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Smethurst DGJ, Shcherbik N. Interchangeable utilization of metals: New perspectives on the impacts of metal ions employed in ancient and extant biomolecules. J Biol Chem 2021; 297:101374. [PMID: 34732319 PMCID: PMC8633580 DOI: 10.1016/j.jbc.2021.101374] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 02/08/2023] Open
Abstract
Metal ions provide considerable functionality across biological systems, and their utilization within biomolecules has adapted through changes in the chemical environment to maintain the activity they facilitate. While ancient earth's atmosphere was rich in iron and manganese and low in oxygen, periods of atmospheric oxygenation significantly altered the availability of certain metal ions, resulting in ion replacement within biomolecules. This adaptation mechanism has given rise to the phenomenon of metal cofactor interchangeability, whereby contemporary proteins and nucleic acids interact with multiple metal ions interchangeably, with different coordinated metals influencing biological activity, stability, and toxic potential. The ability of extant organisms to adapt to fluctuating metal availability remains relevant in a number of crucial biomolecules, including the superoxide dismutases of the antioxidant defense systems and ribonucleotide reductases. These well-studied and ancient enzymes illustrate the potential for metal interchangeability and adaptive utilization. More recently, the ribosome has also been demonstrated to exhibit interchangeable interactions with metal ions with impacts on function, stability, and stress adaptation. Using these and other examples, here we review the biological significance of interchangeable metal ions from a new angle that combines both biochemical and evolutionary viewpoints. The geochemical pressures and chemical properties that underlie biological metal utilization are discussed in the context of their impact on modern disease states and treatments.
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Affiliation(s)
- Daniel G J Smethurst
- Department for Cell Biology and Neuroscience, School of Osteopathic Medicine, Rowan University, Stratford, New Jersey, USA.
| | - Natalia Shcherbik
- Department for Cell Biology and Neuroscience, School of Osteopathic Medicine, Rowan University, Stratford, New Jersey, USA.
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2
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Bonetta R, Hunter GJ, Trinh CH, Borowski T, Fenech AG, Kulp M, Tabares LC, Un S, Hunter T. Substitution of histidine 30 by asparagine in manganese superoxide dismutase alters biophysical properties and supports proliferation in a K562 leukemia cell line. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2021; 50:571-585. [PMID: 34021366 PMCID: PMC8190026 DOI: 10.1007/s00249-021-01544-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 02/07/2023]
Abstract
We have generated a mutant of C. elegans manganese superoxide dismutase at histidine 30 by site-directed mutagenesis. The structure was solved at a resolution of 1.52 Å by X-ray crystallography (pdb: 6S0D). His30 was targeted, as it forms as a gateway residue at the top of the solvent access funnel to the active site, together with Tyr34. In the wild-type protein, these gateway residues are involved in the hydrogen-bonding network providing the protons necessary for the catalytic reaction at the metal center. However, biophysical characterization and cell viability experiments reveal that a mutation from histidine to asparagine in the H30N mutant modifies metal selectivity in the protein, favoring the uptake of iron over manganese in minimal media conditions, alters active-site coordination from the characteristic trigonal bipyramidal to octahedral geometry, and encourages cellular proliferation in K562 cells, when added exogenously to the cells.
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Affiliation(s)
- Rosalin Bonetta
- Centre of Molecular Medicine & Biobanking, University of Malta, Msida, Malta. .,Barts and the London, School of Medicine and Dentistry, QMUL, Victoria, Malta.
| | - Gary J Hunter
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Chi H Trinh
- Astbury Centre for Structural Molecular Biology, Institute of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Tomasz Borowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Krakow, Poland
| | - Anthony G Fenech
- Department of Clinical Pharmacology and Therapeutics, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Maria Kulp
- Department of Chemistry, Tallinn University of Technology, Tallinn, Estonia
| | - Leandro C Tabares
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198, Gif-sur-Yvette, France
| | - Sun Un
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198, Gif-sur-Yvette, France
| | - Thérèse Hunter
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
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3
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An evolutionary path to altered cofactor specificity in a metalloenzyme. Nat Commun 2020; 11:2738. [PMID: 32483131 PMCID: PMC7264356 DOI: 10.1038/s41467-020-16478-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 04/29/2020] [Indexed: 11/28/2022] Open
Abstract
Almost half of all enzymes utilize a metal cofactor. However, the features that dictate the metal utilized by metalloenzymes are poorly understood, limiting our ability to manipulate these enzymes for industrial and health-associated applications. The ubiquitous iron/manganese superoxide dismutase (SOD) family exemplifies this deficit, as the specific metal used by any family member cannot be predicted. Biochemical, structural and paramagnetic analysis of two evolutionarily related SODs with different metal specificity produced by the pathogenic bacterium Staphylococcus aureus identifies two positions that control metal specificity. These residues make no direct contacts with the metal-coordinating ligands but control the metal’s redox properties, demonstrating that subtle architectural changes can dramatically alter metal utilization. Introducing these mutations into S. aureus alters the ability of the bacterium to resist superoxide stress when metal starved by the host, revealing that small changes in metal-dependent activity can drive the evolution of metalloenzymes with new cofactor specificity. Many metalloenzymes are highly specific for their cognate metal ion but the molecular principles underlying this specificity often remain unclear. Here, the authors characterize the structural and biochemical basis for the different metal specificity of two evolutionarily related superoxide dismutases.
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4
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Banerjee A, Tolla AS, Stjepanovic S, Sevilla MD, Goodsell JL, Angerhofer A, Brennessel WW, Loloee R, Chavez FA. Structural, Spectroscopic, Electrochemical, and Magnetic Properties for Manganese(II) Triazamacrocyclic Complexes. Inorganica Chim Acta 2019; 486:546-555. [PMID: 33981118 PMCID: PMC8112617 DOI: 10.1016/j.ica.2018.11.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report the synthesis of [Mn(tacud)2](OTf)2 (1) (tacud = 1,4,8-triazacycloundecane), [Mn(tacd)2](OTf)2 (2) (tacd = 1,4,7-triazacyclodecane), and [Mn(tacn)2](OTf)2 (3) (tacn = 1,4,7-triazacyclononane). Electrochemical measurements on the MnIII/II redox couple show that complex 1 has the largest anodic potential of the set (E 1/2 = 1.16 V vs NHE, ΔE p = 106 mV) compared to 2 (E 1/2 = 0.95 V, ΔE p = 108 mV) and 3 (E 1/2 = 0.93 V, ΔE p = 96 mV). This is due to the fact that 1 has the fewest 5-membered chelate rings and thus is least stabilized. Magnetic studies of 1-3 revealed that all complexes remain high spin throughout the temperature range investigated (2 - 300 K). X-band EPR investigations in methanol glass indicated that the manganese(II) centers for 2 and 3 resided in a more distorted octahedral geometric configuration compared to 1. To ease spectral interpretation and extract ZFS parameters, we performed high-frequency high-field EPR (HFEPR) at frequencies above 200 GHz and a field of 7.5 T. Simulation of the spectral data yielded g = 2.0013 and D = -0.031 cm-1 for 1, g = 2.0008, D = -0.0824 cm-1, |E/D| = 0.12 for 2, and g = 2.00028, D = -0.0884 cm-1 for 3. These results are consistent with 3 possessing the most distorted geometry. Calculations (PBE0/6-31G(d)) were performed on 1-3. Results show that 1 has the largest HOMO-LUMO gap energy (6.37 eV) compared to 2 (6.12 eV) and 3 (6.26 eV). Complex 1 also has the lowest HOMO energies indicating higher stability.
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Affiliation(s)
- Atanu Banerjee
- Department of Chemistry, Oakland University, Rochester, MI 48309-4477, USA
| | - Azam S Tolla
- Department of Chemistry, Oakland University, Rochester, MI 48309-4477, USA
| | | | - Michael D Sevilla
- Department of Chemistry, Oakland University, Rochester, MI 48309-4477, USA
| | - Justin L Goodsell
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
| | | | | | - Reza Loloee
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1322, USA
| | - Ferman A Chavez
- Department of Chemistry, Oakland University, Rochester, MI 48309-4477, USA
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5
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Barwinska-Sendra A, Baslé A, Waldron KJ, Un S. A charge polarization model for the metal-specific activity of superoxide dismutases. Phys Chem Chem Phys 2018; 20:2363-2372. [PMID: 29308487 PMCID: PMC5901066 DOI: 10.1039/c7cp06829h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The pathogenicity of Staphylococcus aureus is enhanced by having two superoxide dismutases (SODs): a Mn-specific SOD and another that can use either Mn or Fe. Using 94 GHz electron-nuclear double resonance (ENDOR) and electron double resonance detected (ELDOR)-NMR we show that, despite their different metal-specificities, their structural and electronic similarities extend down to their active-site 1H- and 14N-Mn(ii) hyperfine interactions. However these interactions, and hence the positions of these nuclei, are different in the inactive Mn-reconstituted Escherichia coli Fe-specific SOD. Density functional theory modelling attributes this to a different angular position of the E. coli H171 ligand. This likely disrupts the Mn-H171-E170' triad causing a shift in charge and in metal redox potential, leading to the loss of activity. This is supported by the correlated differences in the Mn(ii) zero-field interactions of the three SOD types and suggests that the triad is important for determining metal specific activity.
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Affiliation(s)
- Anna Barwinska-Sendra
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Arnaud Baslé
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Kevin J Waldron
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Sun Un
- Department of Biochemistry, Biophysics and Structural Biology, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS UMR 9198, CEA-Saclay, Gif-sur-Yvette, F-91198, France.
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6
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Corzilius B. Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids. Phys Chem Chem Phys 2016; 18:27190-27204. [DOI: 10.1039/c6cp04621e] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Detailed theoretical description of high-spin properties of metal polarizing agents, especially Gd3+, for solid effect and cross effect DNP.
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Affiliation(s)
- Björn Corzilius
- Institute of Physical and Theoretical Chemistry
- Institute of Biophysical Chemistry, and Center for Biomolecular Magnetic Resonance (BMRZ)
- Goethe University Frankfurt
- 60438 Frankfurt am Main
- Germany
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7
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Abstract
EPR spectroscopy combined with quantum chemistry for the investigation of the magnetic anisotropy of MnII, MnIII and MnIV.
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Affiliation(s)
- Carole Duboc
- University Grenoble-Alpes
- CNRS
- UMR 5250
- Département de Chimie Moléculaire
- 38041 Grenoble cedex 9
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8
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Bruch EM, de Groot A, Un S, Tabares LC. The effect of gamma-ray irradiation on the Mn(II) speciation in Deinococcus radiodurans and the potential role of Mn(II)-orthophosphates. Metallomics 2015; 7:908-16. [PMID: 25811292 DOI: 10.1039/c5mt00009b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
D. radiodurans accumulates large quantities of Mn(II), which is believed to form low molecular weight complexes with phosphate and metabolites that protect D. radiodurans from radiation damage. The concentration of Mn(II) species in D. radiodurans during the exponential and stationary phase was determined using high-field EPR and biochemical techniques. In the exponential growth phase cells a large fraction of the manganese was in the form of Mn(II)-orthophosphate complexes. By contrast, the intracellular concentration of these compounds in stationary phase cells was less than 16 μM, while that of Mn superoxide dismutase was 320 μM and that of another, yet unidentified, Mn(II) protein was 250 μM. Stationary cells were found to be equally resistant to irradiation as the exponential cells in spite of having significant lower Mn(II)-orthophosphate concentrations. Gamma irradiation induced no changes in the Mn(II) speciation. During stationary growth phase D. radiodurans favours the production of the two Mn-proteins over low molecular weight complexes suggesting that the latter were not essential for radio-resistance at this stage of growth.
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Affiliation(s)
- E M Bruch
- From the Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, 91191 Gif-sur-Yvette, France.
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Abstract
During the past decade isoindoline-based ligands became the subject of growing interest due to their modular set-up.
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Affiliation(s)
- Róbert Csonka
- Department of Chemistry
- University of Pannonia
- 8201 Veszprém
- Hungary
| | - Gábor Speier
- Department of Chemistry
- University of Pannonia
- 8201 Veszprém
- Hungary
| | - József Kaizer
- Department of Chemistry
- University of Pannonia
- 8201 Veszprém
- Hungary
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10
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Gaffney BJ. Connecting lipoxygenase function to structure by electron paramagnetic resonance. Acc Chem Res 2014; 47:3588-95. [PMID: 25341190 PMCID: PMC4270396 DOI: 10.1021/ar500290r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Indexed: 01/09/2023]
Abstract
CONSPECTUS: Lipoxygenase enzymes insert oxygen in a polyunsaturated lipid, yielding a hydroperoxide product. When the acyl chain is arachidonate, with three cis-pentadiene units, 12 positionally and stereochemically different products might result. The plant lipids, linoleate and linolenate, have, respectively, four and eight potential oxygen insertion sites. The puzzle of how specificity is achieved in these reactions grows as more and more protein structures confirm the conservation of a lipoxygenase protein fold in plants, animals, and bacteria. Lipoxygenases are large enough (60-100 kDa) that they provide a protein shell completely surrounding an active site cavity that has the shape of a long acyl chain and contains a catalytic metal (usually iron). This Account summarizes electron paramagnetic resonance (EPR) spectroscopic, and other, experiments designed to bridge the gap between lipid-lipoxygenase interactions in solution and crystal structures. Experiments with spin-labeled lipids give a picture of bound lipids tethered to protein by an acyl chain, but with a polar end emerging from the cavity to solvent exposure, where the headgroup is highly flexible. The location of a spin on the polar end of a lysolecithin was determined by pulsed, dipolar EPR measurements, by representing the protein structure as a five-point grid of spin-labels with coordinates derived from 10 distance determinations between spin pairs. Distances from the lipid spin to each grid site completed a six-point representation of the enzyme with a bound lipid. Insight into the dynamics that allow substrate/product to enter/exit the cavity was obtained with a different set of spin-labeled protein mutants. Once substrate enters the cavity, the rate-limiting step of catalysis involves redox cycling at the metal center. Here, a mononuclear iron cycles between ferric and ferrous (high-spin) forms. Two helices provide pairs of side-chain ligands to the iron, resulting in characteristic EPR signals. Quantitative comparison of EPR spectra of plant and bacterial lipoxygenases has suggested conservation of a unique geometry of lipoxygenase iron centers. High frequency (94 GHz) EPR is consistent with a similar metal center in a manganese version of lipoxygenase. Overall, established and emerging EPR experiments have been developed and applied to the lipoxygenase family of enzymes to elucidate changes in the solution structures that are related to function.
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Affiliation(s)
- Betty J. Gaffney
- Department
of Biological
Science, Florida State University, Tallahassee, Florida 32306-4295, United States
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11
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Bruch EM, Thomine S, Tabares LC, Un S. Variations in Mn(II) speciation among organisms: what makes D. radiodurans different. Metallomics 2014; 7:136-44. [PMID: 25407388 DOI: 10.1039/c4mt00265b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The manganese(II) speciation in intact cells of D. radiodurans, E. coli, S. cerevisiae and Arabidopsis thaliana seeds was measured using high-field electron paramagnetic resonance techniques. The majority of the Mn(II) ions in these organisms were six-coordinate, bound predominately by water, phosphates and nitrogen-based molecules. The relative distribution of the different phosphates in bacteria and S. cerevisiae was the same and dominated by monophosphate monoesters. Mn(II) was also found bound to the phosphate backbone of nucleic acids in these organisms. Phosphate ligation in Arabidopsis seeds was dominated by phytate. The extent of nitrogen ligation in the four organisms was also determined. On average, the Mn(II) in D. radiodurans had the most nitrogen ligands followed by E. coli. This was attributed to higher concentrations of Mn(II) bound to proteins in these species. Although constitutively expressed in all four organisms, MnSOD was only detected in D. radiodurans. As previously reported, D. radiodurans also accumulates a second abundant Mn containing protein species. The high concentration of proteinaceous Mn(II) is a unique feature of D. radiodurans.
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Affiliation(s)
- E M Bruch
- Service de Bioénergétique, Biologie Structurale et Mécanismes (CNRS UMR-8221), Institut de Biologie et de Technologies de Saclay, CEA-Saclay, F-91191 Gif-sur-Yvette, France.
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12
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Tufts AA, Flores M, Olson TL, Williams JC, Allen JP. Electronic structure of the Mn-cofactor of modified bacterial reaction centers measured by electron paramagnetic resonance and electron spin echo envelope modulation spectroscopies. PHOTOSYNTHESIS RESEARCH 2014; 120:207-220. [PMID: 23868400 DOI: 10.1007/s11120-013-9887-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 07/06/2013] [Indexed: 06/02/2023]
Abstract
The electronic structure of a Mn(II) ion bound to highly oxidizing reaction centers of Rhodobacter sphaeroides was studied in a mutant modified to possess a metal binding site at a location comparable to the Mn4Ca cluster of photosystem II. The Mn-binding site of the previously described mutant, M2, contains three carboxylates and one His at the binding site (Thielges et al., Biochemistry 44:389-7394, 2005). The redox-active Mn-cofactor was characterized using electron paramagnetic resonance (EPR) and electron spin echo envelope modulation (ESEEM) spectroscopies. In the light without bound metal, the Mn-binding mutants showed an EPR spectrum characteristic of the oxidized bacteriochlorophyll dimer and reduced quinone whose intensity was significantly reduced due to the diminished quantum yield of charge separation in the mutant compared to wild type. In the presence of the metal and in the dark, the EPR spectrum measured at the X-band frequency of 9.4 GHz showed a distinctive spin 5/2 Mn(II) signal consisting of 16 lines associated with both allowed and forbidden transitions. Upon illumination, the amplitude of the spectrum is decreased by over 80 % due to oxidation of the metal upon electron transfer to the oxidized bacteriochlorophyll dimer. The EPR spectrum of the Mn-cofactor was also measured at the Q-band frequency of 34 GHz and was better resolved as the signal was composed of the six allowed electronic transitions with only minor contributions from other transitions. A fit of the Q-band EPR spectrum shows that the Mn-cofactor is a high spin Mn(II) species (S = 5/2) that is six-coordinated with an isotropic g-value of 2.0006, a weak zero-field splitting and E/D ratio of approximately 1/3. The ESEEM experiments showed the presence of one (14)N coordinating the Mn-cofactor. The nitrogen atom is assigned to a His by comparing our ESEEM results to those previously reported for Mn(II) ions bound to other proteins and on the basis of the X-ray structure of the M2 mutant that shows the presence of only one His, residue M193, that can coordinate the Mn-cofactor. Together, the data allow the electronic structure and coordination environment of the designed Mn-cofactor in the modified reaction centers to be characterized in detail and compared to those observed in other proteins with Mn-cofactors.
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Affiliation(s)
- A A Tufts
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287-1604, USA
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Direct observation of structurally encoded metal discrimination and ether bond formation in a heterodinuclear metalloprotein. Proc Natl Acad Sci U S A 2013; 110:17189-94. [PMID: 24101498 DOI: 10.1073/pnas.1304368110] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Although metallocofactors are ubiquitous in enzyme catalysis, how metal binding specificity arises remains poorly understood, especially in the case of metals with similar primary ligand preferences such as manganese and iron. The biochemical selection of manganese over iron presents a particularly intricate problem because manganese is generally present in cells at a lower concentration than iron, while also having a lower predicted complex stability according to the Irving-Williams series (Mn(II) < Fe(II) < Ni(II) < Co(II) < Cu(II) > Zn(II)). Here we show that a heterodinuclear Mn/Fe cofactor with the same primary protein ligands in both metal sites self-assembles from Mn(II) and Fe(II) in vitro, thus diverging from the Irving-Williams series without requiring auxiliary factors such as metallochaperones. Crystallographic, spectroscopic, and computational data demonstrate that one of the two metal sites preferentially binds Fe(II) over Mn(II) as expected, whereas the other site is nonspecific, binding equal amounts of both metals in the absence of oxygen. Oxygen exposure results in further accumulation of the Mn/Fe cofactor, indicating that cofactor assembly is at least a two-step process governed by both the intrinsic metal specificity of the protein scaffold and additional effects exerted during oxygen binding or activation. We further show that the mixed-metal cofactor catalyzes a two-electron oxidation of the protein scaffold, yielding a tyrosine-valine ether cross-link. Theoretical modeling of the reaction by density functional theory suggests a multistep mechanism including a valyl radical intermediate.
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14
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Un S. Structure and nature of manganese(II) imidazole complexes in frozen aqueous solutions. Inorg Chem 2013; 52:3803-13. [PMID: 23510244 DOI: 10.1021/ic302415s] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A common feature of a large majority of the manganese metalloenzymes, as well as many synthetic biomimetic complexes, is the bonding between the manganese ion and imidazoles. This interaction was studied by examining the nature and structure of manganese(II) imidazole complexes in frozen aqueous solutions using 285 GHz high magnet-field continuous-wave electron paramagnetic resonance (cw-HFEPR) and 95 GHz pulsed electron-nuclear double resonance (ENDOR) and pulsed electron-double resonance detected nuclear magnetic resonance (PELDOR-NMR). The (55)Mn hyperfine coupling and isotropic g values of Mn(II) in frozen imidazole solutions continuously decreased with increasing imidazole concentration. ENDOR and PELDOR-NMR measurements demonstrated that the structural basis for this behavior arose from the imidazole concentration-dependent distribution of three six-coordinate and two four-coordinate species: [Mn(H2O)6](2+), [Mn(imidazole)(H2O)5](2+), [Mn(imidazole)2(H2O)4](2+), [Mn(imidazole)3(H2O)](2+), and [Mn(imidazole)4](2+). The hyperfine and g values of manganese proteins were also fully consistent with this imidazole effect. Density functional theory methods were used to calculate the structures, spin and charge densities, and hyperfine couplings of a number of different manganese imidazole complexes. The use of density functional theory with large exact-exchange admixture calculations gave isotropic (55)Mn hyperfine couplings that were semiquantitative and of predictive value. The results show that the covalency of the Mn-N bonds play an important role in determining not only magnetic spin parameters but also the structure of the metal binding site. The relationship between the isotropic (55)Mn hyperfine value and the number of imidazole ligands provides a quick and easy test for determining whether a protein binds an Mn(II) ion using histidine residues and, if so, how many are involved. Application of this method shows that as much as 40% of the Mn(II) ions in Deinococcus radiodurans are ligated to two histidines (Tabares, L. C.; Un, S. J. Biol. Chem 2013, in press).
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Affiliation(s)
- Sun Un
- Service de Bioénergétique, Biologie Structurale et Mécanismes (CNRS/UMR-8221), Institut de Biologie et de Technologies de Saclay, CEA-Saclay, 91191 Gif-sur-Yvette, France.
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15
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Tabares LC, Un S. In situ determination of manganese(II) speciation in Deinococcus radiodurans by high magnetic field EPR: detection of high levels of Mn(II) bound to proteins. J Biol Chem 2013; 288:5050-5. [PMID: 23303180 DOI: 10.1074/jbc.c112.444992] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
High magnetic field high frequency electron paramagnetic resonance techniques were used to measure in situ Mn(II) speciation in Deinococcus radiodurans, a radiation-resistant bacteria capable of accumulating high concentrations of Mn(II). It was possible to identify and quantify the evolution of Mn(II) species in intact cells at various stages of growth. Aside from water, 95-GHz high field electron nuclear double resonance showed that the Mn(II) ions are bound to histidines and phosphate groups, mostly from fructose-1,6-bisphosphate but also inorganic phosphates and nucleotides. During stationary growth phase, 285-GHz continuous wave EPR measurements showed that histidine is the most common ligand to Mn(II) and that significant amounts of cellular Mn(II) in D. radiodurans are bound to peptides and proteins. As much as 40% of the total Mn(II) was in manganese superoxide dismutase, and it is this protein and not smaller manganese complexes, as has been suggested recently, that is probably the primary defense against superoxide.
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Affiliation(s)
- Leandro C Tabares
- Service de Bioénergétique, Biologie Structurale et Mécanismes, CNRS/UMR-8221, Institut de Biologie et de Technologies de Saclay, Commissariat à l'Energie Atomique-Saclay, 91191 Gif-sur-Yvette, France.
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16
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Pap JS, Kripli B, Bors I, Bogáth D, Giorgi M, Kaizer J, Speier G. Transition metal complexes bearing flexible N₃ or N₃O donor ligands: reactivity toward superoxide radical anion and hydrogen peroxide. J Inorg Biochem 2012; 117:60-70. [PMID: 23078775 DOI: 10.1016/j.jinorgbio.2012.08.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 08/22/2012] [Accepted: 08/24/2012] [Indexed: 01/25/2023]
Abstract
Mononuclear complexes of N-methylpropanoate-N,N-bis-(2-pyridylmethyl)amine (MPBMPA) and N-propanoate-N,N-bis-(2-pyridylmethyl)amine (HPBMPA) with first row transition metals from Mn to Cu were synthesized and characterized by spectroscopy (infrared, UV-visible), electrochemistry (cyclic voltammetry), microanalysis and in four cases X-ray crystallography. Structure of the complexes revealed high flexibility of these ligands that can adopt facial (Fe) and meridional (Cu) geometry. Activity in the degradation of reactive oxygen species (superoxide radical anion: superoxide dismutase (SOD)-like activity and hydrogen peroxide: catalase-like activity) was tested throughout the complex series in aqueous solutions. In connection with the catalytic dismutation of H(2)O(2), bleaching tests with morin were also conducted in water. Comparison of the two ligands helped in elucidating the possible role of the carboxylate moiety in the different catalytic reactions. Although no general trends could be revealed between reactivity and constitution of the first coordination sphere, plausible explanations for differences are discussed individually for SOD like, catalase-like and bleaching activity.
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Affiliation(s)
- József S Pap
- Department of Chemistry, University of Pannonia, 8201 Veszprém, Hungary
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Belluzzi E, Bisaglia M, Lazzarini E, Tabares LC, Beltramini M, Bubacco L. Human SOD2 modification by dopamine quinones affects enzymatic activity by promoting its aggregation: possible implications for Parkinson's disease. PLoS One 2012; 7:e38026. [PMID: 22723845 PMCID: PMC3377658 DOI: 10.1371/journal.pone.0038026] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 04/28/2012] [Indexed: 01/04/2023] Open
Abstract
Mitochondrial dysfunction and oxidative stress are considered central in dopaminergic neurodegeneration in Parkinson’s disease (PD). Oxidative stress occurs when the endogenous antioxidant systems are overcome by the generation of reactive oxygen species (ROS). A plausible source of oxidative stress, which could account for the selective degeneration of dopaminergic neurons, is the redox chemistry of dopamine (DA) and leads to the formation of ROS and reactive dopamine-quinones (DAQs). Superoxide dismutase 2 (SOD2) is a mitochondrial enzyme that converts superoxide radicals to molecular oxygen and hydrogen peroxide, providing a first line of defense against ROS. We investigated the possible interplay between DA and SOD2 in the pathogenesis of PD using enzymatic essays, site-specific mutagenesis, and optical and high-field-cw-EPR spectroscopies. Using radioactive DA, we demonstrated that SOD2 is a target of DAQs. Exposure to micromolar DAQ concentrations induces a loss of up to 50% of SOD2 enzymatic activity in a dose-dependent manner, which is correlated to the concomitant formation of protein aggregates, while the coordination geometry of the active site appears unaffected by DAQ modifications. Our findings support a model in which DAQ-mediated SOD2 inactivation increases mitochondrial ROS production, suggesting a link between oxidative stress and mitochondrial dysfunction.
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Affiliation(s)
- Elisa Belluzzi
- Department of Biology, University of Padova, Padova, Italy
| | - Marco Bisaglia
- Department of Biology, University of Padova, Padova, Italy
| | | | - Leandro C. Tabares
- CEA, Institut de biologie et de technologies de Saclay, Service de Bioénergétique, Biologie Structurale et Mécanismes, Gif-sur-Yvette, France
| | - Mariano Beltramini
- Department of Biology, University of Padova, Padova, Italy
- * E-mail: (LB); (MB)
| | - Luigi Bubacco
- Department of Biology, University of Padova, Padova, Italy
- * E-mail: (LB); (MB)
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Beckwith MA, Roemelt M, Collomb MN, DuBoc C, Weng TC, Bergmann U, Glatzel P, Neese F, DeBeer S. Manganese Kβ X-ray emission spectroscopy as a probe of metal-ligand interactions. Inorg Chem 2011; 50:8397-409. [PMID: 21805960 DOI: 10.1021/ic200970t] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A systematic series of high-spin mononuclear Mn(II), Mn(III), and Mn(IV) complexes has been investigated by manganese Kβ X-ray emission spectroscopy (XES). The factors contributing to the Kβ main line and the valence to core region are discussed. The Kβ main lines are dominated by 3p-3d exchange correlation (spin state) effects, shifting to lower energy upon oxidation of Mn(II) to Mn(III) due to the decrease in spin state from S = 5/2 to S = 2, whereas the valence to core region shows greater sensitivity to the chemical environment surrounding the Mn center. A density functional theory (DFT) approach has been used to calculate the valence to core spectra and assess the contributions to the energies and intensities. The valence spectra are dominated by manganese np to 1s electric dipole-allowed transitions and are particularly sensitive to spin state and ligand identity (reflected primarily in the transition energies) as well as oxidation state and metal-ligand bond lengths (reflected primarily in the transition intensities). The ability to use these methods to distinguish different ligand contributions within a heteroleptic coordination sphere is highlighted. The similarities and differences between the current Mn XES study and previous studies of Fe XES investigations are discussed. These findings serve as an important calibration for future applications to manganese active sites in biological and chemical catalysis.
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Affiliation(s)
- Martha A Beckwith
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
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Pap JS, Kripli B, Váradi T, Giorgi M, Kaizer J, Speier G. Comparison of the SOD-like activity of hexacoordinate Mn(II), Fe(II) and Ni(II) complexes having isoindoline-based ligands. J Inorg Biochem 2011; 105:911-8. [DOI: 10.1016/j.jinorgbio.2011.01.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 01/11/2011] [Accepted: 01/31/2011] [Indexed: 11/29/2022]
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Iranzo O. Manganese complexes displaying superoxide dismutase activity: A balance between different factors. Bioorg Chem 2011; 39:73-87. [DOI: 10.1016/j.bioorg.2011.02.001] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 02/14/2011] [Accepted: 02/14/2011] [Indexed: 01/05/2023]
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Högbom M. Metal use in ribonucleotide reductase R2, di-iron, di-manganese and heterodinuclear—an intricate bioinorganic workaround to use different metals for the same reaction. Metallomics 2011; 3:110-20. [DOI: 10.1039/c0mt00095g] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Nakamura T, Torikai K, Uegaki K, Morita J, Machida K, Suzuki A, Kawata Y. Crystal structure of the cambialistic superoxide dismutase from Aeropyrum pernix K1 - insights into the enzyme mechanism and stability. FEBS J 2010; 278:598-609. [DOI: 10.1111/j.1742-4658.2010.07977.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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