1
|
Insinna T, Bassey EN, Märker K, Collauto A, Barra AL, Grey CP. Graphite Anodes for Li-Ion Batteries: An Electron Paramagnetic Resonance Investigation. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:5497-5511. [PMID: 37521744 PMCID: PMC10373490 DOI: 10.1021/acs.chemmater.3c00860] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/27/2023] [Indexed: 08/01/2023]
Abstract
Graphite is the most commercially successful anode material for lithium (Li)-ion batteries: its low cost, low toxicity, and high abundance make it ideally suited for use in batteries for electronic devices, electrified transportation, and grid-based storage. The physical and electrochemical properties of graphite anodes have been thoroughly characterized. However, questions remain regarding their electronic structures and whether the electrons occupy localized states on Li, delocalized states on C, or an admixture of both. In this regard, electron paramagnetic resonance (EPR) spectroscopy is an invaluable tool for characterizing the electronic states generated during electrochemical cycling as it measures the properties of the unpaired electrons in lithiated graphites. In this work, ex situ variable-temperature (10-300 K), variable-frequency (9-441 GHz) EPR was carried out to extract the g tensors and line widths and understand the effect of metallicity on the observed EPR spectra of electrochemically lithiated graphites at four different states of lithiation. We show that the increased resolution offered by EPR at high frequencies (>300 GHz) enables up to three different electron environments of axial symmetry to be observed, revealing heterogeneity within the graphite particles and the presence of hyperfine coupling to Li nuclei. Importantly, our work demonstrates the power of EPR spectroscopy to investigate the local electronic structure of graphite at different lithiation stages, paving the way for this technique as a tool for screening and investigating novel materials for use in Li-ion batteries.
Collapse
Affiliation(s)
- Teresa Insinna
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Euan N. Bassey
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Katharina Märker
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Alberto Collauto
- Centre
for Pulse EPR (PEPR), Imperial College London, London W12 0BZ, United Kingdom
| | - Anne-Laure Barra
- LNCMI-CNRS,
EMFL, Univ. Grenoble-Alpes, 25 Rue des Martyrs, B.P. 166, 38042 Grenoble Cedex 9, France
- LNCMI-CNRS,
EMFL, Univ. Toulouse 3, Insa Toulouse, 118 Route de Narbonne 31062 Toulouse Cedex 9, France
| | - Clare P. Grey
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| |
Collapse
|
2
|
Freeman SL, Skafar V, Kwon H, Fielding AJ, Moody PCE, Martínez A, Issoglio FM, Inchausti L, Smircich P, Zeida A, Piacenza L, Radi R, Raven EL. Crystal structure of Trypanosoma cruzi heme peroxidase and characterization of its substrate specificity and compound I intermediate. J Biol Chem 2022; 298:102204. [PMID: 35772495 PMCID: PMC9358470 DOI: 10.1016/j.jbc.2022.102204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 11/26/2022] Open
Abstract
The protozoan parasite Trypanosoma cruzi is the causative agent of American trypanosomiasis, otherwise known as Chagas disease. To survive in the host, the T. cruzi parasite needs antioxidant defense systems. One of these is a hybrid heme peroxidase, the T. cruzi ascorbate peroxidase-cytochrome c peroxidase enzyme (TcAPx-CcP). TcAPx-CcP has high sequence identity to members of the class I peroxidase family, notably ascorbate peroxidase (APX) and cytochrome c peroxidase (CcP), as well as a mitochondrial peroxidase from Leishmania major (LmP). The aim of this work was to solve the structure and examine the reactivity of the TcAPx-CcP enzyme. Low temperature electron paramagnetic resonance spectra support the formation of an exchange-coupled [Fe(IV)=O Trp233•+] compound I radical species, analogous to that used in CcP and LmP. We demonstrate that TcAPx-CcP is similar in overall structure to APX and CcP, but there are differences in the substrate-binding regions. Furthermore, the electron transfer pathway from cytochrome c to the heme in CcP and LmP is preserved in the TcAPx-CcP structure. Integration of steady state kinetic experiments, molecular dynamic simulations, and bioinformatic analyses indicates that TcAPx-CcP preferentially oxidizes cytochrome c but is still competent for oxidization of ascorbate. The results reveal that TcAPx-CcP is a credible cytochrome c peroxidase, which can also bind and use ascorbate in host cells, where concentrations are in the millimolar range. Thus, kinetically and functionally TcAPx-CcP can be considered a hybrid peroxidase.
Collapse
Affiliation(s)
- Samuel L Freeman
- School of Chemistry, University of Bristol, Bristol, United Kingdom
| | - Vera Skafar
- Departamento de Bioquímica, Facultad of Medicina, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Hanna Kwon
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, United Kingdom
| | - Alistair J Fielding
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moore University, Liverpool, United Kingdom
| | - Peter C E Moody
- Department of Molecular and Cell Biology and Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, United Kingdom
| | - Alejandra Martínez
- Departamento de Bioquímica, Facultad of Medicina, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Federico M Issoglio
- CONICET-Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Lucas Inchausti
- Laboratorio de Bioinformática, Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay; Laboratorio de Interacciones Moleculares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Pablo Smircich
- Laboratorio de Bioinformática, Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay; Laboratorio de Interacciones Moleculares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Ari Zeida
- Departamento de Bioquímica, Facultad of Medicina, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Lucía Piacenza
- Departamento de Bioquímica, Facultad of Medicina, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica, Facultad of Medicina, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
| | - Emma L Raven
- School of Chemistry, University of Bristol, Bristol, United Kingdom.
| |
Collapse
|
3
|
Oliw EH. Fatty acid dioxygenase-cytochrome P450 fusion enzymes of filamentous fungal pathogens. Fungal Genet Biol 2021; 157:103623. [PMID: 34520871 DOI: 10.1016/j.fgb.2021.103623] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/07/2021] [Indexed: 11/27/2022]
Abstract
Oxylipins designate oxygenated unsaturated C18 fatty acids. Many filamentous fungi pathogens contain dioxygenases (DOX) in oxylipin biosynthesis with homology to human cyclooxygenases. They contain a DOX domain, which is often fused to a functional cytochrome P450 at the C-terminal end. A Tyr radical in the DOX domain initiates dioxygenation of linoleic acid by hydrogen abstraction with formation of 8-, 9-, or 10-hydroperoxy metabolites. The P450 domains can catalyze heterolytic cleavage of 8- and 10-hydroperoxides with oxidation of the heme thiolate iron for hydroxylation at C-5, C-7, C-9, or C-11 and for epoxidation of the 12Z double bond; thus displaying linoleate diol synthase (LDS) and epoxy alcohol synthase (EAS) activities. LSD activities are present in the rice blast pathogen Magnaporthe oryzae, Botrytis cinerea causing grey mold and the black scurf pathogen Rhizoctonia solani. 10R-DOX-EAS has been found in M. oryzae and Fusarium oxysporum. The P450 domains may also catalyze homolytic cleavage of 8- and 9-hydroperoxy fatty acids and dehydration to produce epoxides with an adjacent double bond, i.e., allene oxides, thus displaying 8- and 9-DOX-allene oxide synthases (AOS). F. oxysporum, F. graminearum, and R. solani express 9S-DOX-AOS and Zymoseptoria tritici 8S-and 9R-DOX-AOS. Homologues are present in endemic human-pathogenic fungi with extensive studies in Aspergillus fumigatus, A. flavus (also a plant pathogen) as well as the genetic model A. nidulans. 8R-and 10R-DOX appear to bind fatty acids "headfirst" in the active site, whereas 9S-DOX binds them "tail first" in analogy with cyclooxygenases. The biological relevance of 8R-DOX-5,8-LDS (also designated PpoA) was first discovered in relation to sporulation of A. nidulans and recently for development and programmed hyphal branching of A. fumigatus. Gene deletion DOX-AOS homologues in F. verticillioides, A. flavus, and A. nidulans alters, inter alia, mycotoxin production, sporulation, and gene expression.
Collapse
Affiliation(s)
- Ernst H Oliw
- Division of Biochemical Pharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Box 591, SE-751 24 Uppsala, Sweden.
| |
Collapse
|
4
|
Oliw EH. WITHDRAWN: Fatty acid dioxygenase-cytochrome P450 fusion enzymes of the top 10 fungal pathogens in molecular plant pathology and human-pathogenic fungi. Fungal Genet Biol 2021:103603. [PMID: 34214670 DOI: 10.1016/j.fgb.2021.103603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 02/21/2021] [Accepted: 06/11/2021] [Indexed: 11/22/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal
Collapse
Affiliation(s)
- Ernst H Oliw
- Division of Biochemical Pharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Box 591, SE-751 24 Uppsala, Sweden.
| |
Collapse
|
5
|
Van Doorslaer S. Understanding heme proteins with hyperfine spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 280:79-88. [PMID: 28579104 DOI: 10.1016/j.jmr.2017.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 06/07/2023]
Abstract
Heme proteins are versatile proteins that are involved in a large number of biological processes. Many spectroscopic methods are used to gain insight into the different mechanistic processes governing heme-protein functions. Since many (intermediate) states of heme proteins are paramagnetic, electron paramagnetic resonance (EPR) methods, such as hyperfine spectroscopy, offer unique tools for these investigations. This perspective gives an overview of the use of state-of-the-art hyperfine spectroscopy in heme research, focusing on the advantages, limits and challenges of the different techniques.
Collapse
Affiliation(s)
- Sabine Van Doorslaer
- BIMEF Laboratory, Department of Physics, University of Antwerp, B-2610 Antwerp, Belgium.
| |
Collapse
|
6
|
Fischer GJ, Keller NP. Production of cross-kingdom oxylipins by pathogenic fungi: An update on their role in development and pathogenicity. J Microbiol 2016; 54:254-64. [PMID: 26920885 DOI: 10.1007/s12275-016-5620-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/05/2016] [Indexed: 01/05/2023]
Abstract
Oxylipins are a class of molecules derived from the incorporation of oxygen into polyunsaturated fatty acid substrates through the action of oxygenases. While extensively investigated in the context of mammalian immune responses, over the last decade it has become apparent that oxylipins are a common means of communication among and between plants, animals, and fungi to control development and alter host-microbe interactions. In fungi, some oxylipins are derived nonenzymatically while others are produced by lipoxygenases, cyclooxygenases, and monooxygenases with homology to plant and human enzymes. Recent investigations of numerous plant and human fungal pathogens have revealed oxylipins to be involved in the establishment and progression of disease. This review highlights oxylipin production by pathogenic fungi and their role in fungal development and pathogen/host interactions.
Collapse
Affiliation(s)
- Gregory J Fischer
- Department of Genetics, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| |
Collapse
|
7
|
Sooman L, Wennman A, Hamberg M, Hoffmann I, Oliw EH. Replacement of two amino acids of 9 R -dioxygenase-allene oxide synthase of Aspergillus niger inverts the chirality of the hydroperoxide and the allene oxide. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:108-118. [DOI: 10.1016/j.bbalip.2015.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 11/10/2015] [Accepted: 11/17/2015] [Indexed: 01/25/2023]
|
8
|
Orlando BJ, Borbat PP, Georgieva ER, Freed JH, Malkowski MG. Pulsed Dipolar Spectroscopy Reveals That Tyrosyl Radicals Are Generated in Both Monomers of the Cyclooxygenase-2 Dimer. Biochemistry 2015; 54:7309-12. [PMID: 26636181 DOI: 10.1021/acs.biochem.5b00979] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cyclooxygenases (COXs) are heme-containing sequence homodimers that utilize tyrosyl radical-based catalysis to oxygenate substrates. Tyrosyl radicals are formed from a single turnover of substrate in the peroxidase active site generating an oxy-ferryl porphyrin cation radical intermediate that subsequently gives rise to a Tyr-385 radical in the cyclooxygenase active site and a Tyr-504 radical nearby. We have utilized double-quantum coherence (DQC) spectroscopy to determine the distance distributions between Tyr-385 and Tyr-504 radicals in COX-2. The distances obtained with DQC confirm that Tyr-385 and Tyr-504 radicals were generated in each monomer and accurately match the distances measured in COX-2 crystal structures.
Collapse
Affiliation(s)
- Benjamin J Orlando
- Department of Structural Biology, The State University of New York at Buffalo , Buffalo, New York 14203, United States
| | - Peter P Borbat
- National Biomedical Center for Advanced Electron Spin Resonance Technology, Cornell University , Ithaca, New York 14853, United States.,Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Elka R Georgieva
- National Biomedical Center for Advanced Electron Spin Resonance Technology, Cornell University , Ithaca, New York 14853, United States.,Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Jack H Freed
- National Biomedical Center for Advanced Electron Spin Resonance Technology, Cornell University , Ithaca, New York 14853, United States.,Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Michael G Malkowski
- Department of Structural Biology, The State University of New York at Buffalo , Buffalo, New York 14203, United States.,Hauptman-Woodward Medical Research Institute , Buffalo, New York 14203, United States
| |
Collapse
|
9
|
New developments in spin labels for pulsed dipolar EPR. Molecules 2014; 19:16998-7025. [PMID: 25342554 PMCID: PMC6271499 DOI: 10.3390/molecules191016998] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/07/2014] [Accepted: 10/13/2014] [Indexed: 11/17/2022] Open
Abstract
Spin labelling is a chemical technique that enables the integration of a molecule containing an unpaired electron into another framework for study. Given the need to understand the structure, dynamics, and conformational changes of biomacromolecules, spin labelling provides a relatively non-intrusive technique and has certain advantages over X-ray crystallography; which requires high quality crystals. The technique relies on the design of binding probes that target a functional group, for example, the thiol group of a cysteine residue within a protein. The unpaired electron is typically supplied through a nitroxide radical and sterically shielded to preserve stability. Pulsed electron paramagnetic resonance (EPR) techniques allow small magnetic couplings to be measured (e.g., <50 MHz) providing information on single label probes or the dipolar coupling between multiple labels. In particular, distances between spin labels pairs can be derived which has led to many protein/enzymes and nucleotides being studied. Here, we summarise recent examples of spin labels used for pulse EPR that serve to illustrate the contribution of chemistry to advancing discoveries in this field.
Collapse
|
10
|
Pievo R, Angerstein B, Fielding AJ, Koch C, Feussner I, Bennati M. A rapid freeze-quench setup for multi-frequency EPR spectroscopy of enzymatic reactions. Chemphyschem 2013; 14:4094-101. [PMID: 24323853 DOI: 10.1002/cphc.201300714] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/22/2013] [Indexed: 11/11/2022]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy in combination with the rapid freeze-quench (RFQ) technique is a well-established method to trap and characterize intermediates in chemical or enzymatic reactions at the millisecond or even shorter time scales. The method is particularly powerful for mechanistic studies of enzymatic reactions when combined with high-frequency EPR (ν≥90 GHz), which permits the identification of substrate or protein radical intermediates by their electronic g values. In this work, we describe a new custom-designed micro-mix rapid freeze-quench apparatus, for which reagent volumes for biological samples as small as 20 μL are required. The apparatus was implemented with homemade sample collectors appropriate for 9, 34, and 94 GHz EPR capillaries (4, 2, and 0.87 mm outer diameter, respectively) and the performance was evaluated. We demonstrate the application potential of the RFQ apparatus by following the enzymatic reaction of PpoA, a fungal dioxygenase producing hydro(pero)xylated fatty acids. The larger spectral resolution at 94 GHz allows the discernment of structural changes in the EPR spectra, which are not detectable in the same samples at the standard 9 GHz frequency.
Collapse
Affiliation(s)
- Roberta Pievo
- Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077 Göttingen (Germany).
| | | | | | | | | | | |
Collapse
|
11
|
Koch C, Tria G, Fielding AJ, Brodhun F, Valerius O, Feussner K, Braus GH, Svergun DI, Bennati M, Feussner I. A structural model of PpoA derived from SAXS-analysis—Implications for substrate conversion. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1449-57. [DOI: 10.1016/j.bbalip.2013.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 05/29/2013] [Accepted: 06/07/2013] [Indexed: 10/26/2022]
|
12
|
|
13
|
Evaluation of structural features in fungal cytochromes P450 predicted to rule catalytic diversification. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:205-20. [DOI: 10.1016/j.bbapap.2012.09.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 09/17/2012] [Accepted: 09/18/2012] [Indexed: 01/11/2023]
|
14
|
Jernerén F, Oliw EH. The fatty acid 8,11-diol synthase of Aspergillus fumigatus is inhibited by imidazole derivatives and unrelated to PpoB. Lipids 2012; 47:707-17. [PMID: 22544380 DOI: 10.1007/s11745-012-3673-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 04/06/2012] [Indexed: 12/13/2022]
Abstract
(8R)-Hydroperoxy-(9Z,12Z)-octadecadienoic acid (8-HPODE) is formed by aspergilli as an intermediate in biosynthesis of oxylipins with effects on sporulation. 8-HPODE is transformed by separate diol synthases to (5S,8R)-dihydroxy- and (8R,11S)-dihydroxy-(9Z,12Z)-octadecadienoic acids (5,8- and 8,11-DiHODE). The former is formed by the cytochrome P450 (P450) domain of 5,8-linoleate diol synthase (5,8-LDS or PpoA). Our aim was to characterize the 8,11-diol synthase of Aspergillus fumigatus, which is prominent in many strains. The 8,11-diol synthase was soluble and had a larger molecular size (>100 kDa) than most P450. Miconazole, ketoconazole, and 1-benzylimidazole, classical inhibitors of P450, reduced the biosynthesis of 8,11-DiHODE from 8-HPODE (apparent IC(50) values ~0.8, ~5, and ~0.6 μM, respectively), but did not inhibit the biosynthesis of 5,8-DiHODE. Analysis of hydroperoxides of regioisomeric C(18) and C(20) fatty acids showed that the 8,11-diol synthase was specific for certain hydroperoxides with R configuration. The suprafacial hydrogen abstraction and oxygen insertion at C-11 of 8-HPODE was associated with a small deuterium kinetic isotope effect ((H) k (cat)/(D) k (cat) ~1.5), consistent with P450-catalyzed oxidation. The genome of A. fumigatus contains over 70 P450 sequences. The reaction mechanism, size, and solubility of 8,11-diol synthase pointed to PpoB, a homologue of 5,8-LDS, as a possible candidate of this activity. Gene deletion of ppoB of A. fumigatus strains AF:∆ku80 and J272 did not inhibit biosynthesis of 8,11-DiHODE and recombinant PpoB appeared to lack diol synthase activity. We conclude that 8,11-DiHODE is formed from 8-HPODE by a soluble and substrate-specific 8,11-diol synthase with catalytic characteristics of class III P450.
Collapse
Affiliation(s)
- Fredrik Jernerén
- Department of Pharmaceutical Biosciences, Uppsala Biomedical Center, Uppsala University, 75124, Uppsala, Sweden
| | | |
Collapse
|
15
|
Koch C, Fielding AJ, Brodhun F, Bennati M, Feussner I. Linoleic acid positioning in psi factor producing oxygenase A, a fusion protein with an atypical cytochrome P450 activity. FEBS J 2011; 279:1594-606. [DOI: 10.1111/j.1742-4658.2011.08352.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
16
|
Oliw EH, Wennman A, Hoffmann I, Garscha U, Hamberg M, Jernerén F. Stereoselective oxidation of regioisomeric octadecenoic acids by fatty acid dioxygenases. J Lipid Res 2011; 52:1995-2004. [PMID: 21852690 DOI: 10.1194/jlr.m018259] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Seven Z-octadecenoic acids having the double bond located in positions 6Z to 13Z were photooxidized. The resulting hydroperoxy-E-octadecenoic acids [HpOME(E)] were resolved by chiral phase-HPLC-MS, and the absolute configurations of the enantiomers were determined by gas chromatographic analysis of diastereoisomeric derivatives. The MS/MS/MS spectra showed characteristic fragments, which were influenced by the distance between the hydroperoxide and carboxyl groups. These fatty acids were then investigated as substrates of cyclooxygenase-1 (COX-1), manganese lipoxygenase (MnLOX), and the (8R)-dioxygenase (8R-DOX) activities of two linoleate diol synthases (LDS) and 10R-DOX. COX-1 and MnLOX abstracted hydrogen at C-11 of (12Z)-18:1 and C-12 of (13Z)-18:1. (11Z)-18:1 was subject to hydrogen abstraction at C-10 by MnLOX and at both allylic positions by COX-1. Both allylic hydrogens of (8Z)-18:1 were also abstracted by 8R-DOX activities of LDS and 10R-DOX, but only the allylic hydrogens close to the carboxyl groups of (11Z)-18:1 and (12Z)-18:1. 8R-DOX also oxidized monoenoic C(14)-C(20) fatty acids with double bonds at the (9Z) position, suggesting that the length of the omega end has little influence on positioning for oxygenation. We conclude that COX-1 and MnLOX can readily abstract allylic hydrogens of octadecenoic fatty acids from C-10 to C-12 and 8R-DOX from C-7 and C-12.
Collapse
Affiliation(s)
- Ernst H Oliw
- Department of Pharmaceutical Biosciences, Division of Biochemical Pharmacology, Uppsala Biomedical Center, SE-75124, Uppsala, Sweden.
| | | | | | | | | | | |
Collapse
|