1
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Lundahl MN, Greiner MB, Piquette MC, Gannon PM, Kaminsky W, Kovacs JA. Exploring the influence of H-bonding and ligand constraints on thiolate ligated non-heme iron mediated dioxygen activation. Chem Sci 2024; 15:12710-12720. [PMID: 39148773 PMCID: PMC11325341 DOI: 10.1039/d4sc02787f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 07/05/2024] [Indexed: 08/17/2024] Open
Abstract
Converting triplet dioxygen into a powerful oxidant is fundamentally important to life. The study reported herein quantitatively examines the formation of a well-characterized, reactive, O2-derived thiolate ligated FeIII-superoxo using low-temperature stopped-flow kinetics. Comparison of the kinetic barriers to the formation of this species via two routes, involving either the addition of (a) O2 to [FeII(S2 Me2N3(Pr,Pr))] (1) or (b) superoxide to [FeIII(S2 Me2N3(Pr,Pr))]+ (3) is shown to provide insight into the mechanism of O2 activation. Route (b) was shown to be significantly slower, and the kinetic barrier 14.9 kJ mol-1 higher than route (a), implying that dioxygen activation involves inner-sphere, as opposed to outer sphere, electron transfer from Fe(ii). H-bond donors and ligand constraints are shown to dramatically influence O2 binding kinetics and reversibility. Dioxygen binds irreversibly to [FeII(S2 Me2N3(Pr,Pr))] (1) in tetrahydrofuran, but reversibly in methanol. Hydrogen bonding decreases the ability of the thiolate sulfur to stabilize the transition state and the FeIII-superoxo, as shown by the 10 kJ mol-1 increase in the kinetic barrier to O2 binding in methanol vs. tetrahydrofuran. Dioxygen release from [FeIII(S2 Me2N3(Pr,Pr))O2] (2) is shown to be 24 kJ mol-1 higher relative to previously reported [FeIII(SMe2N4(tren))(O2)]+ (5), the latter of which contains a more flexible ligand. These kinetic results afford an experimentally determined reaction coordinate that illustrates the influence of H-bonding and ligand constraints on the kinetic barrier to dioxygen activation an essential step in biosynthetic pathways critical to life.
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Affiliation(s)
- Maike N Lundahl
- Department of Chemistry, University of Washington Campus Box 351700 Seattle WA 98195 USA
| | - Maria B Greiner
- Department of Chemistry, University of Washington Campus Box 351700 Seattle WA 98195 USA
| | - Marc C Piquette
- Department of Chemistry, Tufts University 62 Talbot Avenue Medford Massachusetts 02155 USA
| | - Paige M Gannon
- Department of Chemistry, University of Washington Campus Box 351700 Seattle WA 98195 USA
| | - Werner Kaminsky
- Department of Chemistry, University of Washington Campus Box 351700 Seattle WA 98195 USA
| | - Julie A Kovacs
- Department of Chemistry, University of Washington Campus Box 351700 Seattle WA 98195 USA
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2
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Tian YC, Zhang P, Lin KT, Fu CW, Ye S, Lee WZ. A Mechanistic Spectrum of O-H Bond Cleavage Observed for Reactions of Phenols with a Manganese Superoxo Complex. Chemistry 2024; 30:e202401826. [PMID: 38747420 DOI: 10.1002/chem.202401826] [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: 05/09/2024] [Indexed: 05/30/2024]
Abstract
Reaction of a rare and well-characterized MnIII-superoxo species, Mn(BDPBrP)(O2⋅) (1, H2BDPBrP=2,6-bis((2-(S)-di(4-bromo)phenylhydroxylmethyl-1-pyrrolidinyl)methyl)pyridine), with 4-dimethylaminophenol at -80 °C proceeds via concerted proton electron transfer (CPET) to produce a MnIII-hydroperoxo complex, Mn(BDPBrP)(OOH) (2), alongside 4-dimethylaminophenoxy radical; whereas, upon treatment with 4-nitrophenol, complex 1 undergoes a proton transfer process to afford a MnIV-hydroperoxo complex, [Mn(BDPBrP)(OOH)]+ (3). Intriguingly, the reactions of 1 with 4-chlorophenol and 4-methoxyphenol follow two routes of CPET and sequential proton and electron transfer to furnish complex 2 in the end. UV-vis and EPR spectroscopic studies coupled with DFT calculations provided support for this wide mechanistic spectrum of activating various phenol O-H bonds by a single MnIII-superoxo complex, 1.
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Affiliation(s)
- Yao-Cheng Tian
- Department of Chemistry, National Taiwan Normal University, 11677, Taipei, Taiwan
| | - Peng Zhang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023, Dalian, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Kuan-Ting Lin
- Department of Chemistry, National Taiwan Normal University, 11677, Taipei, Taiwan
| | - Chung-Wei Fu
- Department of Chemistry, National Taiwan Normal University, 11677, Taipei, Taiwan
| | - Shengfa Ye
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023, Dalian, China
| | - Way-Zen Lee
- Department of Chemistry, National Taiwan Normal University, 11677, Taipei, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, 807, Kaohsiung, Taiwan
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3
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Pan J, Wenger ES, Lin CY, Zhang B, Sil D, Schaperdoth I, Saryazdi S, Grossman RB, Krebs C, Bollinger JM. An Unusual Ferryl Intermediate and Its Implications for the Mechanism of Oxacyclization by the Loline-Producing Iron(II)- and 2-Oxoglutarate-Dependent Oxygenase, LolO. Biochemistry 2024; 63:1674-1683. [PMID: 38898603 PMCID: PMC11219260 DOI: 10.1021/acs.biochem.4c00166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
N-Acetylnorloline synthase (LolO) is one of several iron(II)- and 2-oxoglutarate-dependent (Fe/2OG) oxygenases that catalyze sequential reactions of different types in the biosynthesis of valuable natural products. LolO hydroxylates C2 of 1-exo-acetamidopyrrolizidine before coupling the C2-bonded oxygen to C7 to form the tricyclic loline core. Each reaction requires cleavage of a C-H bond by an oxoiron(IV) (ferryl) intermediate; however, different carbons are targeted, and the carbon radicals have different fates. Prior studies indicated that the substrate-cofactor disposition (SCD) controls the site of H· abstraction and can affect the reaction outcome. These indications led us to determine whether a change in SCD from the first to the second LolO reaction might contribute to the observed reactivity switch. Whereas the single ferryl complex in the C2 hydroxylation reaction was previously shown to have typical Mössbauer parameters, one of two ferryl complexes to accumulate during the oxacyclization reaction has the highest isomer shift seen to date for such a complex and abstracts H· from C7 ∼ 20 times faster than does the first ferryl complex in its previously reported off-pathway hydroxylation of C7. The detectable hydroxylation of C7 in competition with cyclization by the second ferryl complex is not enhanced in 2H2O solvent, suggesting that the C2 hydroxyl is deprotonated prior to C7-H cleavage. These observations are consistent with the coordination of the C2 oxygen to the ferryl complex, which may reorient its oxo ligand, the substrate, or both to positions more favorable for C7-H cleavage and oxacyclization.
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Affiliation(s)
- Juan Pan
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: New England Biolabs, Ipswich, Massachusetts 01938, United States
| | - Eliott S. Wenger
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Chi-Yun Lin
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Bo Zhang
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: The Janssen Pharmaceutical Companies of Johnson & Johnson, Spring House, Pennsylvania 19477, United States
| | - Debangsu Sil
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: Department of Chemistry, Indian Institute of Science Education and Research, Pune 411008, India
| | - Irene Schaperdoth
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Present address: Department of Engineering, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Setareh Saryazdi
- Department of Chemistry, The University of Kentucky, Lexington, Kentucky 40506, United States
- Present address: College of Pharmacy, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Robert B. Grossman
- Department of Chemistry, The University of Kentucky, Lexington, Kentucky 40506, United States
| | - Carsten Krebs
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - J. Martin Bollinger
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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4
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Paris JC, Hei Cheung Y, Zhang T, Chang WC, Liu P, Guo Y. New Frontiers in Nonheme Enzymatic Oxyferryl Species. Chembiochem 2024:e202400307. [PMID: 38900645 DOI: 10.1002/cbic.202400307] [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: 04/04/2024] [Revised: 06/13/2024] [Accepted: 06/20/2024] [Indexed: 06/22/2024]
Abstract
Non-heme mononuclear iron dependent (NHM-Fe) enzymes exhibit exceedingly diverse catalytic reactivities. Despite their catalytic versatilities, the mononuclear iron centers in these enzymes show a relatively simple architecture, in which an iron atom is ligated with 2-4 amino acid residues, including histidine, aspartic or glutamic acid. In the past two decades, a common high-valent reactive iron intermediate, the S=2 oxyferryl (Fe(IV)-oxo or Fe(IV)=O) species, has been repeatedly discovered in NHM-Fe enzymes containing a 2-His-Fe or 2-His-1-carboxylate-Fe center. However, for 3-His/4-His-Fe enzymes, no common reactive intermediate has been identified. Recently, we have spectroscopically characterized the first S=1 Fe(IV) intermediate in a 3-His-Fe containing enzyme, OvoA, which catalyzes a novel oxidative carbon-sulfur bond formation. In this review, we summarize the broad reactivities demonstrated by S=2 Fe(IV)-oxo intermediates, the discovery of the first S=1 Fe(IV) intermediate in OvoA and the mechanistic implication of such a discovery, and the intrinsic reactivity differences of the S=2 and the S=1 Fe(IV)-oxo species. Finally, we postulate the possible reasons to utilize an S=1 Fe(IV) species in OvoA and their implications to other 3-His/4-His-Fe enzymes.
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Affiliation(s)
- Jared C Paris
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA, 15213, USA
| | - Yuk Hei Cheung
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA, 02215, USA
| | - Tao Zhang
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA, 02215, USA
| | - Wei-Chen Chang
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC, 27695, USA
| | - Pinghua Liu
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA, 02215, USA
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA, 15213, USA
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5
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Chen JY, van der Donk WA. Multinuclear non-heme iron dependent oxidative enzymes (MNIOs) involved in unusual peptide modifications. Curr Opin Chem Biol 2024; 80:102467. [PMID: 38772214 DOI: 10.1016/j.cbpa.2024.102467] [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: 03/04/2024] [Revised: 04/28/2024] [Accepted: 04/29/2024] [Indexed: 05/23/2024]
Abstract
Multinuclear non-heme iron dependent oxidative enzymes (MNIOs), formerly known as domain of unknown function 692 (DUF692), are involved in the post-translational modification of peptides during the biosynthesis of peptide-based natural products. These enzymes catalyze highly unusual and diverse chemical modifications. Several class-defining features of this large family (>14 000 members) are beginning to emerge. Structurally, the enzymes are characterized by a TIM-barrel fold and a set of conserved residues for a di- or tri-iron binding site. They use molecular oxygen to modify peptide substrates, often in a four-electron oxidation taking place at a cysteine residue. This review summarizes the current understanding of MNIOs. Four modifications are discussed in detail: oxazolone-thioamide formation, β-carbon excision, hydantoin-macrocycle formation, and 5-thiooxazole formation. Briefly discussed are two other reactions that do not take place on Cys residues.
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Affiliation(s)
- Jeff Y Chen
- Department of Chemistry, The Carl R. Woese Institute for Genomic Biology, The Howard Hughes Medical Institute at the University of Illinois at Urbana-Champaign, 1206 W Gregory Drive, Urbana, IL 61801, USA
| | - Wilfred A van der Donk
- Department of Chemistry, The Carl R. Woese Institute for Genomic Biology, The Howard Hughes Medical Institute at the University of Illinois at Urbana-Champaign, 1206 W Gregory Drive, Urbana, IL 61801, USA.
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6
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Wang Q, Li H, Bujupi U, Gröning J, Stolz A, Bongiorno A, Gupta R. Oxygen Activation in Aromatic Ring Cleaving Salicylate Dioxygenase: Detection of Reaction Intermediates with a Nitro-substituted Substrate Analog. Chembiochem 2024; 25:e202400023. [PMID: 38363551 DOI: 10.1002/cbic.202400023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 02/17/2024]
Abstract
Cupin dioxygenases such as salicylate 1,2-dioxygense (SDO) perform aromatic C-C bond scission via a 3-His motif tethered iron cofactor. Here, transient kinetics measurements are used to monitor the catalytic cycle of SDO by using a nitro-substituted substrate analog, 3-nitrogentisate. Compared to the natural substrate, the nitro group reduces the enzymatic kcat by 500-fold, thereby facilitating the detection and kinetic characterization of reaction intermediates. Sums and products of reciprocal relaxation times derived from kinetic measurements were found to be linearly dependent on O2 concentration, suggesting reversible formation of two distinct intermediates. Dioxygen binding to the metal cofactor takes place with a forward rate of 5.9×103 M-1 s-1: two orders of magnitude slower than other comparable ring-cleaving dioxygenses. Optical chromophore of the first intermediate is distinct from the in situ generated SDO Fe(III)-O2⋅- complex but closer to the enzyme-substrate precursor.
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Affiliation(s)
- Qian Wang
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Blvd. Staten Island, New York, 10314, United States
| | - Hanbin Li
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Blvd. Staten Island, New York, 10314, United States
- Ph.D. Programs in Chemistry and Physics, The Graduate Center of the City University of New York, New York, 10016, United States
| | - Uran Bujupi
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Blvd. Staten Island, New York, 10314, United States
| | - Janosch Gröning
- Institut für Mikrobiologie, Universität Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Andreas Stolz
- Institut für Mikrobiologie, Universität Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Angelo Bongiorno
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Blvd. Staten Island, New York, 10314, United States
- Ph.D. Programs in Chemistry and Physics, The Graduate Center of the City University of New York, New York, 10016, United States
| | - Rupal Gupta
- Department of Chemistry, College of Staten Island, The City University of New York, 2800 Victory Blvd. Staten Island, New York, 10314, United States
- Ph.D. Programs in Biochemistry, The Graduate Center of the City University of New York, New York, 10016, United States
- Ph.D. Programs in Chemistry and Physics, The Graduate Center of the City University of New York, New York, 10016, United States
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7
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Gao Y, Zhu Y, Awakawa T, Abe I. Unusual cysteine modifications in natural product biosynthesis. RSC Chem Biol 2024; 5:293-311. [PMID: 38576726 PMCID: PMC10989515 DOI: 10.1039/d4cb00020j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 02/08/2024] [Indexed: 04/06/2024] Open
Abstract
l-Cysteine is a highly reactive amino acid that is modified into a variety of chemical structures, including cysteine sulfinic acid in human metabolic pathways, and sulfur-containing scaffolds of amino acids, alkaloids, and peptides in natural product biosynthesis. Among the modification enzymes responsible for these cysteine-derived compounds, metalloenzymes constitute an important family of enzymes that catalyze a wide variety of reactions. Therefore, understanding their reaction mechanisms is important for the biosynthetic production of cysteine-derived natural products. This review mainly summarizes recent mechanistic investigations of metalloenzymes, with a particular focus on recently discovered mononuclear non-heme iron (NHI) enzymes, dinuclear NHI enzymes, and radical-SAM enzymes involved in unusual cysteine modifications in natural product biosynthesis.
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Affiliation(s)
- Yaojie Gao
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
| | - Yuhao Zhu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
| | - Takayoshi Awakawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
- RIKEN Center for Sustainable Resource Science Wako Saitama 351-0198 Japan
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo Yayoi 1-1-1, Bunkyo-ku Tokyo 113-8657 Japan
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8
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Yadav S, Yadav V, Siegler MA, Moënne-Loccoz P, Jameson GNL, Goldberg DP. A Nonheme Iron(III) Superoxide Complex Leads to Sulfur Oxygenation. J Am Chem Soc 2024; 146:7915-7921. [PMID: 38488295 DOI: 10.1021/jacs.3c12337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
A new alkylthiolate-ligated nonheme iron complex, FeII(BNPAMe2S)Br (1), is reported. Reaction of 1 with O2 at -40 °C, or reaction of the ferric form with O2•- at -80 °C, gives a rare iron(III)-superoxide intermediate, [FeIII(O2)(BNPAMe2S)]+ (2), characterized by UV-vis, 57Fe Mössbauer, ATR-FTIR, EPR, and CSIMS. Metastable 2 then converts to an S-oxygenated FeII(sulfinate) product via a sequential O atom transfer mechanism involving an iron-sulfenate intermediate. These results provide evidence for the feasibility of proposed intermediates in thiol dioxygenases.
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Affiliation(s)
- Sudha Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Vishal Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Guy N L Jameson
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road,Parkville, Victoria 3010, Australia
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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9
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Yadav V, Wen L, Yadav S, Siegler MA, Goldberg DP. Selective Radical Transfer in a Series of Nonheme Iron(III) Complexes. Inorg Chem 2023; 62:17830-17842. [PMID: 37857315 PMCID: PMC11296666 DOI: 10.1021/acs.inorgchem.3c02617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
A series of nonheme iron complexes, FeIII(BNPAPh2O)(Lax)(Leq) (Lax/eq = N3-, NCS-, NCO-, and Cl-) have been synthesized using the previously reported BNPAPh2O- ligand. The ferrous analogs FeII(BNPAPh2O)(Lax) (Lax = N3-, NCS-, and NCO-) were also prepared. The complexes were structurally characterized using single crystal X-ray diffraction, which shows that all the FeIII complexes are six-coordinate, with one anionic ligand (Lax) in the H-bonding axial site and the other anionic ligand (Leq) in the equatorial plane, cis to the Lax ligand. The reaction of FeIII(BNPAPh2O-)(Lax)(Leq) with Ph3C• shows that one ligand is selectively transferred in each case. A selectivity trend emerges that shows •N3 is the most favored for transfer in each case to the carbon radical, whereas Cl• is the least favored. The NCO and NCS ligands showed an intermediate propensity for radical transfer, with NCS > NCO. The overall order of selectivity is N3 > NCS > NCO > Cl. In addition, we also demonstrated that H-bonding has a small effect on governing product selectivity by using a non-H-bonded ligand (DPAPh2O-). This study demonstrates the inherent radical transfer selectivity of nonhydroxo-ligated nonheme iron(III) complexes, which could be useful for efforts in synthetic and (bio)catalytic C-H functionalization.
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Affiliation(s)
- Vishal Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Lyupeng Wen
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Sudha Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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10
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Paris JC, Hu S, Wen A, Weitz AC, Cheng R, Gee LB, Tang Y, Kim H, Vegas A, Chang WC, Elliott SJ, Liu P, Guo Y. An S=1 Iron(IV) Intermediate Revealed in a Non-Heme Iron Enzyme-Catalyzed Oxidative C-S Bond Formation. Angew Chem Int Ed Engl 2023; 62:e202309362. [PMID: 37640689 PMCID: PMC10592081 DOI: 10.1002/anie.202309362] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/11/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
Ergothioneine (ESH) and ovothiol A (OSHA) are two natural thiol-histidine derivatives. ESH has been implicated as a longevity vitamin and OSHA inhibits the proliferation of hepatocarcinoma. The key biosynthetic step of ESH and OSHA in the aerobic pathways is the O2 -dependent C-S bond formation catalyzed by non-heme iron enzymes (e.g., OvoA in ovothiol biosynthesis), but due to the lack of identification of key reactive intermediate the mechanism of this novel reaction is unresolved. In this study, we report the identification and characterization of a kinetically competent S=1 iron(IV) intermediate supported by a four-histidine ligand environment (three from the protein residues and one from the substrate) in enabling C-S bond formation in OvoA from Methyloversatilis thermotoleran, which represents the first experimentally observed intermediate spin iron(IV) species in non-heme iron enzymes. Results reported in this study thus set the stage to further dissect the mechanism of enzymatic oxidative C-S bond formation in the OSHA biosynthesis pathway. They also afford new opportunities to study the structure-function relationship of high-valent iron intermediates supported by a histidine rich ligand environment.
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Affiliation(s)
- Jared C Paris
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213, USA
| | - Sha Hu
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Aiwen Wen
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Andrew C Weitz
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Ronghai Cheng
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Leland B Gee
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Yijie Tang
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213, USA
| | - Hyomin Kim
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Arturo Vegas
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Wei-Chen Chang
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Sean J Elliott
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Pinghua Liu
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213, USA
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11
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Zheng Y, Xu X, Fu X, Zhou X, Dou C, Yu Y, Yan W, Yang J, Xiao M, van der Donk WA, Zhu X, Cheng W. Structures of the holoenzyme TglHI required for 3-thiaglutamate biosynthesis. Structure 2023; 31:1220-1232.e5. [PMID: 37652001 PMCID: PMC10880893 DOI: 10.1016/j.str.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/12/2023] [Accepted: 08/04/2023] [Indexed: 09/02/2023]
Abstract
Structural diverse natural products like ribosomally synthesized and posttranslationally modified peptides (RiPPs) display a wide range of biological activities. Currently, the mechanism of an uncommon reaction step during the biosynthesis of 3-thiaglutamate (3-thiaGlu) is poorly understood. The removal of the β-carbon from the Cys in the TglA-Cys peptide catalyzed by the TglHI holoenzyme remains elusive. Here, we present three crystal structures of TglHI complexes with and without bound iron, which reveal that the catalytic pocket is formed by the interaction of TglH-TglI and that its activation is conformation dependent. Biochemical assays suggest a minimum of two iron ions in the active cluster, and we identify the position of a third iron site. Collectively, our study offers insights into the activation and catalysis mechanisms of the non-heme dioxygen-dependent holoenzyme TglHI. Additionally, it highlights the evolutionary and structural conservation in the DUF692 family of biosynthetic enzymes that produce diverse RiPPs.
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Affiliation(s)
- Yanhui Zheng
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China
| | - Xiaoqing Xu
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China
| | - Xiaoli Fu
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China
| | - Xuerong Zhou
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China; Department of Neurology, Affiliated Hospital of North Sichuan Medical College, Institute of Neurological Diseases, North Sichuan Medical College, Nanchong 637000, China
| | - Chao Dou
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China
| | - Yue Yu
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Weizhu Yan
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China
| | - Jingyuan Yang
- Core Facilities of West China Hospital, Sichuan University, Chengdu 610041, China
| | - Minqin Xiao
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China
| | - Wilfred A van der Donk
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Xiaofeng Zhu
- College of Life Sciences, Sichuan University, Chengdu 610065, China.
| | - Wei Cheng
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China.
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12
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Ayikpoe R, Zhu L, Chen JY, Ting CP, van der Donk WA. Macrocyclization and Backbone Rearrangement During RiPP Biosynthesis by a SAM-Dependent Domain-of-Unknown-Function 692. ACS CENTRAL SCIENCE 2023; 9:1008-1018. [PMID: 37252350 PMCID: PMC10214503 DOI: 10.1021/acscentsci.3c00160] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Indexed: 05/31/2023]
Abstract
The domain of unknown function 692 (DUF692) is an emerging family of post-translational modification enzymes involved in the biosynthesis of ribosomally synthesized and post-translationally modified peptide (RiPP) natural products. Members of this family are multinuclear iron-containing enzymes, and only two members have been functionally characterized to date: MbnB and TglH. Here, we used bioinformatics to select another member of the DUF692 family, ChrH, that is encoded in the genomes of the Chryseobacterium genus along with a partner protein ChrI. We structurally characterized the ChrH reaction product and show that the enzyme complex catalyzes an unprecedented chemical transformation that results in the formation of a macrocycle, an imidazolidinedione heterocycle, two thioaminals, and a thiomethyl group. Based on isotopic labeling studies, we propose a mechanism for the four-electron oxidation and methylation of the substrate peptide. This work identifies the first SAM-dependent reaction catalyzed by a DUF692 enzyme complex, further expanding the repertoire of remarkable reactions catalyzed by these enzymes. Based on the three currently characterized DUF692 family members, we suggest the family be called multinuclear non-heme iron dependent oxidative enzymes (MNIOs).
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Affiliation(s)
- Richard
S. Ayikpoe
- Department
of Chemistry, University of Illinois at
Urbana−Champaign, Urbana, 61801, Illinois, United States
- Carl
R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, 61801, Illinois, United States
| | - Lingyang Zhu
- School
of Chemical Sciences NMR Laboratory, University
of Illinois at Urbana−Champaign, Urbana, 61801, Illinois, United States
| | - Jeff Y. Chen
- Department
of Chemistry, University of Illinois at
Urbana−Champaign, Urbana, 61801, Illinois, United States
- Carl
R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, 61801, Illinois, United States
| | - Chi P. Ting
- Department
of Chemistry, University of Illinois at
Urbana−Champaign, Urbana, 61801, Illinois, United States
- Carl
R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, 61801, Illinois, United States
| | - Wilfred A. van der Donk
- Department
of Chemistry, University of Illinois at
Urbana−Champaign, Urbana, 61801, Illinois, United States
- Carl
R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, 61801, Illinois, United States
- Howard
Hughes Medical Institute at the University of Illinois at Urbana−Champaign, Urbana, 61801, Illinois, United States
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13
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Ayikpoe RS, Zhu L, Chen JY, Ting CP, van der Donk WA. A remarkable transformation catalyzed by a domain-of-unknown-function 692 during the biosynthesis of a new RiPP natural product. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.06.527370. [PMID: 36798408 PMCID: PMC9934569 DOI: 10.1101/2023.02.06.527370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The domain of unknown function 692 (DUF692) is an emerging family of posttranslational modification enzymes involved in the biosynthesis of ribosomally-synthesized and posttranslationally modified peptide (RiPP) natural products. Members of this family are multinuclear iron-containing enzymes and only two members have been functionally characterized to date: MbnB and TglH. Here, we used bioinformatics to select another member of the DUF692 family, ChrH, that is ubiquitously encoded in the genomes of the Chryseobacterium genus along with a partner protein ChrI. We structurally characterized the ChrH reaction product and show that the enzyme catalyzes an unprecedented chemical transformation that results in the formation of a macrocycle, an imidazolidinedione heterocycle, two thioaminals, and a thiomethylation. Based on isotopic labeling studies, we propose a mechanism for the four-electron oxidation and methylation of the substrate peptide. This work identifies the first SAM-dependent DUF692 enzyme, further expanding the repertoire of remarkable reactions catalyzed by these enzymes.
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Affiliation(s)
- Richard S. Ayikpoe
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
| | - Lingyang Zhu
- School of Chemical Sciences NMR Laboratory, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
| | - Jeff Y. Chen
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
| | - Chi P. Ting
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
| | - Wilfred A. van der Donk
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
- Howard Hughes Medical Institute at the University of Illinois at Urbana-Champaign, Urbana, 61801, IL, USA
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14
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Gordon JB, Albert T, Yadav S, Thomas J, Siegler MA, Moënne-Loccoz P, Goldberg DP. Oxygen versus Sulfur Coordination in Cobalt Superoxo Complexes: Spectroscopic Properties, O 2 Binding, and H-Atom Abstraction Reactivity. Inorg Chem 2023; 62:392-400. [PMID: 36538786 PMCID: PMC10194424 DOI: 10.1021/acs.inorgchem.2c03484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A five-coordinate, disiloxide-ligated cobalt(II) (S = 3/2) complex (1) was prepared as an oxygen-ligated analogue to the previously reported silanedithiolate-ligated CoII(Me3TACN)(S2SiMe2) (J. Am. Chem. Soc., 2019, 141, 3641-3653). The structural and spectroscopic properties of 1 were analyzed by single-crystal X-ray diffraction, electron paramagnetic resonance (EPR), and NMR spectroscopies. The reactivity of 1 with dioxygen was examined, and it was shown to bind O2 reversibly in a range of solvents at low temperatures. A cobalt(III)-superoxo complex, CoIII(O2·-)(Me3TACN)((OSi2Ph)2O) (2), was generated, and was analyzed by UV-vis, EPR, and resonance Raman spectroscopies. Unlike its sulfur-ligated analogue, complex 2 can thermally release O2 to regenerate 1. Vibrational assignments for selective 18O isotopic labeling of both O2 and disiloxide ligands in 2 are consistent with a 6-coordinate, Co(η1-O2·-)("end-on") complex. Complex 2 reacts with the O-H bond of 4-methoxy-2,2,6,6-tetramethylpiperidin-1-ol (4-MeO-TEMPOH) via H-atom abstraction with a rate of 0.58(2) M-1 s-1 at -105 °C, but it is unable to oxidize phenol substrates. This bracketed reactivity suggests that the O-H bond being formed in the putative CoIII(OOH) product has a relatively weak O-H bond strength (BDFE ∼66-74 kcal mol-1). These thermodynamic and kinetic parameters are similar to those seen for the sulfur-ligated Co(O2)(Me3TACN)(S2SiMe2), indicating that the differences in the electronic structure for O versus S ligation do not have a large impact on H-atom abstraction reactivity.
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Affiliation(s)
- Jesse B Gordon
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Sudha Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Jithin Thomas
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
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15
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Tian YC, Jiang Y, Lin YH, Zhang P, Wang CC, Ye S, Lee WZ. Hydrogen Atom Transfer Thermodynamics of Homologous Co(III)- and Mn(III)-Superoxo Complexes: The Effect of the Metal Spin State. JACS AU 2022; 2:1899-1909. [PMID: 36032524 PMCID: PMC9400055 DOI: 10.1021/jacsau.2c00268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Systematic investigations on H atom transfer (HAT) thermodynamics of metal O2 adducts is of fundamental importance for the design of transition metal catalysts for substrate oxidation and/or oxygenation directly using O2. Such work should help elucidate underlying electronic-structure features that govern the OO-H bond dissociation free energies (BDFEs) of metal-hydroperoxo species, which can be used to quantitatively appraise the HAT activity of the corresponding metal-superoxo complexes. Herein, the BDFEs of two homologous CoIII- and MnIII-hydroperoxo complexes, 3-Co and 3-Mn, were calculated to be 79.3 and 81.5 kcal/mol, respectively, employing the Bordwell relationship based on experimentally determined pK a values and redox potentials of the one-electron-oxidized forms, 4-Co and 4-Mn. To further verify these values, we tested the HAT capability of their superoxo congeners, 2-Co and 2-Mn, toward three different substrates possessing varying O-H BDFEs. Specifically, both metal-superoxo species are capable of activating the O-H bond of 4-oxo-TEMPOH with an O-H BDFE of 68.9 kcal/mol, only 2-Mn is able to abstract a H atom from 2,4-di-tert-butylphenol with an O-H BDFE of 80.9 kcal/mol, and neither of them can react with 3,5-dimethylphenol with an O-H BDFE of 85.6 kcal/mol. Further computational investigations suggested that it is the high spin state of the MnIII center in 3-Mn that renders its OO-H BDFE higher than that of 3-Co, which features a low-spin CoIII center. The present work underscores the role of the metal spin state being as crucial as the oxidation state in modulating BDFEs.
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Affiliation(s)
- Yao-Cheng Tian
- Department
of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Yang Jiang
- State
Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Yen-Hao Lin
- Department
of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Peng Zhang
- State
Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Chun-Chieh Wang
- Department
of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Shengfa Ye
- State
Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Way-Zen Lee
- Department
of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
- Department
of Medicinal and Applied Chemistry, Kaohsiung
Medical University, Kaohsiung 807, Taiwan
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16
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Rabe P, Walla CC, Goodyear NK, Welsh J, Southwart R, Clifton I, Linyard JDS, Tumber A, Claridge TDW, Myers WK, Schofield CJ. Spectroscopic studies reveal details of substrate-induced conformational changes distant from the active site in isopenicillin N synthase. J Biol Chem 2022; 298:102249. [PMID: 35835215 PMCID: PMC9403350 DOI: 10.1016/j.jbc.2022.102249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 11/06/2022] Open
Abstract
Isopenicillin N synthase (IPNS) catalyzes formation of the β-lactam and thiazolidine rings of isopenicillin N from its linear tripeptide l-δ-(α-aminoadipoyl)-l-cysteinyl-d-valine (ACV) substrate in an iron- and dioxygen (O2)-dependent four-electron oxidation without precedent in current synthetic chemistry. Recent X-ray free-electron laser studies including time-resolved serial femtosecond crystallography show that binding of O2 to the IPNS–Fe(II)–ACV complex induces unexpected conformational changes in α-helices on the surface of IPNS, in particular in α3 and α10. However, how substrate binding leads to conformational changes away from the active site is unknown. Here, using detailed 19F NMR and electron paramagnetic resonance experiments with labeled IPNS variants, we investigated motions in α3 and α10 induced by binding of ferrous iron, ACV, and the O2 analog nitric oxide, using the less mobile α6 for comparison. 19F NMR studies were carried out on singly and doubly labeled α3, α6, and α10 variants at different temperatures. In addition, double electron–electron resonance electron paramagnetic resonance analysis was carried out on doubly spin-labeled variants. The combined spectroscopic and crystallographic results reveal that substantial conformational changes in regions of IPNS including α3 and α10 are induced by binding of ACV and nitric oxide. Since IPNS is a member of the structural superfamily of 2-oxoglutarate-dependent oxygenases and related enzymes, related conformational changes may be of general importance in nonheme oxygenase catalysis.
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Affiliation(s)
- Patrick Rabe
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom.
| | - Carla C Walla
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Noelle K Goodyear
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Jordan Welsh
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom; Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK
| | - Rebecca Southwart
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Ian Clifton
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - James D S Linyard
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Anthony Tumber
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Tim D W Claridge
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - William K Myers
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom.
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17
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Dedushko MA, Greiner MB, Downing AN, Coggins M, Kovacs JA. Electronic Structure and Reactivity of Dioxygen-Derived Aliphatic Thiolate-Ligated Fe-Peroxo and Fe(IV) Oxo Compounds. J Am Chem Soc 2022; 144:8515-8528. [PMID: 35522532 DOI: 10.1021/jacs.1c07656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Herein, we examine the electronic and geometric structural properties of O2-derived aliphatic thiolate-ligated Fe-peroxo, Fe-hydroxo, and Fe(IV) oxo compounds. The latter cleaves strong C-H bonds (96 kcal mol-1) on par with the valine C-H bond cleaved by isopencillin N synthase (IPNS). Stopped-flow kinetics studies indicate that the barrier to O2 binding to [FeII(SMe2N4(tren))]+ (3) is extremely low (Ea = 36(2) kJ mol-1), as theoretically predicted for IPNS. Dioxygen binding to 3 is shown to be reversible, and a superoxo intermediate, [FeIII(SMe2N4(tren))(O2)]+ (6), forms in the first 25 ms of the reaction at -40 °C prior to the rate-determining (Ea = 46(2) kJ mol-1) formation of peroxo-bridged [(SMe2N4(tren))Fe(III)]2(μ-O2)2+ (7). A log(kobs) vs log([Fe]) plot for the formation of 7 is consistent with the second-order dependence on iron, and H2O2 assays are consistent with a 2:1 ratio of Fe/H2O2. Peroxo 7 is shown to convert to ferric-hydroxo [FeIII(SMe2N(tren))(OH)]+ (9, g⊥ = 2.24, g∥ = 1.96), the identity of which was determined via its independent synthesis. Rates of the conversion 7 → 9 are shown to be dependent on the X-H bond strength of the H-atom donor, with a kH/kD = 4 when CD3OD is used in place of CH3OH as a solvent. A crystallographically characterized cis thiolate-ligated high-valent iron oxo, [FeIV(O)(SMe2N4(tren))]+ (11), is shown to form en route to hydroxo 9. Electronic structure calculations were shown to be consistent with 11 being an S = 1 Fe(IV)═O with an unusually high νFe-O stretching frequency at 918 cm-1 in line with the extremely short Fe-O bond (1.603(7) Å).
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Affiliation(s)
- Maksym A Dedushko
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Maria B Greiner
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Alexandra N Downing
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Michael Coggins
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Julie A Kovacs
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
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18
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Dou C, Long Z, Li S, Zhou D, Jin Y, Zhang L, Zhang X, Zheng Y, Li L, Zhu X, Liu Z, He S, Yan W, Yang L, Xiong J, Fu X, Qi S, Ren H, Chen S, Dai L, Wang B, Cheng W. Crystal structure and catalytic mechanism of the MbnBC holoenzyme required for methanobactin biosynthesis. Cell Res 2022; 32:302-314. [PMID: 35110668 PMCID: PMC8888699 DOI: 10.1038/s41422-022-00620-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/12/2022] [Indexed: 02/08/2023] Open
Abstract
Methanobactins (Mbns) are a family of copper-binding peptides involved in copper uptake by methanotrophs, and are potential therapeutic agents for treating diseases characterized by disordered copper accumulation. Mbns are produced via modification of MbnA precursor peptides at cysteine residues catalyzed by the core biosynthetic machinery containing MbnB, an iron-dependent enzyme, and MbnC. However, mechanistic details underlying the catalysis of the MbnBC holoenzyme remain unclear. Here, we present crystal structures of MbnABC complexes from two distinct species, revealing that the leader peptide of the substrate MbnA binds MbnC for recruitment of the MbnBC holoenzyme, while the core peptide of MbnA resides in the catalytic cavity created by the MbnB-MbnC interaction which harbors a unique tri-iron cluster. Ligation of the substrate sulfhydryl group to the tri-iron center achieves a dioxygen-dependent reaction for oxazolone-thioamide installation. Structural analysis of the MbnABC complexes together with functional investigation of MbnB variants identified a conserved catalytic aspartate residue as a general base required for MbnBC-mediated MbnA modification. Together, our study reveals the similar architecture and function of MbnBC complexes from different species, demonstrating an evolutionarily conserved catalytic mechanism of the MbnBC holoenzymes.
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Affiliation(s)
- Chao Dou
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Zhaolin Long
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Shoujie Li
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Dan Zhou
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Ying Jin
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Li Zhang
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Xuan Zhang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, China
| | - Yanhui Zheng
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Lin Li
- National Institute of Biological Sciences, NIBS, Beijing, China
| | - Xiaofeng Zhu
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China.,College of Life Science, Sichuan University, Chengdu, Sichuan, China
| | - Zheng Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Beijing Key Laboratory for Magnetoelectric Materials and Devices, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Siyu He
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Weizhu Yan
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Lulu Yang
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Jie Xiong
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Xianghui Fu
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Shiqian Qi
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Haiyan Ren
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - She Chen
- National Institute of Biological Sciences, NIBS, Beijing, China
| | - Lunzhi Dai
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Binju Wang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, China
| | - Wei Cheng
- Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, Sichuan, China.
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19
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Song X, Liu J, Wang B. Emergence of Function from Nonheme Diiron Oxygenases: A Quantum Mechanical/Molecular Mechanical Study of Oxygen Activation and Organophosphonate Catabolism Mechanisms by PhnZ. ACS Catal 2022. [DOI: 10.1021/acscatal.1c05116] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Xitong Song
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Jia Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
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20
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Sacramento JJD, Albert T, Siegler M, Moënne-Loccoz P, Goldberg DP. An Iron(III) Superoxide Corrole from Iron(II) and Dioxygen. Angew Chem Int Ed Engl 2022; 61:e202111492. [PMID: 34850509 PMCID: PMC8789326 DOI: 10.1002/anie.202111492] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/20/2021] [Indexed: 01/12/2023]
Abstract
A new structurally characterized ferrous corrole [FeII (ttppc)]- (1) binds one equivalent of dioxygen to form [FeIII (O2-. )(ttppc)]- (2). This complex exhibits a 16/18 O2 -isotope sensitive ν(O-O) stretch at 1128 cm-1 concomitantly with a single ν(Fe-O2 ) at 555 cm-1 , indicating it is an η1 -superoxo ("end-on") iron(III) complex. Complex 2 is the first well characterized Fe-O2 corrole, and mediates the following biologically relevant oxidation reactions: dioxygenation of an indole derivative, and H-atom abstraction from an activated O-H bond.
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Affiliation(s)
- Jireh Joy D Sacramento
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, 97239-3098, USA
| | - Maxime Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, 97239-3098, USA
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
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21
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Sacramento JJD, Albert T, Siegler M, Moënne‐Loccoz P, Goldberg DP. An Iron(III) Superoxide Corrole from Iron(II) and Dioxygen. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202111492] [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)
- Jireh Joy D. Sacramento
- Department of Chemistry The Johns Hopkins University 3400 North Charles Street Baltimore MD 21218 USA
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry Oregon Health & Science University Portland OR 97239-3098 USA
| | - Maxime Siegler
- Department of Chemistry The Johns Hopkins University 3400 North Charles Street Baltimore MD 21218 USA
| | - Pierre Moënne‐Loccoz
- Department of Chemical Physiology and Biochemistry Oregon Health & Science University Portland OR 97239-3098 USA
| | - David P. Goldberg
- Department of Chemistry The Johns Hopkins University 3400 North Charles Street Baltimore MD 21218 USA
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22
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Gordon JB, Albert T, Dey A, Sabuncu S, Siegler MA, Bill E, Moënne-Loccoz P, Goldberg DP. A Reactive, Photogenerated High-Spin ( S = 2) Fe IV(O) Complex via O 2 Activation. J Am Chem Soc 2021; 143:21637-21647. [PMID: 34913683 PMCID: PMC9109941 DOI: 10.1021/jacs.1c10051] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Addition of dioxygen at low temperature to the non-heme ferrous complex FeII(Me3TACN)((OSiPh2)2O) (1) in 2-MeTHF produces a peroxo-bridged diferric complex Fe2III(μ-O2)(Me3TACN)2((OSiPh2)2O)2 (2), which was characterized by UV-vis, resonance Raman, and variable field Mössbauer spectroscopies. Illumination of a frozen solution of 2 in THF with white light leads to homolytic O-O bond cleavage and generation of a FeIV(O) complex 4 (ν(Fe=O) = 818 cm-1; δ = 0.22 mm s-1, ΔEQ = 0.23 mm s-1). Variable field Mössbauer spectroscopy measurements show that 4 is a rare example of a high-spin S = 2 FeIV(O) complex and the first synthetic example to be generated directly from O2. Complex 4 is highly reactive, as expected for a high-spin ferryl, and decays rapidly in fluid solution at cryogenic temperatures. This decay process in 2-MeTHF involves C-H cleavage of the solvent. However, the controlled photolysis of 2 in situ with visible light and excess phenol substrate leads to competitive phenol oxidation, via the proposed transient generation of 4 as the active oxidant.
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Affiliation(s)
- Jesse B. Gordon
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Aniruddha Dey
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Sinan Sabuncu
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Maxime A. Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Eckhard Bill
- Department of Inorganic Spectroscopy / Joint Workspace, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34−36, 45470 Mülheim-an-der-Ruhr, Germany,Corresponding Author: , ,
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, USA,Corresponding Author: , ,
| | - David P. Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA,Corresponding Author: , ,
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23
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Zhang S, Li X, Wang Y, Yan L, Wei J, Liu Y. Computational Study of the C5-Hydroxylation Mechanism Catalyzed by the Diiron Monooxygenase PtmU3 as Part of the Platensimycin Biosynthesis. Inorg Chem 2021; 60:17783-17796. [PMID: 34762413 DOI: 10.1021/acs.inorgchem.1c02407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PtmU3 is a newly identified nonheme diiron monooxygenase, which installs a C-5 β-hydroxyl group into the C-19 CoA-ester intermediate involved in the biosynthesis of unique diterpene-derived scaffolds of platensimycin and platencin. PtmU3 possesses a noncanonical diiron active site architecture of a saturated six-coordinate iron center and lacks the μ-oxo bridge. Although the hydroxylation process is a simple reaction for nonheme mononuclear iron-dependent enzymes, how PtmU3 employs the diiron center to catalyze the H-abstraction and OH-rebound is still unknown. In particular, the electronic characteristic of diiron is also unclear. To understand the catalytic mechanism of PtmU3, we constructed two reactant models in which both the Fe1II-Fe2III-superoxo and Fe1II-Fe2IV═O are considered to trigger the H-abstraction and performed a series of quantum mechanics/molecular mechanics calculations. Our calculation results reveal that PtmU3 is a special monooxygenase, that is, both atoms of the dioxygen molecule can be incorporated into two molecules of the substrate by the successive reactions. In the first-round reaction, PtmU3 uses the Fe1II-Fe2III-superoxo to install a hydroxyl group into the substrate, generating the high-reactive Fe1II-Fe2IV═O complex. In the second-round reaction, the Fe1II-Fe2IV═O species is responsible for the hydroxylation of another molecule of the substrate. In the diiron center, Fe2 adopts the high spin state (S = 5/2) during the catalysis, whereas for Fe1, in addition to its structural role, it may also play an assistant role for Fe1 catalysis. In the two successive OH-installing steps, the H-abstraction is always the rate-liming step. E241 and D308 not only act as bridging ligands to connect two Fe ions but also take part in the electron reorganization. Owing to the high reactivity of Fe1II-Fe2IV═O compared to Fe1II-Fe2III-superoxo, besides the C5-hydroxylation, the C3- or C18-hydroxylation was also calculated to be feasible.
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Affiliation(s)
- Shiqing Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, Shandong, China
| | - Xinyi Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, Shandong, China
| | - Yijing Wang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, Shandong, China
| | - Lijuan Yan
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, Shandong, China
| | - Jingjing Wei
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, Shandong, China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, Shandong, China
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24
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Solomon EI, DeWeese DE, Babicz JT. Mechanisms of O 2 Activation by Mononuclear Non-Heme Iron Enzymes. Biochemistry 2021; 60:3497-3506. [PMID: 34266238 PMCID: PMC8768060 DOI: 10.1021/acs.biochem.1c00370] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Two major subclasses of mononuclear non-heme ferrous enzymes use two electron-donating organic cofactors (α-ketoglutarate or pterin) to activate O2 to form FeIV═O intermediates that further react with their substrates through hydrogen atom abstraction or electrophilic aromatic substitution. New spectroscopic methodologies have been developed, enabling the study of the active sites in these enzymes and their oxygen intermediates. Coupled to electronic structure calculations, the results of these spectroscopies provide fundamental insight into mechanism. This Perspective summarizes the results of these studies in elucidating the mechanism of dioxygen activation to form the FeIV═O intermediate and the geometric and electronic structure of this intermediate that enables its high reactivity and selectivity in product formation.
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Affiliation(s)
- Edward I. Solomon
- Department of Chemistry, Stanford University, 333 Campus Dr. Stanford, CA, 94305, United States,SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, United States
| | - Dory E. DeWeese
- Department of Chemistry, Stanford University, 333 Campus Dr. Stanford, CA, 94305, United States
| | - Jeffrey T. Babicz
- Department of Chemistry, Stanford University, 333 Campus Dr. Stanford, CA, 94305, United States
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25
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Ekanayake DM, Pham D, Probst AL, Miller JR, Popescu CV, Fiedler AT. Electronic structures and spectroscopic signatures of diiron intermediates generated by O 2 activation of nonheme iron(II)-thiolate complexes. Dalton Trans 2021; 50:14432-14443. [PMID: 34570147 PMCID: PMC8721859 DOI: 10.1039/d1dt02286e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The activation of O2 at thiolate-ligated iron(II) sites is essential to the function of numerous metalloenzymes and synthetic catalysts. Iron-thiolate bonds in the active sites of nonheme iron enzymes arise from either coordination of an endogenous cysteinate residue or binding of a deprotonated thiol-containing substrate. Examples of the latter include sulfoxide synthases, such as EgtB and OvoA, that utilize O2 to catalyze tandem S-C bond formation and S-oxygenation steps in thiohistidine biosyntheses. We recently reported the preparation of two mononuclear nonheme iron-thiolate complexes (1 and 2) that serve as structural active-site models of substrate-bound EgtB and OvoA (Dalton Trans. 2020, 49, 17745-17757). These models feature monodentate thiolate ligands and tripodal N4 ligands with mixed pyridyl/imidazolyl donors. Here, we describe the reactivity of 1 and 2 with O2 at low temperatures to give metastable intermediates (3 and 4, respectively). Characterization with multiple spectroscopic techniques (UV-vis absorption, NMR, variable-field and -temperature Mössbauer, and resonance Raman) revealed that these intermediates are thiolate-ligated iron(III) dimers with a bridging oxo ligand derived from the four-electron reduction of O2. Structural models of 3 and 4 consistent with the experimental data were generated via density functional theory (DFT) calculations. The combined experimental and computational results illuminate the geometric and electronic origins of the unique spectral features of diiron(III)-μ-oxo complexes with thiolate ligands, and the spectroscopic signatures of 3 and 4 are compared to those of closely-related diiron(III)-μ-peroxo species. Collectively, these results will assist in the identification of intermediates that appear on the O2 reaction landscapes of iron-thiolate species in both biological and synthetic environments.
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Affiliation(s)
| | - Dao Pham
- Department of Chemistry, The College of Arts and Sciences, University of St. Thomas, St. Paul, Minnesota 55105, USA.
| | - Andrew L Probst
- Department of Chemistry, The College of Arts and Sciences, University of St. Thomas, St. Paul, Minnesota 55105, USA.
| | - Joshua R Miller
- Department of Chemistry, University of Wisconsin - Madison, Madison, Wisconsin 53706, USA
| | - Codrina V Popescu
- Department of Chemistry, The College of Arts and Sciences, University of St. Thomas, St. Paul, Minnesota 55105, USA.
| | - Adam T Fiedler
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, USA.
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26
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Copeland RA, Zhou S, Schaperdoth I, Shoda TKC, Bollinger JM, Krebs C. Hybrid radical-polar pathway for excision of ethylene from 2-oxoglutarate by an iron oxygenase. Science 2021; 373:1489-1493. [PMID: 34385355 DOI: 10.1126/science.abj4290] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Rachelle A Copeland
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shengbin Zhou
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Irene Schaperdoth
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Tokufu Kent C Shoda
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - J Martin Bollinger
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Carsten Krebs
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
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27
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Toledo S, Yan Poon PC, Gleaves M, Rees J, Rogers DM, Kaminsky W, Kovacs JA. Increasing reactivity by incorporating π-acceptor ligands into coordinatively unsaturated thiolate-ligated iron(II) complexes. Inorganica Chim Acta 2021; 524. [PMID: 34305163 DOI: 10.1016/j.ica.2021.120422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Reported herein is the structural, spectroscopic, redox, and reactivity properties of a series of iron complexes containing both a π-donating thiolate, and π-accepting N-heterocycles in the coordination sphere, in which we systematically vary the substituents on the N-heterocycle, the size of the N-heterocycle, and the linker between the imine nitrogen and tertiary amine nitrogen. In contrast to our primary amine/thiolate-ligated Fe(II) complex, [FeII(SMe2N4(tren))]+ (1), the Fe(II) complexes reported herein are intensely colored, allowing us to visually monitor reactivity. Ferrous complexes with R = H substituents in the 6-position of the pyridines, [FeII(SMe2N4(6-H-DPPN)]+ (6) and [FeII(SMe2N4(6-H-DPEN))(MeOH)]+ (8-MeOH) are shown to readily bind neutral ligands, and all of the Fe(II) complexes are shown to bind anionic ligands regardless of steric congestion. This reactivity is in contrast to 1 and is attributed to an increased metal ion Lewis acidity assessed via aniodic redox potentials, Ep,a, caused by the π-acid ligands. Thermodynamic parameters (ΔH, ΔS) for neutral ligand binding were obtained from T-dependent equilibrium constants. All but the most sterically congested complex, [FeII(SMe2N4(6-Me-DPPN)]+ (5), react with O2. In contrast to our Mn(II)-analogues, dioxygen intermediates are not observed. Rates of formation of the final mono oxo-bridged products were assessed via kinetics and shown to be inversely dependent on redox potentials, Ep,a, consistent with a mechanism involving electron transfer.
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Affiliation(s)
- Santiago Toledo
- The Department of Chemistry, University of Washington, Box 351700 Seattle, WA 98195-1700, United States
| | - Penny Chaau Yan Poon
- The Department of Chemistry, University of Washington, Box 351700 Seattle, WA 98195-1700, United States
| | - Morgan Gleaves
- The Department of Chemistry, University of Washington, Box 351700 Seattle, WA 98195-1700, United States
| | - Julian Rees
- The Department of Chemistry, University of Washington, Box 351700 Seattle, WA 98195-1700, United States
| | - Dylan M Rogers
- The Department of Chemistry, University of Washington, Box 351700 Seattle, WA 98195-1700, United States
| | - Werner Kaminsky
- The Department of Chemistry, University of Washington, Box 351700 Seattle, WA 98195-1700, United States
| | - Julie A Kovacs
- The Department of Chemistry, University of Washington, Box 351700 Seattle, WA 98195-1700, United States
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28
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Winslow C, Lee HB, Field MJ, Teat SJ, Rittle J. Structure and Reactivity of a High-Spin, Nonheme Iron(III)- Superoxo Complex Supported by Phosphinimide Ligands. J Am Chem Soc 2021; 143:13686-13693. [PMID: 34424708 DOI: 10.1021/jacs.1c05276] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nonheme iron oxygenases utilize dioxygen to accomplish challenging chemical oxidations. A further understanding of the Fe-O2 intermediates implicated in these processes is challenged by their highly transient nature. To that end, we have developed a ligand platform featuring phosphinimide donors intended to stabilize oxidized, high-spin iron complexes. O2 exposure of single crystals of a three-coordinate Fe(II) complex of this framework allowed for in crystallo trapping of a terminally bound Fe-O2 complex suitable for XRD characterization. Spectroscopic and computational studies of this species support a high-spin Fe(III) center antiferromagnetically coupled to a superoxide ligand, similar to that proposed for numerous nonheme iron oxygenases. In addition to the apparent stability of this synthetic Fe-O2 complex, its ability to engage in a range of stoichiometric and catalytic oxidation processes demonstrates that this iron-phosphinimide system is primed for development in modeling oxidizing bioinorganic intermediates and green oxidation chemistry.
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Affiliation(s)
- Charles Winslow
- College of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Heui Beom Lee
- College of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Mackenzie J Field
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Simon J Teat
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jonathan Rittle
- College of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
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29
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Rabe P, Kamps JJAG, Sutherlin KD, Linyard JDS, Aller P, Pham CC, Makita H, Clifton I, McDonough MA, Leissing TM, Shutin D, Lang PA, Butryn A, Brem J, Gul S, Fuller FD, Kim IS, Cheah MH, Fransson T, Bhowmick A, Young ID, O'Riordan L, Brewster AS, Pettinati I, Doyle M, Joti Y, Owada S, Tono K, Batyuk A, Hunter MS, Alonso-Mori R, Bergmann U, Owen RL, Sauter NK, Claridge TDW, Robinson CV, Yachandra VK, Yano J, Kern JF, Orville AM, Schofield CJ. X-ray free-electron laser studies reveal correlated motion during isopenicillin N synthase catalysis. SCIENCE ADVANCES 2021; 7:eabh0250. [PMID: 34417180 PMCID: PMC8378823 DOI: 10.1126/sciadv.abh0250] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 06/29/2021] [Indexed: 05/23/2023]
Abstract
Isopenicillin N synthase (IPNS) catalyzes the unique reaction of l-δ-(α-aminoadipoyl)-l-cysteinyl-d-valine (ACV) with dioxygen giving isopenicillin N (IPN), the precursor of all natural penicillins and cephalosporins. X-ray free-electron laser studies including time-resolved crystallography and emission spectroscopy reveal how reaction of IPNS:Fe(II):ACV with dioxygen to yield an Fe(III) superoxide causes differences in active site volume and unexpected conformational changes that propagate to structurally remote regions. Combined with solution studies, the results reveal the importance of protein dynamics in regulating intermediate conformations during conversion of ACV to IPN. The results have implications for catalysis by multiple IPNS-related oxygenases, including those involved in the human hypoxic response, and highlight the power of serial femtosecond crystallography to provide insight into long-range enzyme dynamics during reactions presently impossible for nonprotein catalysts.
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Affiliation(s)
- Patrick Rabe
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Jos J A G Kamps
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
- Diamond Light Source, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA, UK
| | - Kyle D Sutherlin
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - James D S Linyard
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Pierre Aller
- Diamond Light Source, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA, UK
| | - Cindy C Pham
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Hiroki Makita
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Ian Clifton
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Michael A McDonough
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Thomas M Leissing
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Denis Shutin
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Pauline A Lang
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Agata Butryn
- Diamond Light Source, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA, UK
| | - Jürgen Brem
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Sheraz Gul
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Franklin D Fuller
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - In-Sik Kim
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Mun Hon Cheah
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 751 20 Uppsala, Sweden
| | - Thomas Fransson
- Interdisciplinary Center for Scientific Computing, University of Heidelberg, 69120 Heidelberg, Germany
| | - Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Iris D Young
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158, USA
| | - Lee O'Riordan
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Aaron S Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Ilaria Pettinati
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Margaret Doyle
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Yasumasa Joti
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Shigeki Owada
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Alexander Batyuk
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Mark S Hunter
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Uwe Bergmann
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706, USA
| | - Robin L Owen
- Diamond Light Source, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Nicholas K Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Timothy D W Claridge
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Carol V Robinson
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Jan F Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
| | - Allen M Orville
- Diamond Light Source, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK.
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA, UK
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
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30
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Ye Y, Fu H, Hyster TK. Activation modes in biocatalytic radical cyclization reactions. J Ind Microbiol Biotechnol 2021; 48:kuab021. [PMID: 33674826 PMCID: PMC8210684 DOI: 10.1093/jimb/kuab021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/26/2021] [Indexed: 12/17/2022]
Abstract
Radical cyclizations are essential reactions in the biosynthesis of secondary metabolites and the chemical synthesis of societally valuable molecules. In this review, we highlight the general mechanisms utilized in biocatalytic radical cyclizations. We specifically highlight cytochrome P450 monooxygenases (P450s) involved in the biosynthesis of mycocyclosin and vancomycin, nonheme iron- and α-ketoglutarate-dependent dioxygenases (Fe/αKGDs) used in the biosynthesis of kainic acid, scopolamine, and isopenicillin N, and radical S-adenosylmethionine (SAM) enzymes that facilitate the biosynthesis of oxetanocin A, menaquinone, and F420. Beyond natural mechanisms, we also examine repurposed flavin-dependent "ene"-reductases (ERED) for non-natural radical cyclization. Overall, these general mechanisms underscore the opportunity for enzymes to augment and enhance the synthesis of complex molecules using radical mechanisms.
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Affiliation(s)
- Yuxuan Ye
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Haigen Fu
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Todd K Hyster
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
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31
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Dedushko MA, Pikul JH, Kovacs JA. Superoxide Oxidation by a Thiolate-Ligated Iron Complex and Anion Inhibition. Inorg Chem 2021; 60:7250-7261. [PMID: 33900756 DOI: 10.1021/acs.inorgchem.1c00336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Superoxide (O2•-) is a toxic radical, generated via the adventitious reduction of dioxygen (O2), which has been implicated in a number of human disease states. Nonheme iron enzymes, superoxide reductase (SOR) and superoxide dismutase (SOD), detoxify O2•- via reduction to afford H2O2 and disproportionation to afford O2 and H2O2, respectively. The former contains a thiolate in the coordination sphere, which has been proposed to prevent O2•- oxidation to O2. The work described herein shows that, in contrast to this, oxidized thiolate-ligated [FeIII(SMe2N4(tren)(THF)]2+ (1ox-THF) is capable of oxidizing O2•- to O2. Coordinating anions, Cl- and OAc-, are shown to inhibit dioxygen evolution, implicating an inner-sphere mechanism. Previously we showed that the reduced thiolate-ligated [FeII(SMe2N4(tren))]+ (1) is capable of reducing O2•- via a proton-dependent inner-sphere mechanism involving a transient Fe(III)-OOH intermediate. A transient ferric-superoxo intermediate, [FeIII(SMe2N4(tren))(O2)]+ (3), is detected by electronic absorption spectroscopy at -130 °C in the reaction between 1ox-THF and KO2 and shown to evolve O2 upon slight warming to -115 °C. The DFT calculated O-O (1.306 Å) and Fe-O (1.943 Å) bond lengths of 3 are typical of ferric-superoxo complexes, and the time-dependent DFT calculated electronic absorption spectrum of 3 reproduces the experimental spectrum. The electronic structure of 3 is shown to consist of two antiferromagnetically coupled (Jcalc = -180 cm-1) unpaired electrons, one in a superoxo π*(O-O) orbital and the other in an antibonding π*(Fe(dyz)-S(py)) orbital.
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Affiliation(s)
- Maksym A Dedushko
- The Department of Chemistry, University of Washington: Box 351700, Seattle, Washington 98195-1700, United States
| | - Jessica H Pikul
- The Department of Chemistry, University of Washington: Box 351700, Seattle, Washington 98195-1700, United States
| | - Julie A Kovacs
- The Department of Chemistry, University of Washington: Box 351700, Seattle, Washington 98195-1700, United States
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32
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Liu J, Wu P, Yan S, Li Y, Cao Z, Wang B. Spin-Regulated Inner-Sphere Electron Transfer Enables Efficient O—O Bond Activation in Nonheme Diiron Monooxygenase MIOX. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00898] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Jia Liu
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Peng Wu
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Shengheng Yan
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Yuanyuan Li
- College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, China
| | - Zexing Cao
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Binju Wang
- State Key Laboratory of Structural Chemistry of Solid Surface and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
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33
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Gordon JB, McGale JP, Siegler MA, Goldberg DP. Proton-Coupled Electron-Transfer Reactivity Controls Iron versus Sulfur Oxidation in Nonheme Iron-Thiolate Complexes. Inorg Chem 2021; 60:6255-6265. [PMID: 33872005 DOI: 10.1021/acs.inorgchem.0c03779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reaction of the five-coordinate FeII(N4S) complexes, [FeII(iPr3TACN)(abtX)](OTf) (abt = aminobenzenethiolate, X = H, CF3), with a one-electron oxidant and an appropriate base leads to net H atom loss, generating new FeIII(iminobenzenethiolate) complexes that were characterized by single-crystal X-ray diffraction (XRD), as well as UV-vis, EPR, and Mössbauer spectroscopies. The spectroscopic data indicate that the iminobenzenethiolate complexes have S = 3/2 ground states. In the absence of a base, oxidation of the FeII(abt) complexes leads to disulfide formation instead of oxidation at the metal center. Bracketing studies with separated proton-coupled electron-transfer (PCET) reagents show that the FeII(aminobenzenethiolate) and FeIII(iminobenzenethiolate) forms are readily interconvertible by H+/e- transfer and provide a measure of the bond dissociation free energy (BDFE) for the coordinated N-H bond between 64 and 69 kcal mol-1. This work shows that coordination to the iron center causes a dramatic weakening of the N-H bond and that Fe- versus S-oxidation in a nonheme iron complex can be controlled by the protonation state of an ancillary amino donor.
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Affiliation(s)
- Jesse B Gordon
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Jeremy P McGale
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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34
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Han SB, Ali HS, de Visser SP. Glutarate Hydroxylation by the Carbon Starvation-Induced Protein D: A Computational Study into the Stereo- and Regioselectivities of the Reaction. Inorg Chem 2021; 60:4800-4815. [DOI: 10.1021/acs.inorgchem.0c03749] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Sungho Bosco Han
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Hafiz Saqib Ali
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Sam P. de Visser
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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35
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Monkcom EC, de Bruin D, de Vries AJ, Lutz M, Ye S, Klein Gebbink RJM. Structurally Modelling the 2-His-1-Carboxylate Facial Triad with a Bulky N,N,O Phenolate Ligand. Chemistry 2021; 27:5191-5204. [PMID: 33326655 PMCID: PMC8048785 DOI: 10.1002/chem.202004633] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Indexed: 11/25/2022]
Abstract
We present the synthesis and coordination chemistry of a bulky, tripodal N,N,O ligand, ImPh2NNOtBu (L), designed to model the 2‐His‐1‐carboxylate facial triad (2H1C) by means of two imidazole groups and an anionic 2,4‐di‐tert‐butyl‐subtituted phenolate. Reacting K‐L with MCl2 (M = Fe, Zn) affords the isostructural, tetrahedral non‐heme complexes [Fe(L)(Cl)] (1) and [Zn(L)(Cl)] (2) in high yield. The tridentate N,N,O ligand coordination observed in their X‐ray crystal structures remains intact and well‐defined in MeCN and CH2Cl2 solution. Reacting 2 with NaSPh affords a tetrahedral zinc thiolate complex, [Zn(L)(SPh)] (4), that is relevant to isopenicillin N synthase (IPNS) biomimicry. Cyclic voltammetry studies demonstrate the ligand's redox non‐innocence, where phenolate oxidation is the first electrochemical response observed in K‐L, 2 and 4. However, the first electrochemical oxidation in 1 is iron‐centred, the assignment of which is supported by DFT calculations. Overall, ImPh2NNOtBu provides access to well‐defined mononuclear, monoligated, N,N,O‐bound metal complexes, enabling more accurate structural modelling of the 2H1C to be achieved.
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Affiliation(s)
- Emily C Monkcom
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Daniël de Bruin
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Annemiek J de Vries
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Martin Lutz
- Crystal and Structural Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Shengfa Ye
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China.,Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Robertus J M Klein Gebbink
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
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36
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Keshari K, Bera M, Velasco L, Munshi S, Gupta G, Moonshiram D, Paria S. Characterization and reactivity study of non-heme high-valent iron-hydroxo complexes. Chem Sci 2021; 12:4418-4424. [PMID: 34163706 PMCID: PMC8179568 DOI: 10.1039/d0sc07054h] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A terminal FeIIIOH complex, [FeIII(L)(OH)]2− (1), has been synthesized and structurally characterized (H4L = 1,2-bis(2-hydroxy-2-methylpropanamido)benzene). The oxidation reaction of 1 with one equiv. of tris(4-bromophenyl)ammoniumyl hexachloroantimonate (TBAH) or ceric ammonium nitrate (CAN) in acetonitrile at −45 °C results in the formation of a FeIIIOH ligand radical complex, [FeIII(L˙)(OH)]− (2), which is hereby characterized by UV-visible, 1H nuclear magnetic resonance, electron paramagnetic resonance, and X-ray absorption spectroscopy techniques. The reaction of 2 with a triphenylcarbon radical further gives triphenylmethanol and mimics the so-called oxygen rebound step of Cpd II of cytochrome P450. Furthermore, the reaction of 2 was explored with different 4-substituted-2,6-di-tert-butylphenols. Based on kinetic analysis, a hydrogen atom transfer (HAT) mechanism has been established. A pKa value of 19.3 and a BDFE value of 78.2 kcal/mol have been estimated for complex 2. One-electron oxidation of an FeIII–OH complex (1) results in the formation of a FeIII–OH ligand radical complex (2). Its reaction with (C6H5)3C˙ results in the formation of (C6H5)3COH, which is a functional mimic of compound II of cytochrome P450.![]()
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Affiliation(s)
- Kritika Keshari
- Department of Chemistry, Indian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
| | - Moumita Bera
- Department of Chemistry, Indian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
| | - Lucía Velasco
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia Calle Faraday, 9 28049 Madrid Spain
| | - Sandip Munshi
- School of Chemical Sciences, Indian Association for the Cultivation of Science 2A & 2B Raja S. C. Mullick Road, Jadavpur Kolkata 700032 India
| | - Geetika Gupta
- Department of Chemistry, Indian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
| | - Dooshaye Moonshiram
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia Calle Faraday, 9 28049 Madrid Spain
| | - Sayantan Paria
- Department of Chemistry, Indian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
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37
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Yadav V, Siegler MA, Goldberg DP. Temperature-Dependent Reactivity of a Non-heme Fe III(OH)(SR) Complex: Relevance to Isopenicillin N Synthase. J Am Chem Soc 2021; 143:46-52. [PMID: 33356198 DOI: 10.1021/jacs.0c09688] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Non-heme iron complexes with cis-FeIII(OH)(SAr/OAr) coordination were isolated and examined for their reactivity with a tertiary carbon radical. The sulfur-ligated complex shows a temperature dependence on •OH versus ArS• transfer, whereas the oxygen-ligated complex does not. These results provide the first working model for C-S bond formation in isopenicillin N synthase and indicate that kinetic control may be a key factor in the selectivity of non-heme iron "rebound" processes.
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Affiliation(s)
- Vishal Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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38
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Chen TY, Ho PH, Spyra CJ, Meyer F, Bill E, Ye S, Lee WZ. Ambiphilicity of a mononuclear cobalt(III) superoxo complex. Chem Commun (Camb) 2020; 56:14821-14824. [PMID: 33151205 DOI: 10.1039/d0cc05337f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Addition of HOTf to a mixture of CoIII(BDPP)(O2˙) (1, H2BDPP = 2,6-bis((2-(S)-diphenylhydroxylmethyl-1-pyrrolidinyl)methyl)pyridine) and Cp*2Fe produced H2O2 in high yield implying formation of CoIII(BDPP)(OOH) (3), and reaction of Sc(OTf)3 with the same mixture gave a peroxo-bridged CoIII/ScIII5. These findings demonstrate the ambiphilic property of CoIII-superoxo 1.
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Affiliation(s)
- Ting-Yi Chen
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan. and Universität Göttingen, Institut für Anorganische Chemie, D-37077 Göttingen, Germany.
| | - Po-Hsun Ho
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan.
| | - Can-Jerome Spyra
- Universität Göttingen, Institut für Anorganische Chemie, D-37077 Göttingen, Germany.
| | - Franc Meyer
- Universität Göttingen, Institut für Anorganische Chemie, D-37077 Göttingen, Germany.
| | - Eckhard Bill
- Max-Planck-Institut für Chemische Energiekonversion, Mülheim an der Ruhr D-45470, Germany.
| | - Shengfa Ye
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. and Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, D-45470, Germany.
| | - Way-Zen Lee
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan. and Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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39
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Srnec M, Iyer SR, Dassama LMK, Park K, Wong SD, Sutherlin KD, Yoda Y, Kobayashi Y, Kurokuzu M, Saito M, Seto M, Krebs C, Bollinger JM, Solomon EI. Nuclear Resonance Vibrational Spectroscopic Definition of the Facial Triad Fe IV═O Intermediate in Taurine Dioxygenase: Evaluation of Structural Contributions to Hydrogen Atom Abstraction. J Am Chem Soc 2020; 142:18886-18896. [PMID: 33103886 DOI: 10.1021/jacs.0c08903] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The α-ketoglutarate (αKG)-dependent oxygenases catalyze a diverse range of chemical reactions using a common high-spin FeIV═O intermediate that, in most reactions, abstract a hydrogen atom from the substrate. Previously, the FeIV═O intermediate in the αKG-dependent halogenase SyrB2 was characterized by nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT) calculations, which demonstrated that it has a trigonal-pyramidal geometry with the scissile C-H bond of the substrate calculated to be perpendicular to the Fe-O bond. Here, we have used NRVS and DFT calculations to show that the FeIV═O complex in taurine dioxygenase (TauD), the αKG-dependent hydroxylase in which this intermediate was first characterized, also has a trigonal bipyramidal geometry but with an aspartate residue replacing the equatorial halide of the SyrB2 intermediate. Computational analysis of hydrogen atom abstraction by square pyramidal, trigonal bipyramidal, and six-coordinate FeIV═O complexes in two different substrate orientations (one more along [σ channel] and another more perpendicular [π channel] to the Fe-O bond) reveals similar activation barriers. Thus, both substrate approaches to all three geometries are competent in hydrogen atom abstraction. The equivalence in reactivity between the two substrate orientations arises from compensation of the promotion energy (electronic excitation within the d manifold) required to access the π channel by the significantly larger oxyl character present in the pπ orbital oriented toward the substrate, which leads to an earlier transition state along the C-H coordinate.
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Affiliation(s)
- Martin Srnec
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305-5080, United States.,J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences, Dolejškova 3, Prague 8 182 23, Czech Republic
| | - Shyam R Iyer
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305-5080, United States
| | - Laura M K Dassama
- Department of Chemistry and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kiyoung Park
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305-5080, United States
| | - Shaun D Wong
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305-5080, United States
| | - Kyle D Sutherlin
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305-5080, United States
| | - Yoshitaka Yoda
- Japan Synchrotron Radiation Research Institute, Hyogo 679-5198, Japan
| | | | | | - Makina Saito
- Research Reactor Institute, Kyoto University, Osaka 590-0494, Japan
| | - Makoto Seto
- Research Reactor Institute, Kyoto University, Osaka 590-0494, Japan
| | - Carsten Krebs
- Department of Chemistry and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - J Martin Bollinger
- Department of Chemistry and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Edward I Solomon
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305-5080, United States
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40
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Dunham NP, Arnold FH. Nature's Machinery, Repurposed: Expanding the Repertoire of Iron-Dependent Oxygenases. ACS Catal 2020; 10:12239-12255. [PMID: 33282461 PMCID: PMC7710332 DOI: 10.1021/acscatal.0c03606] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Iron is an especially important redox-active cofactor in biology because of its ability to mediate reactions with atmospheric O2. Iron-dependent oxygenases exploit this earth-abundant transition metal for the insertion of oxygen atoms into organic compounds. Throughout the astounding diversity of transformations catalyzed by these enzymes, the protein framework directs reactive intermediates toward the precise formation of products, which, in many cases, necessitates the cleavage of strong C-H bonds. In recent years, members of several iron-dependent oxygenase families have been engineered for new-to-nature transformations that offer advantages over conventional synthetic methods. In this Perspective, we first explore what is known about the reactivity of heme-dependent cytochrome P450 oxygenases and nonheme iron-dependent oxygenases bearing the 2-His-1-carboxylate facial triad by reviewing mechanistic studies with an emphasis on how the protein scaffold maximizes the catalytic potential of the iron-heme and iron cofactors. We then review how these cofactors have been repurposed for abiological transformations by engineering the protein frameworks of these enzymes. Finally, we discuss contemporary challenges associated with engineering these platforms and comment on their roles in biocatalysis moving forward.
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Affiliation(s)
- Noah P. Dunham
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 210-41, Pasadena, California 91125, United States
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 210-41, Pasadena, California 91125, United States
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41
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Rabe P, Beale JH, Butryn A, Aller P, Dirr A, Lang PA, Axford DN, Carr SB, Leissing TM, McDonough MA, Davy B, Ebrahim A, Orlans J, Storm SLS, Orville AM, Schofield CJ, Owen RL. Anaerobic fixed-target serial crystallography. IUCRJ 2020; 7:901-912. [PMID: 32939282 PMCID: PMC7467159 DOI: 10.1107/s2052252520010374] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/27/2020] [Indexed: 05/04/2023]
Abstract
Cryogenic X-ray diffraction is a powerful tool for crystallographic studies on enzymes including oxygenases and oxidases. Amongst the benefits that cryo-conditions (usually employing a nitro-gen cryo-stream at 100 K) enable, is data collection of di-oxy-gen-sensitive samples. Although not strictly anaerobic, at low temperatures the vitreous ice conditions severely restrict O2 diffusion into and/or through the protein crystal. Cryo-conditions limit chemical reactivity, including reactions that require significant conformational changes. By contrast, data collection at room temperature imposes fewer restrictions on diffusion and reactivity; room-temperature serial methods are thus becoming common at synchrotrons and XFELs. However, maintaining an anaerobic environment for di-oxy-gen-dependent enzymes has not been explored for serial room-temperature data collection at synchrotron light sources. This work describes a methodology that employs an adaptation of the 'sheet-on-sheet' sample mount, which is suitable for the low-dose room-temperature data collection of anaerobic samples at synchrotron light sources. The method is characterized by easy sample preparation in an anaerobic glovebox, gentle handling of crystals, low sample consumption and preservation of a localized anaerobic environment over the timescale of the experiment (<5 min). The utility of the method is highlighted by studies with three X-ray-radiation-sensitive Fe(II)-containing model enzymes: the 2-oxoglutarate-dependent l-arginine hy-droxy-lase VioC and the DNA repair enzyme AlkB, as well as the oxidase isopenicillin N synthase (IPNS), which is involved in the biosynthesis of all penicillin and cephalosporin antibiotics.
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Affiliation(s)
- Patrick Rabe
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - John H. Beale
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Agata Butryn
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Pierre Aller
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Anna Dirr
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Pauline A. Lang
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Danny N. Axford
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Stephen B. Carr
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot Oxfordshire OX11 0FA, United Kingdom
| | - Thomas M. Leissing
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Michael A. McDonough
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Bradley Davy
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Ali Ebrahim
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, United Kingdom
| | - Julien Orlans
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
- UMR0203, Biologie Fonctionnelle, Insectes et Interactions, Institut National des Sciences Appliquées de Lyon, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, University of Lyon, Villeurbanne F-69621, France
| | - Selina L. S. Storm
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Allen M. Orville
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Christopher J. Schofield
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Robin L. Owen
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
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42
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The catalytic mechanism of sulfoxide synthases. Curr Opin Chem Biol 2020; 59:111-118. [PMID: 32726707 DOI: 10.1016/j.cbpa.2020.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/09/2020] [Accepted: 06/17/2020] [Indexed: 02/06/2023]
Abstract
Sulfoxide synthases are non-heme iron enzymes that catalyze oxidative carbonsulfur bond formation in the biosynthesis of thiohistidines such as ergothioneine and ovothiol. The catalytic mechanism of these enzymes has been studied by protein crystallography, steady-state kinetics, non-natural amino acid incorporation and computational modeling. This review discusses the current status of this research and also highlights similarities between the CS bond forming activity of sulfoxide synthases with that of synthetic coordination compounds.
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43
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Sacramento JJD, Goldberg DP. Oxidation of an indole substrate by porphyrin iron(iii) superoxide: relevance to indoleamine and tryptophan 2,3-dioxygenases. Chem Commun (Camb) 2020; 56:3089-3092. [PMID: 32052805 PMCID: PMC7065957 DOI: 10.1039/c9cc10019a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Reaction of FeIII(O2˙-)(TPP) with 2,3-dimethylindole at -40 °C gives the ring-opened, dioxygenated N-(2-acetyl-phenyl)-acetamide product. The reaction was monitored in situ by low-temperature UV-vis and 1H NMR spectroscopies. This work demonstrates that a discrete iron(iii)(superoxo) porphyrin is competent to carry out indole oxidation, as proposed for the tryptophan and indoleamine 2,3-dioxygenases.
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Affiliation(s)
- Jireh Joy D Sacramento
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA.
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA.
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44
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Mondal B, Ye S. Hidden ligand noninnocence: A combined spectroscopic and computational perspective. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2019.213115] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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45
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Zhang B, Arcinas AJ, Radle MI, Silakov A, Booker SJ, Krebs C. First Step in Catalysis of the Radical S-Adenosylmethionine Methylthiotransferase MiaB Yields an Intermediate with a [3Fe-4S] 0-Like Auxiliary Cluster. J Am Chem Soc 2020; 142:1911-1924. [PMID: 31899624 PMCID: PMC7008301 DOI: 10.1021/jacs.9b11093] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The enzyme MiaB catalyzes the attachment of a methylthio (-SCH3) group at the C2 position of N6-(isopentenyl)adenosine (i6A) in the final step of the biosynthesis of the hypermodified tRNA nucleotide 2-methythio-N6-(isopentenyl)adenosine (ms2i6A). MiaB belongs to the expanding subgroup of enzymes of the radical S-adenosylmethionine (SAM) superfamily that harbor one or more auxiliary [4Fe-4S] clusters in addition to the [4Fe-4S] cluster that all family members require for the reductive cleavage of SAM to afford the common 5'-deoxyadenosyl 5'-radical (5'-dA•) intermediate. While the role of the radical SAM cluster in generating the 5'-dA• is well understood, the detailed role of the auxiliary cluster, which is essential for MiaB catalysis, remains unclear. It has been proposed that the auxiliary cluster may serve as a coordination site for exogenously derived sulfur destined for attachment to the substrate or that the cluster itself provides the sulfur atom and is sacrificed during turnover. In this work, we report spectroscopic and biochemical evidence that the auxiliary [4Fe-4S]2+ cluster in Bacteroides thetaiotaomicron (Bt) MiaB is converted to a [3Fe-4S]0-like cluster during the methylation step of catalysis. Mössbauer characterization of the MiaB [3Fe-4S]0-like cluster revealed unusual spectroscopic properties compared to those of other well-characterized cuboidal [3Fe-4S]0 clusters. Specifically, the Fe sites of the mixed-valent moiety do not have identical Mössbauer parameters. Our results support a mechanism where the auxiliary [4Fe-4S] cluster is the direct sulfur source during catalysis.
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46
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Zhou S, Pan J, Davis KM, Schaperdoth I, Wang B, Boal AK, Krebs C, Bollinger JM. Steric Enforcement of cis-Epoxide Formation in the Radical C-O-Coupling Reaction by Which ( S)-2-Hydroxypropylphosphonate Epoxidase (HppE) Produces Fosfomycin. J Am Chem Soc 2019; 141:20397-20406. [PMID: 31769979 DOI: 10.1021/jacs.9b10974] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
(S)-2-Hydroxypropylphosphonate [(S)-2-HPP, 1] epoxidase (HppE) reduces H2O2 at its nonheme-iron cofactor to install the oxirane "warhead" of the antibiotic fosfomycin. The net replacement of the C1 pro-R hydrogen of 1 by its C2 oxygen, with inversion of configuration at C1, yields the cis-epoxide of the drug [(1R,2S)-epoxypropylphosphonic acid (cis-Fos, 2)]. Here we show that HppE achieves ∼95% selectivity for C1 inversion and cis-epoxide formation via steric guidance of a radical-coupling mechanism. Published structures of the HppE·FeII·1 and HppE·ZnII·2 complexes reveal distinct pockets for C3 of the substrate and product and identify four hydrophobic residues-Leu120, Leu144, Phe182, and Leu193-close to C3 in one of the complexes. Replacement of Leu193 in the substrate C3 pocket with the bulkier Phe enhances stereoselectivity (cis:trans ∼99:1), whereas the Leu120Phe substitution in the product C3 pocket diminishes it (∼82:18). Retention of C1 configuration and trans-epoxide formation become predominant with the bulk-reducing Phe182Ala substitution in the substrate C3 pocket (∼13:87), trifluorination of C3 (∼23:77), or both (∼1:99). The effect of C3 trifluorination is counteracted by the more constrained substrate C3 pockets in the Leu193Phe (∼56:44) and Leu144Phe/Leu193Phe (∼90:10) variants. The ability of HppE to epoxidize substrate analogues bearing halogens at C3, C1, or both is inconsistent with a published hypothesis of polar cyclization via a C1 carbocation. Rather, specific enzyme-substrate contacts drive inversion of the C1 radical-as proposed in a recent computational study-to direct formation of the more potently antibacterial cis-epoxide by radicaloid C-O coupling.
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Affiliation(s)
- Shengbin Zhou
- Department of Chemistry and Department of Biochemistry & Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Juan Pan
- Department of Chemistry and Department of Biochemistry & Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Katherine M Davis
- Department of Chemistry and Department of Biochemistry & Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Irene Schaperdoth
- Department of Chemistry and Department of Biochemistry & Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Bo Wang
- Department of Chemistry and Department of Biochemistry & Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Amie K Boal
- Department of Chemistry and Department of Biochemistry & Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Carsten Krebs
- Department of Chemistry and Department of Biochemistry & Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - J Martin Bollinger
- Department of Chemistry and Department of Biochemistry & Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
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47
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Lin Y, Stańczak A, Manchev Y, Straganz GD, Visser SP. Can a Mononuclear Iron(III)‐Superoxo Active Site Catalyze the Decarboxylation of Dodecanoic Acid in UndA to Produce Biofuels? Chemistry 2019; 26:2233-2242. [DOI: 10.1002/chem.201903783] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 09/24/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Yen‐Ting Lin
- The Manchester Institute of Biotechnology and Department of, Chemical Engineering and Analytical ScienceThe University of, Manchester 131 Princess Street Manchester M1 7DN UK
| | - Agnieszka Stańczak
- The Manchester Institute of Biotechnology and Department of, Chemical Engineering and Analytical ScienceThe University of, Manchester 131 Princess Street Manchester M1 7DN UK
- Faculty of ChemistrySilesian University of Technology ks. Marcina Strzody 9 44-100 Gliwice Poland
- Tunneling Group, Biotechnology CentreSilesian University of Technology ul. Krzywoustego 8 44–100 Gliwice Poland
| | - Yulian Manchev
- The Manchester Institute of Biotechnology and Department of, Chemical Engineering and Analytical ScienceThe University of, Manchester 131 Princess Street Manchester M1 7DN UK
| | - Grit D. Straganz
- Graz University of TechnologyInstitute of Biochemistry Petergasse 12 8010 Graz Austria
| | - Sam P. Visser
- The Manchester Institute of Biotechnology and Department of, Chemical Engineering and Analytical ScienceThe University of, Manchester 131 Princess Street Manchester M1 7DN UK
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48
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Abril P, Del Río MP, López JA, Lledós A, Ciriano MA, Tejel C. Inner-Sphere Oxygen Activation Promoting Outer-Sphere Nucleophilic Attack on Olefins. Chemistry 2019; 25:14546-14554. [PMID: 31432579 DOI: 10.1002/chem.201903068] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/19/2019] [Indexed: 01/18/2023]
Abstract
Alkoxylation and hydroxylation reactions of 1,5-cyclooctadiene (cod) in an iridium complex with alcohols and water promoted by the reduction of oxygen to hydrogen peroxide are described. The exo configuration of the OH/OR groups in the products agrees with nucleophilic attack at the external face of the olefin as the key step. The reactions also require the presence of a coordinating protic acid (such as picolinic acid (Hpic)) and involve the participation of a cationic diolefin iridium(III) complex, [Ir(cod)(pic)2 ]+ , which has been isolated. Independently, this cation is also involved in easy alkoxy group exchange reactions, which are very unusual for organic ethers. DFT studies on the mechanism of olefin alkoxylation mediated by oxygen show a low-energy proton-coupled electron-transfer step connecting a superoxide-iridium(II) complex with hydroperoxide-iridium(III) intermediates, rather than peroxide complexes. Accordingly, a more complex reaction, with up to four different products, occurred upon reacting the diolefin-peroxide iridium(III) complex with Hpic. Moreover, such hydroperoxide intermediates are the origin of the regio- and stereoselectivity of the hydroxylation/alkoxylation reactions. If this protocol is applied to the diolefin-rhodium(I) complex [Rh(pic)(cod)], free alkyl ethers ORC8 H11 (R=Me, Et) resulted, and the reaction is enantioselective if a chiral amino acid, such as l-proline, is used instead of Hpic.
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Affiliation(s)
- Paula Abril
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - M Pilar Del Río
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - José A López
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Agustí Lledós
- Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Barcelona, Spain
| | - Miguel A Ciriano
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Cristina Tejel
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
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49
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Gordon JB, Vilbert AC, DiMucci IM, MacMillan SN, Lancaster KM, Moënne-Loccoz P, Goldberg DP. Activation of Dioxygen by a Mononuclear Nonheme Iron Complex: Sequential Peroxo, Oxo, and Hydroxo Intermediates. J Am Chem Soc 2019; 141:17533-17547. [PMID: 31647656 DOI: 10.1021/jacs.9b05274] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The activation of dioxygen by FeII(Me3TACN)(S2SiMe2) (1) is reported. Reaction of 1 with O2 at -135 °C in 2-MeTHF generates a thiolate-ligated (peroxo)diiron complex FeIII2(O2)(Me3TACN)2(S2SiMe2)2 (2) that was characterized by UV-vis (λmax = 300, 390, 530, 723 nm), Mössbauer (δ = 0.53, |ΔEQ| = 0.76 mm s-1), resonance Raman (RR) (ν(O-O) = 849 cm-1), and X-ray absorption (XAS) spectroscopies. Complex 2 is distinct from the outer-sphere oxidation product 1ox (UV-vis (λmax = 435, 520, 600 nm), Mössbauer (δ = 0.45, |ΔEQ| = 3.6 mm s-1), and EPR (S = 5/2, g = [6.38, 5.53, 1.99])), obtained by one-electron oxidation of 1. Cleavage of the peroxo O-O bond can be initiated either photochemically or thermally to produce a new species assigned as an FeIV(O) complex, FeIV(O)(Me3TACN)(S2SiMe2) (3), which was identified by UV-vis (λmax = 385, 460, 890 nm), Mössbauer (δ = 0.21, |ΔEQ| = 1.57 mm s-1), RR (ν(FeIV═O) = 735 cm-1), and X-ray absorption spectroscopies, as well as reactivity patterns. Reaction of 3 at low temperature with H atom donors gives a new species, FeIII(OH)(Me3TACN)(S2SiMe2) (4). Complex 4 was independently synthesized from 1 by the stoichiometric addition of a one-electron oxidant and a hydroxide source. This work provides a rare example of dioxygen activation at a mononuclear nonheme iron(II) complex that produces both FeIII-O-O-FeIII and FeIV(O) species in the same reaction with O2. It also demonstrates the feasibility of forming Fe/O2 intermediates with strongly donating sulfur ligands while avoiding immediate sulfur oxidation.
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Affiliation(s)
- Jesse B Gordon
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| | - Avery C Vilbert
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States
| | - Ida M DiMucci
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States
| | - Kyle M Lancaster
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry , Oregon Health & Science University , Portland , Oregon 97239 , United States
| | - David P Goldberg
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
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50
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Pan J, Wenger ES, Matthews ML, Pollock CJ, Bhardwaj M, Kim AJ, Allen BD, Grossman RB, Krebs C, Bollinger JM. Evidence for Modulation of Oxygen Rebound Rate in Control of Outcome by Iron(II)- and 2-Oxoglutarate-Dependent Oxygenases. J Am Chem Soc 2019; 141:15153-15165. [PMID: 31475820 DOI: 10.1021/jacs.9b06689] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Iron(II)- and 2-oxoglutarate-dependent (Fe/2OG) oxygenases generate iron(IV)-oxo (ferryl) intermediates that can abstract hydrogen from aliphatic carbons (R-H). Hydroxylation proceeds by coupling of the resultant substrate radical (R•) and oxygen of the Fe(III)-OH complex ("oxygen rebound"). Nonhydroxylation outcomes result from different fates of the Fe(III)-OH/R• state; for example, halogenation results from R• coupling to a halogen ligand cis to the hydroxide. We previously suggested that halogenases control substrate-cofactor disposition to disfavor oxygen rebound and permit halogen coupling to prevail. Here, we explored the general implication that, when a ferryl intermediate can ambiguously target two substrate carbons for different outcomes, rebound to the site capable of the alternative outcome should be slower than to the adjacent, solely hydroxylated site. We evaluated this prediction for (i) the halogenase SyrB2, which exclusively hydroxylates C5 of norvaline appended to its carrier protein but can either chlorinate or hydroxylate C4 and (ii) two bifunctional enzymes that normally hydroxylate one carbon before coupling that oxygen to a second carbon (producing an oxacycle) but can, upon encountering deuterium at the first site, hydroxylate the second site instead. In all three cases, substrate hydroxylation incorporates a greater fraction of solvent-derived oxygen at the site that can also undergo the alternative outcome than at the other site, most likely reflecting an increased exchange of the initially O2-derived oxygen ligand in the longer-lived Fe(III)-OH/R• states. Suppression of rebound may thus be generally important for nonhydroxylation outcomes by these enzymes.
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Affiliation(s)
| | | | | | | | - Minakshi Bhardwaj
- Department of Chemistry , University of Kentucky , Lexington , Kentucky 40546-0312 , United States
| | | | | | - Robert B Grossman
- Department of Chemistry , University of Kentucky , Lexington , Kentucky 40546-0312 , United States
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