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Liew JJM, Wicht DK, Gonzalez R, Dowling DP, Ellis HR. Current understanding of enzyme structure and function in bacterial two-component flavin-dependent desulfonases: Cleaving C-S bonds of organosulfur compounds. Arch Biochem Biophys 2024; 758:110048. [PMID: 38848996 DOI: 10.1016/j.abb.2024.110048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/09/2024]
Abstract
The inherent structural properties of enzymes are critical in defining catalytic function. Often, studies to evaluate the relationship between structure and function are limited to only one defined structural element. The two-component flavin-dependent desulfonase family of enzymes involved in bacterial sulfur acquisition utilize a comprehensive range of structural features to carry out the desulfonation of organosulfur compounds. These metabolically essential two-component FMN-dependent desulfonase systems have been proposed to utilize oligomeric changes, protein-protein interactions for flavin transfer, and common mechanistic steps for carbon-sulfur bond cleavage. This review is focused on our current functional and structural understanding of two-component FMN-dependent desulfonase systems from multiple bacterial sources. Mechanistic and structural comparisons from recent independent studies provide fresh insights into the overall functional properties of these systems and note areas in need of further investigation. The review acknowledges current studies focused on evaluating the structural properties of these enzymes in relationship to their distinct catalytic function. The role of these enzymes in maintaining adequate sulfur levels, coupled with the conserved nature of these enzymes in diverse bacteria, underscore the importance in understanding the functional and structural nuances of these systems.
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Affiliation(s)
- Jeremy J M Liew
- Department of Chemistry, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - Denyce K Wicht
- Department of Biochemistry, Chemistry, Environment, and Physics, Suffolk University, Boston, MA, 02108, USA
| | - Reyaz Gonzalez
- Department of Chemistry, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - Daniel P Dowling
- Department of Chemistry, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - Holly R Ellis
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA.
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2
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Quaye JA, Wood KE, Snelgrove C, Ouedraogo D, Gadda G. An active site mutation induces oxygen reactivity in D-arginine dehydrogenase: A case of superoxide diverting protons. J Biol Chem 2024; 300:107381. [PMID: 38762175 PMCID: PMC11193025 DOI: 10.1016/j.jbc.2024.107381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024] Open
Abstract
Enzymes are potent catalysts that increase biochemical reaction rates by several orders of magnitude. Flavoproteins are a class of enzymes whose classification relies on their ability to react with molecular oxygen (O2) during catalysis using ionizable active site residues. Pseudomonas aeruginosa D-arginine dehydrogenase (PaDADH) is a flavoprotein that oxidizes D-arginine for P. aeruginosa survival and biofilm formation. The crystal structure of PaDADH reveals the interaction of the glutamate 246 (E246) side chain with the substrate and at least three other active site residues, establishing a hydrogen bond network in the active site. Additionally, E246 likely ionizes to facilitate substrate binding during PaDADH catalysis. This study aimed to investigate how replacing the E246 residue with leucine affects PaDADH catalysis and its ability to react with O2 using steady-state kinetics coupled with pH profile studies. The data reveal a gain of O2 reactivity in the E246L variant, resulting in a reduced flavin semiquinone species and superoxide (O2•-) during substrate oxidation. The O2•- reacts with active site protons, resulting in an observed nonstoichiometric slope of 1.5 in the enzyme's log (kcat/Km) pH profile with D-arginine. Adding superoxide dismutase results in an observed correction of the slope to 1.0. This study demonstrates how O2•- can alter the slopes of limbs in the pH profiles of flavin-dependent enzymes and serves as a model for correcting nonstoichiometric slopes in elucidating reaction mechanisms of flavoproteins.
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Affiliation(s)
- Joanna A Quaye
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | - Kendall E Wood
- Biology Department, Morehouse College, Atlanta, Georgia, USA
| | - Claire Snelgrove
- The Gwinnett School of Mathematics, Science, and Technology, Lawrenceville, Georgia, USA
| | - Daniel Ouedraogo
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | - Giovanni Gadda
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA; Department of Biology, Georgia State University, Atlanta, Georgia, USA; Department of the Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, USA.
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3
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Rehpenn A, Hindelang S, Truong KN, Pöthig A, Storch G. Enhancing Flavins Photochemical Activity in Hydrogen Atom Abstraction and Triplet Sensitization through Ring-Contraction. Angew Chem Int Ed Engl 2024; 63:e202318590. [PMID: 38339882 DOI: 10.1002/anie.202318590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
The isoalloxazine heterocycle of flavin cofactors reacts with various nucleophiles to form covalent adducts with important functions in enzymes. Molecular flavin models allow for the characterization of such adducts and the study of their properties. A fascinating set of reactions occurs when flavins react with hydroxide base, which leads to imidazolonequinoxalines, ring-contracted flavins, with so far unexplored activity. We report a systematic study of the photophysical properties of this new chromophore by absorption and emission spectroscopy as well as cyclic voltammetry. Excited, ring-contracted flavins are significantly stronger hydrogen atom abstractors when compared to the parent flavins, which allowed the direct trifluoromethylthiolation of aliphatic methine positions (bond dissociation energy (BDE) of 400.8 kJ mol-1). In an orthogonal activity, their increased triplet energy (E(S0←T1)=244 kJ mol-1) made sensitized reactions possible which exceeded the power of standard flavins. Combining both properties, ring-contracted flavin catalysts enabled the one-pot, five-step transformation of α-tropolone into trans-3,4-disubstituted cyclopentanones. We envision this new class of flavin-derived chromophores to open up new modes of reactivity that are currently impossible with unmodified flavins.
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Affiliation(s)
- Andreas Rehpenn
- Technical University of Munich (TUM), School of Natural Sciences and Catalysis Research Center (CRC), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Stephan Hindelang
- Technical University of Munich (TUM), School of Natural Sciences and Catalysis Research Center (CRC), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Khai-Nghi Truong
- Rigaku Europe SE, Hugenottenallee 167, 63263, Neu-Isenburg, Germany
| | - Alexander Pöthig
- Technical University of Munich (TUM), School of Natural Sciences and Catalysis Research Center (CRC), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Golo Storch
- Technical University of Munich (TUM), School of Natural Sciences and Catalysis Research Center (CRC), Lichtenbergstr. 4, 85747, Garching, Germany
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4
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Zhang Q, Chen Q, Shaik S, Wang B. Flavin-N5OOH Functions as both a Powerful Nucleophile and a Base in the Superfamily of Flavoenzymes. Angew Chem Int Ed Engl 2024; 63:e202318629. [PMID: 38299700 DOI: 10.1002/anie.202318629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 02/02/2024]
Abstract
Flavoenzymes can mediate a large variety of oxidation reactions through the activation of oxygen. However, the O2 activation chemistry of flavin enzymes is not yet fully exploited. Normally, the O2 activation occurs at the C4a site of the flavin cofactor, yielding the flavin C4a-(hydro)hydroperoxyl species in monooxygenases or oxidases. Using extensive MD simulations, QM/MM calculations and QM calculations, our studies reveal the formation of the common nucleophilic species, Flavin-N5OOH, in two distinct flavoenzymes (RutA and EncM). Our studies show that Flavin-N5OOH acts as a powerful nucleophile that promotes C-N cleavage of uracil in RutA, and a powerful base in the deprotonation of substrates in EncM. We reason that Flavin-N5OOH can be a common reactive species in the superfamily of flavoenzymes, which accomplish generally selective general base catalysis and C-X (X=N, S, Cl, O) cleavage reactions that are otherwise challenging with solvated hydroxide ion base. These results expand our understanding of the chemistry and catalysis of flavoenzymes.
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Affiliation(s)
- Qiaoyu Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Qianqian Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Sason Shaik
- Institute of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
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5
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Liu L, Huang B, Lu Y, Zhao Y, Tang X, Shi Y. Interactions between electromagnetic radiation and biological systems. iScience 2024; 27:109201. [PMID: 38433903 PMCID: PMC10906530 DOI: 10.1016/j.isci.2024.109201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2024] Open
Abstract
Even though the bioeffects of electromagnetic radiation (EMR) have been extensively investigated during the past several decades, our understandings of the bioeffects of EMR and the mechanisms of the interactions between the biological systems and the EMRs are still far from satisfactory. In this article, we introduce and summarize the consensus, controversy, limitations, and unsolved issues. The published works have investigated the EMR effects on different biological systems including humans, animals, cells, and biochemical reactions. Alternative methodologies also include dielectric spectroscopy, detection of bioelectromagnetic emissions, and theoretical predictions. In many studies, the thermal effects of the EMR are not properly controlled or considered. The frequency of the EMR investigated is limited to the commonly used bands, particularly the frequencies of the power line and the wireless communications; far fewer studies were performed for other EMR frequencies. In addition, the bioeffects of the complex EM environment were rarely discussed. In summary, our understanding of the bioeffects of the EMR is quite restrictive and further investigations are needed to answer the unsolved questions.
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Affiliation(s)
- Lingyu Liu
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Bing Huang
- Brain Function and Disease Laboratory, Department of Pharmacology, Shantou University Medical College, 22 Xin-Ling Road, Shantou 515041, China
| | - Yingxian Lu
- Westlake Laboratory of Life Sciences and Biomedicine, Xihu District, Hangzhou 310024, Zhejiang Province, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Yanyu Zhao
- Westlake Laboratory of Life Sciences and Biomedicine, Xihu District, Hangzhou 310024, Zhejiang Province, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Xiaping Tang
- Westlake Laboratory of Life Sciences and Biomedicine, Xihu District, Hangzhou 310024, Zhejiang Province, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Westlake Laboratory of Life Sciences and Biomedicine, Xihu District, Hangzhou 310024, Zhejiang Province, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
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6
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Willetts A. The Role of Dioxygen in Microbial Bio-Oxygenation: Challenging Biochemistry, Illustrated by a Short History of a Long Misunderstood Enzyme. Microorganisms 2024; 12:389. [PMID: 38399793 PMCID: PMC10891995 DOI: 10.3390/microorganisms12020389] [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: 01/02/2024] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
A Special Issue of Microorganisms devoted to 'Microbial Biocatalysis and Biodegradation' would be incomplete without some form of acknowledgement of the many important roles that dioxygen-dependent enzymes (principally mono- and dioxygenases) play in relevant aspects of bio-oxygenation. This is reflected by the multiple strategic roles that dioxygen -dependent microbial enzymes play both in generating valuable synthons for chemoenzymatic synthesis and in facilitating reactions that help to drive the global geochemical carbon cycle. A useful insight into this can be gained by reviewing the evolution of the current status of 2,5-diketocamphane 1,2-monooxygenase (EC 1.14.14.108) from (+)-camphor-grown Pseudomonas putida ATCC 17453, the key enzyme that promotes the initial ring cleavage of this natural bicyclic terpene. Over the last sixty years, the perceived nature of this monooxygenase has transmogrified significantly. Commencing in the 1960s, extensive initial studies consistently reported that the enzyme was a monomeric true flavoprotein dependent on both FMNH2 and nonheme iron as bound cofactors. However, over the last decade, all those criteria have changed absolutely, and the enzyme is currently acknowledged to be a metal ion-independent homodimeric flavin-dependent two-component mono-oxygenase deploying FMNH2 as a cosubstrate. That transition is a paradigm of the ever evolving nature of scientific knowledge.
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Affiliation(s)
- Andrew Willetts
- 4 Sv Ivan, 21400 Sutivan, Croatia;
- Curnow Consultancies, Helston TR13 9PQ, UK
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7
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Austvold CK, Keable SM, Procopio M, Usselman RJ. Quantitative measurements of reactive oxygen species partitioning in electron transfer flavoenzyme magnetic field sensing. Front Physiol 2024; 15:1348395. [PMID: 38370016 PMCID: PMC10869518 DOI: 10.3389/fphys.2024.1348395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
Biological magnetic field sensing that gives rise to physiological responses is of considerable importance in quantum biology. The radical pair mechanism (RPM) is a fundamental quantum process that can explain some of the observed biological magnetic effects. In magnetically sensitive radical pair (RP) reactions, coherent spin dynamics between singlet and triplet pairs are modulated by weak magnetic fields. The resulting singlet and triplet reaction products lead to distinct biological signaling channels and cellular outcomes. A prevalent RP in biology is between flavin semiquinone and superoxide (O2 •-) in the biological activation of molecular oxygen. This RP can result in a partitioning of reactive oxygen species (ROS) products to form either O2 •- or hydrogen peroxide (H2O2). Here, we examine magnetic sensing of recombinant human electron transfer flavoenzyme (ETF) reoxidation by selectively measuring O2 •- and H2O2 product distributions. ROS partitioning was observed between two static magnetic fields at 20 nT and 50 μT, with a 13% decrease in H2O2 singlet products and a 10% increase in O2 •- triplet products relative to 50 µT. RPM product yields were calculated for a realistic flavin/superoxide RP across the range of static magnetic fields, in agreement with experimental results. For a triplet born RP, the RPM also predicts about three times more O2 •- than H2O2, with experimental results exhibiting about four time more O2 •- produced by ETF. The method presented here illustrates the potential of a novel magnetic flavoprotein biological sensor that is directly linked to mitochondria bioenergetics and can be used as a target to study cell physiology.
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Affiliation(s)
- Chase K. Austvold
- Chemistry and Biochemistry, Montana State University, Bozeman, MT, United States
| | - Stephen M. Keable
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Maria Procopio
- Biophysics, Johns Hopkins University, Baltimore, MD, United States
| | - Robert J. Usselman
- Chemistry and Chemical Engineering, Florida Institute of Technology, Melbourne, FL, United States
- Computational Research At Florida Tech, Melbourne, FL, United States
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8
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Ford KC, TerAvest MA. The electron transport chain of Shewanella oneidensis MR-1 can operate bidirectionally to enable microbial electrosynthesis. Appl Environ Microbiol 2024; 90:e0138723. [PMID: 38117056 PMCID: PMC10807441 DOI: 10.1128/aem.01387-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/13/2023] [Indexed: 12/21/2023] Open
Abstract
Extracellular electron transfer is a process by which bacterial cells can exchange electrons with a redox-active material located outside of the cell. In Shewanella oneidensis, this process is natively used to facilitate respiration using extracellular electron acceptors such as Fe(III) or an anode. Previously, it was demonstrated that this process can be used to drive the microbial electrosynthesis (MES) of 2,3-butanediol (2,3-BDO) in S. oneidensis exogenously expressing butanediol dehydrogenase (BDH). Electrons taken into the cell from a cathode are used to generate NADH, which in turn is used to reduce acetoin to 2,3-BDO via BDH. However, generating NADH via electron uptake from a cathode is energetically unfavorable, so NADH dehydrogenases couple the reaction to proton motive force. We therefore need to maintain the proton gradient across the membrane to sustain NADH production. This work explores accomplishing this task by bidirectional electron transfer, where electrons provided by the cathode go to both NADH formation and oxygen (O2) reduction by oxidases. We show that oxidases use trace dissolved oxygen in a microaerobic bioelectrical chemical system (BES), and the translocation of protons across the membrane during O2 reduction supports 2,3-BDO generation. Interestingly, this process is inhibited by high levels of dissolved oxygen in this system. In an aerated BES, O2 molecules react with the strong reductant (cathode) to form reactive oxygen species, resulting in cell death.IMPORTANCEMicrobial electrosynthesis (MES) is increasingly employed for the generation of specialty chemicals, such as biofuels, bioplastics, and cancer therapeutics. For these systems to be viable for industrial scale-up, it is important to understand the energetic requirements of the bacteria to mitigate unnecessary costs. This work demonstrates sustained production of an industrially relevant chemical driven by a cathode. Additionally, it optimizes a previously published system by removing any requirement for phototrophic energy, thereby removing the additional cost of providing a light source. We also demonstrate the severe impact of oxygen intrusion into bioelectrochemical systems, offering insight to future researchers aiming to work in an anaerobic environment. These studies provide insight into both the thermodynamics of electrosynthesis and the importance of the bioelectrochemical systems' design.
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Affiliation(s)
- Kathryne C. Ford
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Michaela A. TerAvest
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
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9
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Vecheck AM, McNamee CM, Reijo Pera R, Usselman RJ. Magnetic Field Intervention Enhances Cellular Migration Rates in Biological Scaffolds. Bioengineering (Basel) 2023; 11:9. [PMID: 38247887 PMCID: PMC10813414 DOI: 10.3390/bioengineering11010009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/15/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024] Open
Abstract
The impact of magnetic fields on cellular function is diverse but can be described at least in part by the radical pair mechanism (RPM), where magnetic field intervention alters reactive oxygen species (ROS) populations and downstream cellular signaling. Here, cellular migration within three-dimensional scaffolds was monitored in an applied oscillating 1.4 MHz radiofrequency (RF) magnetic field with an amplitude of 10 µT and a static 50 µT magnetic field. Given that cellular bioenergetics can be altered based on applied RF magnetic fields, this study focused on a magnetic field configuration that increased cellular respiration. Results suggest that RF accelerated cell clustering and elongation after 1 day, with increased levels of clustering and cellular linkage after 7 days. Cell distribution analysis within the scaffolds revealed that the clustering rate during the first day was increased nearly five times in the RF environment. Electron microscopy provided additional topological information and verified the development of fibrous networks, with a cell-derived matrix (CDM) visualized after 7 days in samples maintained in RF. This work demonstrates time-dependent cellular migration that may be influenced by quantum biology (QB) processes and downstream oxidative signaling, enhancing cellular migration behavior.
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Affiliation(s)
- Amy M. Vecheck
- Department of Biomedical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA
| | - Cameron M. McNamee
- Department of Mathematics, California Institute of Technology, Pasadena, CA 91125, USA
- McLaughlin Research Institute, Great Falls, MT 59405, USA
| | | | - Robert J. Usselman
- Department of Chemistry and Chemical Engineering, Florida Institute of Technology, Melbourne, FL 32901, USA
- Computational Research At Florida Tech (CRAFT), Florida Institute of Technology, Melbourne, FL 32901, USA
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10
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Chalifoux O, Faerman B, Mailloux RJ. Mitochondrial hydrogen peroxide production by pyruvate dehydrogenase and α-ketoglutarate dehydrogenase in oxidative eustress and oxidative distress. J Biol Chem 2023; 299:105399. [PMID: 37898400 PMCID: PMC10692731 DOI: 10.1016/j.jbc.2023.105399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/06/2023] [Accepted: 10/16/2023] [Indexed: 10/30/2023] Open
Abstract
Pyruvate dehydrogenase (PDH) and α-ketoglutarate dehydrogenase (KGDH) are vital entry points for monosaccharides and amino acids into the Krebs cycle and thus integral for mitochondrial bioenergetics. Both complexes produce mitochondrial hydrogen peroxide (mH2O2) and are deactivated by electrophiles. Here, we provide an update on the role of PDH and KGDH in mitochondrial redox balance and their function in facilitating metabolic reprogramming for the propagation of oxidative eustress signals in hepatocytes and how defects in these pathways can cause liver diseases. PDH and KGDH are known to account for ∼45% of the total mH2O2 formed by mitochondria and display rates of production several-fold higher than the canonical source complex I. This mH2O2 can also be formed by reverse electron transfer (RET) in vivo, which has been linked to metabolic dysfunctions that occur in pathogenesis. However, the controlled emission of mH2O2 from PDH and KGDH has been proposed to be fundamental for oxidative eustress signal propagation in several cellular contexts. Modification of PDH and KGDH with protein S-glutathionylation (PSSG) and S-nitrosylation (PSNO) adducts serves as a feedback inhibitor for mH2O2 production in response to glutathione (GSH) pool oxidation. PSSG and PSNO adduct formation also reprogram the Krebs cycle to generate metabolites vital for interorganelle and intercellular signaling. Defects in the redox modification of PDH and KGDH cause the over generation of mH2O2, resulting in oxidative distress and metabolic dysfunction-associated fatty liver disease (MAFLD). In aggregate, PDH and KGDH are essential platforms for emitting and receiving oxidative eustress signals.
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Affiliation(s)
- Olivia Chalifoux
- Faculty of Agricultural and Environmental Sciences, The School of Human Nutrition, McGill University, Ste.-Anne-de-Bellevue, Quebec, Canada
| | - Ben Faerman
- Faculty of Agricultural and Environmental Sciences, The School of Human Nutrition, McGill University, Ste.-Anne-de-Bellevue, Quebec, Canada
| | - Ryan J Mailloux
- Faculty of Agricultural and Environmental Sciences, The School of Human Nutrition, McGill University, Ste.-Anne-de-Bellevue, Quebec, Canada.
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11
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Phintha A, Chaiyen P. Unifying and versatile features of flavin-dependent monooxygenases: Diverse catalysis by a common C4a-(hydro)peroxyflavin. J Biol Chem 2023; 299:105413. [PMID: 37918809 PMCID: PMC10696468 DOI: 10.1016/j.jbc.2023.105413] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/18/2023] [Accepted: 10/22/2023] [Indexed: 11/04/2023] Open
Abstract
Flavin-dependent monooxygenases (FDMOs) are known for their remarkable versatility and for their crucial roles in various biological processes and applications. Extensive research has been conducted to explore the structural and functional relationships of FDMOs. The majority of reported FDMOs utilize C4a-(hydro)peroxyflavin as a reactive intermediate to incorporate an oxygen atom into a wide range of compounds. This review discusses and analyzes recent advancements in our understanding of the structural and mechanistic features governing the enzyme functions. State-of-the-art discoveries related to common and distinct structural properties governing the catalytic versatility of the C4a-(hydro)peroxyflavin intermediate in selected FDMOs are discussed. Specifically, mechanisms of hydroxylation, dehalogenation, halogenation, and light-emitting reactions by FDMOs are highlighted. We also provide new analysis based on the structural and mechanistic features of these enzymes to gain insights into how the same intermediate can be harnessed to perform a wide variety of reactions. Challenging questions to obtain further breakthroughs in the understanding of FDMOs are also proposed.
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Affiliation(s)
- Aisaraphon Phintha
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley, Rayong, Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley, Rayong, Thailand.
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12
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Salerno KM, Domenico J, Le NQ, Balakrishnan K, McQuillen RJ, Stiles CD, Solov'yov IA, Martino CF. Long-Time Oxygen and Superoxide Localization in Arabidopsis thaliana Cryptochrome. J Chem Inf Model 2023; 63:6756-6767. [PMID: 37874902 DOI: 10.1021/acs.jcim.3c00325] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Cryptochromes are proteins that are highly conserved across species and in many instances bind the flavin adenine dinucleotide (FAD) cofactor within their photolyase-homology region (PHR) domain. The FAD cofactor has multiple redox states that help catalyze reactions, and absorbs photons at about 450 nm, a feature linked to the light-related functions of cryptochrome proteins. Reactive oxygen species (ROS) are produced from redox reactions involving molecular oxygen and are involved in a myriad of biological processes. Superoxide O2•- is an exemplary ROS that may be formed through electron transfer from FAD to O2, generating an electron radical pair. Although the formation of a superoxide-FAD radical pair has been speculated, it is still unclear if the required process steps could be realized in cryptochrome. Here, we present results from molecular dynamics (MD) simulations of oxygen interacting with the PHR domain of Arabidopsis thaliana cryptochrome 1 (AtCRY1). Using MD simulation trajectories, oxygen binding locations are characterized through both the O2-FAD intermolecular distance and the local protein environment. Oxygen unbinding times are characterized through replica simulations of the bound oxygen. Simulations reveal that oxygen molecules can localize at certain sites within the cryptochrome protein for tens of nanoseconds, and superoxide molecules can localize for significantly longer. This relatively long-duration molecule binding suggests the possibility of an electron-transfer reaction leading to superoxide formation. Estimates of electron-transfer rates using the Marcus theory are performed for the identified potential binding sites. Molecular oxygen binding results are compared with recent results demonstrating long-time oxygen binding within the electron-transfer flavoprotein (ETF), another FAD binding protein.
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Affiliation(s)
- K Michael Salerno
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Janna Domenico
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Nam Q Le
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Krithika Balakrishnan
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Ryan J McQuillen
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Christopher D Stiles
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
| | - Ilia A Solov'yov
- Institute of Physics, Carl von Ossietzky University Oldenburg, Carl von Ossietzky Straße 9-11, 26129 Oldenburg, Germany
- Centre for Nanoscale Dynamics (CENAD), Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Straße 9-11, 26129 Oldenburg, Germany
- Centre for Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Straße 9-11, 26129 Oldenburg, Germany
| | - Carlos F Martino
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States
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13
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Dulchavsky M, Mitra R, Wu K, Li J, Boer K, Liu X, Zhang Z, Vasquez C, Clark CT, Funckes K, Shankar K, Bonnet-Zahedi S, Siddiq M, Sepulveda Y, Suhandynata RT, Momper JD, Calabrese AN, George O, Stull F, Bardwell JCA. Directed evolution unlocks oxygen reactivity for a nicotine-degrading flavoenzyme. Nat Chem Biol 2023; 19:1406-1414. [PMID: 37770699 PMCID: PMC10611581 DOI: 10.1038/s41589-023-01426-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 08/23/2023] [Indexed: 09/30/2023]
Abstract
The flavoenzyme nicotine oxidoreductase (NicA2) is a promising injectable treatment to aid in the cessation of smoking, a behavior responsible for one in ten deaths worldwide. NicA2 acts by degrading nicotine in the bloodstream before it reaches the brain. Clinical use of NicA2 is limited by its poor catalytic activity in the absence of its natural electron acceptor CycN. Without CycN, NicA2 is instead oxidized slowly by dioxygen (O2), necessitating unfeasibly large doses in a therapeutic setting. Here, we report a genetic selection strategy that directly links CycN-independent activity of NicA2 to growth of Pseudomonas putida S16. This selection enabled us to evolve NicA2 variants with substantial improvement in their rate of oxidation by O2. The encoded mutations cluster around a putative O2 tunnel, increasing flexibility and accessibility to O2 in this region. These mutations further confer desirable clinical properties. A variant form of NicA2 is tenfold more effective than the wild type at degrading nicotine in the bloodstream of rats.
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Affiliation(s)
- Mark Dulchavsky
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Rishav Mitra
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Kevin Wu
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Joshua Li
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Karli Boer
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - Xiaomeng Liu
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Zhiyao Zhang
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - Cristian Vasquez
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | | | - Kaitrin Funckes
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - Kokila Shankar
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Selene Bonnet-Zahedi
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Mohammad Siddiq
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Yadira Sepulveda
- School of Pharmacy and Pharmaceutical Science, University of California, San Diego, La Jolla, CA, USA
| | - Raymond T Suhandynata
- School of Pharmacy and Pharmaceutical Science, University of California, San Diego, La Jolla, CA, USA
- Department of Pathology, University of California, San Diego, La Jolla, CA, USA
| | - Jeremiah D Momper
- School of Pharmacy and Pharmaceutical Science, University of California, San Diego, La Jolla, CA, USA
| | - Antonio N Calabrese
- Astbury Centre for Structural Molecular Biology, S chool of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Olivier George
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Frederick Stull
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - James C A Bardwell
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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14
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Minerdi D, Loqui D, Sabbatini P. Monooxygenases and Antibiotic Resistance: A Focus on Carbapenems. BIOLOGY 2023; 12:1316. [PMID: 37887026 PMCID: PMC10604202 DOI: 10.3390/biology12101316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/08/2023] [Accepted: 09/15/2023] [Indexed: 10/28/2023]
Abstract
Carbapenems are a group of broad-spectrum beta-lactam antibiotics that in many cases are the last effective defense against infections caused by multidrug-resistant bacteria, such as some strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Resistance to carbapenems has emerged and is beginning to spread, becoming an ongoing public-health problem of global dimensions, causing serious outbreaks, and dramatically limiting treatment options. This paper reviews the role of flavin monooxygenases in antibiotic resistance, with a specific focus on carbapenem resistance and the recently discovered mechanism mediated by Baeyer-Villiger monooxygenases. Flavin monooxygenases are enzymes involved in the metabolism and detoxification of compounds, including antibiotics. Understanding their role in antibiotic resistance is crucial. Carbapenems are powerful antibiotics used to treat severe infections caused by multidrug-resistant bacteria. However, the rise of carbapenem-resistant strains poses a significant challenge. This paper explores the mechanisms by which flavin monooxygenases confer resistance to carbapenems, examining molecular pathways and genetic factors. Additionally, this paper highlights the discovery of Baeyer-Villiger monooxygenases' involvement in antibiotic resistance. These enzymes catalyze the insertion of oxygen atoms into specific chemical bonds. Recent studies have revealed their unexpected role in promoting carbapenem resistance. Through a comprehensive analysis of the literature, this paper contributes to the understanding of the interplay between flavin monooxygenases, carbapenem resistance, and Baeyer-Villiger monooxygenases. By exploring these mechanisms, it aims to inform the development of strategies to combat antibiotic resistance, a critical global health concern.
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Affiliation(s)
- Daniela Minerdi
- Department of Agricultural, Forestry and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, TO, Italy;
| | - Davide Loqui
- Emergency Department, Città della Salute e della Scienza of Turin, 10100 Turin, TO, Italy;
| | - Paolo Sabbatini
- Department of Agricultural, Forestry and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, TO, Italy;
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15
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Wang Q, Liu N, Deng Y, Guan Y, Xiao H, Nitka TA, Yang H, Yadav A, Vukovic L, Mathews II, Chen X, Kim CY. Triepoxide formation by a flavin-dependent monooxygenase in monensin biosynthesis. Nat Commun 2023; 14:6273. [PMID: 37805629 PMCID: PMC10560226 DOI: 10.1038/s41467-023-41889-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 09/18/2023] [Indexed: 10/09/2023] Open
Abstract
Monensin A is a prototypical natural polyether polyketide antibiotic. It acts by binding a metal cation and facilitating its transport across the cell membrane. Biosynthesis of monensin A involves construction of a polyene polyketide backbone, subsequent epoxidation of the alkenes, and, lastly, formation of cyclic ethers via epoxide-opening cyclization. MonCI, a flavin-dependent monooxygenase, is thought to transform all three alkenes in the intermediate polyketide premonensin A into epoxides. Our crystallographic study has revealed that MonCI's exquisite stereocontrol is due to the preorganization of the active site residues which allows only one specific face of the alkene to approach the reactive C(4a)-hydroperoxyflavin moiety. Furthermore, MonCI has an unusually large substrate-binding cavity that can accommodate premonensin A in an extended or folded conformation which allows any of the three alkenes to be placed next to C(4a)-hydroperoxyflavin. MonCI, with its ability to perform multiple epoxidations on the same substrate in a stereospecific manner, demonstrates the extraordinary versatility of the flavin-dependent monooxygenase family of enzymes.
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Affiliation(s)
- Qian Wang
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA
| | - Ning Liu
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Yaming Deng
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Yuze Guan
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Hongli Xiao
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Tara A Nitka
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA
| | - Hui Yang
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Anju Yadav
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA
| | - Lela Vukovic
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA
| | - Irimpan I Mathews
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 95124, USA
| | - Xi Chen
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China.
| | - Chu-Young Kim
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA.
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA.
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16
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Hosokawa Y, Morita H, Nakamura M, Yamamoto J. A deazariboflavin chromophore kinetically stabilizes reduced FAD state in a bifunctional cryptochrome. Sci Rep 2023; 13:16682. [PMID: 37794070 PMCID: PMC10551024 DOI: 10.1038/s41598-023-43930-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 09/30/2023] [Indexed: 10/06/2023] Open
Abstract
An animal-like cryptochrome derived from Chlamydomonas reinhardtii (CraCRY) is a bifunctional flavoenzyme harboring flavin adenine dinucleotide (FAD) as a photoreceptive/catalytic center and functions both in the regulation of gene transcription and the repair of UV-induced DNA lesions in a light-dependent manner, using different FAD redox states. To address how CraCRY stabilizes the physiologically relevant redox state of FAD, we investigated the thermodynamic and kinetic stability of the two-electron reduced anionic FAD state (FADH-) in CraCRY and related (6-4) photolyases. The thermodynamic stability of FADH- remained almost the same compared to that of all tested proteins. However, the kinetic stability of FADH- varied remarkably depending on the local structure of the secondary pocket, where an auxiliary chromophore, 8-hydroxy-7,8-didemethyl-5-deazariboflavin (8-HDF), can be accommodated. The observed effect of 8-HDF uptake on the enhancement of the kinetic stability of FADH- suggests an essential role of 8-HDF in the bifunctionality of CraCRY.
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Affiliation(s)
- Yuhei Hosokawa
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
| | - Hiroyoshi Morita
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
| | - Mai Nakamura
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
| | - Junpei Yamamoto
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan.
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17
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Abstract
Endogenous photosensitizers play a critical role in both beneficial and harmful light-induced transformations in biological systems. Understanding their mode of action is essential for advancing fields such as photomedicine, photoredox catalysis, environmental science, and the development of sun care products. This review offers a comprehensive analysis of endogenous photosensitizers in human skin, investigating the connections between their electronic excitation and the subsequent activation or damage of organic biomolecules. We gather the physicochemical and photochemical properties of key endogenous photosensitizers and examine the relationships between their chemical reactivity, location within the skin, and the primary biochemical events following solar radiation exposure, along with their influence on skin physiology and pathology. An important take-home message of this review is that photosensitization allows visible light and UV-A radiation to have large effects on skin. The analysis presented here unveils potential causes for the continuous increase in global skin cancer cases and emphasizes the limitations of current sun protection approaches.
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Affiliation(s)
- Erick L Bastos
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, São Paulo, Brazil
| | - Frank H Quina
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, São Paulo, Brazil
- Department of Chemical Engineering, Polytechnic School, University of São Paulo, 05508-000 São Paulo, São Paulo, Brazil
| | - Maurício S Baptista
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, São Paulo, Brazil
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18
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Minas HA, François RMM, Hemmerling F, Fraley AE, Dieterich CL, Rüdisser SH, Meoded RA, Collin S, Weissman KJ, Gruez A, Piel J. Modular Oxime Formation by a trans-AT Polyketide Synthase. Angew Chem Int Ed Engl 2023; 62:e202304481. [PMID: 37216334 DOI: 10.1002/anie.202304481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/16/2023] [Accepted: 05/22/2023] [Indexed: 05/24/2023]
Abstract
Modular trans-acyltransferase polyketide synthases (trans-AT PKSs) are enzymatic assembly lines that biosynthesize complex polyketide natural products. Relative to their better studied cis-AT counterparts, the trans-AT PKSs introduce remarkable chemical diversity into their polyketide products. A notable example is the lobatamide A PKS, which incorporates a methylated oxime. Here we demonstrate biochemically that this functionality is installed on-line by an unusual oxygenase-containing bimodule. Furthermore, analysis of the oxygenase crystal structure coupled with site-directed mutagenesis allows us to propose a model for catalysis, as well as identifying key protein-protein interactions that support this chemistry. Overall, our work adds oxime-forming machinery to the biomolecular toolbox available for trans-AT PKS engineering, opening the way to introducing such masked aldehyde functionalities into diverse polyketides.
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Affiliation(s)
- Hannah A Minas
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Romain M M François
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
- Université de Lorraine, CNRS, IMoPA, 54000, Nancy, France
| | - Franziska Hemmerling
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Amy E Fraley
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Cora L Dieterich
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Simon H Rüdisser
- Institute of Molecular Biology and Biophysics, Biomolecular NMR Spectroscopy Platform, Eidgenössische Technische Hochschule (ETH) Zürich, Hönggerbergring 64, 8093, Zürich, Switzerland
| | - Roy A Meoded
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
| | - Sabrina Collin
- Université de Lorraine, CNRS, IMoPA, 54000, Nancy, France
| | | | - Arnaud Gruez
- Université de Lorraine, CNRS, IMoPA, 54000, Nancy, France
| | - Jörn Piel
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
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19
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Kozuleva MA, Ivanov BN. Superoxide Anion Radical Generation in Photosynthetic Electron Transport Chain. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1045-1060. [PMID: 37758306 DOI: 10.1134/s0006297923080011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/16/2023] [Accepted: 06/18/2023] [Indexed: 10/03/2023]
Abstract
This review analyzes data available in the literature on the rates, characteristics, and mechanisms of oxygen reduction to a superoxide anion radical at the sites of photosynthetic electron transport chain where this reduction has been established. The existing assumptions about the role of the components of these sites in this process are critically examined using thermodynamic approaches and results of the recent studies. The process of O2 reduction at the acceptor side of PSI, which is considered the main site of this process taking place in the photosynthetic chain, is described in detail. Evolution of photosynthetic apparatus in the context of controlling the leakage of electrons to O2 is explored. The reasons limiting application of the results obtained with the isolated segments of the photosynthetic chain to estimate the rates of O2 reduction at the corresponding sites in the intact thylakoid membrane are discussed.
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Affiliation(s)
- Marina A Kozuleva
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| | - Boris N Ivanov
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
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20
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Goetzman E, Gong Z, Zhang B, Muzumdar R. Complex II Biology in Aging, Health, and Disease. Antioxidants (Basel) 2023; 12:1477. [PMID: 37508015 PMCID: PMC10376733 DOI: 10.3390/antiox12071477] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/11/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
Aging is associated with a decline in mitochondrial function which may contribute to age-related diseases such as neurodegeneration, cancer, and cardiovascular diseases. Recently, mitochondrial Complex II has emerged as an important player in the aging process. Mitochondrial Complex II converts succinate to fumarate and plays an essential role in both the tricarboxylic acid (TCA) cycle and the electron transport chain (ETC). The dysfunction of Complex II not only limits mitochondrial energy production; it may also promote oxidative stress, contributing, over time, to cellular damage, aging, and disease. Intriguingly, succinate, the substrate for Complex II which accumulates during mitochondrial dysfunction, has been shown to have widespread effects as a signaling molecule. Here, we review recent advances related to understanding the function of Complex II, succinate signaling, and their combined roles in aging and aging-related diseases.
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Affiliation(s)
- Eric Goetzman
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Zhenwei Gong
- Division of Endocrinology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Bob Zhang
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Radhika Muzumdar
- Division of Endocrinology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA 15260, USA
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21
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Tong Y, Rozeboom HJ, Loonstra MR, Wijma HJ, Fraaije MW. Characterization of two bacterial multi-flavinylated proteins harboring multiple covalent flavin cofactors. BBA ADVANCES 2023; 4:100097. [PMID: 37455753 PMCID: PMC10339131 DOI: 10.1016/j.bbadva.2023.100097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/27/2023] [Accepted: 07/03/2023] [Indexed: 07/18/2023] Open
Abstract
In recent years, studies have shown that a large number of bacteria secrete multi-flavinylated proteins. The exact roles and properties, of these extracellular flavoproteins that contain multiple covalently anchored FMN cofactors, are still largely unknown. Herein, we describe the biochemical and structural characterization of two multi-FMN-containing covalent flavoproteins, SaFMN3 from Streptomyces azureus and CbFMN4 from Clostridiaceae bacterium. Based on their primary structure, these proteins were predicted to contain three and four covalently tethered FMN cofactors, respectively. The genes encoding SaFMN3 and CbFMN4 were heterologously coexpressed with a flavin transferase (ApbE) in Escherichia coli, and could be purified by affinity chromatography in good yields. Both proteins were found to be soluble and to contain covalently bound FMN molecules. The SaFMN3 protein was studied in more detail and found to display a single redox potential (-184 mV) while harboring three covalently attached flavins. This is in line with the high sequence similarity when the domains of each flavoprotein are compared. The fully reduced form of SaFMN3 is able to use dioxygen as electron acceptor. Single domains from both proteins were expressed, purified and crystallized. The crystal structures were elucidated, which confirmed that the flavin cofactor is covalently attached to a threonine. Comparison of both crystal structures revealed a high similarity, even in the flavin binding pocket. Based on the crystal structure, mutants of the SaFMN3-D2 domain were designed to improve its fluorescence quantum yield by changing the microenvironment of the isoalloxazine moiety of the flavin cofactor. Residues that quench the flavin fluorescence were successfully identified. Our study reveals biochemical details of multi-FMN-containing proteins, contributing to a better understanding of their role in bacteria and providing leads to future utilization of these flavoprotein in biotechnology.
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22
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Zhou B, Gabbaï FP. Four-Electron Reduction of O 2 Using Distibines in the Presence of ortho-Quinones. J Am Chem Soc 2023; 145:13758-13767. [PMID: 37306561 PMCID: PMC10863049 DOI: 10.1021/jacs.3c02223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Indexed: 06/13/2023]
Abstract
This study, which aims to identify atypical platforms for the reduction of dioxygen, describes the reaction of O2 with two distibines, namely, 4,5-bis(diphenylstibino)-2,7-di-tert-butyl-9,9-dimethylxanthene and 4,5-bis(diphenylstibino)-2,7-di-tert-butyl-9,9-dimethyldihydroacridine, in the presence of an ortho-quinone such as phenanthraquinone. The reaction proceeds by oxidation of the two antimony atoms to the + V state in concert with reductive cleavage of the O2 molecule. As confirmed by 18O labeling experiments, the two resulting oxo units combine with the ortho-quinone to form an α,α,β,β-tetraolate ligand that bridges the two antimony(V) centers. This process, which has been studied both experimentally and computationally, involves the formation of asymmetric, mixed-valent derivatives featuring a stibine as well as a catecholatostiborane formed by oxidative addition of the quinone to only one of the antimony centers. Under aerobic conditions, the catecholatostiborane moiety reacts with O2 to form a semiquinone/peroxoantimony intermediate, as supported by NMR spectroscopy in the case of the dimethyldihydroacridine derivative. These intermediates swiftly evolve into the symmetrical bis(antimony(V)) α,α,β,β-tetraolate complexes via low barrier processes. Finally, the controlled protonolysis and reduction of the bis(antimony(V)) α,α,β,β-tetraolate complex based on the 9,9-dimethylxanthene platform have been investigated and shown to regenerate the starting distibine and the ortho-quinone. More importantly, these last reactions also produce two equivalents of water as the product of O2 reduction.
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Affiliation(s)
- Benyu Zhou
- Texas A&M University, Department of Chemistry, College
Station, Texas 77843, United States
| | - François P. Gabbaï
- Texas A&M University, Department of Chemistry, College
Station, Texas 77843, United States
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23
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Emmanuel MA, Bender SG, Bilodeau C, Carceller JM, DeHovitz JS, Fu H, Liu Y, Nicholls BT, Ouyang Y, Page CG, Qiao T, Raps FC, Sorigué DR, Sun SZ, Turek-Herman J, Ye Y, Rivas-Souchet A, Cao J, Hyster TK. Photobiocatalytic Strategies for Organic Synthesis. Chem Rev 2023; 123:5459-5520. [PMID: 37115521 PMCID: PMC10905417 DOI: 10.1021/acs.chemrev.2c00767] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Biocatalysis has revolutionized chemical synthesis, providing sustainable methods for preparing various organic molecules. In enzyme-mediated organic synthesis, most reactions involve molecules operating from their ground states. Over the past 25 years, there has been an increased interest in enzymatic processes that utilize electronically excited states accessed through photoexcitation. These photobiocatalytic processes involve a diverse array of reaction mechanisms that are complementary to one another. This comprehensive review will describe the state-of-the-art strategies in photobiocatalysis for organic synthesis until December 2022. Apart from reviewing the relevant literature, a central goal of this review is to delineate the mechanistic differences between the general strategies employed in the field. We will organize this review based on the relationship between the photochemical step and the enzymatic transformations. The review will include mechanistic studies, substrate scopes, and protein optimization strategies. By clearly defining mechanistically-distinct strategies in photobiocatalytic chemistry, we hope to illuminate future synthetic opportunities in the area.
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Affiliation(s)
- Megan A Emmanuel
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Sophie G Bender
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Catherine Bilodeau
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jose M Carceller
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Institute of Chemical Technology (ITQ), Universitat Politècnica de València, València 46022,Spain
| | - Jacob S DeHovitz
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Haigen Fu
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Yi Liu
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Bryce T Nicholls
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Yao Ouyang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Claire G Page
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Tianzhang Qiao
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Felix C Raps
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Damien R Sorigué
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Shang-Zheng Sun
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Joshua Turek-Herman
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Yuxuan Ye
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Ariadna Rivas-Souchet
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jingzhe Cao
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Todd K Hyster
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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24
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Quaye JA, Gadda G. The Pseudomonas aeruginosa PAO1 metallo flavoprotein d-2-hydroxyglutarate dehydrogenase requires Zn 2+ for substrate orientation and activation. J Biol Chem 2023; 299:103008. [PMID: 36775127 PMCID: PMC10034468 DOI: 10.1016/j.jbc.2023.103008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 02/12/2023] Open
Abstract
Pseudomonas aeruginosa PAO1 d-2-hydroxyglutarate (D2HG) dehydrogenase (PaD2HGDH) oxidizes D2HG to 2-ketoglutarate during the vital l-serine biosynthesis and is a potential therapeutic target against P. aeruginosa. PaD2HGDH, which oxidizes d-malate as an alternative substrate, has been demonstrated to be a metallo flavoprotein that requires Zn2+ for activity. However, the role of Zn2+ in the enzyme has not been elucidated, making it difficult to rationalize why nature employs both a redox center and a metal ion for catalysis in PaD2HGDH and other metallo flavoenzymes. In this study, recombinant His-tagged PaD2HGDH was purified to high levels in the presence of Zn2+ or Co2+ to investigate the metal's role in catalysis. We found that the flavin reduction step was reversible and partially rate limiting for the enzyme's turnover at pH 7.4 with either D2HG or d-malate with similar rate constants for both substrates, irrespective of whether Zn2+ or Co2+ was bound to the enzyme. The steady-state pL profiles of the kcat and kcat/Km values with d-malate demonstrate that Zn2+ mediates the activation of water coordinated to the metal. Our data are consistent with a dual role for the metal, which orients the hydroxy acid substrate in the enzyme's active site and rapidly deprotonates the substrate to yield an alkoxide species for hydride transfer to the flavin. Thus, we propose a catalytic mechanism for PaD2HGDH oxidation that establishes Zn2+ as a cofactor required for substrate orientation and activation during enzymatic turnover.
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Affiliation(s)
- Joanna A Quaye
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | - Giovanni Gadda
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA; Department of Biology, Georgia State University, Atlanta, Georgia, USA; Department of The Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, USA.
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25
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Anghel L, Rada S, Erhan RV. Structural Factors and Electron Transfer Mechanisms in Flavoenzymes. ANAL LETT 2023. [DOI: 10.1080/00032719.2023.2174131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Lilia Anghel
- Laboratory Physical and Quantum Chemistry, Institute of Chemistry, Chisinau, Republic of Moldova
| | - Simona Rada
- INCDTIM Cluj-Napoca, Cluj-Napoca, Romania
- Technical University of Cluj-Napoca, Cluj-Napoca, Romania
| | - Raul-Victor Erhan
- Department of Nuclear Physics, Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Magurele-Ilfov, Romania
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26
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Rogers MS, Gordon AM, Rappe TM, Goodpaster JD, Lipscomb JD. Contrasting Mechanisms of Aromatic and Aryl-Methyl Substituent Hydroxylation by the Rieske Monooxygenase Salicylate 5-Hydroxylase. Biochemistry 2023; 62:507-523. [PMID: 36583545 PMCID: PMC9854337 DOI: 10.1021/acs.biochem.2c00610] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hydroxylase component (S5HH) of salicylate-5-hydroxylase catalyzes C5 ring hydroxylation of salicylate but switches to methyl hydroxylation when a C5 methyl substituent is present. The use of 18O2 reveals that both aromatic and aryl-methyl hydroxylations result from monooxygenase chemistry. The functional unit of S5HH comprises a nonheme Fe(II) site located 12 Å across a subunit boundary from a one-electron reduced Rieske-type iron-sulfur cluster. Past studies determined that substrates bind near the Fe(II), followed by O2 binding to the iron to initiate catalysis. Stopped-flow-single-turnover reactions (STOs) demonstrated that the Rieske cluster transfers an electron to the iron site during catalysis. It is shown here that fluorine ring substituents decrease the rate constant for Rieske electron transfer, implying a prior reaction of an Fe(III)-superoxo intermediate with a substrate. We propose that the iron becomes fully oxidized in the resulting Fe(III)-peroxo-substrate-radical intermediate, allowing Rieske electron transfer to occur. STO using 5-CD3-salicylate-d8 occurs with an inverse kinetic isotope effect (KIE). In contrast, STO of a 1:1 mixture of unlabeled and 5-CD3-salicylate-d8 yields a normal product isotope effect. It is proposed that aromatic and aryl-methyl hydroxylation reactions both begin with the Fe(III)-superoxo reaction with a ring carbon, yielding the inverse KIE due to sp2 → sp3 carbon hybridization. After Rieske electron transfer, the resulting Fe(III)-peroxo-salicylate intermediate can continue to aromatic hydroxylation, whereas the equivalent aryl-methyl intermediate formation must be reversible to allow the substrate exchange necessary to yield a normal product isotope effect. The resulting Fe(III)-(hydro)peroxo intermediate may be reactive or evolve through a high-valent iron intermediate to complete the aryl-methyl hydroxylation.
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Affiliation(s)
- Melanie S. Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Adrian M. Gordon
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Todd M. Rappe
- Minnesota NMR Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Jason D. Goodpaster
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - John D. Lipscomb
- Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
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27
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Regulation of Mitochondrial Hydrogen Peroxide Availability by Protein S-glutathionylation. Cells 2022; 12:cells12010107. [PMID: 36611901 PMCID: PMC9818751 DOI: 10.3390/cells12010107] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND It has been four decades since protein S-glutathionylation was proposed to serve as a regulator of cell metabolism. Since then, this redox-sensitive covalent modification has been identified as a cell-wide signaling platform required for embryonic development and regulation of many physiological functions. SCOPE OF THE REVIEW Mitochondria use hydrogen peroxide (H2O2) as a second messenger, but its availability must be controlled to prevent oxidative distress and promote changes in cell behavior in response to stimuli. Experimental data favor the function of protein S-glutathionylation as a feedback loop for the inhibition of mitochondrial H2O2 production. MAJOR CONCLUSIONS The glutathione pool redox state is linked to the availability of H2O2, making glutathionylation an ideal mechanism for preventing oxidative distress whilst playing a part in desensitizing mitochondrial redox signals. GENERAL SIGNIFICANCE The biological significance of glutathionylation is rooted in redox status communication. The present review critically evaluates the experimental evidence supporting its role in negating mitochondrial H2O2 production for cell signaling and prevention of electrophilic stress.
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28
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Rehpenn A, Walter A, Storch G. Molecular flavin catalysts for C-H functionalisation and derivatisation of dehydroamino acids. Chem Sci 2022; 13:14151-14156. [PMID: 36540823 PMCID: PMC9728571 DOI: 10.1039/d2sc04341f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 11/04/2022] [Indexed: 03/12/2024] Open
Abstract
In nature, the isoalloxazine heterocycle of flavin cofactors undergoes reversible covalent bond formation with a variety of different reaction partners. These intermediates play a crucial role inter alia as the signalling states and in selective catalysis reactions. In the organic laboratory, covalent adducts with a new carbon-carbon bond have been observed with photochemically excited flavins but have, so far, only been regarded as dead-end side products. We have identified a series of molecular flavins that form adducts resulting in a new C-C bond at the C4a-position through allylic C-H activation and dehydroamino acid oxidation. Typically, these reactions are of radical nature and a stepwise pathway is assumed. We could demonstrate that these adducts are no dead-end and that the labile C-C bond can be cleaved by adding the persistent radical TEMPO leading to flavin regeneration and alkoxyamine-functionalised substrates. Our method allows for the catalytic oxidation of dehydroamino acids (16 examples) and we show that the acylimine products serve as versatile starting points for diversification. The present results are envisioned to stimulate the design of further catalytic reactions involving intermediates at the flavin C4a-position and their reactivity towards metal complexes or other persistent organic radicals. Our method for dehydrobutyrine derivatisation is orthogonal to the currently used methods (i.e., nucleophilic attack or radical addition) and offers new perspectives for peptide natural product diversification.
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Affiliation(s)
- Andreas Rehpenn
- School of Natural Sciences and Catalysis Research Center (CRC), Technical University of Munich (TUM) Lichtenbergstr. 4 85747 Garching Germany
| | - Alexandra Walter
- School of Natural Sciences and Catalysis Research Center (CRC), Technical University of Munich (TUM) Lichtenbergstr. 4 85747 Garching Germany
| | - Golo Storch
- School of Natural Sciences and Catalysis Research Center (CRC), Technical University of Munich (TUM) Lichtenbergstr. 4 85747 Garching Germany
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29
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Parmagnani AS, Mannino G, Maffei ME. Transcriptomics and Metabolomics of Reactive Oxygen Species Modulation in Near-Null Magnetic Field-Induced Arabidopsis thaliana. Biomolecules 2022; 12:biom12121824. [PMID: 36551252 PMCID: PMC9775259 DOI: 10.3390/biom12121824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022] Open
Abstract
The geomagnetic field (GMF) is a natural component of Earth's biosphere. GMF reduction to near-null values (NNMF) induces gene expression modulation that generates biomolecular, morphological, and developmental changes. Here, we evaluate the effect of NNMF on gene expression and reactive oxygen species (ROS) production in time-course experiments on Arabidopsis thaliana. Plants exposed to NNMF in a triaxial Helmholtz coils system were sampled from 10 min to 96 h to evaluate differentially expressed genes (DEGs) of oxidative stress responses by gene microarray. In 24-96 h developing stages, H2O2 and polyphenols were also analyzed from roots and shoots. A total of 194 DEGs involved in oxidative reactions were selected, many of which showed a fold change ≥±2 in at least one timing point. Heatmap clustering showed DEGs both between roots/shoots and among the different time points. NNMF induced a lower H2O2 than GMF, in agreement with the expression of ROS-related genes. Forty-four polyphenols were identified, the content of which progressively decreased during NNMF exposition time. The comparison between polyphenols content and DEGs showed overlapping patterns. These results indicate that GMF reduction induces metabolomic and transcriptomic modulation of ROS-scavenging enzymes and H2O2 production in A. thaliana, which is paralleled by the regulation of antioxidant polyphenols.
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30
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Haag M, Kehrer J, Sanchez CP, Deponte M, Lanzer M. Physiological jump in erythrocyte redox potential during Plasmodium falciparum development occurs independent of the sickle cell trait. Redox Biol 2022; 58:102536. [DOI: 10.1016/j.redox.2022.102536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/26/2022] [Accepted: 11/08/2022] [Indexed: 11/11/2022] Open
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31
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Gehrer CM, Hoffmann A, Hilbe R, Grubwieser P, Mitterstiller AM, Talasz H, Fang FC, Meyron-Holtz EG, Atkinson SH, Weiss G, Nairz M. Availability of Ferritin-Bound Iron to Enterobacteriaceae. Int J Mol Sci 2022; 23:13087. [PMID: 36361875 PMCID: PMC9657528 DOI: 10.3390/ijms232113087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/18/2022] [Accepted: 10/20/2022] [Indexed: 11/10/2023] Open
Abstract
The sequestration of iron in case of infection, termed nutritional immunity, is an established strategy of host defense. However, the interaction between pathogens and the mammalian iron storage protein ferritin is hitherto not completely understood. To better characterize the function of ferritin in Gram-negative infections, we incubated iron-starved cultures of Salmonella Typhimurium and knockout mutant strains defective for major iron uptake pathways or Escherichia coli with horse spleen ferritin or ionic iron as the sole iron source. Additionally, we added bovine superoxide dismutase and protease inhibitors to the growth medium to assess the effect of superoxide and bacterial proteases, respectively, on Salmonella proliferation and reductive iron release. Compared to free ionic iron, ferritin-bound iron was less available to Salmonella, but was still sufficient to significantly enhance the growth of the bacteria. In the absence of various iron acquisition genes, the availability of ferritin iron further decreased. Supplementation with superoxide dismutase significantly reduced the growth of the ΔentC knockout strain with holoferritin as the sole iron source in comparison with ionic ferrous iron. In contrast, this difference was not observed in the wildtype strain, suggesting that superoxide dismutase undermines bacterial iron uptake from ferritin by siderophore-independent mechanisms. Ferritin seems to diminish iron availability for bacteria in comparison to ionic iron, and its iron sequestering effect could possibly be enhanced by host superoxide dismutase activity.
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Affiliation(s)
- Clemens M. Gehrer
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Alexander Hoffmann
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Richard Hilbe
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Philipp Grubwieser
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Anna-Maria Mitterstiller
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Heribert Talasz
- Biocenter, Institute of Medical Biochemistry, Medical Universitiy of Innsbruck, 6020 Innsbruck, Austria
| | - Ferric C. Fang
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA 98195-7110, USA
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195-7735, USA
| | - Esther G. Meyron-Holtz
- Laboratory of Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Sarah H. Atkinson
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine Research Coast, KEMRI-Wellcome Trust Research Programme, Kilifi 80108, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7LG, UK
- Department of Paediatrics, University of Oxford, Oxford OX3 9DU, UK
| | - Günter Weiss
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Manfred Nairz
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
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32
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Öeren M, Walton PJ, Suri J, Ponting DJ, Hunt PA, Segall MD. Predicting Regioselectivity of AO, CYP, FMO, and UGT Metabolism Using Quantum Mechanical Simulations and Machine Learning. J Med Chem 2022; 65:14066-14081. [PMID: 36239985 DOI: 10.1021/acs.jmedchem.2c01303] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Unexpected metabolism in modification and conjugation phases can lead to the failure of many late-stage drug candidates or even withdrawal of approved drugs. Thus, it is critical to predict the sites of metabolism (SoM) for enzymes, which interact with drug-like molecules, in the early stages of the research. This study presents methods for predicting the isoform-specific metabolism for human AOs, FMOs, and UGTs and general CYP metabolism for preclinical species. The models use semi-empirical quantum mechanical simulations, validated using experimentally obtained data and DFT calculations, to estimate the reactivity of each SoM in the context of the whole molecule. Ligand-based models, trained and tested using high-quality regioselectivity data, combine the reactivity of the potential SoM with the orientation and steric effects of the binding pockets of the different enzyme isoforms. The resulting models achieve κ values of up to 0.94 and AUC of up to 0.92.
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Affiliation(s)
- Mario Öeren
- Optibrium Limited, Cambridge Innovation Park, Denny End Road, Cambridge CB25 9GL, U.K
| | - Peter J Walton
- Optibrium Limited, Cambridge Innovation Park, Denny End Road, Cambridge CB25 9GL, U.K.,School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K
| | - James Suri
- Optibrium Limited, Cambridge Innovation Park, Denny End Road, Cambridge CB25 9GL, U.K.,School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K
| | - David J Ponting
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds LS11 5PS, U.K
| | - Peter A Hunt
- Optibrium Limited, Cambridge Innovation Park, Denny End Road, Cambridge CB25 9GL, U.K
| | - Matthew D Segall
- Optibrium Limited, Cambridge Innovation Park, Denny End Road, Cambridge CB25 9GL, U.K
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33
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Ramsay J, Kattnig DR. Radical triads, not pairs, may explain effects of hypomagnetic fields on neurogenesis. PLoS Comput Biol 2022; 18:e1010519. [PMID: 36108063 PMCID: PMC9514667 DOI: 10.1371/journal.pcbi.1010519] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/27/2022] [Accepted: 08/27/2022] [Indexed: 12/03/2022] Open
Abstract
Adult hippocampal neurogenesis and hippocampus-dependent cognition in mice have been found to be adversely affected by hypomagnetic field exposure. The effect concurred with a reduction of reactive oxygen species in the absence of the geomagnetic field. A recent theoretical study suggests a mechanistic interpretation of this phenomenon in the framework of the Radical Pair Mechanism. According to this model, a flavin-superoxide radical pair, born in the singlet spin configuration, undergoes magnetic field-dependent spin dynamics such that the pair’s recombination is enhanced as the applied magnetic field is reduced. This model has two ostensible weaknesses: a) the assumption of a singlet initial state is irreconcilable with known reaction pathways generating such radical pairs, and b) the model neglects the swift spin relaxation of free superoxide, which abolishes any magnetic sensitivity in geomagnetic/hypomagnetic fields. We here suggest that a model based on a radical triad and the assumption of a secondary radical scavenging reaction can, in principle, explain the phenomenon without unnatural assumptions, thus providing a coherent explanation of hypomagnetic field effects in biology. The hippocampal region of the brain plays a major role in learning and memory functionality. In male mice, shielding of the Earth’s magnetic field was found to decrease hippocampal neurogenesis, i.e. the formation of new neurons, following from a decrease in levels of reactive oxygen species. In this study, we suggest an explanation in terms of spin dynamics of a three radical system composed of flavin-semiquinone, superoxide and ascorbyl radical. This model agrees with the experimental data whilst retaining realistic parameters for a biological system, unlike the Radical Pair Mechanism.
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Affiliation(s)
- Jess Ramsay
- Living Systems Institute and Department of Physics, University of Exeter, Exeter, Devon, United Kingdom
| | - Daniel R. Kattnig
- Living Systems Institute and Department of Physics, University of Exeter, Exeter, Devon, United Kingdom
- * E-mail:
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34
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Salerno KM, Domenico J, Le NQ, Stiles CD, Solov’yov IA, Martino CF. Long-Time Oxygen Localization in Electron Transfer Flavoprotein. J Chem Inf Model 2022; 62:4191-4199. [PMID: 35998902 PMCID: PMC9472800 DOI: 10.1021/acs.jcim.2c00430] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Indexed: 11/30/2022]
Abstract
Reactive oxygen species (ROS) exert a wide range of biological effects from beneficial regulatory function to deleterious oxidative stress. The electron transfer flavoprotein (ETF) is ubiquitous to life and is associated with aerobic metabolism and ROS production due to its location in the mitochondria. Quantifying oxygen localization within the ETF complex is critical for understanding the potential for electron transfer and radical pair formation between flavin adenine dinucleotide (FAD) cofactor and superoxide during ROS formation. Our study employed all-atom molecular dynamics simulations and identified several novel, long-lived oxygen binding sites within the ETF complex that appear near the FAD cofactor. Site locations, the local electrostatic environment, and characteristic oxygen binding times for each site were evaluated to establish factors that may lead to possible charge transfer reactions and superoxide formation within the ETF complex. The study revealed that some oxygen binding sites are naturally linked to protein domain features, suggesting opportunities to engineer and control ROS production and subsequent dynamics.
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Affiliation(s)
- K. Michael Salerno
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
| | - Janna Domenico
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
| | - Nam Q. Le
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
| | - Christopher D. Stiles
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
| | - Ilia A. Solov’yov
- Institute
of Physics, Carl von Ossietzky University
Oldenburg, Carl von Ossietzky
Straße 9-11, 26129 Oldenburg, Germany
- Centre
for Neurosensory Science, Carl von Ossietzky
University Oldenburg, Carl von Ossietzky Straße 9-11, 26129 Oldenburg, Germany
| | - Carlos F. Martino
- The
Johns Hopkins University Applied Physics
Laboratory, 11100 Johns
Hopkins Road, Laurel, Maryland 20723, United States
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35
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Partipilo M, Yang G, Mascotti ML, Wijma HJ, Slotboom DJ, Fraaije MW. A conserved sequence motif in the E. coli soluble FAD-containing pyridine nucleotide transhydrogenase is important for reaction efficiency. J Biol Chem 2022; 298:102304. [PMID: 35933012 PMCID: PMC9460512 DOI: 10.1016/j.jbc.2022.102304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 11/06/2022] Open
Abstract
Soluble pyridine nucleotide transhydrogenases (STHs) are flavoenzymes involved in the redox homeostasis of the essential cofactors NAD(H) and NADP(H). They catalyze the reversible transfer of reducing equivalents between the two nicotinamide cofactors. The soluble transhydrogenase from Escherichia coli (SthA) has found wide use in both in vivo and in vitro applications to steer reducing equivalents toward NADPH-requiring reactions. However, mechanistic insight into SthA function is still lacking. In this work, we present a biochemical characterization of SthA, focusing for the first time on the reactivity of the flavoenzyme with molecular oxygen. We report on oxidase activity of SthA that takes place both during transhydrogenation and in the absence of an oxidized nicotinamide cofactor as an electron acceptor. We find that this reaction produces the reactive oxygen species hydrogen peroxide and superoxide anion. Furthermore, we explore the evolutionary significance of the well-conserved CXXXXT motif that distinguishes STHs from the related family of flavoprotein disulfide reductases in which a CXXXXC motif is conserved. Our mutational analysis revealed the cysteine and threonine combination in SthA leads to better coupling efficiency of transhydrogenation and reduced reactive oxygen species release compared to enzyme variants with mutated motifs. These results expand our mechanistic understanding of SthA by highlighting reactivity with molecular oxygen and the importance of the evolutionarily conserved sequence motif.
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Affiliation(s)
- Michele Partipilo
- Membrane Enzymology Group, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Guang Yang
- Molecular Enzymology Group, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Maria Laura Mascotti
- Molecular Enzymology Group, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands; IMIBIO-SL CONICET, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejercito de los Andes 950, D5700HHW, San Luis, Argentina
| | - Hein J Wijma
- Molecular Enzymology Group, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Dirk Jan Slotboom
- Membrane Enzymology Group, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Marco W Fraaije
- Molecular Enzymology Group, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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36
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Zhuang B, Vos MH, Aleksandrov A. Photochemical and Molecular Dynamics Studies of Halide Binding in Flavoenzyme Glucose Oxidase. Chembiochem 2022; 23:e202200227. [PMID: 35876386 DOI: 10.1002/cbic.202200227] [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: 04/20/2022] [Revised: 07/11/2022] [Indexed: 11/11/2022]
Abstract
Glucose oxidase (GOX), a characteristic flavoprotein oxidase with widespread industrial applications, binds fluoride (F - ) and chloride (Cl - ). We investigated binding properties of halide inhibitors of GOX through time-resolved spectral characterization of flavin-related photochemical processes and molecular dynamic simulations. Cl - and F - bind differently to the protein active site and have substantial but opposite effects on the population and decay of the flavin excited state. Cl - binds closer to the flavin, whose excited-state decays in <100 fs due to anion-π interactions. Such interactions appear absent in F - binding, which, however, significantly increases the active-site rigidity leading to more homogeneous, picosecond fluorescence decay kinetics. These findings are discussed in relation to the mechanism of halide inhibition of GOX by occupying the accommodation site of catalytic intermediates and increasing the active-site rigidity.
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Affiliation(s)
- Bo Zhuang
- Ecole Polytechnique, LOB, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, FRANCE
| | - Marten H Vos
- CNRS UMR7645, Laboratory of Optics and Biosciences, CNRS, INSERM, École Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, FRANCE
| | - Alexey Aleksandrov
- Ecole Polytechnique, Laboratory of Optics and Biosciences, Department of Biology, rue du Saclay, 91128, Palaiseau, FRANCE
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37
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Nirusimhan V, Andrew Gideon D, Parashar A, Jeyachandran S, Jeyaraman J, Subbaraj G, Kulanthaivel L. Structural Modeling of Drosophila melanogaster Gut Cytochrome P450s and Docking Comparison of Fruit Fly Gut and Human Cytochrome P450s. Curr Drug Metab 2022; 23:299-316. [PMID: 35546755 DOI: 10.2174/1389200223666220511162234] [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: 11/25/2021] [Revised: 02/01/2022] [Accepted: 02/15/2022] [Indexed: 11/22/2022]
Abstract
Drosophila melanogaster is a prominent model organism in developmental biology research and in studies related to pathophysiological conditions like cancer and Alzheimer's disease. The fruit fly gut contains several cytochrome P450s (CYP450s) which have central roles in Drosophila development and in the normal physiology of the gut. Since the crystal structures of these proteins have not been deciphered yet, we modeled the structure of 29 different D. melanogaster gut CYP450s using Prime (Schrödinger). The sequences of chosen D. melanogaster gut CYP450s were compared with that of their human counterparts. The common gut (and liver) microsomal CYP450s in humans were chosen for structural comparison to find the homology and identity % of D. melanogaster CYPs with that of their human counterparts. The modeled structures were validated using PROCHECK and the best fit models were used for docking several known human pharmacological agents/drugs to the modeled D. melanogaster gut CYP450s. Based on the binding affinities (ΔG values) of the selected drug molecules with the modeled fly gut CYPs, the plausible differences in metabolism of the prominent drugs in humans and fly were projected. The gut is involved in absorption of oral drugs/pharmacological agents and hence, upregulation of intestinal CYP450 and their reactions with endobiotics and xenobiotics is envisaged. The insights gleaned from this work can validate D. melanogaster as a model organism for studying intestinal drug metabolism, particularly in the context of a) toxicology of pharmacological agents to the gut cells and b) how gut P450 metabolites/products can influence gut homeostasis. This work can help establish a platform for further in vitro investigations on how intestinal CYP450 metabolism can influence gut health. The data from this work can be used for further in silico studies and this work can serve as a platform for future in vitro investigations on intestinal CYP450-mediated metabolism of endo- and xeno-biotics in D. melanogaster.
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Affiliation(s)
- Vijay Nirusimhan
- Cancer Informatics Laboratory, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi, Tamil Nadu, India
| | - Daniel Andrew Gideon
- Department of Biotechnology and Bioinformatics, Bishop Heber College (Autonomous), Tennur, Tiruchirappalli Tamil Nadu, India
| | - Abhinav Parashar
- Department of Biotechnology, Vignan's Foundation for Science, Technology & Research, Vadlamudi, Guntur, Andhra Pradesh, India
| | - Sangavi Jeyachandran
- Cancer Informatics Laboratory, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi, Tamil Nadu, India
| | - Jeyakanthan Jeyaraman
- Structural Biology and Bio-Computing Lab, Department of Bioinformatics, Science Campus, Alagappa University, Karaikudi, Tamil Nadu, India
| | - Gowthamkumar Subbaraj
- Faculty of Allied Health Sciences, Chettinad Hospital & Research Institute, Chettinad Academy of Research and Education, Kelambakkam, Tamil Nadu, India
| | - Langeswaran Kulanthaivel
- Cancer Informatics Laboratory, Department of Bioinformatics, Alagappa University, Science Campus, Karaikudi, Tamil Nadu, India
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Purdy TN, Moore BS, Lukowski AL. Harnessing ortho-Quinone Methides in Natural Product Biosynthesis and Biocatalysis. JOURNAL OF NATURAL PRODUCTS 2022; 85:688-701. [PMID: 35108487 PMCID: PMC9006567 DOI: 10.1021/acs.jnatprod.1c01026] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The implementation of ortho-quinone methide (o-QM) intermediates in complex molecule assembly represents a remarkably efficient strategy designed by Nature and utilized by synthetic chemists. o-QMs have been taken advantage of in biomimetic syntheses for decades, yet relatively few examples of o-QM-generating enzymes in natural product biosynthetic pathways have been reported. The biosynthetic enzymes that have been discovered thus far exhibit tremendous potential for biocatalytic applications, enabling the selective production of desirable compounds that are otherwise intractable or inherently difficult to achieve by traditional synthetic methods. Characterization of this biosynthetic machinery has the potential to shine a light on new enzymes capable of similar chemistry on diverse substrates, thus expanding our knowledge of Nature's catalytic repertoire. The presently known o-QM-generating enzymes include flavin-dependent oxidases, hetero-Diels-Alderases, S-adenosyl-l-methionine-dependent pericyclases, and α-ketoglutarate-dependent nonheme iron enzymes. In this review, we discuss their diverse enzymatic mechanisms and potential as biocatalysts in constructing natural product molecules such as cannabinoids.
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Affiliation(s)
- Trevor N Purdy
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, La Jolla, California 92093, United States
| | - Bradley S Moore
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, California 92093, United States
| | - April L Lukowski
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, La Jolla, California 92093, United States
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Zhang P, Van Cappellen P, Pi K, Yuan S. Effects of riboflavin and desferrioxamine B on Fe(II) oxidation by O 2. FUNDAMENTAL RESEARCH 2022; 2:208-217. [PMID: 38933163 PMCID: PMC11197622 DOI: 10.1016/j.fmre.2021.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/18/2021] [Accepted: 09/16/2021] [Indexed: 11/17/2022] Open
Abstract
Flavins and siderophores secreted by various plants, fungi and bacteria under iron (Fe) deficient conditions play important roles in the biogeochemical cycling of Fe in the environment. Although the mechanisms of flavin and siderophore mediated Fe(III) reduction and dissolution under anoxic conditions have been widely studied, the influence of these compounds on Fe(II) oxidation under oxic conditions is still unclear. In this study, we investigated the kinetics of aqueous Fe(II) (17.8 μM) oxidation by O2 at pH 5‒7 in the presence of riboflavin (oxidized (RBF) and reduced (RBFH2)) and desferrioxamine B (DFOB) as representative flavins and siderophores, respectively. Results showed that the addition of RBF/RBFH2 or DFOB markedly accelerates the oxidation of aqueous Fe(II) by O2. For instance, at pH 6, the rate of Fe(II) oxidation was enhanced 20‒70 times when 10 μM RBFH2 was added. The mechanisms responsible for the accelerated Fe(II) oxidation are related to the redox reactivity and complexation ability of RBFH2, RBF and DFOB. While RBFH2 does not readily complex Fe(II)/Fe(III), it can activate O2 and generate reactive oxygen species, which then rapidly oxidize Fe(II). In contrast, both RBF and DFOB do not reduce O2 but react with Fe(II) to form RBF/DFOB-complexed Fe(II), which in turn accelerates Fe(II) oxidation. Furthermore, the lower standard reduction potential of the Fe(II)-DFOB complex, compared to the Fe(II)-RBF complex, correlates with a higher oxidation rate constant for the Fe(II)-DFOB complex. Our study reveals an overlooked catalytic role of flavins and siderophores that may contribute to Fe(II)/Fe(III) cycling at oxic-anoxic interfaces.
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Affiliation(s)
- Peng Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, China
| | - Philippe Van Cappellen
- Ecohydrology Research Group, Water Institute and Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Kunfu Pi
- Ecohydrology Research Group, Water Institute and Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, China
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Yoval-Sánchez B, Ansari F, James J, Niatsetskaya Z, Sosunov S, Filipenko P, Tikhonova IG, Ten V, Wittig I, Rafikov R, Galkin A. Redox-dependent loss of flavin by mitochondria complex I is different in brain and heart. Redox Biol 2022; 51:102258. [PMID: 35189550 PMCID: PMC8861397 DOI: 10.1016/j.redox.2022.102258] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/26/2022] [Accepted: 01/31/2022] [Indexed: 12/14/2022] Open
Abstract
Pathologies associated with tissue ischemia/reperfusion (I/R) in highly metabolizing organs such as the brain and heart are leading causes of death and disability in humans. Molecular mechanisms underlying mitochondrial dysfunction during acute injury in I/R are tissue-specific, but their details are not completely understood. A metabolic shift and accumulation of substrates of reverse electron transfer (RET) such as succinate are observed in tissue ischemia, making mitochondrial complex I of the respiratory chain (NADH:ubiquinone oxidoreductase) the most vulnerable enzyme to the following reperfusion. It has been shown that brain complex I is predisposed to losing its flavin mononucleotide (FMN) cofactor when maintained in the reduced state in conditions of RET both in vitro and in vivo. Here we investigated the process of redox-dependent dissociation of FMN from mitochondrial complex I in brain and heart mitochondria. In contrast to the brain enzyme, cardiac complex I does not lose FMN when reduced in RET conditions. We proposed that the different kinetics of FMN loss during RET is due to the presence of brain-specific long 50 kDa isoform of the NDUFV3 subunit of complex I, which is absent in the heart where only the canonical 10 kDa short isoform is found. Our simulation studies suggest that the long NDUFV3 isoform can reach toward the FMN binding pocket and affect the nucleotide affinity to the apoenzyme. For the first time, we demonstrated a potential functional role of tissue-specific isoforms of complex I, providing the distinct molecular mechanism of I/R-induced mitochondrial impairment in cardiac and cerebral tissues. By combining functional studies of intact complex I and molecular structure simulations, we defined the critical difference between the brain and heart enzyme and suggested insights into the redox-dependent inactivation mechanisms of complex I during I/R injury in both tissues.
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Affiliation(s)
- Belem Yoval-Sánchez
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY, 10065, USA
| | - Fariha Ansari
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY, 10065, USA
| | - Joel James
- Division of Endocrinology, Department of Medicine, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Zoya Niatsetskaya
- Department of Pediatrics, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, 08901, USA
| | - Sergey Sosunov
- Department of Pediatrics, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, 08901, USA
| | - Peter Filipenko
- Department of Biochemistry, Weill Cornell Medical College, Cornell University, New York, NY, 10021, USA
| | - Irina G. Tikhonova
- School of Pharmacy, Medical Biology, Centre, Queen's University Belfast, Belfast, BT9 7BL, United Kingdom
| | - Vadim Ten
- Department of Pediatrics, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, 08901, USA
| | - Ilka Wittig
- Functional Proteomics, Cardiovascular Physiology, Goethe University, 60590, Frankfurt am Main, Germany,German Center for Cardiovascular Research (DZHK), Partner site RheinMain, Frankfurt, Germany
| | - Ruslan Rafikov
- Division of Endocrinology, Department of Medicine, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Alexander Galkin
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY, 10065, USA,Corresponding author.
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41
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Leeb E, Wielend D, Schimanofsky C, Sariciftci NS. Substrate and pH‐dependent homogeneous electrocatalysis using riboflavin for oxygen reduction. ELECTROCHEMICAL SCIENCE ADVANCES 2022. [DOI: 10.1002/elsa.202100211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Elisabeth Leeb
- Linz Institute for Organic Solar Cells Institute of Physical Chemistry, Department of Chemistry Johannes Kepler University Linz Linz Austria
| | - Dominik Wielend
- Linz Institute for Organic Solar Cells Institute of Physical Chemistry, Department of Chemistry Johannes Kepler University Linz Linz Austria
| | - Corina Schimanofsky
- Linz Institute for Organic Solar Cells Institute of Physical Chemistry, Department of Chemistry Johannes Kepler University Linz Linz Austria
| | - Niyazi Serdar Sariciftci
- Linz Institute for Organic Solar Cells Institute of Physical Chemistry, Department of Chemistry Johannes Kepler University Linz Linz Austria
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42
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Pereira MS, de Araújo SS, Nagem RAP, Richard JP, Brandão TAS. The role of remote flavin adenine dinucleotide pieces in the oxidative decarboxylation catalyzed by salicylate hydroxylase. Bioorg Chem 2022; 119:105561. [PMID: 34965488 PMCID: PMC8824312 DOI: 10.1016/j.bioorg.2021.105561] [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: 09/17/2021] [Revised: 11/19/2021] [Accepted: 12/11/2021] [Indexed: 02/03/2023]
Abstract
Salicylate hydroxylase (NahG) has a single redox site in which FAD is reduced by NADH, the O2 is activated by the reduced flavin, and salicylate undergoes an oxidative decarboxylation by a C(4a)-hydroperoxyflavin intermediate to give catechol. We report experimental results that show the contribution of individual pieces of the FAD cofactor to the observed enzymatic activity for turnover of the whole cofactor. A comparison of the kinetic parameters and products for the NahG-catalyzed reactions of FMN and riboflavin cofactor fragments reveal that the adenosine monophosphate (AMP) and ribitol phosphate pieces of FAD act to anchor the flavin to the enzyme and to direct the partitioning of the C(4a)-hydroperoxyflavin reaction intermediate towards hydroxylation of salicylate. The addition of AMP or ribitol phosphate pieces to solutions of the truncated flavins results in a partial restoration of the enzymatic activity lost upon truncation of FAD, and the pieces direct the reaction of the C(4a)-hydroperoxyflavin intermediate towards hydroxylation of salicylate.
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Affiliation(s)
- Mozart S. Pereira
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Simara S. de Araújo
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Ronaldo A. P. Nagem
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - John P. Richard
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, New York 14260-3000,CORRESPONDING AUTHOR: ;
| | - Tiago A. S. Brandão
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil.,CORRESPONDING AUTHOR: ;
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43
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Ayer A, Fazakerley DJ, James DE, Stocker R. The role of mitochondrial reactive oxygen species in insulin resistance. Free Radic Biol Med 2022; 179:339-362. [PMID: 34775001 DOI: 10.1016/j.freeradbiomed.2021.11.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 10/31/2021] [Accepted: 11/06/2021] [Indexed: 12/21/2022]
Abstract
Insulin resistance is one of the earliest pathological features of a suite of diseases including type 2 diabetes collectively referred to as metabolic syndrome. There is a growing body of evidence from both pre-clinical studies and human cohorts indicating that reactive oxygen species, such as the superoxide radical anion and hydrogen peroxide are key players in the development of insulin resistance. Here we review the evidence linking mitochondrial reactive oxygen species generated within mitochondria with insulin resistance in adipose tissue and skeletal muscle, two major insulin sensitive tissues. We outline the relevant mitochondria-derived reactive species, how the mitochondrial redox state is regulated, and methodologies available to measure mitochondrial reactive oxygen species. Importantly, we highlight key experimental issues to be considered when studying the role of mitochondrial reactive oxygen species in insulin resistance. Evaluating the available literature on both mitochondrial reactive oxygen species/redox state and insulin resistance in a variety of biological systems, we conclude that the weight of evidence suggests a likely role for mitochondrial reactive oxygen species in the etiology of insulin resistance in adipose tissue and skeletal muscle. However, major limitations in the methods used to study reactive oxygen species in insulin resistance as well as the lack of data linking mitochondrial reactive oxygen species and cytosolic insulin signaling pathways are significant obstacles in proving the mechanistic link between these two processes. We provide a framework to guide future studies to provide stronger mechanistic information on the link between mitochondrial reactive oxygen species and insulin resistance as understanding the source, localization, nature, and quantity of mitochondrial reactive oxygen species, their targets and downstream signaling pathways may pave the way for important new therapeutic strategies.
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Affiliation(s)
- Anita Ayer
- Heart Research Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Daniel J Fazakerley
- Metabolic Research Laboratory, Wellcome-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - David E James
- Charles Perkins Centre, Sydney Medical School, The University of Sydney, Sydney, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Roland Stocker
- Heart Research Institute, The University of Sydney, Sydney, New South Wales, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia.
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Schnerwitzki D, Vabulas RM. Dynamic association of flavin cofactors to regulate flavoprotein function. IUBMB Life 2022; 74:645-654. [PMID: 35015339 DOI: 10.1002/iub.2591] [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: 10/27/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 11/09/2022]
Abstract
Flavoproteins are key players in numerous redox pathways in cells. Flavin cofactors FMN and FAD confer the required chemical reactivity to flavoenzymes. In most cases, the interaction between the proteins and the flavins is noncovalent, yet stronger in comparison to other redox-active cofactors, such as NADH and NADPH. The association is considered static, but this view has started to change with the recent discovery of the dynamic association of flavins and flavoenzymes. Six cases from different organisms and various metabolic pathways are discussed here. The available mechanistic details span the range from rudimentary, as in the case of the ER-resident oxidoreductase Ero1, to comprehensive, as for the bacterial respiratory complex I. The same holds true in regard to the assumed functional role of the dynamic association presented here. More work is needed to clarify the structural and functional determinants of the known examples. Identification of new cases will help to appreciate the generality of the new principle of intracellular flavoenzyme regulation.
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Affiliation(s)
- Danny Schnerwitzki
- Charité-Universitätsmedizin Berlin, Institute of Biochemistry, Berlin, Germany
| | - R Martin Vabulas
- Charité-Universitätsmedizin Berlin, Institute of Biochemistry, Berlin, Germany
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45
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Helicobacter pylori FabX contains a [4Fe-4S] cluster essential for unsaturated fatty acid synthesis. Nat Commun 2021; 12:6932. [PMID: 34836944 PMCID: PMC8626469 DOI: 10.1038/s41467-021-27148-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/29/2021] [Indexed: 11/08/2022] Open
Abstract
Unsaturated fatty acids (UFAs) are essential for functional membrane phospholipids in most bacteria. The bifunctional dehydrogenase/isomerase FabX is an essential UFA biosynthesis enzyme in the widespread human pathogen Helicobacter pylori, a bacterium etiologically related to 95% of gastric cancers. Here, we present the crystal structures of FabX alone and in complexes with an octanoyl-acyl carrier protein (ACP) substrate or with holo-ACP. FabX belongs to the nitronate monooxygenase (NMO) flavoprotein family but contains an atypical [4Fe-4S] cluster absent in all other family members characterized to date. FabX binds ACP via its positively charged α7 helix that interacts with the negatively charged α2 and α3 helices of ACP. We demonstrate that the [4Fe-4S] cluster potentiates FMN oxidation during dehydrogenase catalysis, generating superoxide from an oxygen molecule that is locked in an oxyanion hole between the FMN and the active site residue His182. Both the [4Fe-4S] and FMN cofactors are essential for UFA synthesis, and the superoxide is subsequently excreted by H. pylori as a major resource of peroxide which may contribute to its pathogenic function in the corrosion of gastric mucosa.
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Caux C, Guigliarelli B, Vivès C, Biaso F, Horeau M, Hassoune H, Petit-Hartlein I, Juillan-Binard C, Torelli S, Fieschi F, Nivière V. Membrane-Bound Flavocytochrome MsrQ Is a Substrate of the Flavin Reductase Fre in Escherichia coli. ACS Chem Biol 2021; 16:2547-2559. [PMID: 34550690 DOI: 10.1021/acschembio.1c00613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
MsrPQ is a new type of methionine sulfoxide reductase (Msr) system found in bacteria. It is specifically involved in the repair of periplasmic methionine residues that are oxidized by hypochlorous acid. MsrP is a periplasmic molybdoenzyme that carries out the Msr activity, whereas MsrQ, an integral membrane-bound hemoprotein, acts as the physiological partner of MsrP to provide electrons for catalysis. Although MsrQ (YedZ) was associated since long with a protein superfamily named FRD (ferric reductase domain), including the eukaryotic NADPH oxidases and STEAP proteins, its biochemical properties are still sparsely documented. Here, we have investigated the cofactor content of the E. coli MsrQ and its mechanism of reduction by the flavin reductase Fre. We showed by electron paramagnetic resonance (EPR) spectroscopy that MsrQ contains a single highly anisotropic low-spin (HALS) b-type heme located on the periplasmic side of the membrane. We further demonstrated that MsrQ holds a flavin mononucleotide (FMN) cofactor that occupies the site where a second heme binds in other members of the FDR superfamily on the cytosolic side of the membrane. EPR spectroscopy indicates that the FMN cofactor can accommodate a radical semiquinone species. The cytosolic flavin reductase Fre was previously shown to reduce the MsrQ heme. Here, we demonstrated that Fre uses the FMN MsrQ cofactor as a substrate to catalyze the electron transfer from cytosolic NADH to the heme. Formation of a specific complex between MsrQ and Fre could favor this unprecedented mechanism, which most likely involves transfer of the reduced FMN cofactor from the Fre active site to MsrQ.
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Affiliation(s)
- Christelle Caux
- CNRS, CEA, IRIG-LCBM, Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, Grenoble 38054, France
| | - Bruno Guigliarelli
- CNRS, BIP-UMR 7281 Laboratoire de Bioénergétique et Ingénierie des Protéines, Aix-Marseille Univ., Marseille 13402, France
| | - Corinne Vivès
- CNRS, CEA, Institut de Biologie Structurale, Univ. Grenoble Alpes, Grenoble 38044, France
| | - Frédéric Biaso
- CNRS, BIP-UMR 7281 Laboratoire de Bioénergétique et Ingénierie des Protéines, Aix-Marseille Univ., Marseille 13402, France
| | - Marius Horeau
- CNRS, CEA, IRIG-LCBM, Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, Grenoble 38054, France
| | - Hawra Hassoune
- CNRS, CEA, IRIG-LCBM, Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, Grenoble 38054, France
| | | | - Céline Juillan-Binard
- CNRS, CEA, Institut de Biologie Structurale, Univ. Grenoble Alpes, Grenoble 38044, France
| | - Stephane Torelli
- CNRS, CEA, IRIG-LCBM, Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, Grenoble 38054, France
| | - Franck Fieschi
- CNRS, CEA, Institut de Biologie Structurale, Univ. Grenoble Alpes, Grenoble 38044, France
| | - Vincent Nivière
- CNRS, CEA, IRIG-LCBM, Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, Grenoble 38054, France
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Mitochondrial Management of Reactive Oxygen Species. Antioxidants (Basel) 2021; 10:antiox10111824. [PMID: 34829696 PMCID: PMC8614740 DOI: 10.3390/antiox10111824] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 01/10/2023] Open
Abstract
Mitochondria in aerobic eukaryotic cells are both the site of energy production and the formation of harmful species, such as radicals and other reactive oxygen species, known as ROS. They contain an efficient antioxidant system, including low-molecular-mass molecules and enzymes that specialize in removing various types of ROS or repairing the oxidative damage of biological molecules. Under normal conditions, ROS production is low, and mitochondria, which are their primary target, are slightly damaged in a similar way to other cellular compartments, since the ROS released by the mitochondria into the cytosol are negligible. As the mitochondrial generation of ROS increases, they can deactivate components of the respiratory chain and enzymes of the Krebs cycle, and mitochondria release a high amount of ROS that damage cellular structures. More recently, the feature of the mitochondrial antioxidant system, which does not specifically deal with intramitochondrial ROS, was discovered. Indeed, the mitochondrial antioxidant system detoxifies exogenous ROS species at the expense of reducing the equivalents generated in mitochondria. Thus, mitochondria are also a sink of ROS. These observations highlight the importance of the mitochondrial antioxidant system, which should be considered in our understanding of ROS-regulated processes. These processes include cell signaling and the progression of metabolic and neurodegenerative disease.
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Bapli A, Jana R, Pandit S, Seth D. Selective prototropism of lumichrome in the liposome/graphene oxide interface: A detailed spectroscopic study. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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49
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Matthews A, Schönfelder J, Lagies S, Schleicher E, Kammerer B, Ellis HR, Stull F, Teufel R. Bacterial flavoprotein monooxygenase YxeK salvages toxic S-(2-succino)-adducts via oxygenolytic C-S bond cleavage. FEBS J 2021; 289:787-807. [PMID: 34510734 DOI: 10.1111/febs.16193] [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: 04/30/2021] [Revised: 08/18/2021] [Accepted: 09/09/2021] [Indexed: 01/23/2023]
Abstract
Thiol-containing nucleophiles such as cysteine react spontaneously with the citric acid cycle intermediate fumarate to form S-(2-succino)-adducts. In Bacillus subtilis, a salvaging pathway encoded by the yxe operon has recently been identified for the detoxification and exploitation of these compounds as sulfur sources. This route involves acetylation of S-(2-succino)cysteine to N-acetyl-2-succinocysteine, which is presumably converted to oxaloacetate and N-acetylcysteine, before a final deacetylation step affords cysteine. The critical oxidative cleavage of the C-S bond of N-acetyl-S-(2-succino)cysteine was proposed to depend on the predicted flavoprotein monooxygenase YxeK. Here, we characterize YxeK and verify its role in S-(2-succino)-adduct detoxification and sulfur metabolism. Detailed biochemical and mechanistic investigation of YxeK including 18 O-isotope-labeling experiments, homology modeling, substrate specificity tests, site-directed mutagenesis, and (pre-)steady-state kinetics provides insight into the enzyme's mechanism of action, which may involve a noncanonical flavin-N5-peroxide species for C-S bond oxygenolysis.
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Affiliation(s)
| | | | - Simon Lagies
- Institute of Organic Chemistry, University of Freiburg, Germany
| | - Erik Schleicher
- Institute of Physical Chemistry, University of Freiburg, Germany
| | - Bernd Kammerer
- Institute of Organic Chemistry, University of Freiburg, Germany.,BIOSS Center for Biological Signaling Studies, University of Freiburg, Germany
| | - Holly R Ellis
- Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Frederick Stull
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - Robin Teufel
- Faculty of Biology, University of Freiburg, Germany
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50
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Martínez-Montero L, Tischler D, Süss P, Schallmey A, Franssen MCR, Hollmann F, Paul CE. Asymmetric azidohydroxylation of styrene derivatives mediated by a biomimetic styrene monooxygenase enzymatic cascade. Catal Sci Technol 2021; 11:5077-5085. [PMID: 34381590 PMCID: PMC8328376 DOI: 10.1039/d1cy00855b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/13/2021] [Indexed: 12/18/2022]
Abstract
Enantioenriched azido alcohols are precursors for valuable chiral aziridines and 1,2-amino alcohols, however their chiral substituted analogues are difficult to access. We established a cascade for the asymmetric azidohydroxylation of styrene derivatives leading to chiral substituted 1,2-azido alcohols via enzymatic asymmetric epoxidation, followed by regioselective azidolysis, affording the azido alcohols with up to two contiguous stereogenic centers. A newly isolated two-component flavoprotein styrene monooxygenase StyA proved to be highly selective for epoxidation with a nicotinamide coenzyme biomimetic as a practical reductant. Coupled with azide as a nucleophile for regioselective ring opening, this chemo-enzymatic cascade produced highly enantioenriched aromatic α-azido alcohols with up to >99% conversion. A bi-enzymatic counterpart with halohydrin dehalogenase-catalyzed azidolysis afforded the alternative β-azido alcohol isomers with up to 94% diastereomeric excess. We anticipate our biocatalytic cascade to be a starting point for more practical production of these chiral compounds with two-component flavoprotein monooxygenases.
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Affiliation(s)
- Lía Martínez-Montero
- Department of Biotechnology, Delft University of Technology Van der Maasweg 9 2629 HZ Delft The Netherlands
| | - Dirk Tischler
- Microbial Biotechnology, Ruhr-Universität Bochum Universitätsstr. 150 44780 Bochum Germany
| | - Philipp Süss
- Enzymicals AG Walther-Rathenau-Straße 49a 17489 Greifswald Germany
| | - Anett Schallmey
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig Spielmannstraße 7 38106 Braunschweig Germany
| | - Maurice C R Franssen
- Laboratory of Organic Chemistry, Wageningen University Stippeneng 4 6708 WE Wageningen The Netherlands
| | - Frank Hollmann
- Department of Biotechnology, Delft University of Technology Van der Maasweg 9 2629 HZ Delft The Netherlands
| | - Caroline E Paul
- Department of Biotechnology, Delft University of Technology Van der Maasweg 9 2629 HZ Delft The Netherlands
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