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York NJ, Lockart MM, Pierce BS. Low-Spin Cyanide Complexes of 3-Mercaptopropionic Acid Dioxygenase (MDO) Reveal the Impact of Outer-Sphere SHY-Motif Residues. Inorg Chem 2021; 60:18639-18651. [PMID: 34883020 PMCID: PMC10078988 DOI: 10.1021/acs.inorgchem.1c01519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
3-Mercaptopropionic acid (3MPA) dioxygenase (MDO) is a non-heme Fe(II)/O2-dependent oxygenase that catalyzes the oxidation of thiol-substrates to yield the corresponding sulfinic acid. Hydrogen-bonding interactions between the Fe-site and a conserved set of three outer-sphere residues (Ser-His-Tyr) play an important catalytic role in the mechanism of this enzyme. Collectively referred to as the SHY-motif, the functional role of these residues remains poorly understood. Here, catalytically inactive Fe(III)-MDO precomplexed with 3MPA was titrated with cyanide to yield a low-spin (S = 1/2) (3MPA/CN)-bound ternary complex (referred to as 1C). UV-visible and electron paramagnetic resonance (EPR) spectroscopy were used to monitor the binding of 3MPA and cyanide. Comparisons of results obtained from SHY-motif variants (H157N and Y159F) were performed to investigate specific H-bonding interactions. For the wild-type enzyme, the binding of 3MPA- and cyanide to the enzymatic Fe-site is selective and results in a homogeneous ternary complex. However, this selectivity is lost for the Y159F variant, suggesting that H-bonding interactions contributed from Tyr159 gate ligand coordination at the Fe-site. Significantly, the g-values for the low-spin ferric site are diagnostic of the directionality of Tyr159 H-bond donation. Computational models coupled with CASSCF/NEVPT2-calculated g-values were used to verify that a major shift in the central g-value (g2) displayed between wild-type and SHY variants could be attributed to the loss of Tyr159 H-bond donation to the Fe-bound cyanide. Applied to native cosubstrate, this H-bond donation provides a means to stabilize Fe-bound dioxygen and potentially explains the attenuated (∼15-fold) rate of catalytic turnover previously reported for MDO SHY-motif variants.
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Affiliation(s)
- Nicholas J York
- Department of Chemistry & Biochemistry, University of Alabama, 250 Hackberry Lane, Tuscaloosa, Alabama 35487, United States
| | - Molly M Lockart
- Department of Chemistry & Biochemistry, University of Alabama, 250 Hackberry Lane, Tuscaloosa, Alabama 35487, United States
| | - Brad S Pierce
- Department of Chemistry & Biochemistry, University of Alabama, 250 Hackberry Lane, Tuscaloosa, Alabama 35487, United States
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2
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Chiura T, Mak PJ. Investigation of Cyanide Ligand as an Active Site Probe of Human Heme Oxygenase. Inorg Chem 2021; 60:4633-4645. [PMID: 33754715 DOI: 10.1021/acs.inorgchem.0c03611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human heme oxygenase (hHO-1) is a physiologically important enzyme responsible for free heme catabolism. The enzyme's high regiospecificity is controlled by the distal site hydrogen bond network that involves water molecules and the D140 amino acid residue. In this work, we probe the active site environment of the wild-type (WT) hHO-1 and its D140 mutants using resonance Raman (rR) spectroscopy. Cyanide ligands are more stable than dioxygen adducts and are an effective probe of active site environment of heme proteins. The inherently linear geometry of the Fe-C-N fragment can be altered by the steric, electrostatic, and H-bonding interactions imposed by the amino acid residues present in the heme distal site, resulting in a tilted or bent configuration. The WT hHO-1 and its D140A, D140N, and D140E mutants were studied in the presence of natural abundance CN- and its isotopic analogues (13CN-, C15N-, and 13C15N-). Deconvolution of spectral data revealed that the ν(Fe-CN) stretching and δ(Fe-CN) bending modes are present at 454 and 376 cm-1, respectively. The rR spectral patterns of the CN- adducts of WT revealed that the Fe-C-N fragment adopts a tilted conformation, with a larger bending contribution for the D140A, D140N, and D140E mutants. These studies suggest that the FeCN fragment in hHO-1 is tilted more strongly toward the porphyrin macrocycle compared to other histidine-ligated proteins, reflecting the propensity of the exogenous hHO-l ligands to position toward the α-meso-carbon, which is crucial for the HO reactivity and essential for regioselectivity.
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Affiliation(s)
- Tapiwa Chiura
- Chemistry Department, Saint Louis University, Saint Louis, Missouri 63103, United States
| | - Piotr J Mak
- Chemistry Department, Saint Louis University, Saint Louis, Missouri 63103, United States
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3
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Fischer AA, Miller JR, Jodts RJ, Ekanayake DM, Lindeman SV, Brunold TC, Fiedler AT. Spectroscopic and Computational Comparisons of Thiolate-Ligated Ferric Nonheme Complexes to Cysteine Dioxygenase: Second-Sphere Effects on Substrate (Analogue) Positioning. Inorg Chem 2019; 58:16487-16499. [PMID: 31789510 DOI: 10.1021/acs.inorgchem.9b02432] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Parallel spectroscopic and computational studies of iron(III) cysteine dioxygenase (CDO) and synthetic models are presented. The synthetic complexes utilize the ligand tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (Ph2TIP), which mimics the facial three-histidine triad of CDO and other thiol dioxygenases. In addition to the previously reported [FeII(CysOEt)(Ph2TIP)]BPh4 (1; CysOEt is the ethyl ester of anionic l-cysteine), the formation and crystallographic characterization of [FeII(2-MTS)(Ph2TIP)]BPh4 (2) is reported, where the methyl 2-thiosalicylate anion (2-MTS) resembles the substrate of 3-mercaptopropionate dioxygenase (MDO). One-electron chemical oxidation of 1 and 2 yields ferric species that bind cyanide and azide anions, which have been used as spectroscopic probes of O2 binding in prior studies of FeIII-CDO. The six-coordinate FeIII-CN and FeIII-N3 adducts are examined with UV-vis absorption, electron paramagnetic resonance (EPR), and resonance Raman (rRaman) spectroscopies. In addition, UV-vis and rRaman studies of cysteine- and cyanide-bound FeIII-CDO are reported for both the wild-type (WT) enzyme and C93G variant, which lacks the Cys-Tyr cross-link that is present in the second coordination sphere of the WT active site. Density functional theory (DFT) and ab initio calculations are employed to provide geometric and electronic structure descriptions of the synthetic and enzymatic FeIII adducts. In particular, it is shown that the complete active space self-consistent field (CASSCF) method, in tandem with n-electron valence state second-order perturbation theory (NEVPT2), is capable of elucidating the structural basis of subtle shifts in EPR g values for low-spin FeIII species.
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Affiliation(s)
- Anne A Fischer
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Joshua R Miller
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Richard J Jodts
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Danushka M Ekanayake
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Sergey V Lindeman
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
| | - Thomas C Brunold
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Adam T Fiedler
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53201 , United States
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4
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Fielding AJ, Dornevil K, Ma L, Davis I, Liu A. Probing Ligand Exchange in the P450 Enzyme CYP121 from Mycobacterium tuberculosis: Dynamic Equilibrium of the Distal Heme Ligand as a Function of pH and Temperature. J Am Chem Soc 2017; 139:17484-17499. [PMID: 29090577 PMCID: PMC5765751 DOI: 10.1021/jacs.7b08911] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CYP121 is a cytochrome P450 enzyme from Mycobacterium tuberculosis that catalyzes the formation of a C-C bond between the aromatic groups of its cyclodityrosine substrate (cYY). The crystal structure of CYP121 in complex with cYY reveals that the solvent-derived ligand remains bound to the ferric ion in the enzyme-substrate complex. Whereas in the generally accepted P450 mechanism, binding of the primary substrate in the active-site triggers the release of the solvent-derived ligand, priming the metal center for reduction and subsequent O2 binding. Here we employed sodium cyanide to probe the metal-ligand exchange of the enzyme and the enzyme-substrate complex. The cyano adducts were characterized by UV-vis, EPR, and ENDOR spectroscopies and X-ray crystallography. A 100-fold increase in the affinity of cyanide binding to the enzyme-substrate complex over the ligand-free enzyme was observed. The crystal structure of the [CYP121(cYY)CN] ternary complex showed a rearrangement of the substrate in the active-site, when compared to the structure of the binary [CYP121(cYY)] complex. Transient kinetic studies showed that cYY binding resulted in a lower second-order rate constant (kon (CN)) but a much more stable cyanide adduct with 3 orders of magnitude slower koff (CN) rate. A dynamic equilibrium between multiple high- and low-spin species for both the enzyme and enzyme-substrate complex was also observed, which is sensitive to changes in both pH and temperature. Our data reveal the chemical and physical properties of the solvent-derived ligand of the enzyme, which will help to understand the initial steps of the catalytic mechanism.
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Affiliation(s)
- Andrew J. Fielding
- Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Kednerlin Dornevil
- Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Li Ma
- Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Ian Davis
- Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Aimin Liu
- Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
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5
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Horch M, Utesch T, Hildebrandt P, Mroginski MA, Zebger I. Domain motions and electron transfer dynamics in 2Fe-superoxide reductase. Phys Chem Chem Phys 2016; 18:23053-66. [DOI: 10.1039/c6cp03666j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Theoretical studies on 2Fe-superoxide reductase provide mechanistic insights into structural dynamics and electron transfer efficiencies.
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Affiliation(s)
- Marius Horch
- Institut für Chemie
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Tillmann Utesch
- Institut für Chemie
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Peter Hildebrandt
- Institut für Chemie
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | | | - Ingo Zebger
- Institut für Chemie
- Technische Universität Berlin
- D-10623 Berlin
- Germany
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6
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Sheng Y, Abreu IA, Cabelli DE, Maroney MJ, Miller AF, Teixeira M, Valentine JS. Superoxide dismutases and superoxide reductases. Chem Rev 2014; 114:3854-918. [PMID: 24684599 PMCID: PMC4317059 DOI: 10.1021/cr4005296] [Citation(s) in RCA: 569] [Impact Index Per Article: 56.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Yuewei Sheng
- Department
of Chemistry and Biochemistry, University
of California Los Angeles, Los
Angeles, California 90095, United States
| | - Isabel A. Abreu
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
- Instituto
de Biologia Experimental e Tecnológica, Av. da República,
Qta. do Marquês, Estação Agronómica Nacional,
Edificio IBET/ITQB, 2780-157, Oeiras, Portugal
| | - Diane E. Cabelli
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Michael J. Maroney
- Department
of Chemistry, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Anne-Frances Miller
- Department
of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Miguel Teixeira
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Joan Selverstone Valentine
- Department
of Chemistry and Biochemistry, University
of California Los Angeles, Los
Angeles, California 90095, United States
- Department
of Bioinspired Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea
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7
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Horch M, Pinto AF, Utesch T, Mroginski MA, Romão CV, Teixeira M, Hildebrandt P, Zebger I. Reductive activation and structural rearrangement in superoxide reductase: a combined infrared spectroscopic and computational study. Phys Chem Chem Phys 2014; 16:14220-30. [DOI: 10.1039/c4cp00884g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Local and global structural changes that enable reductive activation of superoxide reductase are revealed by a combined approach of infrared difference spectroscopy and computational methods.
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Affiliation(s)
- M. Horch
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
| | - A. F. Pinto
- Instituto de Tecnologia Química e Biológica António Xavier
- Universidade Nova de Lisboa
- Av. da República (EAN)
- P-2780-157 Oeiras, Portugal
| | - T. Utesch
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
| | - M. A. Mroginski
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
| | - C. V. Romão
- Instituto de Tecnologia Química e Biológica António Xavier
- Universidade Nova de Lisboa
- Av. da República (EAN)
- P-2780-157 Oeiras, Portugal
| | - M. Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier
- Universidade Nova de Lisboa
- Av. da República (EAN)
- P-2780-157 Oeiras, Portugal
| | - P. Hildebrandt
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
| | - I. Zebger
- Technische Universität Berlin
- Institut für Chemie
- 10623 Berlin, Germany
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9
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Namuswe F, Hayashi T, Jiang Y, Kasper GD, Sarjeant AAN, Moënne-Loccoz P, Goldberg DP. Influence of the nitrogen donors on nonheme iron models of superoxide reductase: high-spin Fe(III)-OOR complexes. J Am Chem Soc 2010; 132:157-67. [PMID: 20000711 DOI: 10.1021/ja904818z] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new five-coordinate, (N(4)S(thiolate))Fe(II) complex, containing tertiary amine donors, [Fe(II)(Me(4)[15]aneN(4))(SPh)]BPh(4) (2), was synthesized and structurally characterized as a model of the reduced active site of superoxide reductase (SOR). Reaction of 2 with tert-butyl hydroperoxide (tBuOOH) at -78 degrees C led to the generation of the alkylperoxo-iron(III) complex [Fe(III)(Me(4)[15]aneN(4))(SPh)(OOtBu)](+) (2a). The nonthiolate-ligated complex, [Fe(II)(Me(4)[15]aneN(4))(OTf)(2)] (3), was also reacted with tBuOOH and yielded the corresponding alkylperoxo complex [Fe(III)(Me(4)[15]aneN(4))(OTf)(OOtBu)](+) (3a) at an elevated temperature of -23 degrees C. These species were characterized by low-temperature UV-vis, EPR, and resonance Raman spectroscopies. Complexes 2a and 3a exhibit distinctly different spectroscopic signatures than the analogous alkylperoxo complexes [Fe(III)([15]aneN(4))(SAr)(OOR)](+), which contain secondary amine donors. Importantly, alkylation at nitrogen leads to a change from low-spin (S = 1/2) to high-spin (S = 5/2) of the iron(III) center. The resonance Raman data reveal that this change in spin state has a large effect on the nu(Fe-O) and nu(O-O) vibrations, and a comparison between 2a and the nonthiolate-ligated complex 3a shows that axial ligation has an additional significant impact on these vibrations. To our knowledge this study is the first in which the influence of a ligand trans to a peroxo moiety has been evaluated for a structurally equivalent pair of high-spin/low-spin peroxo-iron(III) complexes. The implications of spin state and thiolate ligation are discussed with regard to the functioning of SOR.
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Affiliation(s)
- Frances Namuswe
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
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10
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Kung Y, Doukov TI, Seravalli J, Ragsdale SW, Drennan CL. Crystallographic snapshots of cyanide- and water-bound C-clusters from bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase. Biochemistry 2009; 48:7432-40. [PMID: 19583207 PMCID: PMC2721637 DOI: 10.1021/bi900574h] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Nickel-containing carbon monoxide dehydrogenases (CODHs) reversibly catalyze the oxidation of carbon monoxide to carbon dioxide and are of vital importance in the global carbon cycle. The unusual catalytic CODH C-cluster has been crystallographically characterized as either a NiFe4S4 or a NiFe4S5 metal center, the latter containing a fifth, additional sulfide that bridges Ni and a unique Fe site. To determine whether this bridging sulfide is catalytically relevant and to further explore the mechanism of the C-cluster, we obtained crystal structures of the 310 kDa bifunctional CODH/acetyl-CoA synthase complex from Moorella thermoacetica bound both with a substrate H2O/OH− molecule and with a cyanide inhibitor. X-ray diffraction data were collected from native crystals and from identical crystals soaked in a solution containing potassium cyanide. In both structures, the substrate H2O/OH− molecule exhibits binding to the unique Fe site of the C-cluster. We also observe cyanide binding in a bent conformation to Ni of the C-cluster, adjacent the substrate H2O/OH− molecule. Importantly, the bridging sulfide is not present in either structure. As these forms of the C-cluster represent the coordination environment immediately before the reaction takes place, our findings do not support a fifth, bridging sulfide playing a catalytic role in the enzyme mechanism. The crystal structures presented here, along with recent structures of CODHs from other organisms, have led us toward a unified mechanism for CO oxidation by the C-cluster, the catalytic center of an environmentally important enzyme.
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Affiliation(s)
- Yan Kung
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Jiang Y, Telser J, Goldberg DP. Evidence for the formation of a mononuclear ferric–hydroperoxo complex via the reaction of dioxygen with an (N4S(thiolate))iron(ii) complex. Chem Commun (Camb) 2009:6828-30. [DOI: 10.1039/b913945a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Dey A, Jenney FE, Adams MWW, Johnson MK, Hodgson KO, Hedman B, Solomon EI. Sulfur K-edge X-ray absorption spectroscopy and density functional theory calculations on superoxide reductase: role of the axial thiolate in reactivity. J Am Chem Soc 2007; 129:12418-31. [PMID: 17887751 PMCID: PMC2533108 DOI: 10.1021/ja064167p] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Superoxide reductase (SOR) is a non-heme iron enzyme that reduces superoxide to peroxide at a diffusion-controlled rate. Sulfur K-edge X-ray absorption spectroscopy (XAS) is used to investigate the ground-state electronic structure of the resting high-spin and CN- bound low-spin FeIII forms of the 1Fe SOR from Pyrococcus furiosus. A computational model with constrained imidazole rings (necessary for reproducing spin states), H-bonding interaction to the thiolate (necessary for reproducing Fe-S bond covalency of the high-spin and low-spin forms), and H-bonding to the exchangeable axial ligand (necessary to reproduce the ground state of the low-spin form) was developed and then used to investigate the enzymatic reaction mechanism. Reaction of the resting ferrous site with superoxide and protonation leading to a high-spin FeIII-OOH species and its subsequent protonation resulting in H2O2 release is calculated to be the most energetically favorable reaction pathway. Our results suggest that the thiolate acts as a covalent anionic ligand. Replacing the thiolate with a neutral noncovalent ligand makes protonation very endothermic and greatly raises the reduction potential. The covalent nature of the thiolate weakens the FeIII bond to the proximal oxygen of this hydroperoxo species, which raises its pKa by an additional 5 log units relative to the pKa of a primarily anionic ligand, facilitating its protonation. A comparison with cytochrome P450 indicates that the stronger equatorial ligand field from the porphyrin results in a low-spin FeIII-OOH species that would not be capable of efficient H2O2 release due to a spin-crossing barrier associated with formation of a high-spin 5C FeIII product. Additionally, the presence of the dianionic porphyrin pi ring in cytochrome P450 allows O-O heterolysis, forming an FeIV-oxo porphyrin radical species, which is calculated to be extremely unfavorable for the non-heme SOR ligand environment. Finally, the 5C FeIII site that results from the product release at the end of the O2- reduction cycle is calculated to be capable of reacting with a second O2-, resulting in superoxide dismutase (SOD) activity. However, in contrast to FeSOD, the 5C FeIII site of SOR, which is more positively charged, is calculated to have a high affinity for binding a sixth anionic ligand, which would inhibit its SOD activity.
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Affiliation(s)
- Abhishek Dey
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Francis E. Jenney
- Department of Chemistry and Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602
| | - Michael W. W. Adams
- Department of Chemistry and Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602
| | - Michael K. Johnson
- Department of Chemistry and Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602
| | - Keith O. Hodgson
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Menlo Park, CA 94025
| | - Britt Hedman
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Menlo Park, CA 94025
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Stanford Synchrotron Radiation Laboratory, SLAC, Stanford University, Menlo Park, CA 94025
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13
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Pereira AS, Tavares P, Folgosa F, Almeida RM, Moura I, Moura JJG. Superoxide Reductases. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Alice S. Pereira
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - Pedro Tavares
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - Filipe Folgosa
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - Rui M. Almeida
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - Isabel Moura
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
| | - José J. G. Moura
- Requimte, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829‐516 Caparica, Portugal, Fax: +351‐21‐2948550
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14
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Katona G, Carpentier P, Nivière V, Amara P, Adam V, Ohana J, Tsanov N, Bourgeois D. Raman-assisted crystallography reveals end-on peroxide intermediates in a nonheme iron enzyme. Science 2007; 316:449-53. [PMID: 17446401 DOI: 10.1126/science.1138885] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Iron-peroxide intermediates are central in the reaction cycle of many iron-containing biomolecules. We trapped iron(III)-(hydro)peroxo species in crystals of superoxide reductase (SOR), a nonheme mononuclear iron enzyme that scavenges superoxide radicals. X-ray diffraction data at 1.95 angstrom resolution and Raman spectra recorded in crystallo revealed iron-(hydro)peroxo intermediates with the (hydro)peroxo group bound end-on. The dynamic SOR active site promotes the formation of transient hydrogen bond networks, which presumably assist the cleavage of the iron-oxygen bond in order to release the reaction product, hydrogen peroxide.
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Affiliation(s)
- Gergely Katona
- Institut de Biologie Structurale (IBS) Jean-Pierre Ebel, Commissariat à l'Energie Atomique (CEA), Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier, 41 rue Jules Horowitz, F-38027 Grenoble, France
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15
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Brines LM, Kovacs JA. Understanding the Mechanism of Superoxide Reductase Promoted Reduction of Superoxide. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200600461] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lisa M. Brines
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195, USA, Fax: +1‐206‐685‐8665
| | - Julie A. Kovacs
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195, USA, Fax: +1‐206‐685‐8665
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