351
|
Fernandes RR, Lasri J, Kirillov AM, Guedes da Silva MFC, da Silva JAL, Fraústo da Silva JJR, Pombeiro AJL. New Fe
II
and Cu
II
Complexes Bearing Azathia Macrocycles – Catalyst Precursors for Mild Peroxidative Oxidation of Cyclohexane and 1‐Phenylethanol. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201100460] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ricardo R. Fernandes
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco Pais, 1049‐001 Lisbon, Portugal, Fax: +351‐218464455
| | - Jamal Lasri
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco Pais, 1049‐001 Lisbon, Portugal, Fax: +351‐218464455
| | - Alexander M. Kirillov
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco Pais, 1049‐001 Lisbon, Portugal, Fax: +351‐218464455
| | - M. Fátima C. Guedes da Silva
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco Pais, 1049‐001 Lisbon, Portugal, Fax: +351‐218464455
- Universidade Lusófona de Humanidades e Tecnologias, ULHT Lisbon, Av. do Campo Grande 376, 1749‐024 Lisbon, Portugal
| | - José A. L. da Silva
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco Pais, 1049‐001 Lisbon, Portugal, Fax: +351‐218464455
| | - João J. R. Fraústo da Silva
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco Pais, 1049‐001 Lisbon, Portugal, Fax: +351‐218464455
| | - Armando J. L. Pombeiro
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco Pais, 1049‐001 Lisbon, Portugal, Fax: +351‐218464455
| |
Collapse
|
352
|
Li L, Li GD, Yan C, Mu XY, Pan XL, Zou XX, Wang KX, Chen JS. Efficient sunlight-driven dehydrogenative coupling of methane to ethane over a Zn(+)-modified zeolite. Angew Chem Int Ed Engl 2011; 50:8299-303. [PMID: 21761525 DOI: 10.1002/anie.201102320] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/28/2011] [Indexed: 11/12/2022]
Affiliation(s)
- Lu Li
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
353
|
Li L, Li GD, Yan C, Mu XY, Pan XL, Zou XX, Wang KX, Chen JS. Efficient Sunlight-Driven Dehydrogenative Coupling of Methane to Ethane over a Zn+-Modified Zeolite. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201102320] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
354
|
|
355
|
Schwarz H. Chemistry with methane: concepts rather than recipes. Angew Chem Int Ed Engl 2011; 50:10096-115. [PMID: 21656876 DOI: 10.1002/anie.201006424] [Citation(s) in RCA: 491] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Indexed: 11/11/2022]
Abstract
Four seemingly simple transformations related to the chemistry of methane will be addressed from mechanistic and conceptual points of view: 1) metal-mediated dehydrogenation to form metal carbene complexes, 2) the hydrogen-atom abstraction step in the oxidative dimerization of methane, 3) the mechanisms of the CH(4)→CH(3)OH conversion, and 4) the initial bond scission (C-H vs. O-H) as well as the rate-limiting step in the selective CH(3)OH→CH(2)O oxidation. State-of-the-art gas-phase experiments, in conjunction with electronic-structure calculations, permit identification of the elementary reactions at a molecular level and thus allow us to unravel detailed mechanistic aspects. Where appropriate, these results are compared with findings from related studies in solution or on surfaces.
Collapse
Affiliation(s)
- Helmut Schwarz
- Institut für Chemie der Technischen Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany.
| |
Collapse
|
356
|
Sayavedra-Soto LA, Hamamura N, Liu CW, Kimbrel JA, Chang JH, Arp DJ. The membrane-associated monooxygenase in the butane-oxidizing Gram-positive bacterium Nocardioides sp. strain CF8 is a novel member of the AMO/PMO family. ENVIRONMENTAL MICROBIOLOGY REPORTS 2011; 3:390-396. [PMID: 23761285 DOI: 10.1111/j.1758-2229.2010.00239.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The Gram-positive bacterium Nocardioides sp. strain CF8 uses a membrane-associated monooxygenase (pBMO) to grow on butane. The nucleotide sequences of the genes encoding this novel monooxygenase were revealed through analysis of a de novo assembled draft genome sequence determined by high-throughput sequencing of the whole genome. The pBMO genes were in a similar arrangement to the genes for ammonia monooxygenase (AMO) from the ammonia-oxidizing bacteria and for particulate methane monooxygenase (pMMO) from the methane-oxidizing bacteria. The pBMO genes likely constitute an operon in the order bmoC, bmoA and bmoB. The nucleotide sequence was less than 50% similar to the genes for AMO and pMMO. The operon for pBMO was confirmed to be a single copy in the genome by Southern and computational analyses. In an incubation on butane the increase of transcriptional activity of the pBmoA gene was congruent with the increase of pBMO activity and suggested correspondence between gene expression and the utilization of butane. Phylogenetic comparison revealed distant but significant similarity of all three pBMO subunits to homologous members of the AMO/pMMO family and indicated that the pBMO represents a deeply branching third lineage of this group of particulate monooxygenases. No other bmoCAB-like genes were found to cluster with pBMO lineage in phylogenetic analysis by database searches including genomic and metagenomic sequence databases. pBMO is the first example of the AMO/pMMO-like monooxygenase from Gram-positive bacteria showing similarities to proteobacterial pMMO and AMO sequences.
Collapse
Affiliation(s)
- Luis A Sayavedra-Soto
- Department of Botany and Plant Pathology Molecular and Cellular Biology Program Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA. Center for Marine Environmental Studies, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan. Department of Chemical Engineering, National Taiwan University, Taipei, 106, Taiwan
| | | | | | | | | | | |
Collapse
|
357
|
Zhang Q, Deng W, Wang Y. Effect of size of catalytically active phases in the dehydrogenation of alcohols and the challenging selective oxidation of hydrocarbons. Chem Commun (Camb) 2011; 47:9275-92. [PMID: 21629889 DOI: 10.1039/c1cc11723h] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The size of the active phase is one of the most important factors in determining the catalytic behaviour of a heterogeneous catalyst. This Feature Article focuses on the size effects in two types of reactions, i.e., the metal nanoparticle-catalysed dehydrogenation of alcohols and the metal oxide nanocluster-catalysed selective oxidation of hydrocarbons (including the selective oxidation of methane and ethane and the epoxidation of propylene). For Pd or Au nanoparticle-catalysed oxidative or non-oxidative dehydrogenation of alcohols, the size of metal nanoparticles mainly controls the catalytic activity by affecting the activation of reactants (either alcohol or O(2)). The size of oxidic molybdenum species loaded on SBA-15 determines not only the activity but also the selectivity of oxygenates in the selective oxidation of ethane; highly dispersed molybdenum species are suitable for acetaldehyde formation, while molybdenum oxide nanoparticles exhibit higher formaldehyde selectivity. Cu(II) and Fe(III) isolated on mesoporous silica are highly efficient for the selective oxidation of methane to formaldehyde, while the corresponding oxide clusters mainly catalyse the complete oxidation of methane. The lattice oxygen in iron or copper oxide clusters is responsible for the complete oxidation, while the isolated Cu(I) or Fe(II) generated during the reaction can activate molecular oxygen forming active oxygen species for the selective oxidation of methane. Highly dispersed Cu(I) and Fe(II) species also function for the epoxidation of propylene by O(2) and N(2)O, respectively. Alkali metal ions work as promoters for the epoxidation of propylene by enhancing the dispersion of copper or iron species and weakening the acidity.
Collapse
Affiliation(s)
- Qinghong Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China
| | | | | |
Collapse
|
358
|
Dietl N, van der Linde C, Schlangen M, Beyer MK, Schwarz H. Diatomic [CuO]+ and Its Role in the Spin-Selective Hydrogen- and Oxygen-Atom Transfers in the Thermal Activation of Methane. Angew Chem Int Ed Engl 2011; 50:4966-9. [DOI: 10.1002/anie.201100606] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Indexed: 11/10/2022]
|
359
|
Dietl N, van der Linde C, Schlangen M, Beyer MK, Schwarz H. Über die Rolle von [CuO]+ bei spinselektiven Wasserstoff- und Sauerstoff-Übertragungen in der Aktivierung von Methan. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201100606] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
360
|
Abstract
The controlled oxidation of methane to methanol is a chemical transformation of great value, particularly in the pursuit of alternative fuels, but the reaction remains underutilized industrially because of inefficient and costly synthetic procedures. In contrast, methane monooxygenase enzymes (MMOs) from methanotrophic bacteria achieve this chemistry efficiently under ambient conditions. In this Account, we discuss the first observable step in the oxidation of methane at the carboxylate-bridged diiron active site of the soluble MMO (sMMO), namely, the reductive activation of atmospheric O(2). The results provide benchmarks against which the dioxygen activation mechanisms of other bacterial multicomponent monooxygenases can be measured. Molecular oxygen reacts rapidly with the reduced diiron(II) cen-ter of the hydroxylase component of sMMO (MMOH). The first spectroscopically characterized intermediate that results from this process is a peroxodiiron(III) species, P*, in which the iron atoms have identical environments. P* converts to a second peroxodiiron(III) unit, H(peroxo), in a process accompanied by the transfer of a proton, probably with the assistance of a residue near the active site. Proton-promoted O-O bond scission and rearrangement of the diiron core then leads to a diiron(IV) unit, termed Q, that is directly responsible for the oxidation of methane to methanol. In one section of this Account, we provide a detailed discussion of these processes, with particular emphasis on possible structures of the intermediates. The geometries of P* and H(peroxo) are currently unknown, and recent synthetic modeling chemistry has highlighted the need for further structural characterization of Q, currently assigned as a di(μ-oxo)diiron(IV) "diamond core." In another section of the Account, we discuss in detail proton transfer during the O(2) activation events. The role of protons in promoting O-O bond cleavage, thereby initiating the conversion of H(peroxo) to Q, was previously a controversial topic. Recent studies of the mechanism, covering a range of pH values and in D(2)O instead of H(2)O, confirmed conclusively that the transfer of protons, possibly at or near the active site, is necessary for both P*-to-H(peroxo) and H(peroxo)-to-Q conversions. Specific mechanistic insights into these processes are provided. In the final section of the Account, we present our view of experiments that need to be done to further define crucial aspects of sMMO chemistry. Here our goal is to detail the challenges that we and others face in this research, particularly with respect to some long-standing questions about the system, as well as approaches that might be used to solve them.
Collapse
Affiliation(s)
- Christine E. Tinberg
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Stephen J. Lippard
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| |
Collapse
|
361
|
Abstract
The development of new catalytic methods to functionalize carbon-hydrogen (C-H) bonds continues to progress at a rapid pace due to the significant economic and environmental benefits of these transformations over traditional synthetic methods. In nature, enzymes catalyze regio- and stereoselective C-H bond functionalization using transformations ranging from hydroxylation to hydroalkylation under ambient reaction conditions. The efficiency of these enzymes relative to analogous chemical processes has led to their increased use as biocatalysts in preparative and industrial applications. Furthermore, unlike small molecule catalysts, enzymes can be systematically optimized via directed evolution for a particular application and can be expressed in vivo to augment the biosynthetic capability of living organisms. While a variety of technical challenges must still be overcome for practical application of many enzymes for C-H bond functionalization, continued research on natural enzymes and on novel artificial metalloenzymes will lead to improved synthetic processes for efficient synthesis of complex molecules. In this critical review, we discuss the most prevalent mechanistic strategies used by enzymes to functionalize non-acidic C-H bonds, the application and evolution of these enzymes for chemical synthesis, and a number of potential biosynthetic capabilities uniquely enabled by these powerful catalysts (110 references).
Collapse
Affiliation(s)
| | - Pedro S. Coelho
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., MC210-41, Pasadena, CA 91125-4100, USA
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., MC210-41, Pasadena, CA 91125-4100, USA
| |
Collapse
|
362
|
|
363
|
Particulate methane monooxygenase from Methylosinus trichosporium OB3b. Methods Enzymol 2011. [PMID: 21419924 DOI: 10.1016/b978-0-12-386905-0.00014-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Particulate methane monooxygenase (pMMO) catalyzes methane hydroxylation to methanol at ambient temperature and pressure. pMMO from Methylosinus trichosporium OB3b is one of the two pMMOs for which the protein structure was determined by X-ray crystallography. Because purified pMMO is inherently instable in vitro, it is difficult to use for time-consuming analysis. Therefore, investigations using crude enzyme preparations of pMMO are useful in some cases. In this chapter, methods for preparing pMMO from M. trichosporium OB3b to varying degrees of purity, including bacterial cells expressing pMMO, membrane fractions containing pMMO, and highly purified pMMO, are described.
Collapse
|
364
|
Zilly FE, Acevedo JP, Augustyniak W, Deege A, Häusig UW, Reetz MT. Tuning a P450 Enzyme for Methane Oxidation. Angew Chem Int Ed Engl 2011; 50:2720-4. [DOI: 10.1002/anie.201006587] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 01/01/2011] [Indexed: 01/24/2023]
Affiliation(s)
- Felipe E. Zilly
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Juan P. Acevedo
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Wojciech Augustyniak
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Alfred Deege
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Ulrich W. Häusig
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Manfred T. Reetz
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| |
Collapse
|
365
|
Solomon EI, Ginsbach JW, Heppner DE, Kieber-Emmons MT, Kjaergaard CH, Smeets PJ, Tian L, Woertink JS. Copper dioxygen (bio)inorganic chemistry. Faraday Discuss 2011; 148:11-39; discussion 97-108. [PMID: 21322475 DOI: 10.1039/c005500j] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cu/O2 intermediates in biological, homogeneous, and heterogeneous catalysts exhibit unique spectral features that reflect novel geometric and electronic structures that make significant contributions to reactivity. This review considers how the respective intermediate electronic structures overcome the spin-forbidden nature of O2 binding, activate O2 for electrophilic aromatic attack and H-atom abstraction, catalyze the 4 e- reduction of O2 to H2O, and discusses the role of exchange coupling between Cu ions in determining reactivity.
Collapse
Affiliation(s)
- Edward I Solomon
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA 94305, USA.
| | | | | | | | | | | | | | | |
Collapse
|
366
|
Anttila J, Heinonen P, Nenonen T, Pino A, Iwaï H, Kauppi E, Soliymani R, Baumann M, Saksi J, Suni N, Haltia T. Is coproporphyrin III a copper-acquisition compound in Paracoccus denitrificans? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:311-8. [DOI: 10.1016/j.bbabio.2010.12.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 12/21/2010] [Accepted: 12/22/2010] [Indexed: 11/25/2022]
|
367
|
Haack P, Limberg C, Ray K, Braun B, Kuhlmann U, Hildebrandt P, Herwig C. Dinuclear Copper Complexes Based on Parallel β-Diiminato Binding Sites and their Reactions with O2: Evidence for a Cu−O−Cu Entity. Inorg Chem 2011; 50:2133-42. [DOI: 10.1021/ic101249k] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter Haack
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin, Germany
| | - Christian Limberg
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin, Germany
| | - Kallol Ray
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin, Germany
| | - Beatrice Braun
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin, Germany
| | - Uwe Kuhlmann
- Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Strasse des 17 Juni 135, D-10623 Berlin, Germany
| | - Peter Hildebrandt
- Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Strasse des 17 Juni 135, D-10623 Berlin, Germany
| | - Christian Herwig
- Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin, Germany
| |
Collapse
|
368
|
Zilly FE, Acevedo JP, Augustyniak W, Deege A, Häusig UW, Reetz MT. Tuning a P450 Enzyme for Methane Oxidation. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201006587] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Felipe E. Zilly
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Juan P. Acevedo
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Wojciech Augustyniak
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Alfred Deege
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Ulrich W. Häusig
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| | - Manfred T. Reetz
- Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr (Germany)
| |
Collapse
|
369
|
Smeets PJ, Hadt RG, Woertink JS, Vanelderen P, Schoonheydt RA, Sels BF, Solomon EI. Oxygen precursor to the reactive intermediate in methanol synthesis by Cu-ZSM-5. J Am Chem Soc 2011; 132:14736-8. [PMID: 20923156 DOI: 10.1021/ja106283u] [Citation(s) in RCA: 173] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The reactive oxidizing species in the selective oxidation of methane to methanol in oxygen activated Cu-ZSM-5 was recently defined to be a bent mono(μ-oxo)dicopper(II) species, [Cu(2)O](2+). In this communication we report the formation of an O(2)-precursor of this reactive site with an associated absorption band at 29,000 cm(-1). Laser excitation into this absorption feature yields a resonance Raman (rR) spectrum characterized by (18)O(2) isotope sensitive and insensitive vibrations, νO-O and νCu-Cu, at 736 (Δ(18)O(2) = 41 cm(-1)) and 269 cm(-1), respectively. These define the precursor to be a μ-(η(2):η(2)) peroxo dicopper(II) species, [Cu(2)(O(2))](2+). rR experiments in combination with UV-vis absorption data show that this [Cu(2)(O(2))](2+) species transforms directly into the [Cu(2)O](2+) reactive site. Spectator Cu(+) sites in the zeolite ion-exchange sites provide the two electrons required to break the peroxo bond in the precursor. O(2)-TPD experiments with (18)O(2) show the incorporation of the second (18)O atom into the zeolite lattice in the transformation of [Cu(2)(O(2))](2+) into [Cu(2)O](2+). This study defines the mechanism of oxo-active site formation in Cu-ZSM-5.
Collapse
Affiliation(s)
- Pieter J Smeets
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | | | | | | | | | | | | |
Collapse
|
370
|
El Ghazouani A, Baslé A, Firbank SJ, Knapp CW, Gray J, Graham DW, Dennison C. Copper-binding properties and structures of methanobactins from Methylosinus trichosporium OB3b. Inorg Chem 2011; 50:1378-91. [PMID: 21254756 DOI: 10.1021/ic101965j] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methanobactins (mbs) are a class of copper-binding peptides produced by aerobic methane oxidizing bacteria (methanotrophs) that have been linked to the substantial copper needs of these environmentally important microorganisms. The only characterized mbs are those from Methylosinus trichosporium OB3b and Methylocystis strain SB2. M. trichosporium OB3b produces a second mb (mb-Met), which is missing the C-terminal Met residue from the full-length form (FL-mb). The as-isolated copper-loaded mbs bind Cu(I). The absence of the Met has little influence on the structure of the Cu(I) site, and both molecules mediate switchover from the soluble iron methane mono-oxygenase to the particulate copper-containing enzyme in M. trichosporium OB3b cells. Cu(II) is reduced in the presence of the mbs under our experimental conditions, and the disulfide plays no role in this process. The Cu(I) affinities of these molecules are extremely high with values of (6-7) × 10(20) M(-1) determined at pH ≥ 8.0. The affinity for Cu(I) is 1 order of magnitude lower at pH 6.0. The reduction potentials of copper-loaded FL-mb and mb-Met are 640 and 590 mV respectively, highlighting the strong preference for Cu(I) and indicating different Cu(II) affinities for the two forms. Cleavage of the disulfide bridge results in a decrease in the Cu(I) affinity to ∼9 × 10(18) M(-1) at pH 7.5. The two thiolates can also bind Cu(I), albeit with much lower affinity (∼ 3 × 10(15) M(-1) at pH 7.5). The high affinity of mbs for Cu(I) is consistent with a physiological role in copper uptake and protection.
Collapse
Affiliation(s)
- Abdelnasser El Ghazouani
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
371
|
Tsui EY, Day MW, Agapie T. Trinucleating Copper: Synthesis and Magnetostructural Characterization of Complexes Supported by a Hexapyridyl 1,3,5-Triarylbenzene Ligand. Angew Chem Int Ed Engl 2011; 50:1668-72. [DOI: 10.1002/anie.201005232] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2010] [Revised: 10/24/2010] [Indexed: 11/10/2022]
|
372
|
Tsui EY, Day MW, Agapie T. Trinucleating Copper: Synthesis and Magnetostructural Characterization of Complexes Supported by a Hexapyridyl 1,3,5-Triarylbenzene Ligand. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201005232] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
373
|
Himes RA, Barnese K, Karlin KD. One is lonely and three is a crowd: two coppers are for methane oxidation. Angew Chem Int Ed Engl 2011; 49:6714-6. [PMID: 20672276 DOI: 10.1002/anie.201003403] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Richard A Himes
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | | |
Collapse
|
374
|
Graham DW, Kim HJ. Production, isolation, purification, and functional characterization of methanobactins. Methods Enzymol 2011; 495:227-45. [PMID: 21419925 DOI: 10.1016/b978-0-12-386905-0.00015-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Aerobic methane-oxidizing bacteria (methanotrophs) have a high conditional need for copper because almost all known species express a copper-containing particulate methane monooxygenase for catalyzing the conversion of methane to methanol. This demands a copper homeostatic system that must both supply and satisfy adequate copper for elevated needs while also shielding the cells from copper toxicity. After considerable effort, it was discovered that some methanotrophs produce small peptidic molecules, called methanobactins, which bind copper, mediate copper transport into the cell, and reduce copper toxicity. Unfortunately, isolating, purifying, and proving the functionality of these molecules has been challenging. In fact, until very recently, only one complete structure had been reported for methanobactins. As such, there is a desperate need for more studies seeking such molecules. The purpose of this chapter is to describe methods used to isolate and purify the original methanobactin with a published complete structure, which is made by Methylosinus trichosporium OB3b. Methods are also included for assessing the function of such molecules under pseudonatural conditions such as growth on mineral copper sources. Special emphasis is placed on verifying that isolated molecules are "true" methanobactins, because recent work has shown that methanotrophs produce other small molecules that also bind metals in solution.
Collapse
Affiliation(s)
- David W Graham
- School of Civil Engineering and Geosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | | |
Collapse
|
375
|
Smith SM, Balasubramanian R, Rosenzweig AC. Metal reconstitution of particulate methane monooxygenase and heterologous expression of the pmoB subunit. Methods Enzymol 2011; 495:195-210. [PMID: 21419923 PMCID: PMC3361753 DOI: 10.1016/b978-0-12-386905-0.00013-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Particulate methane monooxygenase (pMMO) is a multisubunit metalloenzyme complex used by methanotrophic bacteria to oxidize methane in the first step of carbon assimilation and energy production. In this chapter, we detail methods to prepare metal free (apo) membrane-bound pMMO and to reconstitute apo pMMO with metal ions. We also describe protocols to clone, express, and refold metal-loaded soluble domain constructs of the pmoB subunit. These approaches were used to address fundamental questions concerning the metal content and location of the pMMO active site.
Collapse
Affiliation(s)
- Stephen M Smith
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA
| | | | | |
Collapse
|
376
|
Knör G, Monkowius U. Photosensitization and photocatalysis in bioinorganic, bio-organometallic and biomimetic systems. ADVANCES IN INORGANIC CHEMISTRY 2011. [DOI: 10.1016/b978-0-12-385904-4.00005-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
377
|
Chan SI, Nguyen HHT, Chen KHC, Yu SSF. Overexpression and Purification of the Particulate Methane Monooxygenase from Methylococcus capsulatus (Bath). Methods Enzymol 2011; 495:177-93. [DOI: 10.1016/b978-0-12-386905-0.00012-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
378
|
|
379
|
Utz D, Kisslinger S, Heinemann FW, Hampel F, Schindler S. Syntheses, Characterization and Properties of Open-Chain Copper(I) Complexes. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000954] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
380
|
Freedman DE, Han TH, Prodi A, Müller P, Huang QZ, Chen YS, Webb SM, Lee YS, McQueen TM, Nocera DG. Site specific X-ray anomalous dispersion of the geometrically frustrated kagomé magnet, herbertsmithite, ZnCu(3)(OH)(6)Cl(2). J Am Chem Soc 2010; 132:16185-90. [PMID: 20964423 DOI: 10.1021/ja1070398] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Structural characterization, exploiting X-ray scattering differences at elemental absorption edges, is developed to quantitatively determine crystallographic site-specific metal disorder. We apply this technique to the problem of Zn-Cu chemical disorder in ZnCu(3)(OH)(6)Cl(2). This geometrically frustrated kagomé antiferromagnet is one of the best candidates for a spin-liquid ground state, but chemical disorder has been suggested as a mundane explanation for its magnetic properties. Using anomalous scattering at the Zn and Cu edges, we determine that there is no Zn occupation of the intralayer Cu sites within the kagomé layer; however there is Cu present on the Zn intersite, leading to a structural formula of (Zn(0.85)Cu(0.15))Cu(3)(OH)(6)Cl(2). The lack of Zn mixing onto the kagomé lattice sites lends support to the idea that the electronic ground state in ZnCu(3)(OH)(6)Cl(2) and its relatives is nontrivial.
Collapse
Affiliation(s)
- Danna E Freedman
- Department of Chemistry, 6-335, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
381
|
Torelli S, Orio M, Pécaut J, Jamet H, Le Pape L, Ménage S. A {Cu2S}2+ Mixed-Valent Core Featuring a CuCu Bond. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201003411] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
382
|
Torelli S, Orio M, Pécaut J, Jamet H, Le Pape L, Ménage S. A {Cu2S}2+ Mixed-Valent Core Featuring a CuCu Bond. Angew Chem Int Ed Engl 2010; 49:8249-52. [DOI: 10.1002/anie.201003411] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
383
|
Waldron KJ, Firbank SJ, Dainty SJ, Pérez-Rama M, Tottey S, Robinson NJ. Structure and metal loading of a soluble periplasm cuproprotein. J Biol Chem 2010; 285:32504-11. [PMID: 20702411 DOI: 10.1074/jbc.m110.153080] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A copper-trafficking pathway was found to enable Cu(2+) occupancy of a soluble periplasm protein, CucA, even when competing Zn(2+) is abundant in the periplasm. Here, we solved the structure of CucA (a new cupin) and found that binding of Cu(2+), but not Zn(2+), quenches the fluorescence of Trp(165), which is adjacent to the metal site. Using this fluorescence probe, we established that CucA becomes partly occupied by Zn(2+) following exposure to equimolar Zn(2+) and Cu(2+). Cu(2+)-CucA is more thermodynamically stable than Zn(2+)-CucA but k((Zn→Cu)exchange) is slow, raising questions about how the periplasm contains solely the Cu(2+) form. We discovered that a copper-trafficking pathway involving two copper transporters (CtaA and PacS) and a metallochaperone (Atx1) is obligatory for Cu(2+)-CucA to accumulate in the periplasm. There was negligible CucA protein in the periplasm of ΔctaA cells, but the abundance of cucA transcripts was unaltered. Crucially, ΔctaA cells overaccumulate low M(r) copper complexes in the periplasm, and purified apoCucA can readily acquire Cu(2+) from ΔctaA periplasm extracts, but in vivo apoCucA fails to come into contact with these periplasmic copper pools. Instead, copper traffics via a cytoplasmic pathway that is coupled to CucA translocation to the periplasm.
Collapse
Affiliation(s)
- Kevin J Waldron
- Institute for Cell and Molecular Biosciences, University of Newcastle Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | | | | | | | | | | |
Collapse
|
384
|
|
385
|
Schoonheydt RA. UV-VIS-NIR spectroscopy and microscopy of heterogeneous catalysts. Chem Soc Rev 2010; 39:5051-66. [DOI: 10.1039/c0cs00080a] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|