1
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Fortino M, Arnesano F, Pietropaolo A. Unraveling Copper Exchange in the Atox1-Cu(I)-Mnk1 Heterodimer: A Simulation Approach. J Phys Chem B 2024; 128:5336-5343. [PMID: 38780400 DOI: 10.1021/acs.jpcb.4c01026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Copper, an essential metal for various cellular processes, requires tight regulation to prevent cytotoxicity. Intracellular pathways crucial for maintaining optimal copper levels involve soluble and membrane transporters, namely, metallochaperones and P-type ATPases, respectively. In this study, we used a simulation workflow based on free-energy perturbation (FEP) theory and parallel bias metadynamics (PBMetaD) to predict the Cu(I) exchange mechanism between the human Cu(I) chaperone, Atox1, and one of its two physiological partners, ATP7A. ATP7A, also known as the Menkes disease protein, is a transmembrane protein and one of the main copper-transporting ATPases. It pumps copper into the trans-Golgi network for the maturation of cuproenzymes and is also essential for the efflux of excess copper across the plasma membrane. In this analysis, we utilized the nuclear magnetic resonance (NMR) structure of the Cu(I)-mediated complex between Atox1 and the first soluble domain of the Menkes protein (Mnk1) as a starting point. Independent free-energy simulations were conducted to investigate the dissociation of both Atox1 and Mnk1. The calculations revealed that the two dissociations require free energy values of 6.3 and 6.2 kcal/mol, respectively, following a stepwise dissociation mechanism.
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Affiliation(s)
- Mariagrazia Fortino
- Dipartimento di Scienze della Salute, Università Magna Graecia di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Fabio Arnesano
- Dipartimento di Chimica, Università di Bari "Aldo Moro", Via Orabona 4, 70125 Bari, Italy
| | - Adriana Pietropaolo
- Dipartimento di Scienze della Salute, Università Magna Graecia di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
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2
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Ghosh S, Hassan SH, Das A. Role of Explicit Solvation in Computational Modeling of Chemical Reactions: Mechanism of Cu(I) Transfer Between Thiolate-Based Chelators in Water. J Phys Chem B 2024. [PMID: 38503566 DOI: 10.1021/acs.jpcb.3c07327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Solvation plays important roles in controlling the thermodynamic and kinetic aspects of chemical reactions. The conventional approaches to treat solvation via electronic structure methods are likely to become inadequate, when the reacting solutes have strong electrostatic and hydrogen bonding interactions with the solvent and undergo significant structural changes during the course of the reaction. In this article, we present evidence of such solvent and structural effects in the computational study of the Cu(I) transfer reaction between thiolate-based chelators dithiobutylamine (DTBA) and dithiotheritol (DTT) in water, inspired from biological copper trafficking phenomena. We propose a general solution to the problem by combining classical molecular dynamics (MD) simulations of the bulk system and static quantum chemistry calculations. The fluctuating solvation shell was estimated from MD, and energetics was assessed by averaging QM energies of a series of molecular clusters constructed from the MD snapshots. Applying this approach, we propose a reaction pathway with estimates of relative intermediate stabilities and barriers, which suggest the overall reaction to be reversible in nature and likely to go through both two and three coordinated intermediates, confirming previous studies of similar protein analogues. An interesting fact that emerged from our study was the strong indication that the rate-determining step is the deprotonation of initial thiol bound Cu(I) complex, without involving any Cu(I)-S bonds. The proposed method will lead to a better treatment of solvations, and these mechanistic insights will aid our understanding of biological copper(I) trafficking.
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Affiliation(s)
- Soumak Ghosh
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Sk Hasibo Hassan
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Avisek Das
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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3
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Qasem Z, Pavlin M, Ritacco I, Avivi MY, Meron S, Hirsch M, Shenberger Y, Gevorkyan-Airapetov L, Magistrato A, Ruthstein S. Disrupting Cu trafficking as a potential therapy for cancer. Front Mol Biosci 2022; 9:1011294. [PMID: 36299299 PMCID: PMC9589254 DOI: 10.3389/fmolb.2022.1011294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/26/2022] [Indexed: 11/13/2022] Open
Abstract
Copper ions play a crucial role in various cellular biological processes. However, these copper ions can also lead to toxicity when their concentration is not controlled by a sophisticated copper-trafficking system. Copper dys-homeostasis has been linked to a variety of diseases, including neurodegeneration and cancer. Therefore, manipulating Cu-trafficking to trigger selective cancer cell death may be a viable strategy with therapeutic benefit. By exploiting combined in silico and experimental strategies, we identified small peptides able to bind Atox1 and metal-binding domains 3-4 of ATP7B proteins. We found that these peptides reduced the proliferation of cancer cells owing to increased cellular copper ions concentration. These outcomes support the idea of harming copper trafficking as an opportunity for devising novel anti-cancer therapies.
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Affiliation(s)
- Zena Qasem
- Department of Chemistry and the Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, Israel
| | - Matic Pavlin
- National Research Council of Italy (CNR)—Institute of Material (IOM) C/o International School for Advanced Studies (SISSA), Trieste, Italy
- Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Ljubljana, Slovenia
| | - Ida Ritacco
- National Research Council of Italy (CNR)—Institute of Material (IOM) C/o International School for Advanced Studies (SISSA), Trieste, Italy
- Department of Chemistry, University of Salerno, Salerno, Italy
| | - Matan Y. Avivi
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Shelly Meron
- Department of Chemistry and the Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, Israel
| | - Melanie Hirsch
- Department of Chemistry and the Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, Israel
| | - Yulia Shenberger
- Department of Chemistry and the Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, Israel
| | - Lada Gevorkyan-Airapetov
- Department of Chemistry and the Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, Israel
| | - Alessandra Magistrato
- National Research Council of Italy (CNR)—Institute of Material (IOM) C/o International School for Advanced Studies (SISSA), Trieste, Italy
- *Correspondence: Alessandra Magistrato, ; Sharon Ruthstein,
| | - Sharon Ruthstein
- Department of Chemistry and the Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, Israel
- *Correspondence: Alessandra Magistrato, ; Sharon Ruthstein,
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4
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Orädd F, Steffen JH, Gourdon P, Andersson M. Copper binding leads to increased dynamics in the regulatory N-terminal domain of full-length human copper transporter ATP7B. PLoS Comput Biol 2022; 18:e1010074. [PMID: 36070320 PMCID: PMC9484656 DOI: 10.1371/journal.pcbi.1010074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 09/19/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022] Open
Abstract
ATP7B is a human copper-transporting P1B-type ATPase that is involved in copper homeostasis and resistance to platinum drugs in cancer cells. ATP7B consists of a copper-transporting core and a regulatory N-terminal tail that contains six metal-binding domains (MBD1-6) connected by linker regions. The MBDs can bind copper, which changes the dynamics of the regulatory domain and activates the protein, but the underlying mechanism remains unknown. To identify possible copper-specific structural dynamics involved in transport regulation, we constructed a model of ATP7B spanning the N-terminal tail and core catalytic domains and performed molecular dynamics (MD) simulations with (holo) and without (apo) copper ions bound to the MBDs. In the holo protein, MBD2, MBD3 and MBD5 showed enhanced mobilities, which resulted in a more extended N-terminal regulatory region. The observed separation of MBD2 and MBD3 from the core protein supports a mechanism where copper binding activates the ATP7B protein by reducing interactions among MBD1-3 and between MBD1-3 and the core protein. We also observed an increased interaction between MBD5 and the core protein that brought the copper-binding site of MBD5 closer to the high-affinity internal copper-binding site in the core protein. The simulation results assign specific, mechanistic roles to the metal-binding domains involved in ATP7B regulation that are testable in experimental settings. Living organisms depend upon active transport against gradients across biological membranes for survival. Such transport can be accomplished by ATP-dependent membrane protein transporters for which the activity must be regulated to maintain optimal concentrations in the cellular compartments. The regulatory mechanisms often involve structural responses inherent to the protein structure, which because of their dynamic nature can be hard to assess experimentally. A prime example is regulation of cellular copper levels by a copper-binding tail in the human copper transporter ATP7B. Dysregulation can cause severe diseases, for example the copper metabolism disorder Wilson’s disease, which is caused by mutations in ATP7B regulation machinery. Due to the practical difficulties in working with membrane proteins, most studies of ATP7B have been conducted in the absence of the membrane-bound protein core. Here, we used computer simulations of full-length ATP7B to study how structural dynamics in the regulatory tail differ between copper-bound and copper-free states. Copper induced increased dynamics in the tail, resulting in an overall movement towards the ion-binding site in the protein core. The simulations identified several, hitherto not reported, interactions between the regulatory tail and the protein core that can be targeted experimentally to enhance our understanding of this medically relevant regulatory mechanism.
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Affiliation(s)
- Fredrik Orädd
- Department of Chemistry, Umeå University, Umeå, Sweden
| | - Jonas Hyld Steffen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pontus Gourdon
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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5
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Janoš P, Aupič J, Ruthstein S, Magistrato A. The conformational plasticity of the selectivity filter methionines controls the in-cell Cu(I) uptake through the CTR1 transporter. QRB DISCOVERY 2022; 3:e3. [PMID: 37529280 PMCID: PMC10392627 DOI: 10.1017/qrd.2022.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/25/2022] [Accepted: 04/01/2022] [Indexed: 11/05/2022] Open
Abstract
Copper is a trace element vital to many cellular functions. Yet its abnormal levels are toxic to cells, provoking a variety of severe diseases. The high affinity copper transporter 1 (CTR1), being the main in-cell copper [Cu(I)] entry route, tightly regulates its cellular uptake via a still elusive mechanism. Here, all-atoms simulations unlock the molecular terms of Cu(I) transport in eukaryotes disclosing that the two methionine (Met) triads, forming the selectivity filter, play an unprecedented dual role both enabling selective Cu(I) transport and regulating its uptake rate thanks to an intimate coupling between the conformational plasticity of their bulky side chains and the number of bound Cu(I) ions. Namely, the Met residues act as a gate reducing the Cu(I) import rate when two ions simultaneously bind to CTR1. This may represent an elegant autoregulatory mechanism through which CTR1 protects the cells from excessively high, and hence toxic, in-cell Cu(I) levels. Overall, our outcomes resolve fundamental questions in CTR1 biology and open new windows of opportunity to tackle diseases associated with an imbalanced copper uptake.
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Affiliation(s)
- Pavel Janoš
- Consiglio Nazionale delle ricerche/National Research Council (CNR) -IOM c/o International School for Advanced Studies (SISSA/ISAS), via Bonomea 265, 34136Trieste, Italy
| | - Jana Aupič
- Consiglio Nazionale delle ricerche/National Research Council (CNR) -IOM c/o International School for Advanced Studies (SISSA/ISAS), via Bonomea 265, 34136Trieste, Italy
| | - Sharon Ruthstein
- Department of Chemistry, Faculty of Exact Sciences and the Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, 5290002Ramat-Gan, Israel
| | - Alessandra Magistrato
- Consiglio Nazionale delle ricerche/National Research Council (CNR) -IOM c/o International School for Advanced Studies (SISSA/ISAS), via Bonomea 265, 34136Trieste, Italy
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6
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The Advantages of EPR Spectroscopy in Exploring Diamagnetic Metal Ion Binding and Transfer Mechanisms in Biological Systems. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry8010003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy has emerged as an ideal biophysical tool to study complex biological processes. EPR spectroscopy can follow minor conformational changes in various proteins as a function of ligand or protein binding or interactions with high resolution and sensitivity. Resolving cellular mechanisms, involving small ligand binding or metal ion transfer, is not trivial and cannot be studied using conventional biophysical tools. In recent years, our group has been using EPR spectroscopy to study the mechanism underlying copper ion transfer in eukaryotic and prokaryotic systems. This mini-review focuses on our achievements following copper metal coordination in the diamagnetic oxidation state, Cu(I), between biomolecules. We discuss the conformational changes induced in proteins upon Cu(I) binding, as well as the conformational changes induced in two proteins involved in Cu(I) transfer. We also consider how EPR spectroscopy, together with other biophysical and computational tools, can identify the Cu(I)-binding sites. This work describes the advantages of EPR spectroscopy for studying biological processes that involve small ligand binding and transfer between intracellular proteins.
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7
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Spinello A, Borišek J, Pavlin M, Janoš P, Magistrato A. Computing Metal-Binding Proteins for Therapeutic Benefit. ChemMedChem 2021; 16:2034-2049. [PMID: 33740297 DOI: 10.1002/cmdc.202100109] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Indexed: 01/18/2023]
Abstract
Over one third of biomolecules rely on metal ions to exert their cellular functions. Metal ions can play a structural role by stabilizing the structure of biomolecules, a functional role by promoting a wide variety of biochemical reactions, and a regulatory role by acting as messengers upon binding to proteins regulating cellular metal-homeostasis. These diverse roles in biology ascribe critical implications to metal-binding proteins in the onset of many diseases. Hence, it is of utmost importance to exhaustively unlock the different mechanistic facets of metal-binding proteins and to harness this knowledge to rationally devise novel therapeutic strategies to prevent or cure pathological states associated with metal-dependent cellular dysfunctions. In this compendium, we illustrate how the use of a computational arsenal based on docking, classical, and quantum-classical molecular dynamics simulations can contribute to extricate the minutiae of the catalytic, transport, and inhibition mechanisms of metal-binding proteins at the atomic level. This knowledge represents a fertile ground and an essential prerequisite for selectively targeting metal-binding proteins with small-molecule inhibitors aiming to (i) abrogate deregulated metal-dependent (mis)functions or (ii) leverage metal-dyshomeostasis to selectively trigger harmful cells death.
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Affiliation(s)
- Angelo Spinello
- National Research Council of Italy (CNR)-, Institute of Materials (IOM) c/o International School for Advanced Studies (SISSA), via Bonomea 265, 34136, Trieste, Italy
| | - Jure Borišek
- National Institute of Chemistry Institution Hajdrihova ulica 19, 1000, Ljubljana, Slovenia
| | - Matic Pavlin
- Laboratory of Microsensor Structures and Electronics Faculty of Electrical Engineering, University of Ljubljana Tržaška cesta 25, 1000, Ljubljana, Slovenia
| | - Pavel Janoš
- National Research Council of Italy (CNR)-, Institute of Materials (IOM) c/o International School for Advanced Studies (SISSA), via Bonomea 265, 34136, Trieste, Italy
| | - Alessandra Magistrato
- National Research Council of Italy (CNR)-, Institute of Materials (IOM) c/o International School for Advanced Studies (SISSA), via Bonomea 265, 34136, Trieste, Italy
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8
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Perkal O, Qasem Z, Turgeman M, Schwartz R, Gevorkyan-Airapetov L, Pavlin M, Magistrato A, Major DT, Ruthstein S. Cu(I) Controls Conformational States in Human Atox1 Metallochaperone: An EPR and Multiscale Simulation Study. J Phys Chem B 2020; 124:4399-4411. [PMID: 32396355 PMCID: PMC7294806 DOI: 10.1021/acs.jpcb.0c01744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
![]()
Atox1 is a human
copper metallochaperone that is responsible for
transferring copper ions from the main human copper transporter, hCtr1,
to ATP7A/B in the Golgi apparatus. Atox1 interacts with the Ctr1 C-terminal
domain as a dimer, although it transfers the copper ions to ATP7A/B
in a monomeric form. The copper binding site in the Atox1 dimer involves
Cys12 and Cys15, while Lys60 was also suggested to play a role in
the copper binding. We recently showed that Atox1 can adopt various
conformational states, depending on the interacting protein. In the
current study, we apply EPR experiments together with hybrid quantum
mechanics–molecular mechanics molecular dynamics simulations
using a recently developed semiempirical density functional theory
approach, to better understand the effect of Atox1’s conformational
states on copper coordination. We propose that the flexibility of
Atox1 occurs owing to protonation of one or more of the cysteine residues,
and that Cys15 is an important residue for Atox1 dimerization, while
Cys12 is a critical residue for Cu(I) binding. We also show that Lys60
electrostatically stabilizes the Cu(I)–Atox1 dimer.
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Affiliation(s)
- Ortal Perkal
- Department of Chemistry and Institute for Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Zena Qasem
- Department of Chemistry, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Meital Turgeman
- Department of Chemistry, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Renana Schwartz
- Department of Chemistry and Institute for Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Lada Gevorkyan-Airapetov
- Department of Chemistry, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Matic Pavlin
- CNR-IOM at SISSA, via Bonomea 265, 34135, Trieste, Italy
| | | | - Dan Thomas Major
- Department of Chemistry and Institute for Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Sharon Ruthstein
- Department of Chemistry, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
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9
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Bogetti X, Ghosh S, Gamble Jarvi A, Wang J, Saxena S. Molecular Dynamics Simulations Based on Newly Developed Force Field Parameters for Cu 2+ Spin Labels Provide Insights into Double-Histidine-Based Double Electron-Electron Resonance. J Phys Chem B 2020; 124:2788-2797. [PMID: 32181671 DOI: 10.1021/acs.jpcb.0c00739] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Electron paramagnetic resonance (EPR) in combination with the recently developed double-histidine (dHis)-based Cu2+ spin labeling has provided valuable insights into protein structure and conformational dynamics. To relate sparse distance constraints measured by EPR to protein fluctuations in solution, modeling techniques are needed. In this work, we have developed force field parameters for Cu2+-nitrilotriacetic and Cu2+-iminodiacetic acid spin labels. We employed molecular dynamics (MD) simulations to capture the atomic-level details of dHis-labeled protein fluctuations. The interspin distances extracted from 200 ns MD trajectories show good agreement with the experimental results. The MD simulations also illustrate the dramatic rigidity of the Cu2+ labels compared to the standard nitroxide spin label. Further, the relative orientations between spin-labeled sites were measured to provide insight into the use of double electron-electron resonance (DEER) methods for such labels. The relative mean angles, as well as the standard deviations of the relative angles, agree well in general with the spectral simulations published previously. The fluctuations of relative orientations help rationalize why orientation selectivity effects are minimal at X-band frequencies, but observable at the Q-band for such labels. In summary, the results show that by combining the experimental results with MD simulations precise information about protein conformations as well as flexibility can be obtained.
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Affiliation(s)
- Xiaowei Bogetti
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Shreya Ghosh
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Austin Gamble Jarvi
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Junmei Wang
- Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15206, United States
| | - Sunil Saxena
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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10
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Pavlin M, Qasem Z, Sameach H, Gevorkyan-Airapetov L, Ritacco I, Ruthstein S, Magistrato A. Unraveling the Impact of Cysteine-to-Serine Mutations on the Structural and Functional Properties of Cu(I)-Binding Proteins. Int J Mol Sci 2019; 20:E3462. [PMID: 31337158 PMCID: PMC6679193 DOI: 10.3390/ijms20143462] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/09/2019] [Accepted: 07/11/2019] [Indexed: 02/03/2023] Open
Abstract
Appropriate maintenance of Cu(I) homeostasis is an essential requirement for proper cell function because its misregulation induces the onset of major human diseases and mortality. For this reason, several research efforts have been devoted to dissecting the inner working mechanism of Cu(I)-binding proteins and transporters. A commonly adopted strategy relies on mutations of cysteine residues, for which Cu(I) has an exquisite complementarity, to serines. Nevertheless, in spite of the similarity between these two amino acids, the structural and functional impact of serine mutations on Cu(I)-binding biomolecules remains unclear. Here, we applied various biochemical and biophysical methods, together with all-atom simulations, to investigate the effect of these mutations on the stability, structure, and aggregation propensity of Cu(I)-binding proteins, as well as their interaction with specific partner proteins. Among Cu(I)-binding biomolecules, we focused on the eukaryotic Atox1-ATP7B system, and the prokaryotic CueR metalloregulator. Our results reveal that proteins containing cysteine-to-serine mutations can still bind Cu(I) ions; however, this alters their stability and aggregation propensity. These results contribute to deciphering the critical biological principles underlying the regulatory mechanism of the in-cell Cu(I) concentration, and provide a basis for interpreting future studies that will take advantage of cysteine-to-serine mutations in Cu(I)-binding systems.
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Affiliation(s)
- Matic Pavlin
- CNR-IOM at SISSA, via Bonomea 265, 34135 Trieste, Italy
| | - Zena Qasem
- Department of Chemistry, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Hila Sameach
- Department of Chemistry, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Lada Gevorkyan-Airapetov
- Department of Chemistry, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Ida Ritacco
- CNR-IOM at SISSA, via Bonomea 265, 34135 Trieste, Italy
| | - Sharon Ruthstein
- Department of Chemistry, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel.
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11
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Strodel B, Coskuner-Weber O. Transition Metal Ion Interactions with Disordered Amyloid-β Peptides in the Pathogenesis of Alzheimer's Disease: Insights from Computational Chemistry Studies. J Chem Inf Model 2019; 59:1782-1805. [PMID: 30933519 DOI: 10.1021/acs.jcim.8b00983] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Monomers and oligomers of the amyloid-β peptide aggregate to form the fibrils found in the brains of Alzheimer's disease patients. These monomers and oligomers are largely disordered and can interact with transition metal ions, affecting the mechanism and kinetics of amyloid-β aggregation. Due to the disordered nature of amyloid-β, its rapid aggregation, as well as solvent and paramagnetic effects, experimental studies face challenges in the characterization of transition metal ions bound to amyloid-β monomers and oligomers. The details of the coordination chemistry between transition metals and amyloid-β obtained from experiments remain debated. Furthermore, the impact of transition metal ion binding on the monomeric or oligomeric amyloid-β structures and dynamics are still poorly understood. Computational chemistry studies can serve as an important complement to experimental studies and can provide additional knowledge on the binding between amyloid-β and transition metal ions. Many research groups conducted first-principles calculations, ab initio molecular dynamics simulations, quantum mechanics/classical mechanics simulations, and classical molecular dynamics simulations for studying the interplay between transition metal ions and amyloid-β monomers and oligomers. This review summarizes the current understanding of transition metal interactions with amyloid-β obtained from computational chemistry studies. We also emphasize the current view of the coordination chemistry between transition metal ions and amyloid-β. This information represents an important foundation for future metal ion chelator and drug design studies aiming to combat Alzheimer's disease.
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Affiliation(s)
- Birgit Strodel
- Institute of Complex Systems: Structural Biochemistry (ICS-6) , Forschungszentrum Jülich GmbH , Jülich 52425 , Germany.,Institute of Theoretical and Computational Chemistry , Heinrich Heine University Düsseldorf , Universitätstrasse 1 , Düsseldorf 40225 , Germany
| | - Orkid Coskuner-Weber
- Molecular Biotechnology , Turkish-German University , Sahinkaya Caddesi, No. 86, Beykoz , Istanbul 34820 , Turkey
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12
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Qasem Z, Pavlin M, Ritacco I, Gevorkyan-Airapetov L, Magistrato A, Ruthstein S. The pivotal role of MBD4–ATP7B in the human Cu(i) excretion path as revealed by EPR experiments and all-atom simulations. Metallomics 2019; 11:1288-1297. [DOI: 10.1039/c9mt00067d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Atox1–MBD4 interaction mediates the in-cell Cu(i) concentration.
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Affiliation(s)
- Zena Qasem
- Chemistry Department
- Faculty of Exact Sciences
- Bar-Ilan University
- Israel
| | | | | | | | | | - Sharon Ruthstein
- Chemistry Department
- Faculty of Exact Sciences
- Bar-Ilan University
- Israel
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13
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Trapping intermediates in metal transfer reactions of the CusCBAF export pump of Escherichia coli. Commun Biol 2018; 1:192. [PMID: 30456313 PMCID: PMC6235853 DOI: 10.1038/s42003-018-0181-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/13/2018] [Indexed: 12/20/2022] Open
Abstract
Escherichia coli CusCBAF represents an important class of bacterial efflux pump exhibiting selectivity towards Cu(I) and Ag(I). The complex is comprised of three proteins: the CusA transmembrane pump, the CusB soluble adaptor protein, and the CusC outer-membrane pore, and additionally requires the periplasmic metallochaperone CusF. Here we used spectroscopic and kinetic tools to probe the mechanism of copper transfer between CusF and CusB using selenomethionine labeling of the metal-binding Met residues coupled to RFQ-XAS at the Se and Cu edges. The results indicate fast formation of a protein-protein complex followed by slower intra-complex metal transfer. An intermediate coordinated by ligands from each protein forms in 100 ms. Stopped-flow fluorescence of the capping CusF-W44 tryptophan that is quenched by metal transfer also supports this mechanism. The rate constants validate a process in which shared-ligand complex formation assists protein association, providing a driving force that raises the rate into the diffusion-limited regime.
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14
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Shenberger Y, Marciano O, Gottlieb HE, Ruthstein S. Insights into the N-terminal Cu(II) and Cu(I) binding sites of the human copper transporter CTR1. J COORD CHEM 2018. [DOI: 10.1080/00958972.2018.1492717] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Yulia Shenberger
- The Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Ortal Marciano
- The Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Hugo E. Gottlieb
- The Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Sharon Ruthstein
- The Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan, Israel
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15
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Abstract
Metal ions play significant roles in numerous fields including chemistry, geochemistry, biochemistry, and materials science. With computational tools increasingly becoming important in chemical research, methods have emerged to effectively face the challenge of modeling metal ions in the gas, aqueous, and solid phases. Herein, we review both quantum and classical modeling strategies for metal ion-containing systems that have been developed over the past few decades. This Review focuses on classical metal ion modeling based on unpolarized models (including the nonbonded, bonded, cationic dummy atom, and combined models), polarizable models (e.g., the fluctuating charge, Drude oscillator, and the induced dipole models), the angular overlap model, and valence bond-based models. Quantum mechanical studies of metal ion-containing systems at the semiempirical, ab initio, and density functional levels of theory are reviewed as well with a particular focus on how these methods inform classical modeling efforts. Finally, conclusions and future prospects and directions are offered that will further enhance the classical modeling of metal ion-containing systems.
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Affiliation(s)
| | - Kenneth M. Merz
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute of Cyber-Enabled Research, Michigan State University, East Lansing, Michigan 48824, United States
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16
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Chakravorty DK, Li P, Tran TT, Bayse CA, Merz KM. Metal Ion Capture Mechanism of a Copper Metallochaperone. Biochemistry 2016; 55:501-9. [DOI: 10.1021/acs.biochem.5b01217] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dhruva K. Chakravorty
- Institute
for Cyber Enabled Research, Michigan State University, 567 Wilson
Road, East Lansing, Michigan 48824, United States
- Department
of Chemistry, University of New Orleans, 2000 Lakeshore Drive, New Orleans, Louisiana 70148, United States
- Department
of Chemistry and Quantum Theory Project, University of Florida, Gainesville, Florida 32611-8435, United States
- Department
of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Pengfei Li
- Department
of Chemistry and Quantum Theory Project, University of Florida, Gainesville, Florida 32611-8435, United States
- Department
of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Trang T. Tran
- Department
of Chemistry, University of New Orleans, 2000 Lakeshore Drive, New Orleans, Louisiana 70148, United States
| | - Craig A. Bayse
- Department of Chemistry & Biochemistry, Old Dominion University, Norfolk, Virginia 23529, United States
| | - Kenneth M. Merz
- Institute
for Cyber Enabled Research, Michigan State University, 567 Wilson
Road, East Lansing, Michigan 48824, United States
- Department
of Chemistry and Quantum Theory Project, University of Florida, Gainesville, Florida 32611-8435, United States
- Department
of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
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17
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Borisova AS, Isaksen T, Dimarogona M, Kognole AA, Mathiesen G, Várnai A, Røhr ÅK, Payne CM, Sørlie M, Sandgren M, Eijsink VGH. Structural and Functional Characterization of a Lytic Polysaccharide Monooxygenase with Broad Substrate Specificity. J Biol Chem 2015; 290:22955-69. [PMID: 26178376 DOI: 10.1074/jbc.m115.660183] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Indexed: 01/02/2023] Open
Abstract
The recently discovered lytic polysaccharide monooxygenases (LPMOs) carry out oxidative cleavage of polysaccharides and are of major importance for efficient processing of biomass. NcLPMO9C from Neurospora crassa acts both on cellulose and on non-cellulose β-glucans, including cellodextrins and xyloglucan. The crystal structure of the catalytic domain of NcLPMO9C revealed an extended, highly polar substrate-binding surface well suited to interact with a variety of sugar substrates. The ability of NcLPMO9C to act on soluble substrates was exploited to study enzyme-substrate interactions. EPR studies demonstrated that the Cu(2+) center environment is altered upon substrate binding, whereas isothermal titration calorimetry studies revealed binding affinities in the low micromolar range for polymeric substrates that are due in part to the presence of a carbohydrate-binding module (CBM1). Importantly, the novel structure of NcLPMO9C enabled a comparative study, revealing that the oxidative regioselectivity of LPMO9s (C1, C4, or both) correlates with distinct structural features of the copper coordination sphere. In strictly C1-oxidizing LPMO9s, access to the solvent-facing axial coordination position is restricted by a conserved tyrosine residue, whereas access to this same position seems unrestricted in C4-oxidizing LPMO9s. LPMO9s known to produce a mixture of C1- and C4-oxidized products show an intermediate situation.
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Affiliation(s)
- Anna S Borisova
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
| | - Trine Isaksen
- the Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Maria Dimarogona
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden
| | - Abhishek A Kognole
- the Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506
| | - Geir Mathiesen
- the Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Anikó Várnai
- the Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Åsmund K Røhr
- the Department of Biosciences, University of Oslo, N-0316 Oslo, Norway, and
| | - Christina M Payne
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden, the Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506
| | - Morten Sørlie
- the Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Mats Sandgren
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden,
| | - Vincent G H Eijsink
- the Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway,
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18
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Vrontaki E, Leonis G, Avramopoulos A, Papadopoulos MG, Simčič M, Grdadolnik SG, Afantitis A, Melagraki G, Hadjikakou SK, Mavromoustakos T. Stability and binding effects of silver(I) complexes at lipoxygenase-1. J Enzyme Inhib Med Chem 2014; 30:539-49. [DOI: 10.3109/14756366.2014.951348] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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19
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Wise O, Coskuner O. New force field parameters for metalloproteins I: Divalent copper ion centers including three histidine residues and an oxygen-ligated amino acid residue. J Comput Chem 2014; 35:1278-89. [DOI: 10.1002/jcc.23622] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 02/06/2014] [Accepted: 03/23/2014] [Indexed: 01/04/2023]
Affiliation(s)
- Olivia Wise
- Department of Chemistry; The University of Texas at San Antonio, One UTSA Circle; San Antonio Texas 78249
- Neurosciences Institute; The University of Texas at San Antonio, One UTSA Circle; San Antonio Texas 78249
| | - Orkid Coskuner
- Department of Chemistry; The University of Texas at San Antonio, One UTSA Circle; San Antonio Texas 78249
- Neurosciences Institute; The University of Texas at San Antonio, One UTSA Circle; San Antonio Texas 78249
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20
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Pitts AL, Hall MB. Investigating the Electronic Structure of the Atox1 Copper(I) Transfer Mechanism with Density Functional Theory. Inorg Chem 2013; 52:10387-93. [DOI: 10.1021/ic401106z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Amanda L. Pitts
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
| | - Michael B. Hall
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
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21
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Ansbacher T, Chourasia M, Shurki A. Copper-chaperones with dicoordinated Cu(I)-Unique protection mechanism. Proteins 2013; 81:1411-9. [DOI: 10.1002/prot.24291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 03/04/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Tamar Ansbacher
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Lise-Meitner Minerva Center for Computational Quantum Chemistry; The Hebrew University of Jerusalem; Jerusalem; 91120; Israel
| | - Mukesh Chourasia
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Lise-Meitner Minerva Center for Computational Quantum Chemistry; The Hebrew University of Jerusalem; Jerusalem; 91120; Israel
| | - Avital Shurki
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Lise-Meitner Minerva Center for Computational Quantum Chemistry; The Hebrew University of Jerusalem; Jerusalem; 91120; Israel
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22
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Vrontaki E, Leonis G, Papadopoulos MG, Simcic M, Grdadolnik SG, Afantitis A, Melagraki G, Hadjikakou SK, Mavromoustakos T. Comparative Binding Effects of Aspirin and Anti-Inflammatory Cu Complex in the Active Site of LOX-1. J Chem Inf Model 2012; 52:3293-301. [DOI: 10.1021/ci3002759] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- E. Vrontaki
- Organic Chemistry Laboratory,
Department of Chemistry, University of Athens, Panepistimiopolis-Zografou,
15771 Athens, Greece
| | - G. Leonis
- Institute
of Biology, Medicinal
Chemistry and Biotechnology, National Hellenic Research Foundation,
Vas. Constantinou 48, Athens 11635, Greece
| | - M. G. Papadopoulos
- Institute
of Biology, Medicinal
Chemistry and Biotechnology, National Hellenic Research Foundation,
Vas. Constantinou 48, Athens 11635, Greece
| | - M. Simcic
- EN-FIST Centre of Excellence,
Dunajska 156, SI-1000 Ljubljana, Slovenia
| | - S. Golic Grdadolnik
- EN-FIST Centre of Excellence,
Dunajska 156, SI-1000 Ljubljana, Slovenia
- Laboratory of Biomolecular Structure,
National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana,
Slovenia
| | - A. Afantitis
- Department of
Chemoinformatics,
NovaMechanics Ltd, Nicosia, Cyprus
| | - G. Melagraki
- Department of
Chemoinformatics,
NovaMechanics Ltd, Nicosia, Cyprus
| | - S. K. Hadjikakou
- Section of Inorganic and Analytical
Chemistry, Department of Chemistry, University of Ioannina, 45110
Ioannina, Greece
| | - T. Mavromoustakos
- Organic Chemistry Laboratory,
Department of Chemistry, University of Athens, Panepistimiopolis-Zografou,
15771 Athens, Greece
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23
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Arumugam K, Crouzy S. Dynamics and Stability of the Metal Binding Domains of the Menkes ATPase and Their Interaction with Metallochaperone HAH1. Biochemistry 2012; 51:8885-906. [DOI: 10.1021/bi300669e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Karthik Arumugam
- Commissariat
à l’Energie Atomique/CNRS/Université Joseph Fourier,
CEA, iRTSV, LCBM, 38054 Grenoble, France
| | - Serge Crouzy
- Laboratoire de Chimie et Biologie des Métaux,
CEA, iRTSV, LCBM, Commissariat à l’Energie Atomique/CNRS/Université
Joseph Fourier, UMR 5249, 17 rue des martyrs, 38054 Grenoble Cedex
09, France
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24
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Ansbacher T, Shurki A. Predicting the coordination number within copper chaperones: Atox1 as case study. J Phys Chem B 2012; 116:4425-32. [PMID: 22480337 DOI: 10.1021/jp210678n] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The concentration of copper ions in biological systems is tightly regulated by metallochaperone proteins which are responsible for Cu(I) delivery to designated locations in the cell. These proteins contain a unique motif (MXCXXC) that binds Cu(I) very tightly and specifically but at the same time allows efficient metal transfer to target proteins that often contain a similar copper binding motif. It was found that binding to Cu(I) is achieved through the two cysteine residues in a low coordination number of 2-3 due to possible binding of a third external ligand. Understanding copper transport requires better understanding of copper coordination. Here we therefore focused on establishing a computational method that can predict the coordination number of copper in copper chaperones. The method is shown to be successful in predicting the coordination of Cu(I) within the human copper chaperone (Atox1). Based on the results, a possible rationale for this unique Cu(I) dicoordination in Atox1 is suggested.
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Affiliation(s)
- Tamar Ansbacher
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
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25
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Pushie MJ, Zhang L, Pickering IJ, George GN. The fictile coordination chemistry of cuprous-thiolate sites in copper chaperones. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:938-47. [PMID: 22056518 DOI: 10.1016/j.bbabio.2011.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/06/2011] [Accepted: 10/14/2011] [Indexed: 02/03/2023]
Abstract
Copper plays vital roles in the active sites of cytochrome oxidase and in several other enzymes essential for human health. Copper is also highly toxic when dysregulated; because of this an elaborate array of accessory proteins have evolved which act as intracellular carriers or chaperones for the copper ions. In most cases chaperones transport cuprous copper. This review discusses some of the chemistry of these copper sites, with a view to some of the structural factors in copper coordination which are important in the biological function of these chaperones. The coordination chemistry and accessible geometries of the cuprous oxidation state are remarkably plastic and we discuss how this may relate to biological function. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes.
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Affiliation(s)
- M Jake Pushie
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada S7N5E2
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26
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In silico modeling of the Menkes copper-translocating P-type ATPase 3rd metal binding domain predicts that phosphorylation regulates copper-binding. Biometals 2011; 24:477-87. [DOI: 10.1007/s10534-011-9410-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 01/06/2011] [Indexed: 12/17/2022]
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27
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Rodriguez-Granillo A, Crespo A, Estrin DA, Wittung-Stafshede P. Copper-transfer mechanism from the human chaperone Atox1 to a metal-binding domain of Wilson disease protein. J Phys Chem B 2010; 114:3698-706. [PMID: 20166696 DOI: 10.1021/jp911208z] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The molecular details of how copper (Cu) is transferred from the human Cu chaperone Atox1 to metal-binding domains (MBDs) of P(1B)-type ATPases are still unclear. Here, we use a computational approach, employing quantum mechanics/molecular mechanics (QM/MM) methods, to shed light on the reaction mechanism [probable intermediates, Cu(I) coordination geometries, activation barriers, and energetics] of Cu(I) transfer from Atox1 to the fourth MBD of Wilson disease protein (WD4). Both Atox1 and WD4 have solvent-exposed metal-binding motifs with two Cys residues that coordinate Cu(I). After assessing the existence of all possible 2-, 3- and 4-coordinate Cu-intermediate species, one dominant reaction path emerged. First, without activation barrier, WD4's Cys1 binds Cu(I) in Atox1 to form a 3-coordinated intermediate. Next, with an activation barrier of about 9.5 kcal/mol, a second 3-coordinated intermediate forms that involves both of the Cys residues in WD4 and Cys1 of Atox1. This species can then form the product by decoordination of Atox1's Cys1 (barrier of about 8 kcal/mol). Overall, the Cu-transfer reaction from Atox1 to WD4 appears to be kinetically accessible but less energetically favorable (DeltaE = 7.7 kcal/mol). Our results provide unique insights into the molecular mechanism of protein-mediated Cu(I) transfer in the secretory pathway and are in agreement with existing experimental data.
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28
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Sousa SF, Carvalho ES, Ferreira DM, Tavares IS, Fernandes PA, Ramos MJ, Gomes JANF. Comparative analysis of the performance of commonly available density functionals in the determination of geometrical parameters for zinc complexes. J Comput Chem 2010; 30:2752-63. [PMID: 19399915 DOI: 10.1002/jcc.21304] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A set of 44 Zinc-ligand bond-lengths and of 60 ligand-metal-ligand bond angles from 10 diverse transition-metal complexes, representative of the coordination spheres of typical biological Zn systems, were used to evaluate the performance of a total of 18 commonly available density functionals in geometry determination. Five different basis sets were considered for each density functional, namely two all-electron basis sets (a double-zeta and triple-zeta formulation) and three basis sets including popular types of effective-core potentials: Los Alamos, Steven-Basch-Krauss, and Stuttgart-Dresden. The results show that there are presently several better alternatives to the popular B3LYP density functional for the determination of Zn-ligand bond-lengths and angles. BB1K, MPWB1K, MPW1K, B97-2 and TPSS are suggested as the strongest alternatives for this effect presently available in most computational chemistry software packages. In addition, the results show that the use of effective-core potentials (in particular Stuttgart-Dresden) has a very limited impact, in terms of accuracy, in the determination of metal-ligand bond-lengths and angles in Zinc-complexes, and is a good and safe alternative to the use of an all-electron basis set such as 6-31G(d) or 6-311G(d,p).
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Affiliation(s)
- Sérgio F Sousa
- REQUIMTE, Departamento de Química, Faculdade de Ciõncias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
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29
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Kouza M, Gowtham S, Seel M, Hansmann UHE. A numerical investigation into possible mechanisms by that the A629P mutant of ATP7A causes Menkes Disease. Phys Chem Chem Phys 2010; 12:11390-7. [DOI: 10.1039/c003568h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Barry AN, Shinde U, Lutsenko S. Structural organization of human Cu-transporting ATPases: learning from building blocks. J Biol Inorg Chem 2009; 15:47-59. [PMID: 19851794 DOI: 10.1007/s00775-009-0595-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 09/28/2009] [Indexed: 12/29/2022]
Abstract
Copper-transporting ATPases (Cu-ATPases) ATP7A and ATP7B play an essential role in human physiological function. Their primary function is to deliver copper to the secretory pathway and export excess copper from the cell for removal or further utilization. Cells employ Cu-ATPases in numerous physiological processes that include the biosynthesis of copper-dependent enzymes, lactation, and response to hypoxia. Biochemical studies of human Cu-ATPases and their orthologs have demonstrated that Cu-ATPases share many common structural and mechanistic characteristics with other members of the P-type ATPase family. Nevertheless, the Cu-ATPases have a unique coordinate environment for their ligands, copper and ATP, and additional domains that are required for sophisticated regulation of their intracellular localization and activity. Here, we review recent progress that has been made in understanding the structure of Cu-ATPases from the analysis of their individual domains and orthologs from microorganisms, and speculate about the implications of these findings for the function and regulation of human copper pumps.
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Affiliation(s)
- Amanda N Barry
- Department of Physiology, Johns Hopkins University, Baltimore, MD 21205, USA
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31
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Rodriguez-Granillo A, Crespo A, Wittung-Stafshede P. Conformational Dynamics of Metal-Binding Domains in Wilson Disease Protein: Molecular Insights into Selective Copper Transfer. Biochemistry 2009; 48:5849-63. [DOI: 10.1021/bi900235g] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | - Alejandro Crespo
- Department of Bioengineering, Rice University, Houston, 77005 Texas
| | - Pernilla Wittung-Stafshede
- Department of Biochemistry and Cell Biology, Rice University, Houston, 77251 Texas
- Department of Chemistry, Umeå University, 901 87 Umeå, Sweden
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32
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33
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Rodriguez-Granillo A, Wittung-Stafshede P. Structure and dynamics of Cu(I) binding in copper chaperones Atox1 and CopZ: a computer simulation study. J Phys Chem B 2008; 112:4583-93. [PMID: 18361527 DOI: 10.1021/jp711787x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Copper chaperones deliver reduced copper (i.e., Cu(I)) to metal-binding domains of P-type ATPases in the cytoplasm of a range of organisms. Both chaperones and target domains have a ferredoxin-like fold and metal-binding motifs involving two Cys residues. Here, we investigated the Cu-binding geometry and structural dynamics of two homologous Cu(I) chaperones, Homo sapiens Atox1 and Bacillus subtilis CopZ, using a combination of quantum mechanical-molecular mechanics (QM-MM) and classical molecular dynamics (MD) methods. Our QM-MM optimized geometries for the holo- proteins suggested that Cu(I) in Atox1 favors a linear Cys(S)-Cu-Cys(S) arrangement but that this angle is close to 150 degrees in CopZ. Classical MD simulations suggest that both Atox1 and CopZ apo- forms have an increased conformational flexibility as compared to the respective holo- forms. This difference is most pronounced in CopZ and correlates with a lower in vitro thermal stability. Both average fluctuation (i.e., rmsd) and radius of gyration data demonstrate that the effects of Cu(I) coordination extend throughout the proteins. Distinct deviations between the two homologues were found in protein-solvent interactions, entropy of Cu(I) binding, and apo-protein Cys-Cys distance distributions. Our in silico results provide new insights into copper chaperone behavior with direct implications for copper transport mechanisms in vivo.
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