, known as octarepeat, can bind up to four copper ions. Different coordination modes have been observed and are strongly dependent on Cu2+ concentration. Many theoretical studies carried out so far have focused on studying the coordination modes of a single copper ion. In this work we investigate the octarepeat region coordinated with four copper ions. Molecular dynamics (MD) and hybrid quantum mechanics/molecular mechanics (QM/MM) simulations using the polarizable AMOEBA force field have been carried out. The polarizable MD simulations starting from a fully extended conformation indicate that the tetra-Cu2+/octarepeat complex forms a globular structure. The globular form is stabilized by interactions between Cu2+ and tryptophan residues resulting in some coordination sites observed to be in close proximity, in agreement with experimental results. Subsequent QM/MM simulations on several snapshots suggests the system is in a high-spin quintet state, with all Cu2+ bearing one single electron, and all unpaired electrons are ferromagnetically coupled. NMR simulations on selected structures provides insights on the chemical shifts of the first shell ligands around the metals with respect to inter-metal distances.
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Affiliation(s)
- Jorge Nochebuena
- Department of Chemistry, University of North Texas, Denton, Texas, 76201, USA.
| | - Liliana Quintanar
- Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, 07360, Mexico
| | - Alberto Vela
- Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, 07360, Mexico
| | - G Andrés Cisneros
- Department of Chemistry, University of North Texas, Denton, Texas, 76201, USA.
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Benedikter M, Musso J, Kesharwani MK, Sterz KL, Elser I, Ziegler F, Fischer F, Plietker B, Frey W, Kästner J, Winkler M, van Slageren J, Nowakowski M, Bauer M, Buchmeiser MR. Charge Distribution in Cationic Molybdenum Imido Alkylidene N-Heterocyclic Carbene Complexes: A Combined X-ray, XAS, XES, DFT, Mössbauer, and Catalysis Approach. ACS Catal 2020. [DOI: 10.1021/acscatal.0c03978] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Mathis Benedikter
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Janis Musso
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Manoj K. Kesharwani
- Institute of Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - K. Leonard Sterz
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Iris Elser
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Felix Ziegler
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Felix Fischer
- Faculty of Chemistry and Food Chemistry, Technical University of Dresden, Bergstrasse 66, D-01069 Dresden, Germany
| | - Bernd Plietker
- Faculty of Chemistry and Food Chemistry, Technical University of Dresden, Bergstrasse 66, D-01069 Dresden, Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Johannes Kästner
- Institute of Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Mario Winkler
- Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Joris van Slageren
- Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Michal Nowakowski
- Department of Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Matthias Bauer
- Department of Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Michael R. Buchmeiser
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
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