1
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Yadav S, Kardam V, Tripathi A, T G S, Dubey KD. The Performance of Different Water Models on the Structure and Function of Cytochrome P450 Enzymes. J Chem Inf Model 2022; 62:6679-6690. [PMID: 36073971 DOI: 10.1021/acs.jcim.2c00505] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Modeling approaches and modern simulations to investigate the biomolecular structure and function rely on various methods. Since water molecules play a crucial role in all sorts of chemistry, the accurate modeling of water molecules is vital for such simulations. In cytochrome P450 (CYP450), in particular, water molecules play a key role in forming active oxidant that ultimately performs oxidation and metabolism. In the present study, we have highlighted the behavior of the three most widely used water models─TIP3P, SPC/E, and OPC─for three different CYP450 enzymes─CYP450BM3, CYP450OleT, and CYP450BSβ─during MD simulations and QM/MM calculations. We studied the various properties, such as RMSD, RMSF, H-bond, water occupancy, and hydrogen atom transfer (HAT), using QM/MM calculations and compared them for all three water models. Our study shows that the stabilities of the enzyme complexes are well maintained in all three water models. However, the OPC water model performs well for the polar active sites, that is, in CYP450OleT and CYP450BSβ, while the TIP3P water model is superior for the hydrophobic site, such as CYP450BM3.
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Affiliation(s)
- Shalini Yadav
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University Delhi-NCR, Gautam Buddha Nagar, U.P. 201314, India
| | - Vandana Kardam
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University Delhi-NCR, Gautam Buddha Nagar, U.P. 201314, India
| | - Ankita Tripathi
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University Delhi-NCR, Gautam Buddha Nagar, U.P. 201314, India
| | - Shruti T G
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University Delhi-NCR, Gautam Buddha Nagar, U.P. 201314, India
| | - Kshatresh Dutta Dubey
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University Delhi-NCR, Gautam Buddha Nagar, U.P. 201314, India
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2
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Han SG, Zhang M, Fu ZH, Zheng L, Ma DD, Wu XT, Zhu QL. Enzyme-Inspired Microenvironment Engineering of a Single-Molecular Heterojunction for Promoting Concerted Electrochemical CO 2 Reduction. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2202830. [PMID: 35765774 DOI: 10.1002/adma.202202830] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/10/2022] [Indexed: 06/15/2023]
Abstract
Challenges remain in the development of novel multifunctional electrocatalysts and their industrial operation on low-electricity pair-electrocatalysis platforms for the carbon cycle. Herein, an enzyme-inspired single-molecular heterojunction electrocatalyst ((NHx )16 -NiPc/CNTs) with specific atomic nickel centers and amino-rich local microenvironments for industrial-level electrochemical CO2 reduction reaction (eCO2 RR) and further energy-saving integrated CO2 electrolysis is designed and developed. (NHx )16 -NiPc/CNTs exhibit unprecedented catalytic performance with industry-compatible current densities, ≈100% Faradaic efficiency and remarkable stability for CO2 -to-CO conversion, outperforming most reported catalysts. In addition to the enhanced CO2 capture by chemisorption, the sturdy deuterium kinetic isotope effect and proton inventory studies sufficiently reveal that such distinctive local microenvironments provide an effective proton ferry effect for improving local alkalinity and proton transfer and creating local interactions to stabilize the intermediate, ultimately enabling the high-efficiency operation of eCO2 RR. Further, by using (NHx )16 -NiPc/CNTs as a bifunctional electrocatalyst in a flow cell, a low-electricity overall CO2 electrolysis system coupling cathodic eCO2 RR with anodic oxidation reaction is developed to achieve concurrent feed gas production and sulfur recovery, simultaneously decreasing the energy input. This work paves the new way in exploring molecular electrocatalysts and electrolysis systems with techno-economic feasibility.
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Affiliation(s)
- Shu-Guo Han
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Min Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
| | - Zhi-Hua Fu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
| | - Lirong Zheng
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Dong-Dong Ma
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
| | - Xin-Tao Wu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, 350108, P. R. China
| | - Qi-Long Zhu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, 350108, P. R. China
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3
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Bhunia S, Ghatak A, Dey A. Second Sphere Effects on Oxygen Reduction and Peroxide Activation by Mononuclear Iron Porphyrins and Related Systems. Chem Rev 2022; 122:12370-12426. [PMID: 35404575 DOI: 10.1021/acs.chemrev.1c01021] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Activation and reduction of O2 and H2O2 by synthetic and biosynthetic iron porphyrin models have proved to be a versatile platform for evaluating second-sphere effects deemed important in naturally occurring heme active sites. Advances in synthetic techniques have made it possible to install different functional groups around the porphyrin ligand, recreating artificial analogues of the proximal and distal sites encountered in the heme proteins. Using judicious choices of these substituents, several of the elegant second-sphere effects that are proposed to be important in the reactivity of key heme proteins have been evaluated under controlled environments, adding fundamental insight into the roles played by these weak interactions in nature. This review presents a detailed description of these efforts and how these have not only demystified these second-sphere effects but also how the knowledge obtained resulted in functional mimics of these heme enzymes.
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Affiliation(s)
- Sarmistha Bhunia
- School of Chemical Science, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata 700032, India
| | - Arnab Ghatak
- School of Chemical Science, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata 700032, India
| | - Abhishek Dey
- School of Chemical Science, Indian Association for the Cultivation of Science, 2A Raja SC Mullick Road, Kolkata 700032, India
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4
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Schröder GC, Meilleur F. Metalloprotein catalysis: structural and mechanistic insights into oxidoreductases from neutron protein crystallography. Acta Crystallogr D Struct Biol 2021; 77:1251-1269. [PMID: 34605429 PMCID: PMC8489226 DOI: 10.1107/s2059798321009025] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/31/2021] [Indexed: 11/11/2022] Open
Abstract
Metalloproteins catalyze a range of reactions, with enhanced chemical functionality due to their metal cofactor. The reaction mechanisms of metalloproteins have been experimentally characterized by spectroscopy, macromolecular crystallography and cryo-electron microscopy. An important caveat in structural studies of metalloproteins remains the artefacts that can be introduced by radiation damage. Photoreduction, radiolysis and ionization deriving from the electromagnetic beam used to probe the structure complicate structural and mechanistic interpretation. Neutron protein diffraction remains the only structural probe that leaves protein samples devoid of radiation damage, even when data are collected at room temperature. Additionally, neutron protein crystallography provides information on the positions of light atoms such as hydrogen and deuterium, allowing the characterization of protonation states and hydrogen-bonding networks. Neutron protein crystallography has further been used in conjunction with experimental and computational techniques to gain insight into the structures and reaction mechanisms of several transition-state metal oxidoreductases with iron, copper and manganese cofactors. Here, the contribution of neutron protein crystallography towards elucidating the reaction mechanism of metalloproteins is reviewed.
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Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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5
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Kwon H, Basran J, Pathak C, Hussain M, Freeman SL, Fielding AJ, Bailey AJ, Stefanou N, Sparkes HA, Tosha T, Yamashita K, Hirata K, Murakami H, Ueno G, Ago H, Tono K, Yamamoto M, Sawai H, Shiro Y, Sugimoto H, Raven EL, Moody PCE. XFEL Crystal Structures of Peroxidase Compound II. Angew Chem Int Ed Engl 2021; 60:14578-14585. [PMID: 33826799 PMCID: PMC8251747 DOI: 10.1002/anie.202103010] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Indexed: 01/07/2023]
Abstract
Oxygen activation in all heme enzymes requires the formation of high oxidation states of iron, usually referred to as ferryl heme. There are two known intermediates: Compound I and Compound II. The nature of the ferryl heme-and whether it is an FeIV =O or FeIV -OH species-is important for controlling reactivity across groups of heme enzymes. The most recent evidence for Compound I indicates that the ferryl heme is an unprotonated FeIV =O species. For Compound II, the nature of the ferryl heme is not unambiguously established. Here, we report 1.06 Å and 1.50 Å crystal structures for Compound II intermediates in cytochrome c peroxidase (CcP) and ascorbate peroxidase (APX), collected using the X-ray free electron laser at SACLA. The structures reveal differences between the two peroxidases. The iron-oxygen bond length in CcP (1.76 Å) is notably shorter than in APX (1.87 Å). The results indicate that the ferryl species is finely tuned across Compound I and Compound II species in closely related peroxidase enzymes. We propose that this fine-tuning is linked to the functional need for proton delivery to the heme.
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Affiliation(s)
- Hanna Kwon
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Jaswir Basran
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Chinar Pathak
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Mahdi Hussain
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Samuel L. Freeman
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Alistair J. Fielding
- Centre for Natural Products Discovery, Pharmacy and Biomolecular SciencesLiverpool John Moores UniversityJames Parsons Building, Byrom StreetLiverpoolL3 3AFUK
| | - Anna J. Bailey
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Natalia Stefanou
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Hazel A. Sparkes
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | | | - Keitaro Yamashita
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
- Present address: MRC Laboratory of Molecular BiologyFrancis Crick Avenue, Cambridge Biomedical CampusCambridgeCB1 0QHUK
| | - Kunio Hirata
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Hironori Murakami
- Japan Synchrotron Radiation Research Institute1-1-1 KoutoSayoHyogo679-5198Japan
| | - Go Ueno
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Hideo Ago
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute1-1-1 KoutoSayoHyogo679-5198Japan
| | | | - Hitomi Sawai
- Graduate School of Life ScienceUniversity of Hyogo3-2-1 Kouto, Kamigori-choAko-gunHyogo678-1297Japan
| | - Yoshitsugu Shiro
- Graduate School of Life ScienceUniversity of Hyogo3-2-1 Kouto, Kamigori-choAko-gunHyogo678-1297Japan
| | | | - Emma L. Raven
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Peter C. E. Moody
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
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6
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Kwon H, Basran J, Pathak C, Hussain M, Freeman SL, Fielding AJ, Bailey AJ, Stefanou N, Sparkes HA, Tosha T, Yamashita K, Hirata K, Murakami H, Ueno G, Ago H, Tono K, Yamamoto M, Sawai H, Shiro Y, Sugimoto H, Raven EL, Moody PCE. XFEL Crystal Structures of Peroxidase Compound II. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 133:14699-14706. [PMID: 38505375 PMCID: PMC10947387 DOI: 10.1002/ange.202103010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Indexed: 03/21/2024]
Abstract
Oxygen activation in all heme enzymes requires the formation of high oxidation states of iron, usually referred to as ferryl heme. There are two known intermediates: Compound I and Compound II. The nature of the ferryl heme-and whether it is an FeIV=O or FeIV-OH species-is important for controlling reactivity across groups of heme enzymes. The most recent evidence for Compound I indicates that the ferryl heme is an unprotonated FeIV=O species. For Compound II, the nature of the ferryl heme is not unambiguously established. Here, we report 1.06 Å and 1.50 Å crystal structures for Compound II intermediates in cytochrome c peroxidase (CcP) and ascorbate peroxidase (APX), collected using the X-ray free electron laser at SACLA. The structures reveal differences between the two peroxidases. The iron-oxygen bond length in CcP (1.76 Å) is notably shorter than in APX (1.87 Å). The results indicate that the ferryl species is finely tuned across Compound I and Compound II species in closely related peroxidase enzymes. We propose that this fine-tuning is linked to the functional need for proton delivery to the heme.
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Affiliation(s)
- Hanna Kwon
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Jaswir Basran
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Chinar Pathak
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Mahdi Hussain
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
| | - Samuel L. Freeman
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Alistair J. Fielding
- Centre for Natural Products Discovery, Pharmacy and Biomolecular SciencesLiverpool John Moores UniversityJames Parsons Building, Byrom StreetLiverpoolL3 3AFUK
| | - Anna J. Bailey
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Natalia Stefanou
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Hazel A. Sparkes
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | | | - Keitaro Yamashita
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
- Present address: MRC Laboratory of Molecular BiologyFrancis Crick Avenue, Cambridge Biomedical CampusCambridgeCB1 0QHUK
| | - Kunio Hirata
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Hironori Murakami
- Japan Synchrotron Radiation Research Institute1-1-1 KoutoSayoHyogo679-5198Japan
| | - Go Ueno
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Hideo Ago
- RIKEN SPring-8 Center1-1-1 KoutoSayoHyogo679-5148Japan
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute1-1-1 KoutoSayoHyogo679-5198Japan
| | | | - Hitomi Sawai
- Graduate School of Life ScienceUniversity of Hyogo3-2-1 Kouto, Kamigori-choAko-gunHyogo678-1297Japan
| | - Yoshitsugu Shiro
- Graduate School of Life ScienceUniversity of Hyogo3-2-1 Kouto, Kamigori-choAko-gunHyogo678-1297Japan
| | | | - Emma L. Raven
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Peter C. E. Moody
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLancaster RoadLeicesterLE1 7RHUK
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7
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Rai A, Klare JP, Reinke PYA, Englmaier F, Fohrer J, Fedorov R, Taft MH, Chizhov I, Curth U, Plettenburg O, Manstein DJ. Structural and Biochemical Characterization of a Dye-Decolorizing Peroxidase from Dictyostelium discoideum. Int J Mol Sci 2021; 22:ijms22126265. [PMID: 34200865 PMCID: PMC8230527 DOI: 10.3390/ijms22126265] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 05/29/2021] [Accepted: 06/05/2021] [Indexed: 12/23/2022] Open
Abstract
A novel cytoplasmic dye-decolorizing peroxidase from Dictyostelium discoideum was investigated that oxidizes anthraquinone dyes, lignin model compounds, and general peroxidase substrates such as ABTS efficiently. Unlike related enzymes, an aspartate residue replaces the first glycine of the conserved GXXDG motif in Dictyostelium DyPA. In solution, Dictyostelium DyPA exists as a stable dimer with the side chain of Asp146 contributing to the stabilization of the dimer interface by extending the hydrogen bond network connecting two monomers. To gain mechanistic insights, we solved the Dictyostelium DyPA structures in the absence of substrate as well as in the presence of potassium cyanide and veratryl alcohol to 1.7, 1.85, and 1.6 Å resolution, respectively. The active site of Dictyostelium DyPA has a hexa-coordinated heme iron with a histidine residue at the proximal axial position and either an activated oxygen or CN- molecule at the distal axial position. Asp149 is in an optimal conformation to accept a proton from H2O2 during the formation of compound I. Two potential distal solvent channels and a conserved shallow pocket leading to the heme molecule were found in Dictyostelium DyPA. Further, we identified two substrate-binding pockets per monomer in Dictyostelium DyPA at the dimer interface. Long-range electron transfer pathways associated with a hydrogen-bonding network that connects the substrate-binding sites with the heme moiety are described.
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Affiliation(s)
- Amrita Rai
- Institute for Biophysical Chemistry, Hannover Medical School, Fritz Hartmann Centre for Medical Research Carl Neuberg Str. 1, D-30625 Hannover, Germany; (A.R.); (P.Y.A.R.); (M.H.T.); (I.C.); (U.C.)
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, D-44227 Dortmund, Germany
| | - Johann P. Klare
- Department of Physics, University of Osnabrueck, Barbarastrasse 7, D-49076 Osnabrück, Germany;
| | - Patrick Y. A. Reinke
- Institute for Biophysical Chemistry, Hannover Medical School, Fritz Hartmann Centre for Medical Research Carl Neuberg Str. 1, D-30625 Hannover, Germany; (A.R.); (P.Y.A.R.); (M.H.T.); (I.C.); (U.C.)
- Division for Structural Biochemistry, Hannover Medical School, Carl Neuberg Str. 1, D-30625 Hannover, Germany;
- Center for Free-Electron Laser Science, German Electron Synchrotron (DESY), Notkestr. 85, D-22607 Hamburg, Germany
| | - Felix Englmaier
- Institute of Medicinal Chemistry, Helmholtz Zentrum München (GmbH), German Research Center for Environmental Health, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany; (F.E.); (O.P.)
- Center of Biomolecular Drug Research (BMWZ), Institute of Organic Chemistry, Leibniz University Hannover, Schneiderberg 1b, D-30167 Hannover, Germany;
| | - Jörg Fohrer
- Center of Biomolecular Drug Research (BMWZ), Institute of Organic Chemistry, Leibniz University Hannover, Schneiderberg 1b, D-30167 Hannover, Germany;
- NMR Department of the Department of Chemistry, Technical University Darmstadt, Clemens Schöpf Institute for Organic Chemistry and Biochemistry, Alarich-Weiss-Strasse 4, D-64287 Darmstadt, Germany
| | - Roman Fedorov
- Division for Structural Biochemistry, Hannover Medical School, Carl Neuberg Str. 1, D-30625 Hannover, Germany;
| | - Manuel H. Taft
- Institute for Biophysical Chemistry, Hannover Medical School, Fritz Hartmann Centre for Medical Research Carl Neuberg Str. 1, D-30625 Hannover, Germany; (A.R.); (P.Y.A.R.); (M.H.T.); (I.C.); (U.C.)
| | - Igor Chizhov
- Institute for Biophysical Chemistry, Hannover Medical School, Fritz Hartmann Centre for Medical Research Carl Neuberg Str. 1, D-30625 Hannover, Germany; (A.R.); (P.Y.A.R.); (M.H.T.); (I.C.); (U.C.)
- Division for Structural Biochemistry, Hannover Medical School, Carl Neuberg Str. 1, D-30625 Hannover, Germany;
| | - Ute Curth
- Institute for Biophysical Chemistry, Hannover Medical School, Fritz Hartmann Centre for Medical Research Carl Neuberg Str. 1, D-30625 Hannover, Germany; (A.R.); (P.Y.A.R.); (M.H.T.); (I.C.); (U.C.)
- Division for Structural Biochemistry, Hannover Medical School, Carl Neuberg Str. 1, D-30625 Hannover, Germany;
| | - Oliver Plettenburg
- Institute of Medicinal Chemistry, Helmholtz Zentrum München (GmbH), German Research Center for Environmental Health, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany; (F.E.); (O.P.)
- Center of Biomolecular Drug Research (BMWZ), Institute of Organic Chemistry, Leibniz University Hannover, Schneiderberg 1b, D-30167 Hannover, Germany;
| | - Dietmar J. Manstein
- Institute for Biophysical Chemistry, Hannover Medical School, Fritz Hartmann Centre for Medical Research Carl Neuberg Str. 1, D-30625 Hannover, Germany; (A.R.); (P.Y.A.R.); (M.H.T.); (I.C.); (U.C.)
- Division for Structural Biochemistry, Hannover Medical School, Carl Neuberg Str. 1, D-30625 Hannover, Germany;
- RESiST, Cluster of Excellence 2155, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
- Correspondence: ; Tel.: +49-511-5323700
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8
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Petrik ID, Davydov R, Kahle M, Sandoval B, Dwaraknath S, Ädelroth P, Hoffman B, Lu Y. An Engineered Glutamate in Biosynthetic Models of Heme-Copper Oxidases Drives Complete Product Selectivity by Tuning the Hydrogen-Bonding Network. Biochemistry 2021; 60:346-355. [PMID: 33464878 PMCID: PMC7888536 DOI: 10.1021/acs.biochem.0c00852] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Efficiently carrying out the oxygen reduction reaction (ORR) is critical for many applications in biology and chemistry, such as bioenergetics and fuel cells, respectively. In biology, this reaction is carried out by large, transmembrane oxidases such as heme-copper oxidases (HCOs) and cytochrome bd oxidases. Common to these oxidases is the presence of a glutamate residue next to the active site, but its precise role in regulating the oxidase activity remains unclear. To gain insight into its role, we herein report that incorporation of glutamate next to a designed heme-copper center in two biosynthetic models of HCOs improves O2 binding affinity, facilitates protonation of reaction intermediates, and eliminates release of reactive oxygen species. High-resolution crystal structures of the models revealed extended, water-mediated hydrogen-bonding networks involving the glutamate. Electron paramagnetic resonance of the cryoreduced oxy-ferrous centers at cryogenic temperature followed by thermal annealing allowed observation of the key hydroperoxo intermediate that can be attributed to the hydrogen-bonding network. By demonstrating these important roles of glutamate in oxygen reduction biochemistry, this work offers deeper insights into its role in native oxidases, which may guide the design of more efficient artificial ORR enzymes or catalysts for applications such as fuel cells.
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Affiliation(s)
- Igor D. Petrik
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Roman Davydov
- The Department of Chemistry, Northwestern University, Evanston, Illinois 60201
| | - Maximilian Kahle
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Braddock Sandoval
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Sudharsan Dwaraknath
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Brian Hoffman
- The Department of Chemistry, Northwestern University, Evanston, Illinois 60201
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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9
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Kwon H, Basran J, Devos JM, Suardíaz R, van der Kamp MW, Mulholland AJ, Schrader TE, Ostermann A, Blakeley MP, Moody PCE, Raven EL. Visualizing the protons in a metalloenzyme electron proton transfer pathway. Proc Natl Acad Sci U S A 2020; 117:6484-6490. [PMID: 32152099 PMCID: PMC7104402 DOI: 10.1073/pnas.1918936117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
In redox metalloenzymes, the process of electron transfer often involves the concerted movement of a proton. These processes are referred to as proton-coupled electron transfer, and they underpin a wide variety of biological processes, including respiration, energy conversion, photosynthesis, and metalloenzyme catalysis. The mechanisms of proton delivery are incompletely understood, in part due to an absence of information on exact proton locations and hydrogen bonding structures in a bona fide metalloenzyme proton pathway. Here, we present a 2.1-Å neutron crystal structure of the complex formed between a redox metalloenzyme (ascorbate peroxidase) and its reducing substrate (ascorbate). In the neutron structure of the complex, the protonation states of the electron/proton donor (ascorbate) and all of the residues involved in the electron/proton transfer pathway are directly observed. This information sheds light on possible proton movements during heme-catalyzed oxygen activation, as well as on ascorbate oxidation.
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Affiliation(s)
- Hanna Kwon
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Jaswir Basran
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
- Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Juliette M Devos
- Life Sciences Group, Institut Laue-Langevin, 38000 Grenoble, France
| | - Reynier Suardíaz
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Marc W van der Kamp
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
| | | | - Tobias E Schrader
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, 85748 Garching, Germany
| | - Andreas Ostermann
- Heinz Maier-Leibnitz Zentrum, Technische Universität München, D-85748 Garching, Germany
| | - Matthew P Blakeley
- Large-Scale Structures Group, Institut Laue-Langevin, 38000 Grenoble, France
| | - Peter C E Moody
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, United Kingdom;
- Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Emma L Raven
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom;
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10
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Ortmayer M, Fisher K, Basran J, Wolde-Michael EM, Heyes DJ, Levy C, Lovelock SL, Anderson JLR, Raven EL, Hay S, Rigby SEJ, Green AP. Rewiring the "Push-Pull" Catalytic Machinery of a Heme Enzyme Using an Expanded Genetic Code. ACS Catal 2020; 10:2735-2746. [PMID: 32550044 PMCID: PMC7273622 DOI: 10.1021/acscatal.9b05129] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/22/2020] [Indexed: 01/14/2023]
Abstract
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Nature
employs a limited number of genetically encoded axial ligands
to control diverse heme enzyme activities. Deciphering the functional
significance of these ligands requires a quantitative understanding of how their electron-donating
capabilities modulate the structures and reactivities of the iconic
ferryl intermediates compounds I and II. However, probing these relationships
experimentally has proven to be challenging as ligand substitutions
accessible via conventional mutagenesis do not allow fine tuning of
electron donation and typically abolish catalytic function. Here,
we exploit engineered translation components to replace the histidine
ligand of cytochrome c peroxidase (CcP) by a less electron-donating Nδ-methyl histidine (Me-His) with little effect on the enzyme structure.
The rate of formation (k1) and the reactivity
(k2) of compound I are unaffected by ligand
substitution. In contrast, proton-coupled electron transfer to compound
II (k3) is 10-fold slower in CcP Me-His, providing a direct link between electron donation
and compound II reactivity, which can be explained by weaker electron
donation from the Me-His ligand (“the push”) affording
an electron-deficient ferryl oxygen with reduced proton affinity (“the
pull”). The deleterious effects of the Me-His ligand can be
fully compensated by introducing a W51F mutation designed to increase
“the pull” by removing a hydrogen bond to the ferryl
oxygen. Analogous substitutions in ascorbate peroxidase lead to similar
activity trends to those observed in CcP, suggesting
that a common mechanistic strategy is employed by enzymes using distinct
electron transfer pathways. Our study highlights how noncanonical
active site substitutions can be used to directly probe and deconstruct
highly evolved bioinorganic mechanisms.
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Affiliation(s)
- Mary Ortmayer
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Karl Fisher
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Jaswir Basran
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, Henry Wellcome Building, University of Leicester, University Road, Leicester LE1 7RH, U.K
| | - Emmanuel M. Wolde-Michael
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Derren J. Heyes
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Colin Levy
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Sarah L. Lovelock
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - J. L. Ross Anderson
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, U.K
| | - Emma L. Raven
- School of Chemistry, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Sam Hay
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Stephen E. J. Rigby
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Anthony P. Green
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
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11
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Liu Y, Leung KY, Michaud SE, Soucy TL, McCrory CCL. Controlled Substrate Transport to Electrocatalyst Active Sites for Enhanced Selectivity in the Carbon Dioxide Reduction Reaction. COMMENT INORG CHEM 2019. [DOI: 10.1080/02603594.2019.1628025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Yingshuo Liu
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Kwan Yee Leung
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Samuel E. Michaud
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Taylor L. Soucy
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Charles C. L. McCrory
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
- Macromolecular Science and Engineering Program, University of Michigan, Ann Arbor, Michigan, USA
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12
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Modulating the mechanism of electrocatalytic CO 2 reduction by cobalt phthalocyanine through polymer coordination and encapsulation. Nat Commun 2019; 10:1683. [PMID: 30976003 PMCID: PMC6459859 DOI: 10.1038/s41467-019-09626-8] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 03/19/2019] [Indexed: 11/24/2022] Open
Abstract
The selective and efficient electrochemical reduction of CO2 to single products is crucial for solar fuels development. Encapsulating molecular catalysts such as cobalt phthalocyanine within coordination polymers such as poly-4-vinylpyridine leads to dramatically increased activity and selectivity for CO2 reduction. In this study, we use a combination of kinetic isotope effect and proton inventory studies to explain the observed increase in activity and selectivity upon polymer encapsulation. We provide evidence that axial-coordination from the pyridyl moieties in poly-4-vinylpyridine to the cobalt phthalocyanine complex changes the rate-determining step in the CO2 reduction mechanism accounting for the increased activity in the catalyst-polymer composite. Moreover, we show that proton delivery to cobalt centers within the polymer is controlled by a proton relay mechanism that inhibits competitive hydrogen evolution. These mechanistic findings provide design strategies for selective CO2 reduction electrocatalysts and serve as a model for understanding the catalytic mechanism of related heterogeneous systems. Understanding the mechanism behind CO2 reduction catalysis is crucial in the development of high efficiency and activity catalysts. Here, authors employ kinetic isotope effects and proton inventory studies to assess catalyst mechanism and proton delivery in molecular CO2 electroreduction materials.
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13
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Bhakta S, Nayek A, Roy B, Dey A. Induction of Enzyme-like Peroxidase Activity in an Iron Porphyrin Complex Using Second Sphere Interactions. Inorg Chem 2019; 58:2954-2964. [DOI: 10.1021/acs.inorgchem.8b02707] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Snehadri Bhakta
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Abhijit Nayek
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Bijan Roy
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Abhishek Dey
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
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14
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Mukherjee S, Mukherjee M, Mukherjee A, Bhagi-Damodaran A, Lu Y, Dey A. O 2 Reduction by Biosynthetic Models of Cytochrome c Oxidase: Insights into Role of Proton Transfer Residues from Perturbed Active Sites Models of CcO. ACS Catal 2018; 8:8915-8924. [PMID: 35693844 DOI: 10.1021/acscatal.8b02240] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Myoglobin based biosynthetic models of perturbed cytochrome c oxidase (CcO) active site are reconstituted, in situ, on electrodes where glutamate residues are systematically introduced in the distal site of the heme/Cu active site instead of a tyrosine residue. These biochemical electrodes show efficient 4e-/4H+ reduction with turnover rates and numbers more than 107 M-1 s-1 and 104, respectively. The H2O/D2O isotope effects of these series of crystallographically characterized mutants bearing zero, one, and two glutamate residues near the heme Cu active site of these perturbed CcO mimics are 16, 4, and 2, respectively. In situ SERRS-RDE data indicate complete change in the rate-determining step as proton transfer residues are introduced near the active site. The high selectivity for 4e-/4H+ O2 reduction and systematic variation of KSIE demonstrate the dominant role of proton transfer residues on the isotope effect on rate and rate-determining step of O2 reduction.
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Affiliation(s)
- Sohini Mukherjee
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Manjistha Mukherjee
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Arnab Mukherjee
- Department of Chemistry, University of Illinois at Urbana—Champaign, Champaign, Illinois 61801, United States
| | - Ambika Bhagi-Damodaran
- Department of Chemistry, University of Illinois at Urbana—Champaign, Champaign, Illinois 61801, United States
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana—Champaign, Champaign, Illinois 61801, United States
| | - Abhishek Dey
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700032, India
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15
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Huang X, Groves JT. Oxygen Activation and Radical Transformations in Heme Proteins and Metalloporphyrins. Chem Rev 2018; 118:2491-2553. [PMID: 29286645 PMCID: PMC5855008 DOI: 10.1021/acs.chemrev.7b00373] [Citation(s) in RCA: 591] [Impact Index Per Article: 98.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Indexed: 12/20/2022]
Abstract
As a result of the adaptation of life to an aerobic environment, nature has evolved a panoply of metalloproteins for oxidative metabolism and protection against reactive oxygen species. Despite the diverse structures and functions of these proteins, they share common mechanistic grounds. An open-shell transition metal like iron or copper is employed to interact with O2 and its derived intermediates such as hydrogen peroxide to afford a variety of metal-oxygen intermediates. These reactive intermediates, including metal-superoxo, -(hydro)peroxo, and high-valent metal-oxo species, are the basis for the various biological functions of O2-utilizing metalloproteins. Collectively, these processes are called oxygen activation. Much of our understanding of the reactivity of these reactive intermediates has come from the study of heme-containing proteins and related metalloporphyrin compounds. These studies not only have deepened our understanding of various functions of heme proteins, such as O2 storage and transport, degradation of reactive oxygen species, redox signaling, and biological oxygenation, etc., but also have driven the development of bioinorganic chemistry and biomimetic catalysis. In this review, we survey the range of O2 activation processes mediated by heme proteins and model compounds with a focus on recent progress in the characterization and reactivity of important iron-oxygen intermediates. Representative reactions initiated by these reactive intermediates as well as some context from prior decades will also be presented. We will discuss the fundamental mechanistic features of these transformations and delineate the underlying structural and electronic factors that contribute to the spectrum of reactivities that has been observed in nature as well as those that have been invented using these paradigms. Given the recent developments in biocatalysis for non-natural chemistries and the renaissance of radical chemistry in organic synthesis, we envision that new enzymatic and synthetic transformations will emerge based on the radical processes mediated by metalloproteins and their synthetic analogs.
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Affiliation(s)
- Xiongyi Huang
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department
of Chemistry, California Institute of Technology, Pasadena, California 91125, United States
| | - John T. Groves
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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16
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Streit BR, Celis AI, Moraski GC, Shisler KA, Shepard EM, Rodgers KR, Lukat-Rodgers GS, DuBois JL. Decarboxylation involving a ferryl, propionate, and a tyrosyl group in a radical relay yields heme b. J Biol Chem 2018; 293:3989-3999. [PMID: 29414780 DOI: 10.1074/jbc.ra117.000830] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/01/2018] [Indexed: 01/02/2023] Open
Abstract
The H2O2-dependent oxidative decarboxylation of coproheme III is the final step in the biosynthesis of heme b in many microbes. However, the coproheme decarboxylase reaction mechanism is unclear. The structure of the decarboxylase in complex with coproheme III suggested that the substrate iron, reactive propionates, and an active-site tyrosine convey a net 2e-/2H+ from each propionate to an activated form of H2O2 Time-resolved EPR spectroscopy revealed that Tyr-145 formed a radical species within 30 s of the reaction of the enzyme-coproheme complex with H2O2 This radical disappeared over the next 270 s, consistent with a catalytic intermediate. Use of the harderoheme III intermediate as substrate or substitutions of redox-active side chains (W198F, W157F, or Y113S) did not strongly affect the appearance or intensity of the radical spectrum measured 30 s after initiating the reaction with H2O2, nor did it change the ∼270 s required for the radical signal to recede to ≤10% of its initial intensity. These results suggested Tyr-145 as the site of a catalytic radical involved in decarboxylating both propionates. Tyr-145• was accompanied by partial loss of the initially present Fe(III) EPR signal intensity, consistent with the possible formation of Fe(IV)=O. Site-specifically deuterated coproheme gave rise to a kinetic isotope effect of ∼2 on the decarboxylation rate constant, indicating that cleavage of the propionate Cβ-H bond was partly rate-limiting. The inferred mechanism requires two consecutive hydrogen atom transfers, first from Tyr-145 to the substrate Fe/H2O2 intermediate and then from the propionate Cβ-H to Tyr-145•.
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Affiliation(s)
- Bennett R Streit
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717-3400 and
| | - Arianna I Celis
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717-3400 and
| | - Garrett C Moraski
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717-3400 and
| | - Krista A Shisler
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717-3400 and
| | - Eric M Shepard
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717-3400 and
| | - Kenton R Rodgers
- the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050
| | - Gudrun S Lukat-Rodgers
- the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050
| | - Jennifer L DuBois
- From the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717-3400 and
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17
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Chreifi G, Dejam D, Poulos TL. Crystal structure and functional analysis of Leishmania major pseudoperoxidase. J Biol Inorg Chem 2017; 22:919-927. [PMID: 28584975 DOI: 10.1007/s00775-017-1469-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/23/2017] [Indexed: 11/25/2022]
Abstract
Leishmania major pseudoperoxidase (LmPP) is a recently discovered heme protein expressed by the human pathogen. Previous in vivo and in vitro studies suggest that LmPP is a crucial element of the pathogen's defense mechanism against the reactive nitrogen species peroxynitrite produced during the host immune response. To shed light on the potential mechanism of peroxynitrite detoxification, we have determined the 1.76-Å X-ray crystal structure of LmPP, revealing a striking degree of homology with heme peroxidases. The most outstanding structural feature is a Cys/His heme coordination, which corroborates previous spectroscopic and mutagenesis studies. We also used a combination of stopped-flow and electron paramagnetic spectroscopies that together suggest that peroxynitrite is not a substrate for LmPP catalysis, leaving the function of LmPP an open question.
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Affiliation(s)
- Georges Chreifi
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697-3900, USA
| | - Dillon Dejam
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697-3900, USA
| | - Thomas L Poulos
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697-3900, USA.
- Department of Chemistry, University of California, Irvine, CA, USA.
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA.
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18
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Celis AI, Gauss GH, Streit BR, Shisler K, Moraski GC, Rodgers KR, Lukat-Rodgers GS, Peters JW, DuBois JL. Structure-Based Mechanism for Oxidative Decarboxylation Reactions Mediated by Amino Acids and Heme Propionates in Coproheme Decarboxylase (HemQ). J Am Chem Soc 2017; 139:1900-1911. [PMID: 27936663 PMCID: PMC5348300 DOI: 10.1021/jacs.6b11324] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Coproheme decarboxylase catalyzes two sequential oxidative decarboxylations with H2O2 as the oxidant, coproheme III as substrate and cofactor, and heme b as the product. Each reaction breaks a C-C bond and results in net loss of hydride, via steps that are not clear. Solution and solid-state structural characterization of the protein in complex with a substrate analog revealed a highly unconventional H2O2-activating distal environment with the reactive propionic acids (2 and 4) on the opposite side of the porphyrin plane. This suggested that, in contrast to direct C-H bond cleavage catalyzed by a high-valent iron intermediate, the coproheme oxidations must occur through mediating amino acid residues. A tyrosine that hydrogen bonds to propionate 2 in a position analogous to the substrate in ascorbate peroxidase is essential for both decarboxylations, while a lysine that salt bridges to propionate 4 is required solely for the second. A mechanism is proposed in which propionate 2 relays an oxidizing equivalent from a coproheme compound I intermediate to the reactive deprotonated tyrosine, forming Tyr•. This residue then abstracts a net hydrogen atom (H•) from propionate 2, followed by migration of the unpaired propionyl electron to the coproheme iron to yield the ferric harderoheme and CO2 products. A similar pathway is proposed for decarboxylation of propionate 4, but with a lysine residue as an essential proton shuttle. The proposed reaction suggests an extended relay of heme-mediated e-/H+ transfers and a novel route for the conversion of carboxylic acids to alkenes.
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Affiliation(s)
- Arianna I. Celis
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717-3400
| | - George H. Gauss
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717-3400
| | - Bennett R. Streit
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717-3400
| | - Krista Shisler
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717-3400
| | - Garrett C. Moraski
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717-3400
| | - Kenton R. Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050
| | - Gudrun S. Lukat-Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050
| | - John W. Peters
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717-3400
| | - Jennifer L. DuBois
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717-3400
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19
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Direct visualization of a Fe(IV)-OH intermediate in a heme enzyme. Nat Commun 2016; 7:13445. [PMID: 27897163 PMCID: PMC5141285 DOI: 10.1038/ncomms13445] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/05/2016] [Indexed: 11/21/2022] Open
Abstract
Catalytic heme enzymes carry out a wide range of oxidations in biology. They have in common a mechanism that requires formation of highly oxidized ferryl intermediates. It is these ferryl intermediates that provide the catalytic engine to drive the biological activity. Unravelling the nature of the ferryl species is of fundamental and widespread importance. The essential question is whether the ferryl is best described as a Fe(IV)=O or a Fe(IV)–OH species, but previous spectroscopic and X-ray crystallographic studies have not been able to unambiguously differentiate between the two species. Here we use a different approach. We report a neutron crystal structure of the ferryl intermediate in Compound II of a heme peroxidase; the structure allows the protonation states of the ferryl heme to be directly observed. This, together with pre-steady state kinetic analyses, electron paramagnetic resonance spectroscopy and single crystal X-ray fluorescence, identifies a Fe(IV)–OH species as the reactive intermediate. The structure establishes a precedent for the formation of Fe(IV)–OH in a peroxidase. The nature of the ferryl intermediate generated in reactions catalysed by heme-containing enzymes is uncertain, due to the ambiguity of X-ray crystallography data. Here, the authors apply neutron diffraction, kinetics and other spectroscopy to directly observe a protonated ferryl intermediate in a heme peroxidase.
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20
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Chen C, Shrestha R, Jia K, Gao PF, Geisbrecht BV, Bossmann SH, Shi J, Li P. Characterization of Dye-decolorizing Peroxidase (DyP) from Thermomonospora curvata Reveals Unique Catalytic Properties of A-type DyPs. J Biol Chem 2015. [PMID: 26205819 DOI: 10.1074/jbc.m115.658807] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dye-decolorizing peroxidases (DyPs) comprise a new family of heme peroxidases, which has received much attention due to their potential applications in lignin degradation. A new DyP from Thermomonospora curvata (TcDyP) was identified and characterized. Unlike other A-type enzymes, TcDyP is highly active toward a wide range of substrates including model lignin compounds, in which the catalytic efficiency with ABTS (kcat(app)/Km(app) = (1.7 × 10(7)) m(-1) s(-1)) is close to that of fungal DyPs. Stopped-flow spectroscopy was employed to elucidate the transient intermediates as well as the catalytic cycle involving wild-type (wt) and mutant TcDyPs. Although residues Asp(220) and Arg(327) are found necessary for compound I formation, His(312) is proposed to play roles in compound II reduction. Transient kinetics of hydroquinone (HQ) oxidation by wt-TcDyP showed that conversion of the compound II to resting state is a rate-limiting step, which will explain the contradictory observation made with the aspartate mutants of A-type DyPs. Moreover, replacement of His(312) and Arg(327) has significant effects on the oligomerization and redox potential (E°') of the enzyme. Both mutants were found to promote the formation of dimeric state and to shift E°' to a more negative potential. Not only do these results reveal the unique catalytic property of the A-type DyPs, but they will also facilitate the development of these enzymes as lignin degraders.
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Affiliation(s)
| | | | | | - Philip F Gao
- the Protein Production Group, University of Kansas, Lawrence, Kansas 66045
| | | | | | - Jishu Shi
- Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506 and
| | - Ping Li
- From the Departments of Chemistry,
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21
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Boaz NC, Bell SR, Groves JT. Ferryl protonation in oxoiron(IV) porphyrins and its role in oxygen transfer. J Am Chem Soc 2015; 137:2875-85. [PMID: 25651467 PMCID: PMC4363944 DOI: 10.1021/ja508759t] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Ferryl porphyrins, P-Fe(IV)═O, are central reactive intermediates in the catalytic cycles of numerous heme proteins and a variety of model systems. There has been considerable interest in elucidating factors, such as terminal oxo basicity, that may control ferryl reactivity. Here, the sulfonated, water-soluble ferryl porphyrin complexes tetramesitylporphyrin, oxoFe(IV)TMPS (FeTMPS-II), its 2,6-dichlorophenyl analogue, oxoFe(IV)TDClPS (FeTDClPS-II), and two other analogues are shown to be protonated under turnover conditions to produce the corresponding bis-aqua-iron(III) porphyrin cation radicals. The results reveal a novel internal electromeric equilibrium, P-Fe(IV)═O ⇆ P(+)-Fe(III)(OH2)2. Reversible pKa values in the range of 4-6.3 have been measured for this process by pH-jump, UV-vis spectroscopy. Ferryl protonation has important ramifications for C-H bond cleavage reactions mediated by oxoiron(IV) porphyrin cation radicals in protic media. Both solvent O-H and substrate C-H deuterium kinetic isotope effects are observed for these reactions, indicating that hydrocarbon oxidation by these oxoiron(IV) porphyrin cation radicals occurs via a solvent proton-coupled hydrogen atom transfer from the substrate that has not been previously described. The effective FeO-H bond dissociation energies for FeTMPS-II and FeTDClPS-II were estimated from similar kinetic reactivities of the corresponding oxoFe(IV)TMPS(+) and oxoFe(IV)TDClPS(+) species to be ∼92-94 kcal/mol. Similar values were calculated from the two-proton P(+)-Fe(III)(OH2)2 pKa(obs) and the porphyrin oxidation potentials, despite a 230 mV range for the iron porphyrins examined. Thus, the iron porphyrin with the lower ring oxidation potential has a compensating higher basicity of the ferryl oxygen. The solvent-derived proton adds significantly to the driving force for C-H bond scission.
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Affiliation(s)
- Nicholas C. Boaz
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Seth R. Bell
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - John T. Groves
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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22
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Simpson N, Adamczyk K, Hithell G, Shaw DJ, Greetham GM, Towrie M, Parker AW, Hunt NT. The effect on structural and solvent water molecules of substrate binding to ferric horseradish peroxidase. Faraday Discuss 2015; 177:163-79. [DOI: 10.1039/c4fd00161c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ultrafast, multi-dimensional infrared spectroscopy, in the form of 2D-IR and pump–probe measurements, has been employed to investigate the effect of substrate binding on the structural dynamics of the horseradish peroxidase (HRP) enzyme. Using nitric oxide bound to the ferric haem of HRP as a sensitive probe of local dynamics, we report measurements of the frequency fluctuations (spectral diffusion) and vibrational lifetime of the NO stretching mode with benzohydroxamic acid (BHA) located in the substrate-binding position at the periphery of the haem pocket, in both D2O and H2O solvents. The results reveal that, with BHA bound to the enzyme, the local structural dynamics are insensitive to H/D exchange. These results are in stark contrast to those found in studies of the substrate-free enzyme, which demonstrated that the local chemical and dynamic environment of the haem ligand is influenced by water molecules. In light of the large changes in solvent accessibility caused by substrate binding, we discuss the potential for varying roles for the solvent in the haem pocket of HRP at different stages along the reaction coordinate of the enzymatic mechanism.
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Affiliation(s)
- Niall Simpson
- Department of Physics
- University of Strathclyde
- SUPA
- Glasgow
- UK
| | | | - Gordon Hithell
- Department of Physics
- University of Strathclyde
- SUPA
- Glasgow
- UK
| | - Daniel J. Shaw
- Department of Physics
- University of Strathclyde
- SUPA
- Glasgow
- UK
| | - Gregory M. Greetham
- Central Laser Facility, Research Complex at Harwell
- STFC Rutherford Appleton Laboratory
- Didcot
- UK
| | - Michael Towrie
- Central Laser Facility, Research Complex at Harwell
- STFC Rutherford Appleton Laboratory
- Didcot
- UK
| | - Anthony W. Parker
- Central Laser Facility, Research Complex at Harwell
- STFC Rutherford Appleton Laboratory
- Didcot
- UK
| | - Neil T. Hunt
- Department of Physics
- University of Strathclyde
- SUPA
- Glasgow
- UK
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23
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Adamczyk K, Simpson N, Greetham GM, Gumiero A, Walsh MA, Towrie M, Parker AW, Hunt NT. Ultrafast infrared spectroscopy reveals water-mediated coherent dynamics in an enzyme active site. Chem Sci 2014; 6:505-516. [PMID: 28936306 PMCID: PMC5588449 DOI: 10.1039/c4sc02752c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/22/2014] [Indexed: 11/24/2022] Open
Abstract
Ultrafast infrared spectroscopy provides insights into the dynamic nature of water in the active sites of catalase and peroxidase enzymes.
Understanding the impact of fast dynamics upon the chemical processes occurring within the active sites of proteins and enzymes is a key challenge that continues to attract significant interest, though direct experimental insight in the solution phase remains sparse. Similar gaps in our knowledge exist in understanding the role played by water, either as a solvent or as a structural/dynamic component of the active site. In order to investigate further the potential biological roles of water, we have employed ultrafast multidimensional infrared spectroscopy experiments that directly probe the structural and vibrational dynamics of NO bound to the ferric haem of the catalase enzyme from Corynebacterium glutamicum in both H2O and D2O. Despite catalases having what is believed to be a solvent-inaccessible active site, an isotopic dependence of the spectral diffusion and vibrational lifetime parameters of the NO stretching vibration are observed, indicating that water molecules interact directly with the haem ligand. Furthermore, IR pump–probe data feature oscillations originating from the preparation of a coherent superposition of low-frequency vibrational modes in the active site of catalase that are coupled to the haem ligand stretching vibration. Comparisons with an exemplar of the closely-related peroxidase enzyme family shows that they too exhibit solvent-dependent active-site dynamics, supporting the presence of interactions between the haem ligand and water molecules in the active sites of both catalases and peroxidases that may be linked to proton transfer events leading to the formation of the ferryl intermediate Compound I. In addition, a strong, water-mediated, hydrogen bonding structure is suggested to occur in catalase that is not replicated in peroxidase; an observation that may shed light on the origins of the different functions of the two enzymes.
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Affiliation(s)
- Katrin Adamczyk
- Department of Physics , University of Strathclyde , SUPA , 107 Rottenrow East , Glasgow , G4 0NG , UK .
| | - Niall Simpson
- Department of Physics , University of Strathclyde , SUPA , 107 Rottenrow East , Glasgow , G4 0NG , UK .
| | - Gregory M Greetham
- Central Laser Facility , Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford , Didcot, Oxon , OX11 0QX , UK
| | - Andrea Gumiero
- Diamond Light Source , Diamond House, Harwell Science and Innovation Campus , Didcot, Oxfordshire , OX11 0DE , UK
| | - Martin A Walsh
- Diamond Light Source , Diamond House, Harwell Science and Innovation Campus , Didcot, Oxfordshire , OX11 0DE , UK
| | - Michael Towrie
- Central Laser Facility , Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford , Didcot, Oxon , OX11 0QX , UK
| | - Anthony W Parker
- Central Laser Facility , Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford , Didcot, Oxon , OX11 0QX , UK
| | - Neil T Hunt
- Department of Physics , University of Strathclyde , SUPA , 107 Rottenrow East , Glasgow , G4 0NG , UK .
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24
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Davydov R, Laryukhin M, Ledbetter-Rogers A, Sono M, Dawson JH, Hoffman BM. Electron paramagnetic resonance and electron-nuclear double resonance studies of the reactions of cryogenerated hydroperoxoferric-hemoprotein intermediates. Biochemistry 2014; 53:4894-903. [PMID: 25046203 PMCID: PMC4144713 DOI: 10.1021/bi500296d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
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The fleeting ferric peroxo and hydroperoxo
intermediates of dioxygen
activation by hemoproteins can be readily trapped and characterized
during cryoradiolytic reduction of ferrous hemoprotein–O2 complexes at 77 K. Previous cryoannealing studies suggested
that the relaxation of cryogenerated hydroperoxoferric intermediates
of myoglobin (Mb), hemoglobin, and horseradish peroxidase (HRP), either
trapped directly at 77 K or generated by cryoannealing of a trapped
peroxo-ferric state, proceeds through dissociation of bound H2O2 and formation of the ferric heme without formation
of the ferryl porphyrin π-cation radical intermediate, compound
I (Cpd I). Herein we have reinvestigated the mechanism of decays of
the cryogenerated hydroperoxyferric intermediates of α- and
β-chains of human hemoglobin, HRP, and chloroperoxidase (CPO).
The latter two proteins are well-known to form spectroscopically detectable
quasistable Cpds I. Peroxoferric intermediates are trapped during
77 K cryoreduction of oxy Mb, α-chains, and β-chains of
human hemoglobin and CPO. They convert into hydroperoxoferric intermediates
during annealing at temperatures above 160 K. The hydroperoxoferric
intermediate of HRP is trapped directly at 77 K. All studied hydroperoxoferric
intermediates decay with measurable rates at temperatures above 170
K with appreciable solvent kinetic isotope effects. The hydroperoxoferric
intermediate of β-chains converts to the S =
3/2 Cpd I, which in turn decays to an electron paramagnetic resonance
(EPR)-silent product at temperature above 220 K. For all the other
hemoproteins studied, cryoannealing of the hydroperoxo intermediate
directly yields an EPR-silent majority product. In each case, a second
follow-up 77 K γ-irradiation of the annealed samples yields
low-spin EPR signals characteristic of cryoreduced ferrylheme (compound
II, Cpd II). This indicates that in general the hydroperoxoferric
intermediates relax to Cpd I during cryoanealing at low temperatures,
but when this state is not captured by reaction with a bound substrate,
it is reduced to Cpd II by redox-active products of radiolysis.
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Affiliation(s)
- Roman Davydov
- Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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25
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Casadei CM, Gumiero A, Metcalfe CL, Murphy EJ, Basran J, Concilio MG, Teixeira SCM, Schrader TE, Fielding AJ, Ostermann A, Blakeley MP, Raven EL, Moody PCE. Heme enzymes. Neutron cryo-crystallography captures the protonation state of ferryl heme in a peroxidase. Science 2014; 345:193-7. [PMID: 25013070 DOI: 10.1126/science.1254398] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Heme enzymes activate oxygen through formation of transient iron-oxo (ferryl) intermediates of the heme iron. A long-standing question has been the nature of the iron-oxygen bond and, in particular, the protonation state. We present neutron structures of the ferric derivative of cytochrome c peroxidase and its ferryl intermediate; these allow direct visualization of protonation states. We demonstrate that the ferryl heme is an Fe(IV)=O species and is not protonated. Comparison of the structures shows that the distal histidine becomes protonated on formation of the ferryl intermediate, which has implications for the understanding of O-O bond cleavage in heme enzymes. The structures highlight the advantages of neutron cryo-crystallography in probing reaction mechanisms and visualizing protonation states in enzyme intermediates.
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Affiliation(s)
- Cecilia M Casadei
- Department of Biochemistry and Henry Wellcome Laboratories for Structural Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK. Institut Laue-Langevin, 71 Avenue des Martyrs, 38000, Grenoble, France
| | - Andrea Gumiero
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Clive L Metcalfe
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Emma J Murphy
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Jaswir Basran
- Department of Biochemistry and Henry Wellcome Laboratories for Structural Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | | | - Susana C M Teixeira
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38000, Grenoble, France. EPSAM, Keele University, Keele, Staffordshire ST5 5BG, UK
| | - Tobias E Schrader
- Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching, Germany
| | - Alistair J Fielding
- The Photon Science Institute, The University of Manchester, Manchester M13 9PL, UK
| | - Andreas Ostermann
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstraße 1, D-85748 Garching, Germany
| | | | - Emma L Raven
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK.
| | - Peter C E Moody
- Department of Biochemistry and Henry Wellcome Laboratories for Structural Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
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26
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Dutta A, Roberts JAS, Shaw WJ. Arginine-containing ligands enhance H₂ oxidation catalyst performance. Angew Chem Int Ed Engl 2014; 53:6487-91. [PMID: 24820824 DOI: 10.1002/anie.201402304] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Indexed: 12/25/2022]
Abstract
Hydrogenase enzymes use Ni and Fe to oxidize H2 at high turnover frequencies (TOF) (up to 10,000 s(-1)) and low overpotentials (<100 mV). In comparison, the fastest reported synthetic electrocatalyst, [Ni(II)(P(Cy)2N(tBu)2)2](2+), oxidizes H2 at 60 s(-1) in MeCN under 1 atm H2 with an unoptimized overpotential of ca. 500 mV using triethylamine as a base. Here we show that a structured outer coordination sphere in a Ni electrocatalyst enhances H2 oxidation activity: [Ni(II)(P(Cy)2N(Arg)2)2](8+) (Arg=arginine) has a TOF of 210 s(-1) in water with high energy efficiency (180 mV overpotential) under 1 atm H2 , and 144,000 s(-1) (460 mV overpotential) under 133 atm H2. The complex is active from pH 0-14 and is faster at low pH, the most relevant condition for fuel cells. The arginine substituents increase TOF and may engage in an intramolecular guanidinium interaction that assists in H2 activation, while the COOH groups facilitate rapid proton movement. These results emphasize the critical role of features beyond the active site in achieving fast, efficient catalysis.
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Affiliation(s)
- Arnab Dutta
- Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352 (USA)
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27
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Dutta A, Roberts JAS, Shaw WJ. Arginine‐Containing Ligands Enhance H
2
Oxidation Catalyst Performance. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402304] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Arnab Dutta
- Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352 (USA)
| | - John A. S. Roberts
- Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352 (USA)
| | - Wendy J. Shaw
- Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352 (USA)
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28
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Gumiero A, Guimero A, Badyal SK, Leeks T, Moody PCE, Raven EL. Probing the conformational mobility of the active site of a heme peroxidase. Dalton Trans 2013; 42:3170-5. [PMID: 23202589 DOI: 10.1039/c2dt32455e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
We have previously demonstrated (Badyal et al., J. Biol. Chem., 2006, 281, 24512) that removal of the active site tryptophan (Trp41) in ascorbate peroxidase increases the conformational mobility of the distal histidine residue (His42) and that His42 coordinates to the iron in the oxidised W41A enzyme to give a 6-coordinate, low-spin peroxidase. In this work, we probe the conformational flexibility of the active site in more detail. We examine whether other residues (Cys, Tyr, Met) can also ligate to the heme at position 42; we find that introduction of other ligating amino acids created a cavity in the heme pocket, but that formation of 6-coordinate heme is not observed. In addition, we examine the role of Asn-71, which hydrogen bonds to His42 and tethers the distal histidine in the active site pocket; we find that removal of this hydrogen bond increases the proportion of low-spin heme. We suggest that, in addition to its well-known role in facilitating the reaction with peroxide, His42 also plays a role in defining the shape and folding of the active site pocket.
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Affiliation(s)
| | - Andrea Guimero
- Department of Chemistry, University of Leicester, University Road, Leicester, LE1 9HN, England, UK
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29
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Yoshida T, Tsuge H, Hisabori T, Sugano Y. Crystal structures of dye-decolorizing peroxidase with ascorbic acid and 2,6-dimethoxyphenol. FEBS Lett 2012; 586:4351-6. [PMID: 23159941 DOI: 10.1016/j.febslet.2012.10.049] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/19/2012] [Accepted: 10/26/2012] [Indexed: 11/27/2022]
Abstract
The structure of dye-decolorizing peroxidase (DyP)-type peroxidase differs from that of other peroxidase families, indicating that DyP-type peroxidases have a different reaction mechanism. We have determined the crystal structures of DyP with ascorbic acid and 2,6-dimethoxyphenol at 1.5 and 1.4Å, respectively. The common binding site for both substrates was located at the entrance of the second cavity leading from the DyP molecular surface to heme. This resulted in a hydrogen bond network connection between each substrate and the heme distal side. This network consisted of water molecules occupying the second cavity, heme 6-propionate, Arg329, and Asn313. This network is consistent with the proton transfer pathway from substrate to DyP.
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Affiliation(s)
- Toru Yoshida
- Chemical Resources Laboratory, Tokyo Institute of Technology, R1-8, 4259 Nagatsuta, Yokohama 226-8503, Japan
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30
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Singh R, Grigg JC, Armstrong Z, Murphy MEP, Eltis LD. Distal heme pocket residues of B-type dye-decolorizing peroxidase: arginine but not aspartate is essential for peroxidase activity. J Biol Chem 2012; 287:10623-10630. [PMID: 22308037 DOI: 10.1074/jbc.m111.332171] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
DypB from Rhodococcus jostii RHA1 is a bacterial dye-decolorizing peroxidase (DyP) that oxidizes lignin and Mn(II). Three residues interact with the iron-bound solvent species in ferric DypB: Asn-246 and the conserved Asp-153 and Arg-244. Substitution of either Asp-153 or Asn-246 with alanine minimally affected the second order rate constant for Compound I formation (k(1) ∼ 10(5) M(-1)s(-1)) and the specificity constant (k(cat)/K(m)) for H(2)O(2). Even in the D153A/N246A double variant, these values were reduced less than 30-fold. However, these substitutions dramatically reduced the stability of Compound I (t(1/2) ∼ 0.13 s) as compared with the wild-type enzyme (540 s). By contrast, substitution of Arg-244 with leucine abolished the peroxidase activity, and heme iron of the variant showed a pH-dependent transition from high spin (pH 5) to low spin (pH 8.5). Two variants were designed to mimic the plant peroxidase active site: D153H, which was more than an order of magnitude less reactive with H(2)O(2), and N246H, which had no detectable peroxidase activity. X-ray crystallographic studies revealed that structural changes in the variants are confined to the distal heme environment. The data establish an essential role for Arg-244 in Compound I formation in DypB, possibly through charge stabilization and proton transfer. The principle roles of Asp-153 and Asn-246 appear to be in modulating the subsequent reactivity of Compound I. These results expand the range of residues known to catalyze Compound I formation in heme peroxidases.
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Affiliation(s)
- Rahul Singh
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Zachary Armstrong
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael E P Murphy
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Lindsay D Eltis
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
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