1
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Kagawa Y, Oohora K, Himiyama T, Suzuki A, Hayashi T. Redox Engineering of Myoglobin by Cofactor Substitution to Enhance Cyclopropanation Reactivity. Angew Chem Int Ed Engl 2024:e202403485. [PMID: 38780472 DOI: 10.1002/anie.202403485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/23/2024] [Accepted: 05/23/2024] [Indexed: 05/25/2024]
Abstract
Design of metal cofactor ligands is essential for controlling the reactivity of metalloenzymes. We investigated a carbene transfer reaction catalyzed by myoglobins containing iron porphyrin cofactors with one and two trifluoromethyl groups at peripheral sites (FePorCF3 and FePor(CF3)2, respectively), native heme and iron porphycene (FePc). These four myoglobins show a wide range of Fe(II)/Fe(III) redox potentials in the protein of +147 mV, +87 mV, +42 mV and -198 mV vs. NHE, respectively. Myoglobin reconstituted with FePor(CF3)2 has a more positive potential, which enhances the reactivity of a carbene intermediate with alkenes, and demonstrates superior cyclopropanation of inert alkenes, such as aliphatic and internal alkenes. In contrast, engineered myoglobin reconstituted with FePc has a more negative redox potential, which accelerates the formation of the intermediate, but has low reactivity for inert alkenes. Mechanistic studies indicate that myoglobin with FePor(CF3)2 generates an undetectable active intermediate with a radical character. In contrast, this reaction catalyzed by myoglobin with FePc includes a detectable iron-carbene species with electrophilic character. This finding highlights the importance of redox-focused design of the iron porphyrinoid cofactor in hemoproteins to tune the reactivity of the carbene transfer reaction.
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Affiliation(s)
- Yoshiyuki Kagawa
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Koji Oohora
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka, 565-0871, Japan
| | - Tomoki Himiyama
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ikeda, Osaka, 563-8577, Japan
| | - Akihiro Suzuki
- National Institute of Technology, Ibaraki College, Hitachinaka, Ibaraki, 312-8508, Japan
| | - Takashi Hayashi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
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2
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Lewis LC, Sanabria-Gracia JA, Lee Y, Jenkins AJ, Shafaat HS. Electronic isomerism in a heterometallic nickel-iron-sulfur cluster models substrate binding and cyanide inhibition of carbon monoxide dehydrogenase. Chem Sci 2024; 15:5916-5928. [PMID: 38665523 PMCID: PMC11040638 DOI: 10.1039/d4sc00023d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/04/2024] [Indexed: 04/28/2024] Open
Abstract
The nickel-iron carbon monoxide dehydrogenase (CODH) enzyme uses a heterometallic nickel-iron-sulfur ([NiFe4S4]) cluster to catalyze the reversible interconversion of carbon dioxide (CO2) and carbon monoxide (CO). These reactions are essential for maintaining the global carbon cycle and offer a route towards sustainable greenhouse gas conversion but have not been successfully replicated in synthetic models, in part due to a poor understanding of the natural system. Though the general protein architecture of CODH is known, the electronic structure of the active site is not well-understood, and the mechanism of catalysis remains unresolved. To better understand the CODH enzyme, we have developed a protein-based model containing a heterometallic [NiFe3S4] cluster in the Pyrococcus furiosus (Pf) ferredoxin (Fd). This model binds small molecules such as carbon monoxide and cyanide, analogous to CODH. Multiple redox- and ligand-bound states of [NiFe3S4] Fd (NiFd) have been investigated using a suite of spectroscopic techniques, including resonance Raman, Ni and Fe K-edge X-ray absorption spectroscopy, and electron paramagnetic resonance, to resolve charge and spin delocalization across the cluster, site-specific electron density, and ligand activation. The facile movement of charge through the cluster highlights the fluidity of electron density within iron-sulfur clusters and suggests an electronic basis by which CN- inhibits the native system while the CO-bound state continues to elude isolation in CODH. The detailed characterization of isolable states that are accessible in our CODH model system provides valuable insight into unresolved enzymatic intermediates and offers design principles towards developing functional mimics of CODH.
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Affiliation(s)
- Luke C Lewis
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - José A Sanabria-Gracia
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - Yuri Lee
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles Los Angeles CA 90095 USA
| | - Adam J Jenkins
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - Hannah S Shafaat
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles Los Angeles CA 90095 USA
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3
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Kagawa Y, Oohora K, Hayashi T. Intramolecular C-H bond amination catalyzed by myoglobin reconstituted with iron porphycene. J Inorg Biochem 2024; 252:112459. [PMID: 38181613 DOI: 10.1016/j.jinorgbio.2023.112459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/10/2023] [Accepted: 12/16/2023] [Indexed: 01/07/2024]
Abstract
C-H bond amination is an effective way to obtain nitrogen-containing products. In this work, we demonstrate that myoglobin reconstituted with iron porphycene (rMb(FePc)) catalyzes intramolecular C(sp3)-H bond amination of arylsulfonyl azides to yield corresponding sultam analogs. The total turnover number of rMb(FePc) is up to 5.7 × 104 for the C-H bond amination of 2,4,6-triisopropylbenzenesulfonyl azide. Moreover, rMb(FePc) exhibits higher selectivity for the desired C-H bond amination than the competing azide reduction compared to native myoglobin. Kinetic studies reveal that the kcat value of rMb(FePc) is 4-fold higher than that of native myoglobin. Furthermore, H64A, H64V and H64I mutants of rMb(FePc) enhance the turnover number (TON) and enantioselectivity for the C-H bond amination of 2,4,6-triethylbenzenesulfonyl azide. The present findings indicate that iron porphycene is an attractive artificial cofactor for myoglobin toward the C-H bond amination reaction.
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Affiliation(s)
- Yoshiyuki Kagawa
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Koji Oohora
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan; Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka, 565-0871, Japan.
| | - Takashi Hayashi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan.
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4
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Lemon CM. Diversifying the functions of heme proteins with non-porphyrin cofactors. J Inorg Biochem 2023; 246:112282. [PMID: 37320889 DOI: 10.1016/j.jinorgbio.2023.112282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/09/2023] [Accepted: 05/30/2023] [Indexed: 06/17/2023]
Abstract
Heme proteins perform diverse biochemical functions using a single iron porphyrin cofactor. This versatility makes them attractive platforms for the development of new functional proteins. While directed evolution and metal substitution have expanded the properties, reactivity, and applications of heme proteins, the incorporation of porphyrin analogs remains an underexplored approach. This review discusses the replacement of heme with non-porphyrin cofactors, such as porphycene, corrole, tetradehydrocorrin, phthalocyanine, and salophen, and the attendant properties of these conjugates. While structurally similar, each ligand exhibits distinct optical and redox properties, as well as unique chemical reactivity. These hybrids serve as model systems to elucidate the effects of the protein environment on the electronic structure, redox potentials, optical properties, or other features of the porphyrin analog. Protein encapsulation can confer distinct chemical reactivity or selectivity of artificial metalloenzymes that cannot be achieved with the small molecule catalyst alone. Additionally, these conjugates can interfere with heme acquisition and uptake in pathogenic bacteria, providing an inroad to innovative antibiotic strategies. Together, these examples illustrate the diverse functionality that can be achieved by cofactor substitution. The further expansion of this approach will access unexplored chemical space, enabling the development of superior catalysts and the creation of heme proteins with emergent properties.
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Affiliation(s)
- Christopher M Lemon
- Department of Chemistry and Biochemistry, Montana State University, PO Box 173400, Bozeman, MT 59717, United States.
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5
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Ghosh A, Conradie J. B12 and F430 models: Metal- versus ligand-centered redox in cobalt and nickel tetradehydrocorrin derivatives. J Inorg Biochem 2023; 243:112199. [PMID: 36996695 DOI: 10.1016/j.jinorgbio.2023.112199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 03/18/2023] [Indexed: 03/29/2023]
Abstract
DFT calculations with the well-tested OLYP and B3LYP* exchange-correlation functionals (along with D3 dispersion corrections and all-electron ZORA STO-TZ2P basis sets) and careful use of group theory have led to significant insights into the question of metal- versus ligand-centered redox in Co and Ni B,C-tetradehydrocorrin complexes. For the cationic complexes, both metals occur in their low-spin M(II) forms. In contrast, the charge-neutral states vary for the two metals: while the Co(I) and CoII-TDC•2- state are comparable in energy for cobalt, a low-spin NiII-TDC•2- state is clearly preferred for nickel. The latter behavior stands in sharp contrast to other corrinoids that reportedly stabilize a Ni(I) center.
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Affiliation(s)
- Abhik Ghosh
- Department of Chemistry, UiT The Arctic University of Norway, N-9037 Tromsø, Norway.
| | - Jeanet Conradie
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa.
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Sun LJ, Yuan H, Xu JK, Luo J, Lang JJ, Wen GB, Tan X, Lin YW. Phenoxazinone Synthase-like Activity of Rationally Designed Heme Enzymes Based on Myoglobin. Biochemistry 2023; 62:369-377. [PMID: 34665595 DOI: 10.1021/acs.biochem.1c00554] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The design of functional metalloenzymes is attractive for the biosynthesis of biologically important compounds, such as phenoxazinones and phenazines catalyzed by native phenoxazinone synthase (PHS). To design functional heme enzymes, we used myoglobin (Mb) as a model protein and introduced an artificial CXXC motif into the heme distal pocket by F46C and L49C mutations, which forms a de novo disulfide bond, as confirmed by the X-ray crystal structure. We further introduced a catalytic Tyr43 into the heme distal pocket and found that the F43Y/F46C/L49C Mb triple mutant and the previously designed F43Y/F46S Mb exhibit PHS-like activity (80-98% yields in 5-15 min), with the catalytic efficiency exceeding those of natural metalloenzymes, including o-aminophenol oxidase, laccase, and dye-decolorizing peroxidase. Moreover, we showed that the oxidative coupling product of 1,6-disulfonic-2,7-diaminophenazine is a potential pH indicator, with the orange-magenta color change at pH 4-5 (pKa = 4.40). Therefore, this study indicates that functional heme enzymes can be rationally designed by structural modifications of Mb, exhibiting the functionality of the native PHS for green biosynthesis.
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Affiliation(s)
- Li-Juan Sun
- Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Hong Yuan
- Department of Chemistry and Institute of Biomedical Science, Fudan University, Shanghai 200433, China
| | - Jia-Kun Xu
- Key Lab of Sustainable Development of Polar Fisheries, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Jie Luo
- Lab of Protein Structure and Function, University of South China, Hengyang 421001, China
| | - Jia-Jia Lang
- Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Ge-Bo Wen
- Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Xiangshi Tan
- Department of Chemistry and Institute of Biomedical Science, Fudan University, Shanghai 200433, China
| | - Ying-Wu Lin
- Hengyang Medical School, University of South China, Hengyang 421001, China.,Lab of Protein Structure and Function, University of South China, Hengyang 421001, China
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Shisaka Y, Shoji O. Bridging the gap: Unveiling novel functions of a bacterial haem-acquisition protein capturing diverse synthetic porphyrinoids. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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8
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Liu Y, Lai KL, Vong K. Transition Metal Scaffolds Used To Bring New‐to‐Nature Reactions into Biological Systems. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yifei Liu
- Department of Chemistry The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon Hong Kong China
| | - Ka Lun Lai
- Department of Chemistry The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon Hong Kong China
| | - Kenward Vong
- Department of Chemistry The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon Hong Kong China
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9
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Shisaka Y, Sakakibara E, Suzuki K, Stanfield JK, Onoda H, Ueda G, Hatano M, Sugimoto H, Shoji O. Tetraphenylporphyrin Enters the Ring: First Example of a Complex Between Highly Bulky Porphyrins and a Protein. Chembiochem 2022; 23:e202200095. [PMID: 35352458 DOI: 10.1002/cbic.202200095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/17/2022] [Indexed: 11/08/2022]
Abstract
Tetraphenylporphyrin (TPP) is a symmetrically substituted synthetic porphyrin whose properties can be readily modified, providing it with significant advantages over naturally occurring porphyrins. Herein, we report the first example of a stable complex between a native biomolecule, the haemoprotein HasA, and TPP as well as its derivatives. The X-ray crystal structures of nine different HasA-TPP complexes were solved at high resolutions. HasA capturing TPP derivatives was also demonstrated to inhibit growth of the opportunistic pathogen Pseudomonas aeruginosa . Mutant variants of HasA binding FeTPP were shown to possess a different mode of coordination, permitting the cyclopropanation of styrene.
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Affiliation(s)
- Yuma Shisaka
- Nagoya University, Chemistry, Furo-cho, Chikusa-ku, 464-8602, Nagoya, JAPAN
| | - Erika Sakakibara
- Nagoya University, Chemistry, Furo-cho, Chikusa-ku, 464-8602, Nagoya, JAPAN
| | - Kazuto Suzuki
- Nagoya University, Chemistry, Furo-cho, Chikusa-ku, 464-8602, Nagoya, JAPAN
| | | | - Hiroki Onoda
- Nagoya University, Chemistry, Furo-cho, Chikusa-ku, 464-8602, Nagoya, JAPAN
| | - Garyo Ueda
- Nagoya University, Chemistry, Furo-cho, Chikusa-ku, 464-8602, Nagoya, JAPAN
| | - Miu Hatano
- Nagoya University, Chemistry, Furo-cho, Chikusa-ku, 464-8602, Nagoya, JAPAN
| | - Hiroshi Sugimoto
- RIKEN: Rikagaku Kenkyujo, SPring-8 Centre, 1-1-1 Kouto, 679-5148, Sayo, JAPAN
| | - Osami Shoji
- Nagoya University, Graduate School of Science, Furo, Chikusa,, 464-8602, Nagoya, JAPAN
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10
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Miyazaki Y, Oohora K, Hayashi T. Focusing on a nickel hydrocorphinoid in a protein matrix: methane generation by methyl-coenzyme M reductase with F430 cofactor and its models. Chem Soc Rev 2022; 51:1629-1639. [PMID: 35148362 DOI: 10.1039/d1cs00840d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Methyl-coenzyme M reductase (MCR) containing a nickel hydrocorphinoid cofactor, F430, is an essential enzyme that catalyzes anaerobic methane generation and oxidation. The active Ni(I) species in MCR converts methyl-coenzyme M (CH3S-CoM) and coenzyme B (HS-CoB) to methane and heterodisulfide (CoM-S-S-CoB). Extensive experimental and theoretical studies focusing on the substrate-binding cavity including the F430 cofactor in MCR have suggested two principally different reaction mechanisms involving an organonickel CH3-Ni(III) species or a transient methyl radical species. In parallel with research on native MCR itself, the functionality of MCR has been investigated in the context of model complexes of F430 and recent protein-based functional models, which include a nickel complex. In the latter case, hemoproteins reconstituted with tetradehydro- and didehydrocorrinoid nickel complexes have been found to represent useful model systems that are responsible for methane generation. These efforts support the proposed mechanism of the enzymatic reaction and provide important insight into replicating the MCR-like methane-generation process. Furthermore, the modeling of MCR described here is expected to lead to understanding of protein-supported nickel porphyrinoid chemistry as well as the creation of MCR-inspired catalysis.
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Affiliation(s)
- Yuta Miyazaki
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan.
| | - Koji Oohora
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan.
| | - Takashi Hayashi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan.
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11
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Treviño RE, Shafaat HS. Protein-based models offer mechanistic insight into complex nickel metalloenzymes. Curr Opin Chem Biol 2022; 67:102110. [PMID: 35101820 DOI: 10.1016/j.cbpa.2021.102110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/22/2021] [Accepted: 12/06/2021] [Indexed: 11/03/2022]
Abstract
There are ten nickel enzymes found across biological systems, each with a distinct active site and reactivity that spans reductive, oxidative, and redox-neutral processes. We focus on the reductive enzymes, which catalyze reactions that are highly germane to the modern-day climate crisis: [NiFe] hydrogenase, carbon monoxide dehydrogenase, acetyl coenzyme A synthase, and methyl coenzyme M reductase. The current mechanistic understanding of each enzyme system is reviewed along with existing knowledge gaps, which are addressed through the development of protein-derived models, as described here. This opinion is intended to highlight the advantages of using robust protein scaffolds for modeling multiscale contributions to reactivity and inspire the development of novel artificial metalloenzymes for other small molecule transformations.
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Affiliation(s)
- Regina E Treviño
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Hannah S Shafaat
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA.
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12
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Lemon CM, Nissley AJ, Latorraca NR, Wittenborn EC, Marletta MA. Corrole–protein interactions in H-NOX and HasA. RSC Chem Biol 2022; 3:571-581. [PMID: 35656484 PMCID: PMC9092467 DOI: 10.1039/d2cb00004k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/20/2022] [Indexed: 02/04/2023] Open
Abstract
Mutagenesis was utilised to reveal corrole–protein interactions in H-NOX and HasA. The key interaction is a hydrogen bond between the PO unit of the corrole and a protonated histidine residue.
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Affiliation(s)
- Christopher M. Lemon
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720, USA
- Miller Institute for Basic Research in Science, University of California, Berkeley, CA 94720, USA
| | - Amos J. Nissley
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Naomi R. Latorraca
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- Miller Institute for Basic Research in Science, University of California, Berkeley, CA 94720, USA
| | - Elizabeth C. Wittenborn
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720, USA
| | - Michael A. Marletta
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720, USA
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
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13
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Lewis LC, Shafaat HS. Reversible Electron Transfer and Substrate Binding Support [NiFe 3S 4] Ferredoxin as a Protein-Based Model for [NiFe] Carbon Monoxide Dehydrogenase. Inorg Chem 2021; 60:13869-13875. [PMID: 34488341 DOI: 10.1021/acs.inorgchem.1c01323] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The nickel-iron carbon monoxide dehydrogenase (CODH) enzyme catalyzes the reversible and selective interconversion of carbon dioxide (CO2) to carbon monoxide (CO) with high rates and negligible overpotential. Despite decades of research, many questions remain about this complex metalloenzyme system. A simplified model enzyme could provide substantial insight into biological carbon cycling. Here, we demonstrate reversible electron transfer and binding of both CO and cyanide, a substrate and an inhibitor of CODH, respectively, in a Pyrococcus furiosus (Pf) ferredoxin (Fd) protein that has been reconstituted with a nickel-iron sulfide cluster ([NiFe3S4] Fd). The [NiFe3S4] cluster mimics the core of the native CODH active site and thus serves as a protein-based structural model of the CODH subsite. Notably, despite binding cyanide, no CO binding is observed for the physiological [Fe4S4] clusters in Pf Fd, providing chemical rationale underlying the evolution of a site-differentiated cluster for substrate conversion in native CODH. The demonstration of a substrate-binding metalloprotein model of CODH sets the stage for high-resolution spectroscopic and mechanistic studies correlating the subsite structure and function, ultimately guiding the design of anthropogenic catalysts that harness the advantages of CODH for effective CO2 reduction.
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Affiliation(s)
- Luke C Lewis
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Hannah S Shafaat
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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14
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Pott M, Tinzl M, Hayashi T, Ota Y, Dunkelmann D, Mittl PRE, Hilvert D. Noncanonical Heme Ligands Steer Carbene Transfer Reactivity in an Artificial Metalloenzyme*. Angew Chem Int Ed Engl 2021; 60:15063-15068. [PMID: 33880851 DOI: 10.1002/anie.202103437] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Indexed: 11/06/2022]
Abstract
Changing the primary metal coordination sphere is a powerful strategy for tuning metalloprotein properties. Here we used amber stop codon suppression with engineered pyrrolysyl-tRNA synthetases, including two newly evolved enzymes, to replace the proximal histidine in myoglobin with Nδ -methylhistidine, 5-thiazoylalanine, 4-thiazoylalanine and 3-(3-thienyl)alanine. In addition to tuning the heme redox potential over a >200 mV range, these noncanonical ligands modulate the protein's carbene transfer activity with ethyl diazoacetate. Variants with increased reduction potential proved superior for cyclopropanation and N-H insertion, whereas variants with reduced Eo values gave higher S-H insertion activity. Given the functional importance of histidine in many enzymes, these genetically encoded analogues could be valuable tools for probing mechanism and enabling new chemistries.
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Affiliation(s)
- Moritz Pott
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Matthias Tinzl
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Takahiro Hayashi
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Yusuke Ota
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Daniel Dunkelmann
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Peer R E Mittl
- Department of Biochemistry, University of Zürich, 8057, Zürich, Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
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15
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Pott M, Tinzl M, Hayashi T, Ota Y, Dunkelmann D, Mittl PRE, Hilvert D. Noncanonical Heme Ligands Steer Carbene Transfer Reactivity in an Artificial Metalloenzyme**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Moritz Pott
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
| | - Matthias Tinzl
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
| | - Takahiro Hayashi
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
| | - Yusuke Ota
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
| | | | - Peer R. E. Mittl
- Department of Biochemistry University of Zürich 8057 Zürich Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
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16
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DiPrimio DJ, Holland PL. Repurposing metalloproteins as mimics of natural metalloenzymes for small-molecule activation. J Inorg Biochem 2021; 219:111430. [PMID: 33873051 DOI: 10.1016/j.jinorgbio.2021.111430] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 12/12/2022]
Abstract
Artificial metalloenzymes (ArMs) consist of an unnatural metal or cofactor embedded in a protein scaffold, and are an excellent platform for applying the concepts of protein engineering to catalysis. In this Focused Review, we describe the application of ArMs as simple, tunable artificial models of the active sites of complex natural metalloenzymes for small-molecule activation. In this sense, ArMs expand the strategies of synthetic model chemistry to protein-based supporting ligands with potential for participation from the second coordination sphere. We focus specifically on ArMs that are structural, spectroscopic, and functional models of enzymes for activation of small molecules like CO, CO2, O2, N2, and NO, as well as production/consumption of H2. These ArMs give insight into the identities and roles of metalloenzyme structural features within and near the cofactor. We give examples of ArM work relevant to hydrogenases, acetyl-coenzyme A synthase, superoxide dismutase, heme oxygenases, nitric oxide reductase, methyl-coenzyme M reductase, copper-O2 enzymes, and nitrogenases.
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Affiliation(s)
- Daniel J DiPrimio
- Department of Chemistry, Yale University, New Haven, CT, 06520, United States
| | - Patrick L Holland
- Department of Chemistry, Yale University, New Haven, CT, 06520, United States.
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Vong K, Nasibullin I, Tanaka K. Exploring and Adapting the Molecular Selectivity of Artificial Metalloenzymes. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20200316] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Kenward Vong
- Biofunctional Synthetic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
- GlycoTargeting Research Laboratory, RIKEN Baton Zone Program, Wako, Saitama 351-0198, Japan
| | - Igor Nasibullin
- Biofunctional Synthetic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
- Biofunctional Chemistry Laboratory, A. Butlerov Institute of Chemistry, Kazan Federal University, Kazan 420008, Russia
| | - Katsunori Tanaka
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan
- Biofunctional Synthetic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
- Biofunctional Chemistry Laboratory, A. Butlerov Institute of Chemistry, Kazan Federal University, Kazan 420008, Russia
- GlycoTargeting Research Laboratory, RIKEN Baton Zone Program, Wako, Saitama 351-0198, Japan
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Oohora K, Hayashi T. Myoglobins engineered with artificial cofactors serve as artificial metalloenzymes and models of natural enzymes. Dalton Trans 2021; 50:1940-1949. [PMID: 33433532 DOI: 10.1039/d0dt03597a] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Metalloenzymes naturally achieve various reactivities by assembling limited types of cofactors with endogenous amino acid residues. Enzymes containing metal porphyrinoid cofactors such as heme, cobalamin and F430 exert precise control over the reactivities of the cofactors with protein matrices. This perspective article focuses on our recent efforts to assemble metal complexes of non-natural porphyrinoids within the protein matrix of myoglobin, an oxygen storage hemoprotein. Engineered myoglobins with suitable metal complexes as artificial cofactors demonstrate unique reactivities toward C-H bond hydroxylation, olefin cyclopropanation, methyl group transfer and methane generation. In these cases, the protein matrix enhances the catalytic activities of the cofactors and allows us to monitor the active intermediates. The present findings indicate that placing artificial cofactors in protein matrices provides a useful strategy for creating artificial metalloenzymes that catalyse otherwise unfavourable reactions and providing enzyme models for elucidating the complicated reaction mechanisms of natural enzymes.
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Affiliation(s)
- Koji Oohora
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, 565-0871, Japan.
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Miyazaki Y, Oohora K, Hayashi T. Methane Generation and Reductive Debromination of Benzylic Position by Reconstituted Myoglobin Containing Nickel Tetradehydrocorrin as a Model of Methyl-coenzyme M Reductase. Inorg Chem 2020; 59:11995-12004. [PMID: 32794737 DOI: 10.1021/acs.inorgchem.0c00901] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Methyl-coenzyme M reductase (MCR), which contains the nickel hydrocorphinoid cofactor F430, is responsible for biological methane generation under anaerobic conditions via a reaction mechanism which has not been completely elucidated. In this work, myoglobin reconstituted with an artificial cofactor, nickel(I) tetradehydrocorrin (NiI(TDHC)), is used as a protein-based functional model for MCR. The reconstituted protein, rMb(NiI(TDHC)), is found to react with methyl donors such as methyl p-toluenesulfonate and trimethylsulfonium iodide with methane evolution observed in aqueous media containing dithionite. Moreover, rMb(NiI(TDHC)) is found to convert benzyl bromide derivatives to reductively debrominated products without homocoupling products. The reactivity increases in the order of primary > secondary > tertiary benzylic carbons, indicating steric effects on the reaction of the nickel center with the benzylic carbon in the initial step. In addition, Hammett plots using a series of para-substituted benzyl bromides exhibit enhancement of the reactivity with introduction of electron-withdrawing substituents, as shown by the positive slope against polar substituent constants. These results suggest a nucleophilic SN2-type reaction of the Ni(I) species with the benzylic carbon to provide an organonickel species as an intermediate. The reaction in D2O buffer at pD 7.0 causes a complete isotope shift of the product by +1 mass unit, supporting our proposal that protonation of the organonickel intermediate occurs during product formation. Although the turnover numbers are limited due to inactivation of the cofactor by side reactions, the present findings will contribute to elucidating the reaction mechanism of MCR-catalyzed methane generation from activated methyl sources and dehalogenation.
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Affiliation(s)
- Yuta Miyazaki
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
| | - Koji Oohora
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
| | - Takashi Hayashi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
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