1
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Babicz JT, Rogers MS, DeWeese DE, Sutherlin KD, Banerjee R, Böttger LH, Yoda Y, Nagasawa N, Saito M, Kitao S, Kurokuzu M, Kobayashi Y, Tamasaku K, Seto M, Lipscomb JD, Solomon EI. Nuclear Resonance Vibrational Spectroscopy Definition of Peroxy Intermediates in Catechol Dioxygenases: Factors that Determine Extra- versus Intradiol Cleavage. J Am Chem Soc 2023; 145:15230-15250. [PMID: 37414058 PMCID: PMC10804917 DOI: 10.1021/jacs.3c02242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
The extradiol dioxygenases (EDOs) and intradiol dioxygenases (IDOs) are nonheme iron enzymes that catalyze the oxidative aromatic ring cleavage of catechol substrates, playing an essential role in the carbon cycle. The EDOs and IDOs utilize very different FeII and FeIII active sites to catalyze the regiospecificity in their catechol ring cleavage products. The factors governing this difference in cleavage have remained undefined. The EDO homoprotocatechuate 2,3-dioxygenase (HPCD) and IDO protocatechuate 3,4-dioxygenase (PCD) provide an opportunity to understand this selectivity, as key O2 intermediates have been trapped for both enzymes. Nuclear resonance vibrational spectroscopy (in conjunction with density functional theory calculations) is used to define the geometric and electronic structures of these intermediates as FeII-alkylhydroperoxo (HPCD) and FeIII-alkylperoxo (PCD) species. Critically, in both intermediates, the initial peroxo bond orientation is directed toward extradiol product formation. Reaction coordinate calculations were thus performed to evaluate both the extra- and intradiol O-O cleavage for the simple organic alkylhydroperoxo and for the FeII and FeIII metal catalyzed reactions. These results show the FeII-alkylhydroperoxo (EDO) intermediate undergoes facile extradiol O-O bond homolysis due to its extra e-, while for the FeIII-alkylperoxo (IDO) intermediate the extradiol cleavage involves a large barrier and would yield the incorrect extradiol product. This prompted our evaluation of a viable mechanism to rearrange the FeIII-alkylperoxo IDO intermediate for intradiol cleavage, revealing a key role in the rebinding of the displaced Tyr447 ligand in this rearrangement, driven by the proton delivery necessary for O-O bond cleavage.
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Affiliation(s)
- Jeffrey T. Babicz
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, California 94305, United States
| | - Melanie S. Rogers
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55391, United States
| | - Dory E. DeWeese
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, California 94305, United States
| | - Kyle D. Sutherlin
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, California 94305, United States
| | - Rahul Banerjee
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55391, United States
| | - Lars H. Böttger
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, California 94305, United States
| | - Yoshitaka Yoda
- Japan Synchrotron Radiation Research Institute, Hyogo 679-5198, Japan
| | - Nobumoto Nagasawa
- Japan Synchrotron Radiation Research Institute, Hyogo 679-5198, Japan
| | - Makina Saito
- Department of Physics, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Shinji Kitao
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka 590-0494, Japan
| | - Masayuki Kurokuzu
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka 590-0494, Japan
| | - Yasuhiro Kobayashi
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka 590-0494, Japan
| | - Kenji Tamasaku
- RIKEN SPring-8 Center, RIKEN, Sayo, Hyogo 679-5148, Japan
| | - Makoto Seto
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka 590-0494, Japan
| | - John D. Lipscomb
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55391, United States
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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2
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Ash PA, Kendall-Price SET, Evans RM, Carr SB, Brasnett AR, Morra S, Rowbotham JS, Hidalgo R, Healy AJ, Cinque G, Frogley MD, Armstrong FA, Vincent KA. The crystalline state as a dynamic system: IR microspectroscopy under electrochemical control for a [NiFe] hydrogenase. Chem Sci 2021; 12:12959-12970. [PMID: 34745526 PMCID: PMC8514002 DOI: 10.1039/d1sc01734a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/03/2021] [Indexed: 12/24/2022] Open
Abstract
Controlled formation of catalytically-relevant states within crystals of complex metalloenzymes represents a significant challenge to structure-function studies. Here we show how electrochemical control over single crystals of [NiFe] hydrogenase 1 (Hyd1) from Escherichia coli makes it possible to navigate through the full array of active site states previously observed in solution. Electrochemical control is combined with synchrotron infrared microspectroscopy, which enables us to measure high signal-to-noise IR spectra in situ from a small area of crystal. The output reports on active site speciation via the vibrational stretching band positions of the endogenous CO and CN- ligands at the hydrogenase active site. Variation of pH further demonstrates how equilibria between catalytically-relevant protonation states can be deliberately perturbed in the crystals, generating a map of electrochemical potential and pH conditions which lead to enrichment of specific states. Comparison of in crystallo redox titrations with measurements in solution or of electrode-immobilised Hyd1 confirms the integrity of the proton transfer and redox environment around the active site of the enzyme in crystals. Slowed proton-transfer equilibria in the hydrogenase in crystallo reveals transitions which are only usually observable by ultrafast methods in solution. This study therefore demonstrates the possibilities of electrochemical control over single metalloenzyme crystals in stabilising specific states for further study, and extends mechanistic understanding of proton transfer during the [NiFe] hydrogenase catalytic cycle.
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Affiliation(s)
- Philip A Ash
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
- School of Chemistry, University of Leicester Leicester LE1 7RH UK
- Leicester Institute of Structural and Chemical Biology, University of Leicester LE1 7RH UK
| | - Sophie E T Kendall-Price
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
| | - Rhiannon M Evans
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
| | - Stephen B Carr
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus Didcot UK
| | - Amelia R Brasnett
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
| | - Simone Morra
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
| | - Jack S Rowbotham
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
| | - Ricardo Hidalgo
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
| | - Adam J Healy
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
| | - Gianfelice Cinque
- Diamond Light Source, Harwell Science and Innovation Campus Didcot OX11 0QX UK
- Department of Engineering Sciences, University of Oxford Parks Road Oxford OX1 3PJ UK
| | - Mark D Frogley
- Diamond Light Source, Harwell Science and Innovation Campus Didcot OX11 0QX UK
| | - Fraser A Armstrong
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
| | - Kylie A Vincent
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR UK
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3
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Li J, Wan W, Triana CA, Chen H, Zhao Y, Mavrokefalos CK, Patzke GR. Reaction kinetics and interplay of two different surface states on hematite photoanodes for water oxidation. Nat Commun 2021; 12:255. [PMID: 33431853 PMCID: PMC7801602 DOI: 10.1038/s41467-020-20510-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/30/2020] [Indexed: 11/09/2022] Open
Abstract
Understanding the function of surface states on photoanodes is crucial for unraveling the underlying reaction mechanisms of water oxidation. For hematite photoanodes, only one type of surface states with higher oxidative energy (S1) has been proposed and verified as reaction intermediate, while the other surface state located at lower potentials (S2) was assigned to inactive or recombination sites. Through employing rate law analyses and systematical (photo)electrochemical characterizations, here we show that S2 is an active reaction intermediate for water oxidation as well. Furthermore, we demonstrate that the reaction kinetics and dynamic interactions of both S1 and S2 depend significantly on operational parameters, such as illumination intensity, nature of the electrolyte, and applied potential. These insights into the individual reaction kinetics and the interplay of both surface states are decisive for designing efficient photoanodes.
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Affiliation(s)
- Jingguo Li
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Wenchao Wan
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Carlos A Triana
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Hang Chen
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Yonggui Zhao
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Christos K Mavrokefalos
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Greta R Patzke
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
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4
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Tu N, Zhang D, Niu X, Du C, Zhang L, Xie W, Niu X, Liu Y, Li Y. A novel concept for the biodegradation mechanism of dianionic catechol with homoprotocatechuate 2,3-dioxygenase: A non-proton-assisted process. CHEMOSPHERE 2020; 246:125796. [PMID: 31918103 DOI: 10.1016/j.chemosphere.2019.125796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/15/2019] [Accepted: 12/29/2019] [Indexed: 06/10/2023]
Abstract
The theory of "proton-assisted process" can well explain the catalytic mechanism of homoprotocatechuate 2,3-dioxygenase (2,3-HPCD) with a monoanionic substrate (homoprotocatechuate, HPCA). Here a "non-proton-assisted process" is presented to interpret catalytic mechanism of 2,3-HPCD with a dianionic substrate (4-nitrocatechol, 4NC). The ONIOM calculation is performed to investigate the reaction pathway of a wild-type 2,3-HPCD with 4NC (H200H-4NC system). The catalytic reaction is comprised of four steps: (1) A dioxygen attacks the aromatic ring to produce an alkylperoxo species. (2) O-O bond cleavage and the formation of an epoxide species occur. (3) A seven-membered O-heterocyclic compound is generated by the extinction of the epoxy structure. (4) The seven-membered ring undergoes ring opening to form the final product (C2-C3 cleavage product). The effective free energy barrier of the catalytic reaction of the H200H-4NC system is 26.2 kcal mol-1, which is much higher than that of the H200H-HPCA system. Furthermore, two calculated electronic configurations (Fe(III)-O2•- and Fe(III)-SQ•) have a high similarity to previously detected ones, which demonstrates that the Asn200 variant (H200N-4NC variant system) employs a C4 (para-carbon) pathway to produce a C4-C5 cleavage product. Our findings provide an in-depth understanding of the catalytic mechanisms of dianionic catechol and its derivatives.
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Affiliation(s)
- Ningyu Tu
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, 525000, China
| | - Dongmei Zhang
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, 525000, China
| | - Xianchun Niu
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, 525000, China
| | - Cheng Du
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, 525000, China
| | - Li Zhang
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, 525000, China
| | - Wenyu Xie
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, 525000, China
| | - Xiaojun Niu
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, 525000, China; School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Yang Liu
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, 525000, China.
| | - Youming Li
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China
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5
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Colabroy KL, Horwitz AD, Basciano VR, Fu Y, Travitz KM, Robinson MK, Shimanski BA, Hoffmann TW. A New Way of Belonging: Active-Site Investigation of L-DOPA Dioxygenase, a VOC Family Enzyme from Lincomycin Biosynthesis. Biochemistry 2019; 58:4794-4798. [DOI: 10.1021/acs.biochem.9b00456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Keri L. Colabroy
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Alyssa D. Horwitz
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Victoria R. Basciano
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Yizhi Fu
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Kelly M. Travitz
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Miranda K. Robinson
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Brittany A. Shimanski
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
| | - Thomas W. Hoffmann
- Department of Chemistry, Muhlenberg College, Allentown, Pennsylvania 18104, United States
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6
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Sutherlin KD, Wasada-Tsutsui Y, Mbughuni MM, Rogers MS, Park K, Liu LV, Kwak Y, Srnec M, Böttger LH, Frenette M, Yoda Y, Kobayashi Y, Kurokuzu M, Saito M, Seto M, Hu M, Zhao J, Alp EE, Lipscomb JD, Solomon EI. Nuclear Resonance Vibrational Spectroscopy Definition of O 2 Intermediates in an Extradiol Dioxygenase: Correlation to Crystallography and Reactivity. J Am Chem Soc 2018; 140:16495-16513. [PMID: 30418018 DOI: 10.1021/jacs.8b06517] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The extradiol dioxygenases are a large subclass of mononuclear nonheme Fe enzymes that catalyze the oxidative cleavage of catechols distal to their OH groups. These enzymes are important in bioremediation, and there has been significant interest in understanding how they activate O2. The extradiol dioxygenase homoprotocatechuate 2,3-dioxygenase (HPCD) provides an opportunity to study this process, as two O2 intermediates have been trapped and crystallographically defined using the slow substrate 4-nitrocatechol (4NC): a side-on Fe-O2-4NC species and a Fe-O2-4NC peroxy bridged species. Also with 4NC, two solution intermediates have been trapped in the H200N variant, where H200 provides a second-sphere hydrogen bond in the wild-type enzyme. While the electronic structure of these solution intermediates has been defined previously as FeIII-superoxo-catecholate and FeIII-peroxy-semiquinone, their geometric structures are unknown. Nuclear resonance vibrational spectroscopy (NRVS) is an important tool for structural definition of nonheme Fe-O2 intermediates, as all normal modes with Fe displacement have intensity in the NRVS spectrum. In this study, NRVS is used to define the geometric structure of the H200N-4NC solution intermediates in HPCD as an end-on FeIII-superoxo-catecholate and an end-on FeIII-hydroperoxo-semiquinone. Parallel calculations are performed to define the electronic structures and protonation states of the crystallographically defined wild-type HPCD-4NC intermediates, where the side-on intermediate is found to be a FeIII-hydroperoxo-semiquinone. The assignment of this crystallographic intermediate is validated by correlation to the NRVS data through computational removal of H200. While the side-on hydroperoxo semiquinone intermediate is computationally found to be nonreactive in peroxide bridge formation, it is isoenergetic with a superoxo catecholate species that is competent in performing this reaction. This study provides insight into the relative reactivities of FeIII-superoxo and FeIII-hydroperoxo intermediates in nonheme Fe enzymes and into the role H200 plays in facilitating extradiol catalysis.
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Affiliation(s)
- Kyle D Sutherlin
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Yuko Wasada-Tsutsui
- Department of Life Science and Applied Chemistry, Graduate School of Engineering , Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555 , Japan
| | - Michael M Mbughuni
- Department of Biochemistry, Molecular Biology, & Biophysics , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Melanie S Rogers
- Department of Biochemistry, Molecular Biology, & Biophysics , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Kiyoung Park
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Lei V Liu
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Yeonju Kwak
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Martin Srnec
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Lars H Böttger
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Mathieu Frenette
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Yoshitaka Yoda
- Japan Synchrotron Radiation Research Institute , Hyogo 679-5198 , Japan
| | | | - Masayuki Kurokuzu
- Research Reactor Institute, Kyoto University , Osaka 590-0494 , Japan
| | - Makina Saito
- Research Reactor Institute, Kyoto University , Osaka 590-0494 , Japan
| | - Makoto Seto
- Research Reactor Institute, Kyoto University , Osaka 590-0494 , Japan
| | - Michael Hu
- Advanced Photon Source , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Jiyong Zhao
- Advanced Photon Source , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - E Ercan Alp
- Advanced Photon Source , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - John D Lipscomb
- Department of Biochemistry, Molecular Biology, & Biophysics , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Edward I Solomon
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States.,SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
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7
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Speciation in iron epoxidation catalysis: A perspective on the discovery and role of non-heme iron(III)-hydroperoxo species in iron-catalyzed oxidation reactions. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.09.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Kamnev AA, Tugarova AV. Sample treatment in Mössbauer spectroscopy for protein-related analyses: Nondestructive possibilities to look inside metal-containing biosystems. Talanta 2017; 174:819-837. [PMID: 28738659 DOI: 10.1016/j.talanta.2017.06.057] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/01/2017] [Accepted: 06/19/2017] [Indexed: 01/07/2023]
Abstract
In this review, the unique possibilities are considered of the 57Fe transmission (TMS) and 57Co emission (EMS) variants of Mössbauer (nuclear γ-resonance) spectroscopy as nondestructive techniques with minimal sample preparation/treatment and a significant analytical potential, with a focus on the analysis of cation-binding sites in metalloproteins. The techniques are shown to provide unique structural and quantitative information on the coordination microenvironment, the chemical state and transformations of the Mössbauer nuclides in sophisticated metal-containing proteins, including those within complicated supramolecular structures, and in microbial cells or tissues. Recent representative examples of analyses of Fe-containing proteins by 57Fe TMS are briefly discussed, along with the newly emerging data on using 57Co EMS for probing the structural organisation of 57Co-doped cation-binding sites in sophisticated biocomplexes including metalloenzymes. Finally, some rare or exotic applications of Mössbauer spectroscopy (including the synchrotron-based methodology) in protein-related studies are outlined.
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Affiliation(s)
- Alexander A Kamnev
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia.
| | - Anna V Tugarova
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia
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9
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Abstract
The non-heme Fe enzymes are ubiquitous in nature and perform a wide range of functions involving O2 activation. These had been difficult to study relative to heme enzymes; however, spectroscopic methods that provide significant insight into the correlation of structure with function have now been developed. This Current Topics article summarizes both the molecular mechanism these enzymes use to control O2 activation in the presence of cosubstrates and the oxygen intermediates these reactions generate. Three types of O2 activation are observed. First, non-heme reactivity is shown to be different from heme chemistry where a low-spin FeIII-OOH non-heme intermediate directly reacts with substrate. Also, two subclasses of non-heme Fe enzymes generate high-spin FeIV═O intermediates that provide both σ and π frontier molecular orbitals that can control selectivity. Finally, for several subclasses of non-heme Fe enzymes, binding of the substrate to the FeII site leads to the one-electron reductive activation of O2 to an FeIII-superoxide capable of H atom abstraction and electrophilic attack.
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Affiliation(s)
- Edward I Solomon
- Department of Chemistry, Stanford University , Stanford, California 94305, United States.,SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
| | - Serra Goudarzi
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Kyle D Sutherlin
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
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10
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Sutherlin KD, Liu LV, Lee YM, Kwak Y, Yoda Y, Saito M, Kurokuzu M, Kobayashi Y, Seto M, Que L, Nam W, Solomon EI. Nuclear Resonance Vibrational Spectroscopic Definition of Peroxy Intermediates in Nonheme Iron Sites. J Am Chem Soc 2016; 138:14294-14302. [PMID: 27726349 DOI: 10.1021/jacs.6b07227] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
FeIII-(hydro)peroxy intermediates have been isolated in two classes of mononuclear nonheme Fe enzymes that are important in bioremediation: the Rieske dioxygenases and the extradiol dioxygenases. The binding mode and protonation state of the peroxide moieties in these intermediates are not well-defined, due to a lack of vibrational structural data. Nuclear resonance vibrational spectroscopy (NRVS) is an important technique for obtaining vibrational information on these and other intermediates, as it is sensitive to all normal modes with Fe displacement. Here, we present the NRVS spectra of side-on FeIII-peroxy and end-on FeIII-hydroperoxy model complexes and assign these spectra using calibrated DFT calculations. We then use DFT calculations to define and understand the changes in the NRVS spectra that arise from protonation and from opening the Fe-O-O angle. This study identifies four spectroscopic handles that will enable definition of the binding mode and protonation state of FeIII-peroxy intermediates in mononuclear nonheme Fe enzymes. These structural differences are important in determining the frontier molecular orbitals available for reactivity.
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Affiliation(s)
- Kyle D Sutherlin
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Lei V Liu
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Yong-Min Lee
- Department of Bioinspired Science, Department of Chemistry and Nano Science, Center for Biomimetic Systems, Ewha Womans University , Seoul 120-750, Korea
| | - Yeonju Kwak
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | | | - Makina Saito
- Research Reactor Institute, Kyoto University , Osaka 590-0494, Japan
| | - Masayuki Kurokuzu
- Research Reactor Institute, Kyoto University , Osaka 590-0494, Japan
| | | | - Makoto Seto
- Research Reactor Institute, Kyoto University , Osaka 590-0494, Japan
| | - Lawrence Que
- Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Wonwoo Nam
- Department of Bioinspired Science, Department of Chemistry and Nano Science, Center for Biomimetic Systems, Ewha Womans University , Seoul 120-750, Korea
| | - Edward I Solomon
- Department of Chemistry, Stanford University , Stanford, California 94305, United States.,SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
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11
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Meier KK, Rogers MS, Kovaleva EG, Lipscomb JD, Bominaar EL, Münck E. Enzyme Substrate Complex of the H200C Variant of Homoprotocatechuate 2,3-Dioxygenase: Mössbauer and Computational Studies. Inorg Chem 2016; 55:5862-70. [PMID: 27275865 PMCID: PMC4924929 DOI: 10.1021/acs.inorgchem.6b00148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The extradiol, aromatic ring-cleaving enzyme homoprotocatechuate 2,3-dioxygenase (HPCD) catalyzes a complex chain of reactions that involve second sphere residues of the active site. The importance of the second-sphere residue His200 was demonstrated in studies of HPCD variants, such as His200Cys (H200C), which revealed significant retardations of certain steps in the catalytic process as a result of the substitution, allowing novel reaction cycle intermediates to be trapped for spectroscopic characterization. As the H200C variant largely retains the wild-type active site structure and produces the correct ring-cleaved product, this variant presents a valuable target for mechanistic HPCD studies. Here, the high-spin Fe(II) states of resting H200C and the H200C-homoprotocatechuate enzyme-substrate (ES) complex have been characterized with Mössbauer spectroscopy to assess the electronic structures of the active site in these states. The analysis reveals a high-spin Fe(II) center in a low symmetry environment that is reflected in the values of the zero-field splitting (ZFS) (D ≈ - 8 cm(-1), E/D ≈ 1/3 in ES), as well as the relative orientations of the principal axes of the (57)Fe magnetic hyperfine (A) and electric field gradient (EFG) tensors relative to the ZFS tensor axes. A spin Hamiltonian analysis of the spectra for the ES complex indicates that the magnetization axis of the integer-spin S = 2 Fe(II) system is nearly parallel to the symmetry axis, z, of the doubly occupied dxy ground orbital deduced from the EFG and A-values, an observation, which cannot be rationalized by DFT assisted crystal-field theory. In contrast, ORCA/CASSCF calculations for the ZFS tensor in combination with DFT calculations for the EFG- and A-tensors describe the experimental data remarkably well.
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Affiliation(s)
- Katlyn K. Meier
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Melanie S. Rogers
- Department of Biochemistry, Molecular Biology and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Elena G. Kovaleva
- Stanford Synchrotron Radiation Lightsource, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - John D. Lipscomb
- Department of Biochemistry, Molecular Biology and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Emile L. Bominaar
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Eckard Münck
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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Mono- and binuclear non-heme iron chemistry from a theoretical perspective. J Biol Inorg Chem 2016; 21:619-44. [DOI: 10.1007/s00775-016-1357-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
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Dong G, Lu J, Lai W. Insights into the Mechanism of Aromatic Ring Cleavage of Noncatecholic Compound 2-Aminophenol by Aminophenol Dioxygenase: A Quantum Mechanics/Molecular Mechanics Study. ACS Catal 2016. [DOI: 10.1021/acscatal.6b00372] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Geng Dong
- Department of Chemistry, Renmin University of China, Beijing 100872, China
| | - Jiarui Lu
- Department of Chemistry, Renmin University of China, Beijing 100872, China
| | - Wenzhen Lai
- Department of Chemistry, Renmin University of China, Beijing 100872, China
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Stout HD, Kleespies ST, Chiang CW, Lee WZ, Que L, Münck E, Bominaar EL. Spectroscopic and Theoretical Study of Spin-Dependent Electron Transfer in an Iron(III) Superoxo Complex. Inorg Chem 2016; 55:5215-26. [PMID: 27159412 DOI: 10.1021/acs.inorgchem.6b00134] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It was shown previously (J. Am. Chem. Soc. 2014, 136, 10846) that bubbling of O2 into a solution of Fe(II)(BDPP) (H2BDPP = 2,6-bis[[(S)-2-(diphenylhydroxymethyl)-1-pyrrolidinyl]methyl]pyridine) in tetrahydrofuran at -80 °C generates a high-spin (SFe = (5)/2) iron(III) superoxo adduct, 1. Mössbauer studies revealed that 1 is an exchange-coupled system, [Formula: see text], where SR = (1)/2 is the spin of the superoxo radical, of which the spectra were not well enough resolved to determine whether the coupling was ferromagnetic (S = 3 ground state) or antiferromagnetic (S = 2). The glass-forming 2-methyltetrahydrofuran solvent yields highly resolved Mössbauer spectra from which the following data have been extracted: (i) the ground state of 1 has S = 3 (J < 0); (ii) |J| > 15 cm(-1); (iii) the zero-field-splitting parameters are D = -1.1 cm(-1) and E/D = 0.02; (iv) the major component of the electric-field-gradient tensor is tilted ≈7° relative to the easy axis of magnetization determined by the MS = ±3 and ±2 doublets. The excited-state MS = ±2 doublet yields a narrow parallel-mode electron paramagnetic resonance signal at g = 8.03, which was used to probe the magnetic hyperfine splitting of (17)O-enriched O2. A theoretical model that considers spin-dependent electron transfer for the cases where the doubly occupied π* orbital of the superoxo ligand is either "in" or "out" of the plane defined by the bent Fe-OO moiety correctly predicts that 1 has an S = 3 ground state, in contrast to the density functional theory calculations for 1, which give a ground state with both the wrong spin and orbital configuration. This failure has been traced to a basis set superposition error in the interactions between the superoxo moiety and the adjacent five-membered rings of the BDPP ligand and signals a fundamental problem in the quantum chemistry of O2 activation.
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Affiliation(s)
- Heather D Stout
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Scott T Kleespies
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Chien-Wei Chiang
- Department of Chemistry, National Taiwan Normal University , 88, Section 4, Ting-Chow Road, Taipei 11677, Taiwan (R.O.C.)
| | - Way-Zen Lee
- Department of Chemistry, National Taiwan Normal University , 88, Section 4, Ting-Chow Road, Taipei 11677, Taiwan (R.O.C.)
| | - Lawrence Que
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Eckard Münck
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Emile L Bominaar
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
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Christian GJ, Neese F, Ye S. Unravelling the Molecular Origin of the Regiospecificity in Extradiol Catechol Dioxygenases. Inorg Chem 2016; 55:3853-64. [PMID: 27050565 DOI: 10.1021/acs.inorgchem.5b02978] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many factors have been suggested to control the selectivity for extradiol or intradiol cleavage in catechol dioxygenases. The varied selectivity of model complexes and the ability to force an extradiol enzyme to do intradiol cleavage indicate that the problem may be complex. In this paper we focus on the regiospecificity of the proximal extradiol dioxygenase, homoprotocatechuate 2,3-dioxygenase (HPCD), for which considerable advances have been made in our understanding of the mechanism from an experimental and computational standpoint. Two key steps in the reaction mechanism were investigated: (1) attack of the substrate by the superoxide moiety and (2) attack of the substrate by the oxyl radical generated by O-O bond cleavage. The selectivity at both steps was investigated through a systematic study of the role of the substrate and the first and second coordination spheres. For the isolated native substrate, intradiol cleavage is calculated to be both kinetically and thermodynamically favored, therefore nature must use the enzyme environment to reverse this preference. Two second sphere residues were found to play key roles in controlling the regiospecificity of the reaction: Tyr257 and His200. Tyr257 controls the selectivity by modulating the electronic structure of the substrate, while His200 controls selectivity through steric effects and by preventing alternative pathways to intradiol cleavage.
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Affiliation(s)
- Gemma J Christian
- Max-Planck Institute for Chemical Energy Conversion , Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.,Avondale College of Higher Education , Cooranbong, New South Wales 2265, Australia
| | - Frank Neese
- Max-Planck Institute for Chemical Energy Conversion , Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Shengfa Ye
- Max-Planck Institute for Chemical Energy Conversion , Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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