Relevant bibliographies by topics / Copper monooxygenases

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  2. Dissertations / Theses
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Academic literature on the topic 'Copper monooxygenases'

Author: Grafiati
Published: 25 May 2024

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Journal articles on the topic "Copper monooxygenases"

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Fukatsu, Arisa, Yuma Morimoto, Hideki Sugimoto, and Shinobu Itoh. "Modelling a ‘histidine brace’ motif in mononuclear copper monooxygenases." Chemical Communications 56, no. 38 (2020): 5123–26. http://dx.doi.org/10.1039/d0cc01392g.

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A mononuclear copper complex bearing a ‘histidine brace’ is synthesised and characterised as an active-site model of mononuclear copper monooxygenases such as lytic polysaccharide monooxygenases (LPMOs) and particulate methane monooxygenase (pMMO).
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Musiani, Francesco, Valquiria Broll, Elisa Evangelisti, and Stefano Ciurli. "The model structure of the copper-dependent ammonia monooxygenase." JBIC Journal of Biological Inorganic Chemistry 25, no. 7 (September 14, 2020): 995–1007. http://dx.doi.org/10.1007/s00775-020-01820-0.

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Abstract Ammonia monooxygenase is a copper-dependent membrane-bound enzyme that catalyzes the first step of nitrification in ammonia-oxidizing bacteria to convert ammonia to hydroxylamine, through the reductive insertion of a dioxygen-derived O atom in an N–H bond. This reaction is analogous to that carried out by particulate methane monooxygenase, which catalyzes the conversion of methane to methanol. The enzymatic activity of ammonia monooxygenase must be modulated to reduce the release of nitrogen-based soil nutrients for crop production into the atmosphere or underground waters, a phenomenon known to significantly decrease the efficiency of primary production as well as increase air and water pollution. The structure of ammonia monooxygenase is not available, rendering the rational design of enzyme inhibitors impossible. This study describes a successful attempt to build a structural model of ammonia monooxygenase, and its accessory proteins AmoD and AmoE, from Nitrosomonas europaea, taking advantage of the high sequence similarity with particulate methane monooxygenase and the homologous PmoD protein, for which crystal structures are instead available. The results obtained not only provide the structural details of the proteins ternary and quaternary structures, but also suggest a location for the copper-containing active site for both ammonia and methane monooxygenases, as well as support a proposed structure of a CuA-analogue dinuclear copper site in AmoD and PmoD. Graphic abstract
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Liew, Elissa F., Daochen Tong, Nicholas V. Coleman, and Andrew J. Holmes. "Mutagenesis of the hydrocarbon monooxygenase indicates a metal centre in subunit-C, and not subunit-B, is essential for copper-containing membrane monooxygenase activity." Microbiology 160, no. 6 (June 1, 2014): 1267–77. http://dx.doi.org/10.1099/mic.0.078584-0.

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The hydrocarbon monooxygenase (HMO) of Mycobacterium NBB4 is a member of the copper-containing membrane monooxygenase (CuMMO) superfamily, which also contains particulate methane monooxygenases (pMMOs) and ammonia monooxygenases (AMOs). CuMMOs have broad applications due to their ability to catalyse the oxidation of difficult substrates of environmental and industrial relevance. Most of our understanding of CuMMO biochemistry is based on pMMOs and AMOs as models. All three available structures are from pMMOs. These share two metal sites: a dicopper centre coordinated by histidine residues in subunit-B and a ‘variable-metal’ site coordinated by carboxylate and histidine residues from subunit-C. The exact nature and role of these sites is strongly debated. Significant barriers to progress have been the physiologically specialized nature of methanotrophs and autotrophic ammonia-oxidizers, lack of a recombinant expression system for either enzyme and difficulty in purification of active protein. In this study we use the newly developed HMO model system to perform site-directed mutagenesis on the predicted metal-binding residues in the HmoB and HmoC of NBB4 HMO. All mutations of predicted HmoC metal centre ligands abolished enzyme activity. Mutation of a predicted copper-binding residue of HmoB (B-H155V) reduced activity by 81 %. Mutation of a site that shows conservation within physiologically defined subgroups of CuMMOs was shown to reduce relative HMO activity towards larger alkanes. The study demonstrates that the modelled dicopper site of subunit-B is not sufficient for HMO activity and that a metal centre predicted to be coordinated by residues in subunit-C is essential for activity.
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Farhan Ul Haque, Muhammad, Bhagyalakshmi Kalidass, Nathan Bandow, Erick A. Turpin, Alan A. DiSpirito, and Jeremy D. Semrau. "Cerium Regulates Expression of Alternative Methanol Dehydrogenases in Methylosinus trichosporium OB3b." Applied and Environmental Microbiology 81, no. 21 (August 21, 2015): 7546–52. http://dx.doi.org/10.1128/aem.02542-15.

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ABSTRACTMethanotrophs have multiple methane monooxygenases that are well known to be regulated by copper, i.e., a “copper switch.” At low copper/biomass ratios the soluble methane monooxygenase (sMMO) is expressed while expression and activity of the particulate methane monooxygenase (pMMO) increases with increasing availability of copper. In many methanotrophs there are also multiple methanol dehydrogenases (MeDHs), one based on Mxa and another based on Xox. Mxa-MeDH is known to have calcium in its active site, while Xox-MeDHs have been shown to have rare earth elements in their active site. We show here that the expression levels of Mxa-MeDH and Xox-MeDH inMethylosinus trichosporiumOB3b significantly decreased and increased, respectively, when grown in the presence of cerium but the absence of copper compared to the absence of both metals. Expression of sMMO and pMMO was not affected. In the presence of copper, the effect of cerium on gene expression was less significant, i.e., expression of Mxa-MeDH in the presence of copper and cerium was slightly lower than in the presence of copper alone, but Xox-MeDH was again found to increase significantly. As expected, the addition of copper caused sMMO and pMMO expression levels to significantly decrease and increase, respectively, but the simultaneous addition of cerium had no discernible effect on MMO expression. As a result, it appears Mxa-MeDH can be uncoupled from methane oxidation by sMMO inM. trichosporiumOB3b but not from pMMO.
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Vu, Van V., and Son Tung Ngo. "Copper active site in polysaccharide monooxygenases." Coordination Chemistry Reviews 368 (August 2018): 134–57. http://dx.doi.org/10.1016/j.ccr.2018.04.005.

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Blackburn, Ninian J., Brian Reedy, Eilleen Zhou, Robert Carr, and Steven J. Benkovic. "Chemistry and spectroscopy of copper monooxygenases." Journal of Inorganic Biochemistry 47, no. 3-4 (July 1992): 8. http://dx.doi.org/10.1016/0162-0134(92)84079-3.

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Choi, Dong-W., Ryan C. Kunz, Eric S. Boyd, Jeremy D. Semrau, William E. Antholine, J. I. Han, James A. Zahn, Jeffrey M. Boyd, Arlene M. de la Mora, and Alan A. DiSpirito. "The Membrane-Associated Methane Monooxygenase (pMMO) and pMMO-NADH:Quinone Oxidoreductase Complex from Methylococcus capsulatus Bath." Journal of Bacteriology 185, no. 19 (October 1, 2003): 5755–64. http://dx.doi.org/10.1128/jb.185.19.5755-5764.2003.

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ABSTRACT Improvements in purification of membrane-associated methane monooxygenase (pMMO) have resulted in preparations of pMMO with activities more representative of physiological rates: i.e., >130 nmol · min−1 · mg of protein−1. Altered culture and assay conditions, optimization of the detergent/protein ratio, and simplification of the purification procedure were responsible for the higher-activity preparations. Changes in the culture conditions focused on the rate of copper addition. To document the physiological events that occur during copper addition, cultures were initiated in medium with cells expressing soluble methane monooxygenase (sMMO) and then monitored for morphological changes, copper acquisition, fatty acid concentration, and pMMO and sMMO expression as the amended copper concentration was increased from 0 (approximately 0.3 μM) to 95 μM. The results demonstrate that copper not only regulates the metabolic switch between the two methane monooxygenases but also regulates the level of expression of the pMMO and the development of internal membranes. With respect to stabilization of cell-free pMMO activity, the highest cell-free pMMO activity was observed when copper addition exceeded maximal pMMO expression. Optimization of detergent/protein ratios and simplification of the purification procedure also contributed to the higher activity levels in purified pMMO preparations. Finally, the addition of the type 2 NADH:quinone oxidoreductase complex (NADH dehydrogenase [NDH]) from M. capsulatus Bath, along with NADH and duroquinol, to enzyme assays increased the activity of purified preparations. The NDH and NADH were added to maintain a high duroquinol/duroquinone ratio.
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Hedegård, Erik Donovan, and Ulf Ryde. "Molecular mechanism of lytic polysaccharide monooxygenases." Chemical Science 9, no. 15 (2018): 3866–80. http://dx.doi.org/10.1039/c8sc00426a.

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The lytic polysaccharide monooxygenases (LPMOs) are copper metalloenzymes that can enhance polysaccharide depolymerization through an oxidative mechanism and hence boost generation of biofuel from e.g. cellulose. By employing density functional theory in a combination of quantum mechanics and molecular mechanics (QM/MM), we report a complete description of the molecular mechanism of LPMOs.
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Itoh, Shinobu, and Shunichi Fukuzumi. "Dioxygen Activation by Copper Complexes. Mechanistic Insights into Copper Monooxygenases and Copper Oxidases." Bulletin of the Chemical Society of Japan 75, no. 10 (October 2002): 2081–95. http://dx.doi.org/10.1246/bcsj.75.2081.

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Maiti, Debabrata, Amy A. Narducci Sarjeant, and Kenneth D. Karlin. "Copper−Hydroperoxo-Mediated N-Debenzylation Chemistry Mimicking Aspects of Copper Monooxygenases." Inorganic Chemistry 47, no. 19 (October 6, 2008): 8736–47. http://dx.doi.org/10.1021/ic800617m.

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Dissertations / Theses on the topic "Copper monooxygenases"

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Gómez-Piñeiro, Rogelio Javier. "Experimental and theoretical investigation of bioinspired mononuclear copper complexes." Electronic Thesis or Diss., Aix-Marseille, 2021. http://theses.univ-amu.fr.lama.univ-amu.fr/211213_GOMEZPINEIRO_886mtbc444s58hp471nxwde_TH.pdf.

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Les monooxygénases polysaccharidiques lytiques (LPMO) cassent des polysaccharides et sont étudiés dans la valorisation de la biomasse. Ces enzymes contiennent un centre mononucléaire à cuivre, étudié grâce à ses propriétés magnétiques. Le mécanisme et les intermédiaires mis en jeu demeurent inconnus. On a utilisé un ensemble de complexes de la littérature pour développer un protocole pour prédire les propriétés magnétiques de systèmes à cuivre grâce aux calculs théoriques. Ce protocole a été utilisé sur des modèles de LPMO et sur un complexe tripeptidique afin de comprendre leurs propriétés. De plus, on a développé une série de complexes pour isoler des intermédiaires de haute-valence des LPMO. La réactivité d’un complexe en particulier a été étudié pour sa capacité à produire du formate dans des alcools. Le formate a été produit avec un rendement de 120%. De futures générations de complexes ont été synthétisés et seront étudiés pour mieux comprendre les chemins réactionnels des LPMOs
Lytic polysaccharide monooxygenases (LPMO) break down polysaccharides and are greatly studied in the context of biomass conversion. They contain a mononuclear copper center which is studied by its magnetic properties. The mechanism of reaction and its intermediates are still unknown. We use a large set of well-known complexes to develop a protocol to predict the magnetic properties of copper systems using computational calculations. This protocol was applied to LPMO models and to an LPMO-inspired tripeptidic complex to elucidate their structural and spectroscopic properties. In addition, we produced a series of complexes to capture potential high-valent reaction intermediates of LPMO. Eventually, the reactivity of one specific complex was studied for its capacity to produce formate in alcohol solvents. Formate was produced at around 120% conversion. Future generations of ligands and complexes were also synthesized and envisioned to understand the reaction pathways of LPMO
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Munzone, Alessia. "Structure-reactivity relationship of the copper-dependent lytic polysaccharide monooxygenase." Electronic Thesis or Diss., Aix-Marseille, 2021. http://theses.univ-amu.fr.lama.univ-amu.fr/210316_MUNZONE_559lhuy192l910eww669so_TH.pdf.

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Les lytic polysaccharide monooxygenases (LPMO) sont des métalloenzymes à cuivre impliquées dans la dégradation des polysaccharides récalcitrants, tels que la cellulose et la chitine. L'ion cuivre du site actif est lié par un motif de coordination très inhabituel, composé de deux histidines entièrement conservées, dont l'une située à l'extrémité N-terminale qui est liée au cuivre à la fois par l'imidazole de la chaîne latérale et l’amine terminale. Ce motif de coordination, appelé «histidine brace», permet de catalyser le clivage oxydatif de liaisons glycosidiques dans des polysaccharides récalcitrants, en présence de dioxygène ou de peroxyde d'hydrogène et d'un donneur d'électrons. Ce travail a été réalisé par une approche interdisciplinaire avec des outils et des concepts fondamentaux allant de la biologie à la chimie. Nous nous sommes tout d'abord intéressés aux propriétés natives du site actif dans des LPMOs bactériennes appartenant à la sous-famille AA10. Notamment, la variabilité d'un résidu d'alanine en deuxième sphère de coordination a été étudiée, conduisant à la découverte de nouvelles enzymes avec des caractéristiques inhabituelles. Le rôle de l'alanine a ensuite été sondé en remplaçant ce résidu dans l'enzyme modèle SmAA10, par d’autres résidus naturellement présents chez certaines AA10s. Cette même enzyme modèle a ensuite été utilisée pour étudier l'influence du motif histidine brace sur les propriétés du site actif. Variants du site actif de SmAA10 nous ont permis de créer des sites de coordination originaux dans la perspective de catalyser de nouvelles réactions abiologiques dépendantes d’un ion métallique
Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes involved in the breakdown of recalcitrant polysaccharides, such as cellulose and chitin. The active site copper ion is coordinated by a very unusual coordination motif, consisting of two fully conserved histidines, one of which is located at the N-terminus and binds copper by both its the side chain nitrogen and the free amino terminal group. Such organization, known as “histidine brace” motif allows the oxidative cleavage of glycosidic bonds in recalcitrant polysaccharides, in the presence of dioxygen or hydrogen peroxide and an electron donor. The objectives of the present work have been pursued via an interdisciplinary approach, using tools and fundamental concepts that span from biology to chemistry. The focus was firstly addressed on the natural properties of the active site in the bacterial LPMOs belonging to the AA10 subfamily. Notably, the variability of a second coordination sphere alanine residue (~ 4 Å from the copper ion) was firstly investigated, leading to the discovery of new enzymes with unusual active-site features. The role of active site alanine was then probed by exploring the mutational effect induced by the other occurring residues on both the activity and the physico-chemical properties on the model enzyme SmAA10. Our results emphasize that this unusual coordination motif imparts unique structural and functional features to the copper centre. Furthermore, the SmAA10 active site variants allowed us to create original metal binding sites with the perspective of exploring new abiological metal-based biocatalytic reactions
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Antypas, Elias J. "The characterization of Menkes copper transporter and dopamine ß- monooxygenase carboxy-terminus in neuroendocrine cells." Connect to full text in OhioLINK ETD Center, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=mco1213789670.

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Dissertation (Ph.D.)--University of Toledo, 2008.
"In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biomedical Sciences." Title from title page of PDF document. Bibliography: p. 126-146.
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Antypas, Elias Joseph. "The Characterization of Menkes Copper Transporter and Dopamine ß-monooxygenase Carboxy-Terminus in Neuroendocrine Cells." University of Toledo Health Science Campus / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=mco1213789670.

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Menil, Sidiky. "Cascade bi-enzymatique autosuffisante in vivo : le jeu des plasmides." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0040.

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Une attention croissante est portée aux cascades multi enzymatiques pour l’élaboration de procédés de synthèse plus efficaces. Cependant, le contrôle de l’expression hétérologue de plusieurs gènes dans un même hôte s’avère difficile et peut mener à un déséquilibre du flux réactionnel. Pour exploiter au mieux les avantages d’une cascade in vivo, il est nécessaire d’ajuster les activités de chaque étape, et de construire des catalyseurs cellulaires capables de programmer la stœchiométrie des enzymes. Nous avons développé dans ce projet une approche originale pour moduler le ratio de deux enzymes in cellulo en jouant sur le nombre de copies de plasmides par cellule (PCN). Nous avons choisi comme modèle un système autosuffisant associant une Alcool Déshydrogénase (ADH) et une Baeyer-Villiger MonoOxygenase (BVMO), NADP(H)-dépendantes. Plusieurs plasmides recombinants portant les deux gènes ont été conçus et combinés dans E. coli. Les souches de co-expression construites ont été comparées en termes de PCN, de production d’enzymes et d’activité. Nous avons montré l’importance d’un choix judicieux de la combinaison de plasmides ainsi que l’existence d’une corrélation entre ratios d’enzymes et activité. Nos biocatalyseurs s’étendent sur une gamme allant du système inactif à un système affichant un TTN d’environ 6000. Ce système a permis la synthèse de lactones d’intérêt industriel, la dihydrocoumarine et la caprolactone, à partir d’indanol et de cyclohexanol. Enfin, sur ce modèle de combinaison de plasmides, trois nouveaux biocatalyseurs cellulaires, associant l’ADH à diverses BVMOs, ont été créés afin d’élargir la gamme d’esters et de lactones synthétisables à partir d’alcools
Growing attention is paid to multienzymatic cascades to develop more efficient synthetic processes. However, in in cellulo process, the control of the simultaneous heterologous expression of several genes in the same host is often difficult and can lead to imbalances in the reaction flow. To exploit the benefits of cascades, activities of each step have to be adjusted and thus, cellular biocatalysts capable of programming enzymes stoichiometry have to be constructed. In this work, to modulate the stoichiometry of two enzymes in vivo, we developed an original approach based on the copy number per cell of plasmids (PCN) used as vectors. The PCN is regulated in bacteria by three main mechanisms leading, according to the replicon, to low, medium or high PCN. As proof of concept, we chose a self-sufficient system combining an Alcohol Dehydrogenase (ADH) and a Baeyer-Villiger MonoOxygenase (BVMO), both NADP(H)-dependent. Several recombinant plasmids harboring both genes were designed and combined in E. coli. Coexpression strains constructed were compared in terms of PCN, enzyme production and activity. We showed the importance of a judicious choice of plasmids combination and the existence of a correlation between enzymes ratios and activity. Our biocatalysts ranged from an inactive system to a system with a TTN of about 6000. This system allowed the synthesis of lactones of industrial interest, dihydrocoumarin and caprolactone, via double oxidation of indanol and cyclohexanol. Finally, based on this plasmids combination model, three new cellular biocatalysts combining ADH with various BVMOs were designed to broaden the range of esters and lactones synthesizable from alcohols
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Menil, Sidiky. "Cascade bi-enzymatique autosuffisante in vivo : le jeu des plasmides." Electronic Thesis or Diss., Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0040.

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Une attention croissante est portée aux cascades multi enzymatiques pour l’élaboration de procédés de synthèse plus efficaces. Cependant, le contrôle de l’expression hétérologue de plusieurs gènes dans un même hôte s’avère difficile et peut mener à un déséquilibre du flux réactionnel. Pour exploiter au mieux les avantages d’une cascade in vivo, il est nécessaire d’ajuster les activités de chaque étape, et de construire des catalyseurs cellulaires capables de programmer la stœchiométrie des enzymes. Nous avons développé dans ce projet une approche originale pour moduler le ratio de deux enzymes in cellulo en jouant sur le nombre de copies de plasmides par cellule (PCN). Nous avons choisi comme modèle un système autosuffisant associant une Alcool Déshydrogénase (ADH) et une Baeyer-Villiger MonoOxygenase (BVMO), NADP(H)-dépendantes. Plusieurs plasmides recombinants portant les deux gènes ont été conçus et combinés dans E. coli. Les souches de co-expression construites ont été comparées en termes de PCN, de production d’enzymes et d’activité. Nous avons montré l’importance d’un choix judicieux de la combinaison de plasmides ainsi que l’existence d’une corrélation entre ratios d’enzymes et activité. Nos biocatalyseurs s’étendent sur une gamme allant du système inactif à un système affichant un TTN d’environ 6000. Ce système a permis la synthèse de lactones d’intérêt industriel, la dihydrocoumarine et la caprolactone, à partir d’indanol et de cyclohexanol. Enfin, sur ce modèle de combinaison de plasmides, trois nouveaux biocatalyseurs cellulaires, associant l’ADH à diverses BVMOs, ont été créés afin d’élargir la gamme d’esters et de lactones synthétisables à partir d’alcools
Growing attention is paid to multienzymatic cascades to develop more efficient synthetic processes. However, in in cellulo process, the control of the simultaneous heterologous expression of several genes in the same host is often difficult and can lead to imbalances in the reaction flow. To exploit the benefits of cascades, activities of each step have to be adjusted and thus, cellular biocatalysts capable of programming enzymes stoichiometry have to be constructed. In this work, to modulate the stoichiometry of two enzymes in vivo, we developed an original approach based on the copy number per cell of plasmids (PCN) used as vectors. The PCN is regulated in bacteria by three main mechanisms leading, according to the replicon, to low, medium or high PCN. As proof of concept, we chose a self-sufficient system combining an Alcohol Dehydrogenase (ADH) and a Baeyer-Villiger MonoOxygenase (BVMO), both NADP(H)-dependent. Several recombinant plasmids harboring both genes were designed and combined in E. coli. Coexpression strains constructed were compared in terms of PCN, enzyme production and activity. We showed the importance of a judicious choice of plasmids combination and the existence of a correlation between enzymes ratios and activity. Our biocatalysts ranged from an inactive system to a system with a TTN of about 6000. This system allowed the synthesis of lactones of industrial interest, dihydrocoumarin and caprolactone, via double oxidation of indanol and cyclohexanol. Finally, based on this plasmids combination model, three new cellular biocatalysts combining ADH with various BVMOs were designed to broaden the range of esters and lactones synthesizable from alcohols
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Shin, Jieun. "Investigating the Catalytic Mechanisms of Bio-degrading Copper Proteins: Multi-copper Oxidases (MCOs) and Lytic Polysaccharide Monooxygenases (LPMOs)." Thesis, 2021. https://thesis.library.caltech.edu/14252/5/Jieun-Shin_PhD-Thesis_May2021_Final.pdf.

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Lignin and cellulose comprise a large portion of the renewable biomass on Earth. However, substantially due to laborious course of processing, the conversion efficiency of these biomaterials to accessible biofuel is very low. Therefore, effective depolymerization and utilization of these biopolymers are requirements for environmentally friendly and sustainable energy development. In the hope of finding solutions to these biomass utilization challenges, there have been growing interests in using biodegrading metalloenzymes as active biocatalysts. However, there still remain many questions regarding mechanistic details of enzyme catalysis and effective application of these enzymes. This thesis focuses on investigating the redox chemistry involved in the catalytic mechanisms of two main lignin- and cellulose- degrading copper enzymes: multicopper oxidases (MCOs) and lytic polysaccharide monooxygenases (LPMOs).

MCOs are capable of aerobic oxidation of lignin as their primary function, but the nature of their substrate variability also allows the oxidation of not only diverse high potential organic and inorganic complexes, but also earth abundant divalent metal ions such as manganese. LPMOs, on the other hand, enable the cleavage of glycosidic bonds in recalcitrant insoluble cellulosic substances, which are not degradable by other hydrolytic enzymes such as endoglucanases and cellulobiohydrolases.

It is remarkable that nature has created such versatile enzymes with specific active site metals and redox-active amino acids involved in electron transfer, which contribute to substrate oxidation as well as enzyme survival against oxidative damage during catalysis. By gaining a deeper understanding of how these enzymes work, we could greatly enhance current usage efficiencies and develop more energy-efficient biocatalysts.

Chapter I gives an introduction to biological coppers, two groups of bio-degrading copper enzymes: multicopper oxidases (MCOs) and lytic polysaccharide monooxygenases (LPMOs), and the role of redox-active amino acids in electron transfer and enzyme catalysis. For the MCO work, a thermophilic laccase (Tth-lac) from Thermus thermophilus HB27 and a CotA laccase (CotA-lac) from Bacillus Subtilis were studied. For the LPMO work, two cellulose active LPMOs (ScLPMO10B and ScLPMO10C) and a chitin active LPMO (BlLPMO10A) were studied.

Chapter II describes thermodynamic aspects of Tth-lac catalysis. The temperature dependence of the formal potential of type I copper (CuT1) in Tth-lac is reported, and the interplay between many competing dynamic and thermodynamic factors which results in thermostability and activity of Tth-lac is discussed.

Chapter III reports the electron transfer (ET) kinetics data obtained with Tth-lac using the transient absorption spectroscopy. The results of photochemical electron/hole transfer studies indicate that the chains of Trp and Tyr can participate in electron transfer through Tth-lac, which could potentially have a role in enzyme catalysis as well.

Chapter IV discusses the protective role of a Trp/Tyr pair positioned close to the trinuclear copper cluster (TNC) in Tth-lac. It is indeed remarkable that laccases are capable of utilizing the power of oxygen to catalyze the oxidation of diverse high-potential substrates. But, as a tradeoff, the utilization of dioxygen can make the enzyme highly susceptible to oxidative damage. Chapter IV provides supporting evidence that led us to conclude that the TNC-proximal Trp/Tyr pair functions as an internal antioxidant for prolonging the enzyme lifetime.

Chapter V describes investigations on the factors that affect MCO catalysis, which include the potentials of the active site coppers, possible reactive intermediates, and common structural motifs. Based on the structural homology between Tth-lac and CotA-lac, some preliminary work done on CotA-lac is also reported.

Chapter VI outlines the work on LPMOs. After the successful expression and purification of ScLPMO10B, ScLPMO10B and BlLPMO10A, standard activity assays were done with insoluble cellulose and chitin substrates to confirm the enzyme activity. The results are compared with that from the photo-degradation experiments to investigate if the photochemically generated Cu(III) species are active intermediates in LPMO catalysis.

Chapter VII reports the results on bioinformatics analysis on the distribution of vicinal amino acids in different enzyme classes. This study was to examine the biological significance of amino acid pairs and clusters existing in many different enzyme classes, with vicinal surface tyrosines in CotA-lac as an underlying motivation behind the work.

This thesis demonstrates that MCOs and LPMOs are truly versatile enzymes which can oxidize such diverse refractory substrates, and there could be multiple pathways that the enzymes achieve this task. As shown so far, not only the active site metals but also the chain of redox-active amino acids as well as metal coordinating residues can contribute to enzyme catalysis.

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蘇柏瑋. "Models of the Particulate Methane Monooxygenase(pMMO): Trinuclear Copper Clusters." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/12381536418153308701.

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碩士
國立臺灣師範大學
化學系
100
In this study, two new ligands 7-Impy and 7-MeImpy have been synthesized, and they can coordinate with 3 equivalents of CuI ions to form a trinuclear copper complex [CuICuICuI(7-Impy)](BF4) and [CuICuICuI(7-MeImpy)](BF4). These ligands are similar to our previous developed 7-Dipy ligand in the scaffold to trap three CuI ions. It is known that the hydroxylation of alkane molecules catalyzed by trinuclear copper complexes through the “oxene” insertion mechanism. The active “oxene” with a “1D” spin state will have lower reaction energy barrier when it is tuned by three copper ions. In this study, these new catalysts, [CuICuICuI(7-ImPy)](BF4) and [CuICuICuI(7-MeImPy)](BF4), are also able to catalyze the oxidation of cyclohexane converting to cyclohexanol and cyclohexanone. Compared to our previous developed 7-Dipy ligand, the catalytic reaction is more favorable for the product of cyclohexanol. In this study, we replaced traditional heating by microwave for the ligand synthesis. Microwave can enhance internal heating efficiently, which significantly reduce the reaction time, increase the purity, and reduce the byproducts. In addition, for proving the reaction catalyzed by our trinuclear copper cluster via the O-atom insertion mechanism or radical mechanism, we designed a series of experiments using 5,5-Dimethyl-Pyrroline-N-Oxide (DMPO), which is very sensitive to radical. We added DMPO in catalytic reaction, and measured EPR while in the reaction. We found that there are no radical EPR peaks related to DMPO derivatives, similar to the case of 7-Dipy.
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Chen, Chang-Li, and 陳昌立. "Copper Ions and The Particulate Methane Monooxygenase from Methylococcus capsulatus (Bath)." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/bk48ja.

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博士
國立清華大學
化學系
92
Copper ions play an essential role in particulate methane monooxygenase (pMMO) from Methylococcus capsulatus (Bath). The particulate methane monooxygenase (pMMO) contains 15 reduced copper ions which are arranged in five trinuclear clusters. Two of these clusters were subsequently found to participate in dioxygen chemistry and hydrocarbon hydroxylation chemistry, called C-clusters. The remaining copper ions were in the reduced d10 state, and were thought to be responsible for channeling electrons to the C-clusters from NADH, called E-clusters. The low temperature EPR spectrum of as-isolated pMMO was deconvoluted into a type 2 Cu(II) signal and a broad, but nearly isotropic EPR signal centered at g ~ 2.1. Earlier magnetization and magnetic susceptibility measurements have suggested that the latter EPR signal, which is not sensitive to microwave power saturation, arise from a ferromagnetically exchange-coupled trinuclear Cu(II) cluster with J = 15�{20 cm–1 and with a zero-field splitting D of +0.018cm-1 (175 G) and E value of 0.005 cm-1 (50 G). By combining EPR spectroscopy and rapid cryogenically trap, we successfully observed the different oxidative phases of the turnover cycle and practically proved the catalytic mechanisms of pMMO. Processing cell growth in a fermentor adapted with a hollow-fiber bioreactor, we successfully prepared the (Cu, Zn)-pMMO. The bulk of the copper ions of the E-clusters have been replaced by divalent Zn ions in (Cu, Zn)-pMMO. The Cu and Zn contents in the (Zn, Cu)-pMMO were determined by both ICP-MS and x-ray absorption K-edge spectroscopy. Further characterization of the (Zn, Cu)-pMMO was provided by low temperature electron paramagnetic spectroscopy during reductive titration and hydrocarbon hydroxylation. These studies indicate that the (Zn, Cu)-pMMO is still capable of supporting the activation of dioxygen, but that the replacement of the E-cluster copper ions has compromised the ability of the protein to mediate the transfer of reducing equivalents to the C-clusters. These observations provide strong support for the electron transfer and catalytic roles that we have previously proposed for the E-cluster and C-cluster copper ions, respectively.
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10

Yang, Bing-Gong, and 楊秉恭. "Models for the Trinuclear Copper Clusters of the Particulate Methane Monooxygenase from Methanotrophic Bacteria: Synthesis, Spectroscopic Characterization of Trinuclear Copper Complexes." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/04856074935855023692.

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碩士
國立中央大學
化學研究所
94
Recent DFT electronic calculations of a trinuclear copper cluster bis(��3-oxo)trinuclear copper(II, II, III) complex have showed that this structure harnesses a singlet “oxene”, mimicking one of the C-clusters in the particulate methane monooxygenase (pMMO), an important membrane enzyme that mediate the facile hydroxylation of methane and other small hydrocarbons. A series of supporting ligands that are capable to trap three copper ions toward developing a model compound to mimic this chemistry, we have designed and synthesized. Oxygenation of their corresponding [Cu3(I, I, I)L](X) complexes of these ligands leads to the formation of [Cu3(II, II, II)L(O)](X)2 (L = 7-Et, 7-Me, 6-Et, 6-Me; X = ClO4- and BF4-) through mass spectrometry analysis. Only one oxygen atom is locked in the trinuclear copper(II, II, II) complex. When the [Cu3(II, II, II)L(O)](X)2 complex is treated with three equivalent amounts of benzoin and triethylamine in CH3CN, and the solution purged by dioxygen, the benzoin is oxidized to benzil, which in turn is cleaved by further oxidation and hydrolyzes to 2 benzoic acid molecules. This chemistry is mediated by efficient oxo-transfer from the bis(μ3-oxo)trinuclear copper(II, II, III) complex to the benzil, as verified by 18O2 isotope labeling experiments and subsequent GC-MS analysis. We propose a mechanism involving intermolecular oxo-insertion across the C-C bond of the benzil by the bis(μ3-oxo)Cu(II)Cu(II)Cu(III) trinuclear copper intermediate.
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Book chapters on the topic "Copper monooxygenases"

1

Réglier, Marius, and Catherine Belle. "Copper, Mononuclear Monooxygenases." In Encyclopedia of Metalloproteins, 723–29. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-1533-6_97.

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Tyeklár, Zoltán, and Kenneth D. Karlin. "Functional Models for Hemocyanin and Copper Monooxygenases." In Bioinorganic Chemistry of Copper, 277–91. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-6875-5_22.

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Blackburn, Ninian J. "Chemical and Spectroscopic Studies on Dopamine-β-Hydroxylase and other Copper Monooxygenases." In Bioinorganic Chemistry of Copper, 164–83. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-6875-5_14.

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4

Osborne, Robert L., and Judith P. Klinman. "Insights into the Proposed Copper-Oxygen Intermediates that Regulate the Mechanism of Reactions Catalyzed by Dopamine β-Monooxygenase, Peptidylglycine α-Hydroxylating Monooxygenase, and Tyramine β-Monooxygenase." In Copper-Oxygen Chemistry, 1–22. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118094365.ch1.

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5

Chan, Sunney I., Hiep-Hoa T. Nguyen, Andrew K. Shiemke, and Mary E. Lidstrom. "The Copper Ions in the Membrane-Associated Methane Monooxygenase." In Bioinorganic Chemistry of Copper, 184–95. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-6875-5_15.

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Klinman, Judith P., Joseph A. Berry, and Gaochao Tian. "New Probes of Oxygen Binding and Activation: Application to Dopamine β-Monooxygenase." In Bioinorganic Chemistry of Copper, 151–63. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-6875-5_13.

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Sazinsky, Matthew H., and Stephen J. Lippard. "Methane Monooxygenase: Functionalizing Methane at Iron and Copper." In Sustaining Life on Planet Earth: Metalloenzymes Mastering Dioxygen and Other Chewy Gases, 205–56. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-12415-5_6.

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8

Castillo, Ivan. "Inorganic Models of Lytic Polysaccharide Monooxygenases." In Copper Bioinorganic Chemistry, 187–209. WORLD SCIENTIFIC, 2023. http://dx.doi.org/10.1142/9789811269493_0006.

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9

Bhatia, B., T. Punniyamurthy, and J. Iqbal. "Oxidation of the C—H bond." In Asymmetric Oxidation Reactions, 5–18. Oxford University PressOxford, 2001. http://dx.doi.org/10.1093/oso/9780198502012.003.0002.

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Abstract The development of methodology for asymmetric functionalization of the C—H bond offers a challenge in the strive for acquiring optically active building-blocks from simple starting materials. Asymmetric synthesis has emerged as an exciting area of chemistry by judiciously employing the principles of organic synthesis, molecular recognition, metal coordination chemistry, and catalysis. Among the various strategies available for exploiting the pools of chiral compounds, catalytic asymmetric induction offers a distinct advantage in achieving a high level of enantioselectivity during bond formation mainly due to the influence of asymmetry possessed by the ligands in the catalyst. The titanium-catalysed epoxidation1−3 of allylic alcohols, the osmium-catalysed dihydroxylation4−7 of alkenes, the copper-catalysed cyclopropanation8−10 of alkenes, and the ruthenium-catalysed asymmetric hydrogenation11,12 of alkenes are outstanding achievements in the catalytic asymmetric induction approach. Another approach is inspired by the analogy derived from nature, where the monooxygenase enzymes are, for example, known to effect stereospecific oxidation of organic compounds. This biomimetic approach has led to widespread research activity in this area and as a result an impressive start has been made in achieving good levels of selectivity in the oxidation of organic substrates by employing well-crafted small molecular catalysts. The possibility of mimicking the enantio-selective reaction of monooxygenases is a highly viable proposition from the point of view of synthetic organic chemists. Indeed, the design and development of synthetic monooxygenase mimics that catalyse enantioselective epoxidation of unfunctionalized alkenes have already made an impressive impact on stereoselective synthesis mainly due to the pioneering efforts of the research groups of Groves, Jacobsen,15,17 and Katsuki,18−22 respectively. On the other hand, the enantioselective oxidation of the saturated C—H bond has proven more difficult to accomplish with synthetic catalysts. Consequently, there has been continual effort to achieve a high level of enantioselectivity in the oxidation of the saturated C—H bond over the past few years. The following sections deal with the results achieved so far on the enantioselective oxidation of the C—H bond by employing chiral catalysts derived from ligands easily prepared from simple and easily accessible starting materials. The emphasis is on the experimental procedures of those reactions which are operationally simple and easy to perform on a synthetically useful scale.
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10

"Copper-Containing Monooxygenase." In Encyclopedia of Metalloproteins, 735. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-1533-6_100378.

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Reports on the topic "Copper monooxygenases"

1

Xu, Jin-Rong, and Amir Sharon. Comparative studies of fungal pathogeneses in two hemibiotrophs: Magnaporthe grisea and Colletotrichum gloeosporioides. United States Department of Agriculture, May 2008. http://dx.doi.org/10.32747/2008.7695585.bard.

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Plant pathogenic fungi have various life styles and different plant infection strategies. Hemibiotrophs like Magnaporthe grisea and Colletotrichum species develop specialized structures during plant infection. The goal of this study was to identify, characterize, and compare genes required for plant infection in M. grisea and C. gloeosporioides. Specific objectives are to: 1) further characterize genes identified in the preliminary studies of C. gloeosporioides and M. grisea;2) identify and characterize additional fungal genes tagged by GFP; and 3) identify in planta growth and appressorium-specific genes by subtractive hybridization and transcript profiling by the LongSAGE method. In this study, the PI and Co-PI collaborated closely on studies in M. grisea and C. gloeosporioides. In M. grisea, REMI and ATMT were used to transform the wildtype with promoter-less EGFP constructs. A total of 28 mutants defective in different plant infection processes or expressing EGFP during plant infection were identified. Genes disrupted in five selected mutants have been identified, including MG03295 that encodes a putative Rho GTPase. In transformant L1320, the transforming vector was inserted in the MIRI gene that encodes a nuclear protein. The expression of MIRI was highly induced during infection. Deletion and site-directed mutagenesis analyses were used to identify the promoter regions and elements that were essential for induced in planta expression of MIRI. This was the first detailed characterization of the promoter of an in planta gene in M. grisea and the MIRI promoter can be used to monitor infectious growth. In addition, the Agilent whole-genome array of M. grisea was used for microarray analyses with RNA samples from appressoria formed by the wild-type shain and the pmkl and mstl2 mutants. Over 200 genes were downregulated in the mst I 2 and pmkl mutants. Some of them are putative transcription factors that may regulate appressorium formation and infectious hyphal growth. In C. gloeosporioides, various REMI mutants showing different pathogenic behavior were identified and characterized. Mutants N3736 had a single insertion and was hyper-virulent. The gene disrupted in mutant3736 (named CgFMOI) encodes a FAD-dependent monooxygenase. Expression analyses linked the expression of the CgFMOI gene with the necrotrophic phase of fungal infection, and also suggest that expression of CgFMOl is unnecessary for the first stages of infection and for biotrophy establishment. All CgFMOl-silenced mutants had reduced virulence. In REMI mutant N159, the tagged gene encodes a putative copper transporter that is homologue of S. cerevisiae CTR2. In yeast, Ctr2 is a vacuolar transporter for moving copper from the vacuole to the cytoplasm. The gene was therefore termed CgCTR2. In addition to characterization of CgCTR2, we also conducted comparative analyses in M. grisea. The M. grisea CgCTR-2 homolog was isolated, knockout strains were generated and characterized and the M. grisea was used to complement the Nl 59 C. gloeosporioides mutant. Overall, we have accomplished most of proposed experiments and are in the process of organizing and publishing other data generated in this project. For objective 3, we used the microarray analysis approach. Several genes identified in this study are novel fungal virulence factors. They have the potential to be used as targets for developing more specific or effective fungicides. In the long run, comparative studies of fungal genes, such as our CgCTR2 work, may lead to better disease control strategies.
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