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Qin H, Guo M, Zhou C, Li J, Jing X, Wan Y, Song W, Yu H, Peng G, Yao Z, Liu J, Hu K. Enhancing singlet oxygen production of dioxygen activation on the carbon-supported rare-earth oxide nanocluster and rare-earth single atom catalyst to remove antibiotics. Water Res 2024; 252:121184. [PMID: 38377699 DOI: 10.1016/j.watres.2024.121184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/20/2024] [Accepted: 01/23/2024] [Indexed: 02/22/2024]
Abstract
Singlet oxygen (1O2) is extensively employed in the fields of chemical, biomedical and environmental. However, it is still a challenge to produce high- concentration 1O2 by dioxygen activation. Herein, a system of carbon-supported rare-earth oxide nanocluster and single atom catalysts (named as RE2O3/RE-C, RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y) with similar morphology, structure, and physicochemical characteristic are constructed to activate dissolved oxygen (DO) to enhance 1O2 production. The catalytic activity trends and mechanisms are revealed experimentally and are also proven by theoretical analyses and calculations. The 1O2 generation activity trend is Gd2O3/Gd-C>Er2O3/Er-C>Sm2O3/Sm-C>pristine carbon (C). More than 95.0% of common antibiotics (ciprofloxacin, ofloxacin, norfloxacin and carbamazepine) can be removed in 60 min by Gd2O3/Gd-C. Density functional theory calculations indicate that Gd2O3 nanoclusters and Gd single atoms exhibit the moderate adsorption energy of ·O2- to enhance 1O2 production. This study offers a universal strategy to enhance 1O2 production in dioxygen activation for future application and reveals the natural essence of basic mechanisms of 1O2 production via rare-earth oxide nanoclusters and rare-earth single atoms.
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Affiliation(s)
- Haonan Qin
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Meina Guo
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China; Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganzhou 341000, China
| | - Chenliang Zhou
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Jiarong Li
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Xuequan Jing
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Yinhua Wan
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China; Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganzhou 341000, China; Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Weijie Song
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China; Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganzhou 341000, China; Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongdong Yu
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China; Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganzhou 341000, China
| | - Guan Peng
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China; Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganzhou 341000, China
| | - Zhangwei Yao
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Jiaming Liu
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China
| | - Kang Hu
- School of Rare Earths, University of Science and Technology of China, Hefei, Anhui 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China; Key Laboratory of Rare Earth, Chinese Academy of Sciences, Ganzhou 341000, China; Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Ganzhou 341000, China.
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Podgorski MN, Lee JHZ, Harbort JS, Nguyen GTH, Doherty DZ, Donald WA, Harmer JR, Bruning JB, Bell SG. Characterisation of the heme aqua-ligand coordination environment in an engineered peroxygenase cytochrome P450 variant. J Inorg Biochem 2023; 249:112391. [PMID: 37837941 DOI: 10.1016/j.jinorgbio.2023.112391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 09/30/2023] [Accepted: 10/02/2023] [Indexed: 10/16/2023]
Abstract
The cytochrome P450 enzymes (CYPs) are heme-thiolate monooxygenases that catalyse the insertion of an oxygen atom into the C-H bonds of organic molecules. In most CYPs, the activation of dioxygen by the heme is aided by an acid-alcohol pair of residues located in the I-helix of the enzyme. Mutation of the threonine residue of this acid-alcohol pair of CYP199A4, from the bacterium Rhodospeudomonas palustris HaA2, to a glutamate residue induces peroxygenase activity. In the X-ray crystal structures of this variant an interaction of the glutamate side chain and the distal aqua ligand of the heme was observed and this results in this ligand not being readily displaced in the peroxygenase mutant on the addition of substrate. Here we use a range of bulky hydrophobic and nitrogen donor containing ligands in an attempt to displace the distal aqua ligand of the T252E mutant of CYP199A4. Ligand binding was assessed by UV-visible absorbance spectroscopy, native mass spectrometry, electron paramagnetic resonance and X-ray crystallography. None of the ligands tested, even the nitrogen donor ligands which bind directly to the iron in the wild-type enzyme, resulted in displacement of the aqua ligand. Therefore, modification of the I-helix threonine residue to a glutamate residue results in a significant strengthening of the ferric distal aqua ligand. This ligand was not displaced using any of the ligands during this study and this provides a rationale as to why this mutant can shutdown the monooxygenase pathway of this enzyme and switch to peroxygenase activity.
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Affiliation(s)
- Matthew N Podgorski
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia
| | - Joel H Z Lee
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia
| | - Joshua S Harbort
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, QLD 4072, Australia
| | - Giang T H Nguyen
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Daniel Z Doherty
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia
| | - William A Donald
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Jeffrey R Harmer
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, QLD 4072, Australia
| | - John B Bruning
- School of Biological Sciences, University of Adelaide, SA 5005, Australia
| | - Stephen G Bell
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.
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Zhang X, Jia Q, Wu F, Zhu L, Huang LZ. Charging and discharging of humic acid geobattery induced by green rust and oxygenation: Impact on the fate and degradation of tribromophenol in redox-alternating groundwater environments. J Hazard Mater 2023; 458:131872. [PMID: 37379598 DOI: 10.1016/j.jhazmat.2023.131872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 05/31/2023] [Accepted: 06/14/2023] [Indexed: 06/30/2023]
Abstract
Humic acid (HA) and ferrous minerals (e.g. green rust, GR) are abundant in groundwater. HA acts as a geobattery that take up and release electrons in redox-alternating groundwater environments. However, the impact of this process on the fate and transformation of groundwater pollutants is not fully understood. In this work, we found that the adsorption of HA on GR inhibited the adsorption of tribromophenol (TBP) under anoxic conditions. Meanwhile, GR could donate electrons to HA, causing the electron donating capacity of HA rapidly increase from 12.7% to 27.4% in 5 min. The electron transfer process from GR to HA significantly increased the yield of hydroxyl radicals (•OH) and the degradation efficiency of TBP during GR-involved dioxygen activation process. Compared to the limited electronic selectivity (ES) of GR for •OH production (ES = 0.83%), GR-reduced HA improves the ES by an order of magnitude (ES = 8.4%). HA-involved dioxygen activation process expands the •OH generation interface from solid phase to aqueous phase, which is conducive to the degradation of TBP. This study not only deepens our understanding on the role of HA in •OH production during GR oxygenation, but also provides a promising approach for groundwater remediation under redox-fluctuating conditions.
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Affiliation(s)
- Xuejie Zhang
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan 430072, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, PR China
| | - Qianqian Jia
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan 430072, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, PR China
| | - Feng Wu
- School of Resources and Environmental Science, Wuhan University, Wuhan, PR China
| | - Liandong Zhu
- School of Resources and Environmental Science, Wuhan University, Wuhan, PR China
| | - Li-Zhi Huang
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan 430072, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, PR China.
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Fan Q, Wang L, Fu Y, Li Q, Liu Y, Wang Z, Zhu H. Iron redox cycling in layered clay minerals and its impact on contaminant dynamics: A review. Sci Total Environ 2023; 855:159003. [PMID: 36155041 DOI: 10.1016/j.scitotenv.2022.159003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/30/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
A majority of clay minerals contain Fe, and the redox cycling of Fe(III)/Fe(II) in clay minerals has been extensively studied as it may fuel the biogeochemical cycles of nutrients and govern the mobility, toxicity and bioavailability of a number of environmental contaminants. There are three types of Fe in clay minerals, including structural Fe sandwiched in the lattice of clays, Fe species in interlayer space and adsorbed on the external surface of clays. They exhibit distinct reactivity towards contaminants due to their differences in redox properties and accessibility to contaminant species. In natural environments, microbially driven Fe(III)/Fe(II) redox cycling in clay minerals is thought to be important, whereas reductants (e.g., dithionite and Fe(II)) or oxidants (e.g., peroxygens) are capable of enhancing the rates and extents of redox dynamics in engineered systems. Fe(III)-containing clay minerals can directly react with oxidizable pollutants (e.g., phenols and polycyclic aromatic hydrocarbons (PAHs)), whereas structural Fe(II) is able to react with reducible pollutants, such as nitrate, nitroaromatic compounds, chlorinated aliphatic compounds. Also structural Fe(II) can transfer electrons to oxygen (O2), peroxymonosulfate (PMS), or hydrogen peroxide (H2O2), yielding reactive radicals that can promote the oxidative transformation of contaminants. This review summarizes the recent discoveries on redox reactivity of Fe in clay minerals and its links to fates of environmental contaminants. The biological and chemical reduction mechanisms of Fe(III)-clay minerals, as well as the interaction mechanism between Fe(III) or Fe(II)-containing clay minerals and contaminants are elaborated. Some knowledge gaps are identified for better understanding and modelling of clay-associated contaminant behavior and effective design of remediation solutions.
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Affiliation(s)
- Qingya Fan
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Lingli Wang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Yu Fu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Qingchao Li
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Yunjiao Liu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Zhaohui Wang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; State Key Laboratory of Mineral Processing, Beijing 102628, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai 200062, China.
| | - Huaiyong Zhu
- School of Chemistry and Physics, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4001, Australia
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Zhang X, Deng J, Jia Q, Ji B, Dai Y, Huang LZ. Mineralization of tribromophenol under anoxic/oxic conditions in the presence of copper(II) doped green rust: Importance of sequential reduction-oxidation process. Water Res 2022; 222:118959. [PMID: 35964514 DOI: 10.1016/j.watres.2022.118959] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
The groundwater environment often undergoes the transition from anoxic to oxic due to natural processes or human activities, but the influence of this transition on the fate of groundwater contaminates are not entirely understood. In this work, the degradation of tribromophenol (TBP) in the presence of environmentally relevant iron (oxyhydr)oxides (green rust, GR) and trace metal ions Cu(II) under anoxic/oxic-alternating conditions was investigated. Under anoxic conditions, GR-Cu(II) reduced TBP to 4-BP completely within 7 h while GR only had an adsorption effect on TBP. Under oxic conditions, GR-Cu(II) could generate •OH via dioxygen activation, which resulted in the oxidative transformation of TBP. Sixty-five percentage of TBP mineralization was achieved via a sequential reduction-oxidation process, which was not achieved through single reduction or oxidation process. The produced Cu(I) in GR-Cu(II) enhanced not only the reductive dehalogenation under anoxic conditions, but also the O2 activation under oxic conditions. Thus, the fate of TBP in anoxic/oxic-alternating groundwater environment is greatly influenced by the presence of GR-Cu(II). The sequential reduction-oxidation degradation of TBP by GR-Cu(II) is promising for future remediation of TBP-contaminated groundwater.
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Affiliation(s)
- Xuejie Zhang
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan 430072, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, PR China
| | - Jia Deng
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan 430072, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, PR China
| | - Qianqian Jia
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan 430072, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, PR China
| | - Bingbing Ji
- School of Resources and Environmental Science, Wuhan University, Wuhan, PR China
| | - Yitao Dai
- Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Li-Zhi Huang
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan 430072, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, PR China.
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Zhang X, Jia Q, Deng J, Wu F, Huang LZ. Interaction between green rust and tribromophenol under anoxic, oxic and anoxic-to-oxic conditions: Adsorption, desorption and oxidative degradation. Water Res 2022; 217:118398. [PMID: 35413564 DOI: 10.1016/j.watres.2022.118398] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 03/27/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
As a reductive Fe(II)-bearing mineral, green rust (GR) is able to reduce halogenated compounds in anoxic subsurface environments. The redox condition of subsurface environment often changes from anoxic to oxic due to natural and anthropogenic disturbances, but the interaction of GR with halogenated compounds in oxic, and anoxic-to-oxic transition conditions has not been studied. This study reveals that GR can sequester TBP for a short time (4 to 10 h) under anoxic conditions. Later, GR undergoes structural transformation to ferrihydrite and magnetite with the desorption of TBP. GR-derived iron (hydr)oxides can generate 33.8 μM of •OH upon 50 h exposure to dioxygen, which leads to 67% of oxidative degradation of TBP. The anoxic-to-oxic transition during the TBP adsorption process initiates the TBP desorption immediately, and also results in the oxidative degradation of TBP via the production of •OH. The oxygenation of GR immediately forms magnetite which activate dioxygen to produce •OH. Also, the GR-derived magnetite acts as a Fe(II) source, and free Fe(II) in solution and Fe(II) adsorbed on magnetite surface both contribute to dioxygen activation. This work provides vital evidence on the role of GR in the fate and transformation of TBP in redox alternating subsurface environments.
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Affiliation(s)
- Xuejie Zhang
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan, 430072, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, China
| | - Qianqian Jia
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan, 430072, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, China
| | - Jia Deng
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan, 430072, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, China
| | - Feng Wu
- School of Resources and Environmental Science, Wuhan University, Wuhan, China
| | - Li-Zhi Huang
- School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan, 430072, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, China.
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Paul M, Teubner M, Grimm-Lebsanft B, Buchenau S, Hoffmann A, Rübhausen M, Herres-Pawlis S. Influence of the amine donor on hybrid guanidine-stabilized Bis(μ-oxido) dicopper(III) complexes and their tyrosinase-like oxygenation activity towards polycyclic aromatic alcohols. J Inorg Biochem 2021; 224:111541. [PMID: 34416481 DOI: 10.1016/j.jinorgbio.2021.111541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 06/30/2021] [Accepted: 07/11/2021] [Indexed: 10/20/2022]
Abstract
The tyrosinase-like activity of hybrid guanidine-stabilized bis(μ-oxido) dicopper(III) complexes [Cu2(μ-O)2(L)2](X)2 (L = 2-{2-((Diethylamino)methyl)phenyl}-1,1,3,3-tetramethylguanidine (TMGbenzNEt2, L2) and 2-{2-((Di-isopropylamino)methyl)phenyl}-1,1,3,3-tetramethylguanidine (TMGbenzNiPr2, L3); X = PF6-, BF4-, CF3SO3-) is described. New aromatic hybrid guanidine amine ligands were developed with varying amine donor function. Their copper(I) complexes were analyzed towards their ability to activate dioxygen in the presence of different weakly coordinating anions. The resulting bis(μ-oxido) species were characterized at low temperatures by UV/Vis and resonance Raman spectroscopy, cryo-ESI mass spectrometry and density functional theory calculations. Small structural changes in the ligand sphere were found to influence the characteristic ligand-to-metal charge transfer (LMCT) features of the bis(μ-oxido) species, correlating a redshift in the UV/Vis spectrum with weaker N-donor function of the ligand. DFT calculations elucidated the influence of the steric and electronic properties of the bis(μ-oxido) species leading to a higher twist of the Cu2O2 plane against the CuN2 plane and a stretching of the Cu2O2 core. Despite their moderate stability at -100 °C, the bis(μ-oxido) complexes exhibited a remarkable activity in catalytic oxygenation reactions of polycyclic aromatic alcohols. Further the selectivity of the catalyst in the hydroxylation reactions of challenging phenolic substrates is not changed despite an increasing shield of the reactive bis(μ-oxido) core. The generated quinones were found to form exclusively bent phenazines, providing a promising strategy to access tailored phenazine derivatives.
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Affiliation(s)
- Melanie Paul
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Melissa Teubner
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany; Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | | | - Sören Buchenau
- Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Alexander Hoffmann
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
| | - Michael Rübhausen
- Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Sonja Herres-Pawlis
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany.
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Brückmann T, Becker J, Würtele C, Seuffert MT, Heuler D, Müller-Buschbaum K, Weiß M, Schindler S. Characterization of copper complexes with derivatives of the ligand (2-aminoethyl)bis(2-pyridylmethyl)amine (uns-penp) and their reactivity towards oxygen. J Inorg Biochem 2021; 223:111544. [PMID: 34333248 DOI: 10.1016/j.jinorgbio.2021.111544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 07/05/2021] [Accepted: 07/12/2021] [Indexed: 11/18/2022]
Abstract
A series of copper(I) complexes with ligands derived from the tripodal ligand (2-aminoethyl)bis(2-pyridylmethyl)amine (uns-penp) have been structurally characterized and their redox chemistry analyzed by cyclic voltammetry. While the redox potentials of most of the complexes were similar their reactivity towards dioxygen was quite different. While the complex with a ferrocene derived ligand of uns-penp reacted in solution at low temperatures in a two-step reaction from the preliminary formed mononuclear end-on superoxido complex to a quite stable dinuclear peroxido complex it did not react with dioxygen in the solid state. Other complexes also did not react with dioxygen in the solid state while some showed a reversible formation to a green compound, indicating formation of an end-on superoxido complex that unfortunately so far could not be characterized. In contrast, copper complexes with the Me2uns-penp and Et-iProp-uns-penp formed dinuclear peroxido complexes in a solid-state reaction. While the reaction of dioxygen with the [Cu(Me2uns-penp]BPh4 was quite slow an instant reaction took place for [Cu(Et-iProp-uns-penp]BPh. Very unusual, it turned out that crystals of the copper(I) complex that could be structurally characterized still were crystalline when reacted with dioxygen. Therefore, it was possible to solve the structure of the corresponding dinuclear peroxido complex directly from the same batch of crystals. The crystalline structures of the copper(I) and copper(II) complex revealed that the reason for this is the fact, that the copper(I) complex is kind of preorganized for the uptake of dioxygen and does not really change in its overall structure when being oxidized.
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Affiliation(s)
- Tim Brückmann
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Jonathan Becker
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Christian Würtele
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Marcel Thomas Seuffert
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Dominik Heuler
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Klaus Müller-Buschbaum
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany
| | - Morten Weiß
- Fakultät für Biologie, Chemie und Geowissenschaften, Universität Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany
| | - Siegfried Schindler
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 17, 35392 Gießen, Germany.
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Paul M, Hoffmann A, Herres-Pawlis S. Room temperature stable multitalent: highly reactive and versatile copper guanidine complexes in oxygenation reactions. J Biol Inorg Chem 2021; 26:249-263. [PMID: 33595752 PMCID: PMC8068697 DOI: 10.1007/s00775-021-01849-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/20/2021] [Indexed: 12/24/2022]
Abstract
Inspired by the efficiency of natural enzymes in organic transformation reactions, the development of synthetic catalysts for oxygenation and oxidation reactions under mild conditions still remains challenging. Tyrosinases serve as archetype when it comes to hydroxylation reactions involving molecular oxygen. We herein present new copper(I) guanidine halide complexes, capable of the activation of molecular oxygen at room temperature. The formation of the reactive bis(µ-oxido) dicopper(III) species and the influence of the anion are investigated by UV/Vis spectroscopy, mass spectrometry, and density functional theory. We highlight the catalytic hydroxylation activity towards diverse polycyclic aromatic alcohols under mild reaction conditions. The selective formation of reactive quinones provides a promising tool to design phenazine derivatives for medical applications.
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Affiliation(s)
- Melanie Paul
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Alexander Hoffmann
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Sonja Herres-Pawlis
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany.
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10
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Coleman T, Stok JE, Podgorski MN, Bruning JB, De Voss JJ, Bell SG. Structural insights into the role of the acid-alcohol pair of residues required for dioxygen activation in cytochrome P450 enzymes. J Biol Inorg Chem 2020; 25:583-596. [PMID: 32248305 DOI: 10.1007/s00775-020-01781-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/22/2020] [Indexed: 10/24/2022]
Abstract
The cytochrome P450 heme monooxygenases commonly use an acid-alcohol pair of residues, within the I-helix, to activate iron-bound dioxygen. This work aims to clarify conflicting reports on the importance of the alcohol functionality in this process. Mutants of the P450, CYP199A4 (CYP199A4D251N and CYP199A4T252A), were prepared, characterised and their crystal structures were solved. The acid residue of CYP199A4 is not part of a salt bridge network, a key feature of paradigmatic model system P450cam. Instead, there is a direct proton delivery network, via a chain of water molecules, extending to the surface. Nevertheless, CYP199A4D251N dramatically reduced the activity of the enzyme consistent with a role in proton delivery. CYP199A4T252A decreased the coupling efficiency of the enzyme with a concomitant increase in the hydrogen peroxide uncoupling pathway. However, the effect of this mutation was much less pronounced than reported with P450cam. Its crystal structures revealed fewer changes at the I-helix, compared to the P450cam system. The structural changes observed within the I-helix of P450cam during oxygen activation do not seem to be required in this P450. These differences are due to the presence of a second threonine residue at position 253, which is absent in P450cam. This threonine forms part of the hydrogen bonding network, resulting in subtle structural changes and is also present across the majority of the P450 superfamily. Overall, the results suggest that while the acid-alcohol pair is important for dioxygen activation this process and the method of proton delivery can differ across P450s.Graphic abstract.
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Affiliation(s)
- Tom Coleman
- Department of Chemistry, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Jeanette E Stok
- School of Chemistry and Molecular Bioscience, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Matthew N Podgorski
- Department of Chemistry, University of Adelaide, Adelaide, SA, 5005, Australia
| | - John B Bruning
- School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - James J De Voss
- School of Chemistry and Molecular Bioscience, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Stephen G Bell
- Department of Chemistry, University of Adelaide, Adelaide, SA, 5005, Australia.
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Dedushko MA, Schweitzer D, Blakely MN, Swartz RD, Kaminsky W, Kovacs JA. Geometric and electronic structure of a crystallographically characterized thiolate-ligated binuclear peroxo-bridged cobalt(III) complex. J Biol Inorg Chem 2019; 24:919-26. [PMID: 31342141 DOI: 10.1007/s00775-019-01686-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/11/2019] [Indexed: 10/26/2022]
Abstract
In order to shed light on metal-dependent mechanisms for O-O bond cleavage, and its microscopic reverse, we compare herein the electronic and geometric structures of O2-derived binuclear Co(III)- and Mn(III)-peroxo compounds. Binuclear metal peroxo complexes are proposed to form as intermediates during Mn-promoted photosynthetic H2O oxidation, and a Co-containing artificial leaf inspired by nature's photosynthetic H2O oxidation catalyst. Crystallographic characterization of an extremely activated peroxo is made possible by working with substitution-inert, low-spin Co(III). Density functional theory (DFT) calculations show that the frontier orbitals of the Co(III)-peroxo compound differ noticeably from the analogous Mn(III)-peroxo compound. The highest occupied molecular orbital (HOMO) associated with the Co(III)-peroxo is more localized on the peroxo in an antibonding π*(O-O) orbital, whereas the HOMO of the structurally analogous Mn(III)-peroxo is delocalized over both the metal d-orbitals and peroxo π*(O-O) orbital. With low-spin d6 Co(III), filled t2g orbitals prevent π-back-donation from the doubly occupied antibonding π*(O-O) orbital onto the metal ion. This is not the case with high-spin d4 Mn(III), since these orbitals are half-filled. This weakens the peroxo O-O bond of the former relative to the latter.
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Rydel-Ciszek K, Charczuk M, Pacześniak T, Chmielarz P. Manganese(II) complexes with Bn-tpen as powerful catalysts of cyclohexene oxidation. Chem Zvesti 2017; 71:2085-2093. [PMID: 29104351 PMCID: PMC5655609 DOI: 10.1007/s11696-017-0201-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 05/11/2017] [Indexed: 11/12/2022]
Abstract
Manganese(II) complex [(Bn-tpen)MnII]2+ activated dioxygen for oxidation of cyclohexene in acetonitrile (MeCN) and methanol (MeOH). In MeCN, ketone (2-cyclohexen-1-one), alcohol (2-cyclohexen-1-ol) and small amounts of epoxide (cyclohexene oxide) were produced in this reaction, while in MeOH only ketone was formed. In the most efficient experiment, the combination of 2.5 × 10−4 mol% [(Bn-tpen)MnII]2+ and 4 M cyclohexene under dioxygen atmosphere (pO2 = 1 atm) in MeCN after 24 h of reaction, gave the TON equal to 716, and the main oxidation products were ketone (196 mM) and alcohol (147 mM), whereas epoxide was formed in insignificant amounts (15 mM). The formation of [(Bn-tpen)MnIV=O]2+ and [(Bn-tpen)MnIII–OH]2+ species was confirmed. The novelty of this work is the observation, that in both solvents, [(Bn-tpen)MnII]2+ complex is initially oxidized by t-BuOOH to produce Mn(III)-complex, which is reduced back by cyclohexene to [(Bn-tpen)MnII]2+, and the latter species is an active catalyst of c-C6H10 oxidation. Knowledge of the electrochemical properties of the system components may contribute to understanding the mechanisms involving participation of the active agents created in the system.
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Affiliation(s)
- Katarzyna Rydel-Ciszek
- Department of Physical Chemistry, Faculty of Chemistry, Rzeszów University of Technology, 35-959 Rzeszów, Poland
| | - Maria Charczuk
- Department of Physical Chemistry, Faculty of Chemistry, Rzeszów University of Technology, 35-959 Rzeszów, Poland
| | - Tomasz Pacześniak
- Department of Physical Chemistry, Faculty of Chemistry, Rzeszów University of Technology, 35-959 Rzeszów, Poland
| | - Paweł Chmielarz
- Department of Physical Chemistry, Faculty of Chemistry, Rzeszów University of Technology, 35-959 Rzeszów, Poland
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Quist DA, Diaz DE, Liu JJ, Karlin KD. Activation of dioxygen by copper metalloproteins and insights from model complexes. J Biol Inorg Chem 2017; 22:253-288. [PMID: 27921179 PMCID: PMC5600896 DOI: 10.1007/s00775-016-1415-2] [Citation(s) in RCA: 156] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 11/11/2016] [Indexed: 02/08/2023]
Abstract
Nature uses dioxygen as a key oxidant in the transformation of biomolecules. Among the enzymes that are utilized for these reactions are copper-containing metalloenzymes, which are responsible for important biological functions such as the regulation of neurotransmitters, dioxygen transport, and cellular respiration. Enzymatic and model system studies work in tandem in order to gain an understanding of the fundamental reductive activation of dioxygen by copper complexes. This review covers the most recent advancements in the structures, spectroscopy, and reaction mechanisms for dioxygen-activating copper proteins and relevant synthetic models thereof. An emphasis has also been placed on cofactor biogenesis, a fundamentally important process whereby biomolecules are post-translationally modified by the pro-enzyme active site to generate cofactors which are essential for the catalytic enzymatic reaction. Significant questions remaining in copper-ion-mediated O2-activation in copper proteins are addressed.
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Affiliation(s)
- David A Quist
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Daniel E Diaz
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Jeffrey J Liu
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Kenneth D Karlin
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, USA.
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Abstract
Methane monooxygenase (MMO) enzymes activate O2 for oxidation of methane. Two distinct MMOs exist in nature, a soluble form that uses a diiron active site (sMMO) and a membrane-bound form with a catalytic copper center (pMMO). Understanding the reaction mechanisms of these enzymes is of fundamental importance to biologists and chemists, and is also relevant to the development of new biocatalysts. The sMMO catalytic cycle has been elucidated in detail, including O2 activation intermediates and the nature of the methane-oxidizing species. By contrast, many aspects of pMMO catalysis remain unclear, most notably the nuclearity and molecular details of the copper active site. Here, we review the current state of knowledge for both enzymes, and consider pMMO O2 activation intermediates suggested by computational and synthetic studies in the context of existing biochemical data. Further work is needed on all fronts, with the ultimate goal of understanding how these two remarkable enzymes catalyze a reaction not readily achieved by any other metalloenzyme or biomimetic compound.
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Affiliation(s)
- Matthew O Ross
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, IL, 60208, USA
| | - Amy C Rosenzweig
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, IL, 60208, USA.
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Abstract
Amyloid-like fibrils assembled from de novo designed peptides lock ligands in a conformation optimal for metal binding and catalysis in a manner similar to how metalloenzymes provide proper coordination environment through fold. These supramolecular assemblies efficiently catalyze p-nitrophenyl ester hydrolysis in the presence of zinc and phenol oxidation by dioxygen in the presence of copper. The resulting heterogeneous catalysts are inherently switchable, as addition and removal of the metal ions turns the catalytic activity on and off, respectively. The ease of peptide preparation and self-assembly makes amyloid-like fibrils an attractive platform for developing catalysts for a broad range of chemical reactions. Here, we present a detailed protocol for the preparation of copper-containing fibrils and for kinetic characterization of their abilities to oxidize phenols.
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Affiliation(s)
- Alex Sternisha
- Department of Chemistry, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA
| | - Olga Makhlynets
- Department of Chemistry, Syracuse University, 111 College Place, Syracuse, NY, 13244, USA.
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Keown W, Gary JB, Stack TD. High-valent copper in biomimetic and biological oxidations. J Biol Inorg Chem 2017; 22:289-305. [PMID: 27909921 DOI: 10.1007/s00775-016-1420-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/17/2016] [Indexed: 10/20/2022]
Abstract
A long-standing debate in the Cu-O2 field has revolved around the relevance of the Cu(III) oxidation state in biological redox processes. The proposal of Cu(III) in biology is generally challenged as no spectroscopic or structural evidence exists currently for its presence. The reaction of synthetic Cu(I) complexes with O2 at low temperature in aprotic solvents provides the opportunity to investigate and define the chemical landscape of Cu-O2 species at a small-molecule level of detail; eight different types are characterized structurally, three of which contain at least one Cu(III) center. Simple imidazole or histamine ligands are competent in these oxygenation reactions to form Cu(III) complexes. The combination of synthetic structural and reactivity data suggests (1) that Cu(I) should be considered as either a one or two electron reductant reacting with O2, (2) that Cu(III) reduction potentials of these formed complexes are modest and well within the limits of a protein matrix and (3) that primary amine and imidazole ligands are surprisingly good at stabilizing Cu(III) centers. These Cu(III) complexes are efficient oxidants for hydroxylating phenolate substrates with reaction hallmarks similar to that performed in biological systems. The remarkable ligation similarity of the synthetic and biological systems makes it difficult to continue to exclude Cu(III) from biological discussions.
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Fiedler AT, Fischer AA. Oxygen activation by mononuclear Mn, Co, and Ni centers in biology and synthetic complexes. J Biol Inorg Chem 2017; 22:407-24. [PMID: 27853875 DOI: 10.1007/s00775-016-1402-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 10/21/2016] [Indexed: 10/20/2022]
Abstract
The active sites of metalloenzymes that catalyze O2-dependent reactions generally contain iron or copper ions. However, several enzymes are capable of activating O2 at manganese or nickel centers instead, and a handful of dioxygenases exhibit activity when substituted with cobalt. This minireview summarizes the catalytic properties of oxygenases and oxidases with mononuclear Mn, Co, or Ni active sites, including oxalate-degrading oxidases, catechol dioxygenases, and quercetin dioxygenase. In addition, recent developments in the O2 reactivity of synthetic Mn, Co, or Ni complexes are described, with an emphasis on the nature of reactive intermediates featuring superoxo-, peroxo-, or oxo-ligands. Collectively, the biochemical and synthetic studies discussed herein reveal the possibilities and limitations of O2 activation at these three "overlooked" metals.
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18
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Buongiorno D, Straganz GD. Structure and function of atypically coordinated enzymatic mononuclear non-heme-Fe(II) centers. Coord Chem Rev 2013; 257:541-563. [PMID: 24850951 PMCID: PMC4019311 DOI: 10.1016/j.ccr.2012.04.028] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 04/17/2012] [Accepted: 04/18/2012] [Indexed: 11/17/2022]
Abstract
Mononuclear, non-heme-Fe(II) centers are key structures in O2 metabolism and catalyze an impressive variety of enzymatic reactions. While most are bound via two histidines and a carboxylate, some show a different organization. A short overview of atypically coordinated O2 dependent mononuclear-non-heme-Fe(II) centers is presented here Enzymes with 2-His, 3-His, 3-His-carboxylate and 4-His bound Fe(II) centers are discussed with a focus on their reactivity, metal ion promiscuity and recent progress in the elucidation of their enzymatic mechanisms. Observations concerning these and classically coordinated Fe(II) centers are used to understand the impact of the metal binding motif on catalysis.
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Key Words
- 1,3-bis(2-pyridylimino)isoindoline, ind
- 2OH-1,3-Ph2PD, 2-hydroxy-1,3-diphenylpropanedione
- 6-Ph2TPA, N,N-bis[(6-phenyl-2-pyridyl)methyl]-N-[(2-pyridyl)-methyl]amine
- ADO, cysteamine dioxygenase
- AO, apocarotenoid 15,15′-oxygenase
- ARD, aci-reductone dioxygenase
- BsQDO, quercetin 2,3-dioxygenase from Bacillus subtilis
- CD, circular dichroism
- CDO, cysteine dioxygenase
- CGDO, 5-chloro-gentisate 1,2-dioxygenase
- CS2, clavaminate synthase
- CarOs, carotenoid oxygenases
- DFT, density functional theory
- Dioxygen activation
- Dioxygenase
- Dke1, diketone dioxygenase
- EPR, electron paramagnetic resonance
- EXAFS, extended X-ray absorption fine structure spectroscopy
- Enzyme catalysis
- Facial triad
- GDO, gentisate 1,2-dioxygenase
- HADO, 3-hydroxyanthranilate 3,4-dioxygenase
- HGDO, homogentisate 1,2-dioxygenase
- HNDO, hydroxy-2-naphthoate dioxygenase
- MCD, magnetic circular dichroism
- MNHEs, mononuclear non-heme-Fe(II) dependent enzymes
- Metal binding motif
- NRP, nonribosomal peptide
- OTf-, trifluormethanesulfonate
- PDB, protein data bank
- QDO, quercetin 2,3-dioxygenase
- SDO, salicylate 1,2-dioxygenase
- Structure–function relationships
- TauD, taurine hydroxylase
- XAS, X-ray absorption spectroscopy
- acac, acetylacetone (2,4-pentanedione)
- fla, flavonolate
- α-KG, α-ketoglutarate
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Affiliation(s)
- Daniela Buongiorno
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12 A-8010 Graz, Austria
| | - Grit D Straganz
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12 A-8010 Graz, Austria
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Abstract
The present work highlights recent advances in elucidating the methane oxidation mechanism of inorganic Cu-ZSM-5 biomimic and in identifying the reactive intermediates that are involved. Such molecular understanding is important in view of upgrading abundantly available methane, but also to comprehend the working mechanism of genuine Cu-containing oxidation enzymes.
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Affiliation(s)
- Pieter Vanelderen
- Center for Surface Chemistry and Catalysis, K.U.Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
| | - Ryan G. Hadt
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Pieter J. Smeets
- Center for Surface Chemistry and Catalysis, K.U.Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Robert A. Schoonheydt
- Center for Surface Chemistry and Catalysis, K.U.Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
| | - Bert F. Sels
- Center for Surface Chemistry and Catalysis, K.U.Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium
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