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Grayson C, Faerman B, Koufos O, Mailloux RJ. Fatty acid oxidation drives mitochondrial hydrogen peroxide production by α-ketoglutarate dehydrogenase. J Biol Chem 2024; 300:107159. [PMID: 38479602 PMCID: PMC10997840 DOI: 10.1016/j.jbc.2024.107159] [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: 12/27/2023] [Revised: 02/29/2024] [Accepted: 03/06/2024] [Indexed: 04/07/2024] Open
Abstract
In the present study, we examined the mitochondrial hydrogen peroxide (mH2O2) generating capacity of α-ketoglutarate dehydrogenase (KGDH) and compared it to components of the electron transport chain using liver mitochondria isolated from male and female C57BL6N mice. We show for the first time there are some sex dimorphisms in the production of mH2O2 by electron transport chain complexes I and III when mitochondria are fueled with different substrates. However, in our investigations into these sex effects, we made the unexpected and compelling discovery that 1) KGDH serves as a major mH2O2 supplier in male and female liver mitochondria and 2) KGDH can form mH2O2 when liver mitochondria are energized with fatty acids but only when malate is used to prime the Krebs cycle. Surprisingly, 2-keto-3-methylvaleric acid (KMV), a site-specific inhibitor for KGDH, nearly abolished mH2O2 generation in both male and female liver mitochondria oxidizing palmitoyl-carnitine. KMV inhibited mH2O2 production in liver mitochondria from male and female mice oxidizing myristoyl-, octanoyl-, or butyryl-carnitine as well. S1QEL 1.1 (S1) and S3QEL 2 (S3), compounds that inhibit reactive oxygen species generation by complexes I and III, respectively, without interfering with OxPhos and respiration, had a negligible effect on the rate of mH2O2 production when pyruvate or acyl-carnitines were used as fuels. However, inclusion of KMV in reaction mixtures containing S1 and/or S3 almost abolished mH2O2 generation. Together, our findings suggest KGDH is the main mH2O2 generator in liver mitochondria, even when fatty acids are used as fuel.
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Affiliation(s)
- Cathryn Grayson
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada
| | - Ben Faerman
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada
| | - Olivia Koufos
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada
| | - Ryan J Mailloux
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada.
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2
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Szabo E, Nagy B, Czajlik A, Komlodi T, Ozohanics O, Tretter L, Ambrus A. Mitochondrial Alpha-Keto Acid Dehydrogenase Complexes: Recent Developments on Structure and Function in Health and Disease. Subcell Biochem 2024; 104:295-381. [PMID: 38963492 DOI: 10.1007/978-3-031-58843-3_13] [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] [Indexed: 07/05/2024]
Abstract
The present work delves into the enigmatic world of mitochondrial alpha-keto acid dehydrogenase complexes discussing their metabolic significance, enzymatic operation, moonlighting activities, and pathological relevance with links to underlying structural features. This ubiquitous family of related but diverse multienzyme complexes is involved in carbohydrate metabolism (pyruvate dehydrogenase complex), the citric acid cycle (α-ketoglutarate dehydrogenase complex), and amino acid catabolism (branched-chain α-keto acid dehydrogenase complex, α-ketoadipate dehydrogenase complex); the complexes all function at strategic points and also participate in regulation in these metabolic pathways. These systems are among the largest multienzyme complexes with at times more than 100 protein chains and weights ranging up to ~10 million Daltons. Our chapter offers a wealth of up-to-date information on these multienzyme complexes for a comprehensive understanding of their significance in health and disease.
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Affiliation(s)
- Eszter Szabo
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Balint Nagy
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Andras Czajlik
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Timea Komlodi
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Oliver Ozohanics
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Laszlo Tretter
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Attila Ambrus
- Department of Biochemistry, Semmelweis University, Budapest, Hungary.
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3
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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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4
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Yakoviichuk A, Krivova Z, Maltseva S, Kochubey A, Kulikovskiy M, Maltsev Y. Antioxidant Status and Biotechnological Potential of New Vischeria vischeri (Eustigmatophyceae) Soil Strains in Enrichment Cultures. Antioxidants (Basel) 2023; 12:654. [PMID: 36978902 PMCID: PMC10045218 DOI: 10.3390/antiox12030654] [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: 02/07/2023] [Revised: 03/03/2023] [Accepted: 03/04/2023] [Indexed: 03/08/2023] Open
Abstract
The functional state of enrichment cultures of the Eustigmatophycean strains Vischeria vischeri MZ-E3 and MZ-E4 after 25-day cultivation in the BBM medium was studied. The concentrations of chlorophyll a, total carotenoids, protein, vitamins A and E, fatty acid peroxidation product content, an antioxidant enzyme, and succinate dehydrogenase activity were measured. MZ-E3 succinate dehydrogenase activity was significantly higher by 2.21 times; the MZ-E4 strain had 2.94 times higher glutathione peroxidase activity. The MZ-E3 antioxidant activity index and the MZ-E3 unsaturation of fatty acids were 1.3 and 1.25 times higher than the MZ-E4. The retinol and α-tocopherol content of the MZ-E3 was 28.6% and 38.76% higher than MZ-E4. The main fatty acid profile differences were the 3.46-fold and 3.92-fold higher stearic and eicosapentaenoic acid content in the MZ-E4 biomass. MZ-E3 had higher antioxidant, energy, and metabolic and photosynthetic status than MZ-E4. The antioxidant status of the studied strains showed the dependence of the adaptive mechanisms of each, associated with differences in the ecological conditions of the biotopes from which they were isolated. These strains are promising for producing α-tocopherol and biomass enriched with omega-3 and omega-6 fatty acids.
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Affiliation(s)
- Aleksandr Yakoviichuk
- Faculty of Natural Sciences, A. Makarenko Melitopol State University, Melitopol 72312, Russia
| | - Zinaida Krivova
- Laboratory of Molecular Systematics of Aquatic Plants, K.A. Timiryazev Institute of Plant Physiology RAS, IPP RAS, Moscow 127276, Russia
| | - Svetlana Maltseva
- Laboratory of Molecular Systematics of Aquatic Plants, K.A. Timiryazev Institute of Plant Physiology RAS, IPP RAS, Moscow 127276, Russia
| | - Angelica Kochubey
- Faculty of Natural Sciences, A. Makarenko Melitopol State University, Melitopol 72312, Russia
| | - Maxim Kulikovskiy
- Laboratory of Molecular Systematics of Aquatic Plants, K.A. Timiryazev Institute of Plant Physiology RAS, IPP RAS, Moscow 127276, Russia
| | - Yevhen Maltsev
- Laboratory of Molecular Systematics of Aquatic Plants, K.A. Timiryazev Institute of Plant Physiology RAS, IPP RAS, Moscow 127276, Russia
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5
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Probing the E1o-E2o and E1a-E2o Interactions in Binary Subcomplexes of the Human 2-Oxoglutarate Dehydrogenase and 2-Oxoadipate Dehydrogenase Complexes by Chemical Cross-Linking Mass Spectrometry and Molecular Dynamics Simulation. Int J Mol Sci 2023; 24:ijms24054555. [PMID: 36901986 PMCID: PMC10003691 DOI: 10.3390/ijms24054555] [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: 12/19/2022] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/02/2023] Open
Abstract
The human 2-oxoglutarate dehydrogenase complex (hOGDHc) is a key enzyme in the tricarboxylic acid cycle and is one of the main regulators of mitochondrial metabolism through NADH and reactive oxygen species levels. Evidence was obtained for formation of a hybrid complex between the hOGDHc and its homologue the 2-oxoadipate dehydrogenase complex (hOADHc) in the L-lysine metabolic pathway, suggesting a crosstalk between the two distinct pathways. Findings raised fundamental questions about the assembly of hE1a (2-oxoadipate-dependent E1 component) and hE1o (2-oxoglutarate-dependent E1) to the common hE2o core component. Here we report chemical cross-linking mass spectrometry (CL-MS) and molecular dynamics (MD) simulation analyses to understand assembly in binary subcomplexes. The CL-MS studies revealed the most prominent loci for hE1o-hE2o and hE1a-hE2o interactions and suggested different binding modes. The MD simulation studies led to the following conclusions: (i) The N-terminal regions in E1s are shielded by, but do not interact directly with hE2o. (ii) The hE2o linker region exhibits the highest number of H-bonds with the N-terminus and α/β1 helix of hE1o, yet with the interdomain linker and α/β1 helix of hE1a. (iii) The C-termini are involved in dynamic interactions in complexes, suggesting the presence of at least two conformations in solution.
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Horváth G, Sváb G, Komlódi T, Ravasz D, Kacsó G, Doczi J, Chinopoulos C, Ambrus A, Tretter L. Reverse and Forward Electron Flow-Induced H2O2 Formation Is Decreased in α-Ketoglutarate Dehydrogenase (α-KGDH) Subunit (E2 or E3) Heterozygote Knock Out Animals. Antioxidants (Basel) 2022; 11:antiox11081487. [PMID: 36009207 PMCID: PMC9404749 DOI: 10.3390/antiox11081487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 12/04/2022] Open
Abstract
α-ketoglutarate dehydrogenase complex (KGDHc), or 2-oxoglutarate dehydrogenase complex (OGDHc) is a rate-limiting enzyme in the tricarboxylic acid cycle, that has been identified in neurodegenerative diseases such as in Alzheimer’s disease. The aim of the present study was to establish the role of the KGDHc and its subunits in the bioenergetics and reactive oxygen species (ROS) homeostasis of brain mitochondria. To study the bioenergetic profile of KGDHc, genetically modified mouse strains were used having a heterozygous knock out (KO) either in the dihydrolipoyl succinyltransferase (DLST+/−) or in the dihydrolipoyl dehydrogenase (DLD+/−) subunit. Mitochondrial oxygen consumption, hydrogen peroxide (H2O2) production, and expression of antioxidant enzymes were measured in isolated mouse brain mitochondria. Here, we demonstrate that the ADP-stimulated respiration of mitochondria was partially arrested in the transgenic animals when utilizing α-ketoglutarate (α-KG or 2-OG) as a fuel substrate. Succinate and α-glycerophosphate (α-GP), however, did not show this effect. The H2O2 production in mitochondria energized with α-KG was decreased after inhibiting the adenine nucleotide translocase and Complex I (CI) in the transgenic strains compared to the controls. Similarly, the reverse electron transfer (RET)-evoked H2O2 formation supported by succinate or α-GP were inhibited in mitochondria isolated from the transgenic animals. The decrease of RET-evoked ROS production by DLST+/− or DLD+/− KO-s puts the emphasis of the KGDHc in the pathomechanism of ischemia-reperfusion evoked oxidative stress. Supporting this notion, expression of the antioxidant enzyme glutathione peroxidase was also decreased in the KGDHc transgenic animals suggesting the attenuation of ROS-producing characteristics of KGDHc. These findings confirm the contribution of the KGDHc to the mitochondrial ROS production and in the pathomechanism of ischemia-reperfusion injury.
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7
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Functional Versatility of the Human 2-Oxoadipate Dehydrogenase in the L-Lysine Degradation Pathway toward Its Non-Cognate Substrate 2-Oxopimelic Acid. Int J Mol Sci 2022; 23:ijms23158213. [PMID: 35897808 PMCID: PMC9367764 DOI: 10.3390/ijms23158213] [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: 06/23/2022] [Revised: 07/23/2022] [Accepted: 07/24/2022] [Indexed: 11/17/2022] Open
Abstract
The human 2-oxoadipate dehydrogenase complex (OADHc) in L-lysine catabolism is involved in the oxidative decarboxylation of 2-oxoadipate (OA) to glutaryl-CoA and NADH (+H+). Genetic findings have linked the DHTKD1 encoding 2-oxoadipate dehydrogenase (E1a), the first component of the OADHc, to pathogenesis of AMOXAD, eosinophilic esophagitis (EoE), and several neurodegenerative diseases. A multipronged approach, including circular dichroism spectroscopy, Fourier Transform Mass Spectrometry, and computational approaches, was applied to provide novel insight into the mechanism and functional versatility of the OADHc. The results demonstrate that E1a oxidizes a non-cognate substrate 2-oxopimelate (OP) as well as OA through the decarboxylation step, but the OADHc was 100-times less effective in reactions producing adipoyl-CoA and NADH from the dihydrolipoamide succinyltransferase (E2o) and dihydrolipoamide dehydrogenase (E3). The results revealed that the E2o is capable of producing succinyl-CoA, glutaryl-CoA, and adipoyl-CoA. The important conclusions are the identification of: (i) the functional promiscuity of E1a and (ii) the ability of the E2o to form acyl-CoA products derived from homologous 2-oxo acids with five, six, and even seven carbon atoms. The findings add to our understanding of both the OADHc function in the L-lysine degradative pathway and of the molecular mechanisms leading to the pathogenesis associated with DHTKD1 variants.
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8
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Engineering the 2-Oxoglutarate Dehydrogenase Complex to Understand Catalysis and Alter Substrate Recognition. REACTIONS 2022. [DOI: 10.3390/reactions3010011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The E. coli 2-oxoglutarate dehydrogenase complex (OGDHc) is a multienzyme complex in the tricarboxylic acid cycle, consisting of multiple copies of three components, 2-oxoglutarate dehydrogenase (E1o), dihydrolipoamide succinyltransferase (E2o) and dihydrolipoamide dehydrogenase (E3), which catalyze the formation of succinyl-CoA and NADH (+H+) from 2-oxoglutarate. This review summarizes applications of the site saturation mutagenesis (SSM) to engineer E. coli OGDHc with mechanistic and chemoenzymatic synthetic goals. First, E1o was engineered by creating SSM libraries at positions His260 and His298.Variants were identified that: (a) lead to acceptance of substrate analogues lacking the 5-carboxyl group and (b) performed carboligation reactions producing acetoin-like compounds with good enantioselectivity. Engineering the E2o catalytic (core) domain enabled (a) assignment of roles for pivotal residues involved in catalysis, (b) re-construction of the substrate-binding pocket to accept substrates other than succinyllysyldihydrolipoamide and (c) elucidation of the mechanism of trans-thioesterification to involve stabilization of a tetrahedral oxyanionic intermediate with hydrogen bonds by His375 and Asp374, rather than general acid–base catalysis which has been misunderstood for decades. The E. coli OGDHc is the first example of a 2-oxo acid dehydrogenase complex which was evolved to a 2-oxo aliphatic acid dehydrogenase complex by engineering two consecutive E1o and E2o components.
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9
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Leandro J, Dodatko T, Aten J, Nemeria NS, Zhang X, Jordan F, Hendrickson RC, Sanchez R, Yu C, DeVita RJ, Houten SM. DHTKD1 and OGDH display substrate overlap in cultured cells and form a hybrid 2-oxo acid dehydrogenase complex in vivo. Hum Mol Genet 2021; 29:1168-1179. [PMID: 32160276 DOI: 10.1093/hmg/ddaa037] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/27/2020] [Accepted: 03/04/2020] [Indexed: 11/14/2022] Open
Abstract
Glutaric aciduria type 1 (GA1) is an inborn error of lysine degradation characterized by a specific encephalopathy that is caused by toxic accumulation of lysine degradation intermediates. Substrate reduction through inhibition of DHTKD1, an enzyme upstream of the defective glutaryl-CoA dehydrogenase, has been investigated as a potential therapy, but revealed the existence of an alternative enzymatic source of glutaryl-CoA. Here, we show that loss of DHTKD1 in glutaryl-CoA dehydrogenase-deficient HEK-293 cells leads to a 2-fold decrease in the established GA1 clinical biomarker glutarylcarnitine and demonstrate that oxoglutarate dehydrogenase (OGDH) is responsible for this remaining glutarylcarnitine production. We furthermore show that DHTKD1 interacts with OGDH, dihydrolipoyl succinyltransferase and dihydrolipoamide dehydrogenase to form a hybrid 2-oxoglutaric and 2-oxoadipic acid dehydrogenase complex. In summary, 2-oxoadipic acid is a substrate for DHTKD1, but also for OGDH in a cell model system. The classical 2-oxoglutaric dehydrogenase complex can exist as a previously undiscovered hybrid containing DHTKD1 displaying improved kinetics towards 2-oxoadipic acid.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jan Aten
- Department of Pathology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, 1105 AZ The Netherlands
| | - Natalia S Nemeria
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA
| | - Xu Zhang
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA
| | - Frank Jordan
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA
| | - Ronald C Hendrickson
- Microchemistry and Proteomics Core, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Roberto Sanchez
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Mount Sinai Genomics, Inc., Stamford, CT 06902, USA
| | - Robert J DeVita
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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10
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Fleminger G, Dayan A. The moonlighting activities of dihydrolipoamide dehydrogenase: Biotechnological and biomedical applications. J Mol Recognit 2021; 34:e2924. [PMID: 34164859 DOI: 10.1002/jmr.2924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 06/13/2021] [Indexed: 12/13/2022]
Abstract
Dihydrolipoamide dehydrogenase (DLDH) is a homodimeric flavin-dependent enzyme that catalyzes the NAD+ -dependent oxidation of dihydrolipoamide. The enzyme is part of several multi-enzyme complexes such as the Pyruvate Dehydrogenase system that transforms pyruvate into acetyl-co-A. Concomitantly with its redox activity, DLDH produces Reactive Oxygen Species (ROS), which are involved in cellular apoptotic processes. DLDH possesses several moonlighting functions. One of these is the capacity to adhere to metal-oxides surfaces. This was first exemplified by the presence of an exocellular form of the enzyme on the cell-wall surface of Rhodococcus ruber. This capability was evolutionarily conserved and identified in the human, mitochondrial, DLDH. The enzyme was modified with Arg-Gly-Asp (RGD) groups, which enabled its interaction with integrin-rich cancer cells followed by "integrin-assisted-endocytosis." This allowed harnessing the enzyme for cancer therapy. Combining the TiO2 -binding property with DLDH's ROS-production, enabled us to develop several medical applications including improving oesseointegration of TiO2 -based implants and photodynamic treatment for melanoma. The TiO2 -binding sites of both the bacterial and human DLDH's were identified on the proteins' molecules at regions that overlap with the binding site of E3-binding protein (E3BP). This protein is essential in forming the multiunit structure of PDC. Another moonlighting activity of DLDH, which is described in this Review, is its DNA-binding capacity that may affect DNA chelation and shredding leading to apoptotic processes in living cells. The typical ROS-generation by DLDH, which occurs in association with its enzymatic activity and its implications in cancer and apoptotic cell death are also discussed.
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Affiliation(s)
- Gideon Fleminger
- The Shmunis School of Biomedicine and Cancer Research, The George Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
| | - Avraham Dayan
- The Shmunis School of Biomedicine and Cancer Research, The George Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
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11
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Nemeria NS, Zhang X, Leandro J, Zhou J, Yang L, Houten SM, Jordan F. Toward an Understanding of the Structural and Mechanistic Aspects of Protein-Protein Interactions in 2-Oxoacid Dehydrogenase Complexes. Life (Basel) 2021; 11:407. [PMID: 33946784 PMCID: PMC8146983 DOI: 10.3390/life11050407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 12/24/2022] Open
Abstract
The 2-oxoglutarate dehydrogenase complex (OGDHc) is a key enzyme in the tricarboxylic acid (TCA) cycle and represents one of the major regulators of mitochondrial metabolism through NADH and reactive oxygen species levels. The OGDHc impacts cell metabolic and cell signaling pathways through the coupling of 2-oxoglutarate metabolism to gene transcription related to tumor cell proliferation and aging. DHTKD1 is a gene encoding 2-oxoadipate dehydrogenase (E1a), which functions in the L-lysine degradation pathway. The potentially damaging variants in DHTKD1 have been associated to the (neuro) pathogenesis of several diseases. Evidence was obtained for the formation of a hybrid complex between the OGDHc and E1a, suggesting a potential cross talk between the two metabolic pathways and raising fundamental questions about their assembly. Here we reviewed the recent findings and advances in understanding of protein-protein interactions in OGDHc and 2-oxoadipate dehydrogenase complex (OADHc), an understanding that will create a scaffold to help design approaches to mitigate the effects of diseases associated with dysfunction of the TCA cycle or lysine degradation. A combination of biochemical, biophysical and structural approaches such as chemical cross-linking MS and cryo-EM appears particularly promising to provide vital information for the assembly of 2-oxoacid dehydrogenase complexes, their function and regulation.
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Affiliation(s)
- Natalia S. Nemeria
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
| | - Xu Zhang
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
| | - Joao Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (J.L.); (S.M.H.)
| | - Jieyu Zhou
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
| | - Luying Yang
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
| | - Sander M. Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (J.L.); (S.M.H.)
| | - Frank Jordan
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
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12
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Nagy B, Polak M, Ozohanics O, Zambo Z, Szabo E, Hubert A, Jordan F, Novaček J, Adam-Vizi V, Ambrus A. Structure of the dihydrolipoamide succinyltransferase (E2) component of the human alpha-ketoglutarate dehydrogenase complex (hKGDHc) revealed by cryo-EM and cross-linking mass spectrometry: Implications for the overall hKGDHc structure. Biochim Biophys Acta Gen Subj 2021; 1865:129889. [PMID: 33684457 DOI: 10.1016/j.bbagen.2021.129889] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/05/2021] [Accepted: 03/02/2021] [Indexed: 12/19/2022]
Abstract
BACKGROUND The human mitochondrial alpha-ketoglutarate dehydrogenase complex (hKGDHc) converts KG to succinyl-CoA and NADH. Malfunction of and reactive oxygen species generation by the hKGDHc as well as its E1-E2 subcomplex are implicated in neurodegenerative disorders, ischemia-reperfusion injury, E3-deficiency and cancers. METHODS We performed cryo-EM, cross-linking mass spectrometry (CL-MS) and molecular modeling analyses to determine the structure of the E2 component of the hKGDHc (hE2k); hE2k transfers a succinyl group to CoA and forms the structural core of hKGDHc. We also assessed the overall structure of the hKGDHc by negative-stain EM and modeling. RESULTS We report the 2.9 Å resolution cryo-EM structure of the hE2k component. The cryo-EM map comprises density for hE2k residues 151-386 - the entire (inner) core catalytic domain plus a few additional residues -, while residues 1-150 are not observed due to the inherent flexibility of the N-terminal region. The structure of the latter segment was also determined by CL-MS and homology modeling. Negative-stain EM on in vitro assembled hKGDHc and previous data were used to build a putative overall structural model of the hKGDHc. CONCLUSIONS The E2 core of the hKGDHc is composed of 24 hE2k chains organized in octahedral (8 × 3 type) assembly. Each lipoyl domain is oriented towards the core domain of an adjacent chain in the hE2k homotrimer. hE1k and hE3 are most likely tethered at the edges and faces, respectively, of the cubic hE2k assembly. GENERAL SIGNIFICANCE The revealed structural information will support the future pharmacologically targeting of the hKGDHc.
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Affiliation(s)
- Balint Nagy
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Martin Polak
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Oliver Ozohanics
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Zsofia Zambo
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Eszter Szabo
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Agnes Hubert
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Frank Jordan
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Jiří Novaček
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Vera Adam-Vizi
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Attila Ambrus
- Department of Biochemistry, Institute of Biochemistry and Molecular Biology, Semmelweis University, Budapest, Hungary.
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13
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Zhang X, Nemeria NS, Leandro J, Houten S, Lazarus M, Gerfen G, Ozohanics O, Ambrus A, Nagy B, Brukh R, Jordan F. Structure-function analyses of the G729R 2-oxoadipate dehydrogenase genetic variant associated with a disorder of l-lysine metabolism. J Biol Chem 2020; 295:8078-8095. [PMID: 32303640 PMCID: PMC7278340 DOI: 10.1074/jbc.ra120.012761] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/16/2020] [Indexed: 12/13/2022] Open
Abstract
2-Oxoadipate dehydrogenase (E1a, also known as DHTKD1, dehydrogenase E1, and transketolase domain-containing protein 1) is a thiamin diphosphate-dependent enzyme and part of the 2-oxoadipate dehydrogenase complex (OADHc) in l-lysine catabolism. Genetic findings have linked mutations in the DHTKD1 gene to several metabolic disorders. These include α-aminoadipic and α-ketoadipic aciduria (AMOXAD), a rare disorder of l-lysine, l-hydroxylysine, and l-tryptophan catabolism, associated with clinical presentations such as developmental delay, mild-to-severe intellectual disability, ataxia, epilepsy, and behavioral disorders that cannot currently be managed by available treatments. A heterozygous missense mutation, c.2185G→A (p.G729R), in DHTKD1 has been identified in most AMOXAD cases. Here, we report that the G729R E1a variant when assembled into OADHc in vitro displays a 50-fold decrease in catalytic efficiency for NADH production and a significantly reduced rate of glutaryl-CoA production by dihydrolipoamide succinyl-transferase (E2o). However, the G729R E1a substitution did not affect any of the three side-reactions associated solely with G729R E1a, prompting us to determine the structure-function effects of this mutation. A multipronged systematic analysis of the reaction rates in the OADHc pathway, supplemented with results from chemical cross-linking and hydrogen-deuterium exchange MS, revealed that the c.2185G→A DHTKD1 mutation affects E1a-E2o assembly, leading to impaired channeling of OADHc intermediates. Cross-linking between the C-terminal region of both E1a and G729R E1a with the E2o lipoyl and core domains suggested that correct positioning of the C-terminal E1a region is essential for the intermediate channeling. These findings may inform the development of interventions to counter the effects of pathogenic DHTKD1 mutations.
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Affiliation(s)
- Xu Zhang
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Natalia S Nemeria
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Sander Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Michael Lazarus
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Gary Gerfen
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10641-2304
| | - Oliver Ozohanics
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - Attila Ambrus
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - Balint Nagy
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - Roman Brukh
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Frank Jordan
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
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14
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Dobolyi A, Bago A, Palkovits M, Nemeria NS, Jordan F, Doczi J, Ambrus A, Adam-Vizi V, Chinopoulos C. Exclusive neuronal detection of KGDHC-specific subunits in the adult human brain cortex despite pancellular protein lysine succinylation. Brain Struct Funct 2020; 225:639-667. [PMID: 31982949 PMCID: PMC7046601 DOI: 10.1007/s00429-020-02026-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 01/11/2020] [Indexed: 12/31/2022]
Abstract
The ketoglutarate dehydrogenase complex (KGDHC) consists of three different subunits encoded by OGDH (or OGDHL), DLST, and DLD, combined in different stoichiometries. DLD subunit is shared between KGDHC and pyruvate dehydrogenase complex, branched-chain alpha-keto acid dehydrogenase complex, and the glycine cleavage system. Despite KGDHC's implication in neurodegenerative diseases, cell-specific localization of its subunits in the adult human brain has never been investigated. Here, we show that immunoreactivity of all known isoforms of OGDHL, OGDH, and DLST was detected exclusively in neurons of surgical human cortical tissue samples identified by their morphology and visualized by double labeling with fluorescent Nissl, while being absent from glia expressing GFAP, Aldhl1, myelin basic protein, Olig2, or IBA1. In contrast, DLD immunoreactivity was evident in both neurons and glia. Specificity of anti-KGDHC subunits antisera was verified by a decrease in staining of siRNA-treated human cancer cell lines directed against the respective coding gene products; furthermore, immunoreactivity of KGDHC subunits in human fibroblasts co-localized > 99% with mitotracker orange, while western blotting of 63 post-mortem brain samples and purified recombinant proteins afforded further assurance regarding antisera monospecificity. KGDHC subunit immunoreactivity correlated with data from the Human Protein Atlas as well as RNA-Seq data from the Allen Brain Atlas corresponding to genes coding for KGDHC components. Protein lysine succinylation, however, was immunohistochemically evident in all cortical cells; this was unexpected, because this posttranslational modification requires succinyl-CoA, the product of KGDHC. In view of the fact that glia of the human brain cortex lack succinate-CoA ligase, an enzyme producing succinyl-CoA when operating in reverse, protein lysine succinylation in these cells must exclusively rely on propionate and/or ketone body metabolism or some other yet to be discovered pathway encompassing succinyl-CoA.
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Affiliation(s)
- Arpad Dobolyi
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences and Eotvos Lorand University, Budapest, 1117, Hungary
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, 1094, Hungary
| | - Attila Bago
- National Institute of Neurosurgery, Budapest, 1145, Hungary
| | - Miklos Palkovits
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences and Eotvos Lorand University, Budapest, 1117, Hungary
| | - Natalia S Nemeria
- Department of Chemistry, Rutgers University, Newark, NJ, 07102-1811, USA
| | - Frank Jordan
- Department of Chemistry, Rutgers University, Newark, NJ, 07102-1811, USA
| | - Judit Doczi
- Department of Medical Biochemistry, Semmelweis University, Tuzolto st. 37-47, Budapest, 1094, Hungary
| | - Attila Ambrus
- Department of Medical Biochemistry, Semmelweis University, Tuzolto st. 37-47, Budapest, 1094, Hungary
- MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, 1094, Hungary
| | - Vera Adam-Vizi
- Department of Medical Biochemistry, Semmelweis University, Tuzolto st. 37-47, Budapest, 1094, Hungary
- MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, 1094, Hungary
| | - Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Tuzolto st. 37-47, Budapest, 1094, Hungary.
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15
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Bunik VI. Redox-Driven Signaling: 2-Oxo Acid Dehydrogenase Complexes as Sensors and Transmitters of Metabolic Imbalance. Antioxid Redox Signal 2019; 30:1911-1947. [PMID: 30187773 DOI: 10.1089/ars.2017.7311] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
SIGNIFICANCE This article develops a holistic view on production of reactive oxygen species (ROS) by 2-oxo acid dehydrogenase complexes. Recent Advances: Catalytic and structural properties of the complexes and their components evolved to minimize damaging effects of side reactions, including ROS generation, simultaneously exploiting the reactions for homeostatic signaling. CRITICAL ISSUES Side reactions of the complexes, characterized in vitro, are analyzed in view of protein interactions and conditions in vivo. Quantitative data support prevalence of the forward 2-oxo acid oxidation over the backward NADH oxidation in feeding physiologically significant ROS production by the complexes. Special focus on interactions between the active sites within 2-oxo acid dehydrogenase complexes highlights the central relevance of the complex-bound thiyl radicals in regulation of and signaling by complex-generated ROS. The thiyl radicals arise when dihydrolipoyl residues of the complexes regenerate FADH2 from the flavin semiquinone coproduced with superoxide anion radical in 1e- oxidation of FADH2 by molecular oxygen. FUTURE DIRECTIONS Interaction of 2-oxo acid dehydrogenase complexes with thioredoxins (TRXs), peroxiredoxins, and glutaredoxins mediates scavenging of the thiyl radicals and ROS generated by the complexes, underlying signaling of disproportional availability of 2-oxo acids, CoA, and NAD+ in key metabolic branch points through thiol/disulfide exchange and medically important hypoxia-inducible factor, mammalian target of rapamycin (mTOR), poly (ADP-ribose) polymerase, and sirtuins. High reactivity of the coproduced ROS and thiyl radicals to iron/sulfur clusters and nitric oxide, peroxynitrite reductase activity of peroxiredoxins and transnitrosylating function of thioredoxin, implicate the side reactions of 2-oxo acid dehydrogenase complexes in nitric oxide-dependent signaling and damage.
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Affiliation(s)
- Victoria I Bunik
- 1 Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation.,2 Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russian Federation
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16
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Human 2-Oxoglutarate Dehydrogenase and 2-Oxoadipate Dehydrogenase Both Generate Superoxide/H 2O 2 in a Side Reaction and Each Could Contribute to Oxidative Stress in Mitochondria. Neurochem Res 2019; 44:2325-2335. [PMID: 30847859 DOI: 10.1007/s11064-019-02765-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 12/30/2022]
Abstract
According to recent findings, the human 2-oxoglutarate dehydrogenase complex (hOGDHc) could be an important source of the reactive oxygen species in the mitochondria and could contribute to mitochondrial abnormalities associated with multiple neurodegenerative diseases, including Alzheimer's disease, Huntington disease, and Parkinson's disease. The human 2-oxoadipate dehydrogenase (hE1a) is a novel protein, which is encoded by the DHTKD1 gene. Both missence and nonsense mutations were identified in the DHTKD1 that lead to alpha-aminoadipic and alpha-oxoadipic aciduria, a metabolic disorder with a wide variety of the neurological abnormalities, and Charcot-Marie-Tooth disease type 2Q, an inherited neurological disorder affecting the peripheral nervous system. Recently, the rare pathogenic mutations in DHTKD1 and an increased H2O2 production were linked to the genetic ethiology of Eosinophilic Esophagitis (EoE), a chronic allergic inflammatory esophageal disorder. In view of the importance of hOGDHc in the tricarboxylic acid cycle (TCA cycle) and hE1a on the L-lysine, L-hydroxylysine and L-tryptophan degradation pathway in mitochondria, and to enhance our current understanding of the mechanism of superoxide/H2O2 generation by hOGDHc, and by human 2-oxoadipate dehydrogenase complex (hOADHc), this review focuses on several novel and unanticipated recent findings in vitro that emerged from the Jordan group's research. Most significantly, the hE1o and hE1a now join the hE3 as being able to generate the superoxide/H2O2 in mitochondria.
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17
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Mailloux RJ. Cysteine Switches and the Regulation of Mitochondrial Bioenergetics and ROS Production. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1158:197-216. [PMID: 31452142 DOI: 10.1007/978-981-13-8367-0_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mitochondria are dynamic organelles that perform a number of interconnected tasks that are elegantly intertwined with the regulation of cell functions. This includes the provision of ATP, reactive oxygen species (ROS), and building blocks for the biosynthesis of macromolecules while also serving as signaling platforms for the cell. Although the functions executed by mitochondria are complex, at its core these roles are, to a certain degree, fulfilled by electron transfer reactions and the establishment of a protonmotive force (PMF). Indeed, mitochondria are energy conserving organelles that extract electrons from nutrients to establish a PMF, which is then used to drive ATP and NADPH production, solute import, and many other functions including the propagation of cell signals. These same electrons extracted from nutrients are also used to produce ROS, pro-oxidants that can have potentially damaging effects at high levels, but also serve as secondary messengers at low amounts. Mitochondria are also enriched with antioxidant defenses, which are required to buffer cellular ROS. These same redox buffering networks also fulfill another important role; regulation of proteins through the reversible oxidation of cysteine switches. The modification of cysteine switches with the antioxidant glutathione, a process called protein S-glutathionylation, has been found to play an integral role in controlling various mitochondrial functions. In addition, recent findings have demonstrated that disrupting mitochondrial protein S-glutathionylation reactions can have some dire pathological consequences. Accordingly, this chapter focuses on the role of mitochondrial cysteine switches in the modulation of different physiological functions and how defects in these pathways contribute to the development of disease.
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Affiliation(s)
- Ryan J Mailloux
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada.
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18
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Regnier V, Romero EA, Molton F, Jazzar R, Bertrand G, Martin D. What Are the Radical Intermediates in Oxidative N-Heterocyclic Carbene Organocatalysis? J Am Chem Soc 2018; 141:1109-1117. [PMID: 30561990 DOI: 10.1021/jacs.8b11824] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The oxidation of the Breslow intermediate resulting from the addition of an N-heterocyclic carbene (NHC) to benzaldehyde triggers a fast deprotonation, followed by a second electron transfer, directly affording the corresponding acylium at E > -0.8 V (versus Fc/Fc+). Similarly, the oxidation of the cinnamaldehyde analogue occurs at an even higher potential and is not a reversible electrochemical process. As a whole, and contrary to previous beliefs, it is demonstrated that Breslow intermediates, which are the key intermediates in NHC-catalyzed transformations of aldehydes, cannot undergo a single electron transfer (SET) with mild oxidants ( E < -1.0 V). Moreover, the corresponding enol radical cations are ruled out as relevant intermediates. It is proposed that oxidative NHC-catalyzed radical transformations of enals proceed either through SET from the corresponding electron-rich enolate or through coupled electron-proton transfer from the enol, in any case generating neutral capto-dative radicals. Relevant electrochemical surrogates of these paramagnetic species have been isolated.
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Affiliation(s)
| | - Erik A Romero
- UMI CNRS 3555, Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093-0343 , United States
| | - Florian Molton
- Univ. Grenoble Alpes , CNRS, DCM , 38000 Grenoble , France
| | - Rodolphe Jazzar
- UMI CNRS 3555, Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093-0343 , United States
| | - Guy Bertrand
- UMI CNRS 3555, Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093-0343 , United States
| | - David Martin
- Univ. Grenoble Alpes , CNRS, DCM , 38000 Grenoble , France
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19
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Hsu N, Wang Y, Lin K, Chang C, Ke S, Lyu S, Hsu L, Li Y, Chen S, Wang K, Li T. Evidence of Diradicals Involved in the Yeast Transketolase Catalyzed Keto-Transferring Reactions. Chembiochem 2018; 19:2395-2402. [PMID: 30155962 PMCID: PMC6282555 DOI: 10.1002/cbic.201800378] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Indexed: 11/12/2022]
Abstract
Transketolase (TK) catalyzes a reversible transfer of a two-carbon (C2 ) unit between phosphoketose donors and phosphoaldose acceptors, for which the group-transfer reaction that follows a one- or two-electron mechanism and the force that breaks the C2"-C3" bond of the ketose donors remain unresolved. Herein, we report ultrahigh-resolution crystal structures of a TK (TKps) from Pichia stipitis in previously undiscovered intermediate states and support a diradical mechanism for a reversible group-transfer reaction. In conjunction with MS, NMR spectroscopy, EPR and computational analyses, it is concluded that the enzyme-catalyzed non-Kekulé diradical cofactor brings about the C2"-C3" bond cleavage/formation for the C2 -unit transfer reaction, for which suppression of activation energy and activation and destabilization of enzymatic intermediates are facilitated.
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Affiliation(s)
- Ning‐Shian Hsu
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
- Institute of Biochemistry and Molecular BiologyNational Yang-Ming UniversityTaipei112Taiwan
| | - Yung‐Lin Wang
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | - Kuan‐Hung Lin
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
- Institute of Biochemistry and Molecular BiologyNational Yang-Ming UniversityTaipei112Taiwan
| | - Chi‐Fon Chang
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | - Shyue‐Chu Ke
- Department of PhysicsNational Dong Hwa UniversityHualien974Taiwan
| | - Syue‐Yi Lyu
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | - Li‐Jen Hsu
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | - Yi‐Shan Li
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
| | | | | | - Tsung‐Lin Li
- Genomics Research CenterAcademia SinicaTaipei115Taiwan
- Biotechnology CenterNational Chung Hsing UniversityTaichung City402Taiwan
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20
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Zhou J, Yang L, Ozohanics O, Zhang X, Wang J, Ambrus A, Arjunan P, Brukh R, Nemeria NS, Furey W, Jordan F. A multipronged approach unravels unprecedented protein-protein interactions in the human 2-oxoglutarate dehydrogenase multienzyme complex. J Biol Chem 2018; 293:19213-19227. [PMID: 30323066 DOI: 10.1074/jbc.ra118.005432] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 09/17/2018] [Indexed: 10/28/2022] Open
Abstract
The human 2-oxoglutaric acid dehydrogenase complex (hOGDHc) plays a pivotal role in the tricarboxylic acid (TCA) cycle, and its diminished activity is associated with neurodegenerative diseases. The hOGDHc comprises three components, hE1o, hE2o, and hE3, and we recently reported functionally active E1o and E2o components, enabling studies on their assembly. No atomic-resolution structure for the hE2o component is currently available, so here we first studied the interactions in the binary subcomplexes (hE1o-hE2o, hE1o-hE3, and hE2o-hE3) to gain insight into the strength of their interactions and to identify the interaction loci in them. We carried out multiple physico-chemical studies, including fluorescence, hydrogen-deuterium exchange MS (HDX-MS), and chemical cross-linking MS (CL-MS). Our fluorescence studies suggested a strong interaction for the hE1o-hE2o subcomplex, but a much weaker interaction in the hE1o-hE3 subcomplex, and failed to identify any interaction in the hE2o-hE3 subcomplex. The HDX-MS studies gave evidence for interactions in the hE1o-hE2o and hE1o-hE3 subcomplexes comprising full-length components, identifying: (i) the N-terminal region of hE1o, in particular the two peptides 18YVEEM22 and 27ENPKSVHKSWDIF39 as constituting the binding region responsible for the assembly of the hE1o with both the hE2o and hE3 components into hOGDHc, an hE1 region absent in available X-ray structures; and (ii) a novel hE2o region comprising residues from both a linker region and from the catalytic domain as being a critical region interacting with hE1o. The CL-MS identified the loci in the hE1o and hE2o components interacting with each other.
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Affiliation(s)
- Jieyu Zhou
- From the Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Luying Yang
- From the Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Oliver Ozohanics
- the Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 27-29 Tuzolto Utca, Budapest H-1094, Hungary
| | - Xu Zhang
- From the Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Junjie Wang
- From the Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Attila Ambrus
- the Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 27-29 Tuzolto Utca, Budapest H-1094, Hungary
| | - Palaniappa Arjunan
- the Biocrystallography Laboratory, Veterans Affairs Medical Center, Pittsburgh, Pennsylvania 15240.,the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, and
| | - Roman Brukh
- From the Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Natalia S Nemeria
- From the Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102,
| | - William Furey
- the Biocrystallography Laboratory, Veterans Affairs Medical Center, Pittsburgh, Pennsylvania 15240.,the Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, and
| | - Frank Jordan
- From the Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102,
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21
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Chakraborty J, Nemeria NS, Farinas E, Jordan F. Catalysis of transthiolacylation in the active centers of dihydrolipoamide acyltransacetylase components of 2-oxo acid dehydrogenase complexes. FEBS Open Bio 2018; 8:880-896. [PMID: 29928569 PMCID: PMC5986005 DOI: 10.1002/2211-5463.12431] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 03/29/2018] [Accepted: 04/09/2018] [Indexed: 11/25/2022] Open
Abstract
The Escherichia coli 2‐oxoglutarate dehydrogenase complex (OGDHc) comprises multiple copies of three enzymes—E1o, E2o, and E3—and transthioesterification takes place within the catalytic domain of E2o. The succinyl group from the thiol ester of S8‐succinyldihydrolipoyl‐E2o is transferred to the thiol group of coenzyme A (CoA), forming the all‐important succinyl‐CoA. Here, we report mechanistic studies of enzymatic transthioesterification on OGDHc. Evidence is provided for the importance of His375 and Asp374 in E2o for the succinyl transfer reaction. The magnitude of the rate acceleration provided by these residues (54‐fold from each with alanine substitution) suggests a role in stabilization of the symmetrical tetrahedral oxyanionic intermediate by formation of two hydrogen bonds, rather than in acid–base catalysis. Further evidence ruling out a role in acid–base catalysis is provided by site‐saturation mutagenesis studies at His375 (His375Trp substitution with little penalty) and substitutions to other potential hydrogen bond participants at Asp374. Taking into account that the rate constant for reductive succinylation of the E2o lipoyl domain (LDo) by E1o and 2‐oxoglutarate (99 s−1) was approximately twofold larger than the rate constant for kcat of 48 s−1 for the overall reaction (NADH production), it could be concluded that succinyl transfer to CoA and release of succinyl‐CoA, rather than reductive succinylation, is the rate‐limiting step. The results suggest a revised mechanism of catalysis for acyl transfer in the superfamily of 2‐oxo acid dehydrogenase complexes, thus provide fundamental information regarding acyl‐CoA formation, so important for several biological processes including post‐translational succinylation of protein lysines. Enzymes 2‐oxoglutarate dehydrogenase (http://www.chem.qmul.ac.uk/iubmb/enzyme/EC1/2/4/2.html); dihydrolipoamide succinyltransferase (http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/3/1/61.html); dihydrolipoamide dehydrogenase (http://www.chem.qmul.ac.uk/iubmb/enzyme/EC1/8/1/4.html); pyruvate dehydrogenase (http://www.chem.qmul.ac.uk/iubmb/enzyme/EC1/2/4/1.html); dihydrolipoamide acetyltransferase (http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/3/1/12.html).
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Affiliation(s)
- Joydeep Chakraborty
- Department of Chemistry and Environmental Science New Jersey Institute of Technology Newark NJ USA
| | | | - Edgardo Farinas
- Department of Chemistry and Environmental Science New Jersey Institute of Technology Newark NJ USA
| | - Frank Jordan
- Department of Chemistry Rutgers University Newark NJ USA
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22
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DeColli AA, Nemeria NS, Majumdar A, Gerfen GJ, Jordan F, Freel Meyers CL. Oxidative decarboxylation of pyruvate by 1-deoxy-d-xyulose 5-phosphate synthase, a central metabolic enzyme in bacteria. J Biol Chem 2018; 293:10857-10869. [PMID: 29784878 DOI: 10.1074/jbc.ra118.001980] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/17/2018] [Indexed: 01/06/2023] Open
Abstract
The underexploited antibacterial target 1-deoxy-d-xyluose 5-phosphate (DXP) synthase catalyzes the thiamin diphosphate (ThDP)-dependent formation of DXP from pyruvate and d-glyceraldehyde 3-phosphate (d-GAP). DXP is an essential intermediate in the biosynthesis of ThDP, pyridoxal phosphate, and isoprenoids in many pathogenic bacteria. DXP synthase catalyzes a distinct mechanism in ThDP decarboxylative enzymology in which the first enzyme-bound pre-decarboxylation intermediate, C2α-lactyl-ThDP (LThDP), is stabilized by DXP synthase in the absence of d-GAP, and d-GAP then induces efficient LThDP decarboxylation. Despite the observed LThDP accumulation and lack of evidence for C2α-carbanion formation in the absence of d-GAP, CO2 is released at appreciable levels under these conditions. Here, seeking to resolve these conflicting observations, we show that DXP synthase catalyzes the oxidative decarboxylation of pyruvate under conditions in which LThDP accumulates. O2-dependent LThDP decarboxylation led to one-electron transfer from the C2α-carbanion/enamine to O2, with intermediate ThDP-enamine radical formation, followed by peracetic acid formation en route to acetate. Thus, LThDP formation and decarboxylation and DXP formation were studied under anaerobic conditions. Our results support a model in which O2-dependent LThDP decarboxylation and peracetic acid formation occur in the absence of d-GAP, decreasing the levels of pyruvate and O2 in solution. The relative pyruvate and O2 concentrations then dictate the extent of LThDP accumulation, and its buildup can be observed when [pyruvate] > [O2]. The finding that O2 acts as a structurally distinct trigger of LThDP decarboxylation supports the hypothesis that a mechanism involving small molecule-dependent LThDP decarboxylation equips DXP synthase for diverse, yet uncharacterized cellular functions.
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Affiliation(s)
| | - Natalia S Nemeria
- the Department of Chemistry, Rutgers University, Newark, New Jersey 07102, and
| | - Ananya Majumdar
- Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Gary J Gerfen
- the Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Frank Jordan
- the Department of Chemistry, Rutgers University, Newark, New Jersey 07102, and
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23
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Nemeria NS, Gerfen G, Yang L, Zhang X, Jordan F. Evidence for functional and regulatory cross-talk between the tricarboxylic acid cycle 2-oxoglutarate dehydrogenase complex and 2-oxoadipate dehydrogenase on the l-lysine, l-hydroxylysine and l-tryptophan degradation pathways from studies in vitro. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:932-939. [PMID: 29752936 DOI: 10.1016/j.bbabio.2018.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/30/2018] [Accepted: 05/03/2018] [Indexed: 12/22/2022]
Abstract
Herein are reported findings in vitro suggesting both functional and regulatory cross-talk between the human 2-oxoglutarate dehydrogenase complex (hOGDHc), a key regulatory enzyme within the tricarboxylic acid cycle (TCA cycle), and a novel 2-oxoadipate dehydrogenase complex (hOADHc) from the final degradation pathway of l-lysine, l-hydroxylysine and l-tryptophan. The following could be concluded from our studies by using hOGDHc and hOADHc assembled from their individually expressed components in vitro: (i) Different substrate preferences (kcat/Km) were displayed by the two complexes even though they share the same dihydrolipoyl succinyltransferase (hE2o) and dihydrolipoyl dehydrogenase (hE3) components; (ii) Different binding modes were in evidence for the binary hE1o-hE2o and hE1a-hE2o subcomplexes according to fluorescence titrations using site-specifically labeled hE2o-derived proteins; (iii) Similarly to hE1o, the hE1a also forms the ThDP-enamine radical from 2-oxoadipate (electron paramagnetic resonance detection) in the oxidative half reaction; (iv) Both complexes produced superoxide/H2O2 from O2 in the reductive half reaction suggesting that hE1o, and hE1a (within their complexes) could both be sources of reactive oxygen species generation in mitochondria from 2-oxoglutarate and 2-oxoadipate, respectively; (v) Based on our findings, we speculate that hE2o can serve as a trans-glutarylase, in addition to being a trans-succinylase, a role suggested by others; (vi) The glutaryl-CoA produced by hOADHc inhibits hE1o, as does succinyl-CoA, suggesting a regulatory cross-talk between the two complexes on the different metabolic pathways.
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Affiliation(s)
- Natalia S Nemeria
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA.
| | - Gary Gerfen
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY 10641-2304, USA
| | - Luying Yang
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA
| | - Xu Zhang
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA
| | - Frank Jordan
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA.
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24
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Zheng Y, Ma AG, Zheng MC, Wang QZ, Liang H, Han XX, Schouten EG. B Vitamins Can Reduce Body Weight Gain by Increasing Metabolism-related Enzyme Activities in Rats Fed on a High-Fat Diet. Curr Med Sci 2018; 38:174-183. [DOI: 10.1007/s11596-018-1862-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 07/07/2017] [Indexed: 12/11/2022]
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25
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Hsu NS, Wang YL, Lin KH, Chang CF, Lyu SY, Hsu LJ, Liu YC, Chang CY, Wu CJ, Li TL. The Mesomeric Effect of Thiazolium on non-Kekulé Diradicals in Pichia stipitis
Transketolase. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201709799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ning-Shian Hsu
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
- Institute of Biochemistry and Molecular Biology; National Yang-Ming University; Taipei 112 Taiwan
| | - Yung-Lin Wang
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Kuan-Hung Lin
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
- Institute of Biochemistry and Molecular Biology; National Yang-Ming University; Taipei 112 Taiwan
| | - Chi-Fon Chang
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Syue-Yi Lyu
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Li-Jen Hsu
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Yu-Chen Liu
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Chin-Yuan Chang
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Chang-Jer Wu
- Department of Food Science; National (Taiwan) Ocean University; Keelung 202 Taiwan
| | - Tsung-Lin Li
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
- Biotechnology Center; National Chung Hsing University; Taichung City 402 Taiwan
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26
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Nemeria NS, Gerfen G, Nareddy PR, Yang L, Zhang X, Szostak M, Jordan F. The mitochondrial 2-oxoadipate and 2-oxoglutarate dehydrogenase complexes share their E2 and E3 components for their function and both generate reactive oxygen species. Free Radic Biol Med 2018; 115:136-145. [PMID: 29191460 DOI: 10.1016/j.freeradbiomed.2017.11.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 12/22/2022]
Abstract
Herein are reported unique properties of the novel human thiamin diphosphate (ThDP)-dependent enzyme 2-oxoadipate dehydrogenase (hE1a), known as dehydrogenase E1 and transketolase domain-containing protein 1 that is encoded by the DHTKD1 gene. It is involved in the oxidative decarboxylation of 2-oxoadipate (OA) to glutaryl-CoA on the final degradative pathway of L-lysine and is critical for mitochondrial metabolism. Functionally active recombinant hE1a has been produced according to both kinetic and spectroscopic criteria in our toolbox leading to the following conclusions: (i) The hE1a has recruited the dihydrolipoyl succinyltransferase (hE2o) and the dihydrolipoyl dehydrogenase (hE3) components of the tricarboxylic acid cycle 2-oxoglutarate dehydrogenase complex (OGDHc) for its activity. (ii) 2-Oxoglutarate (OG) and 2-oxoadipate (OA) could be oxidized by hE1a, however, hE1a displays an approximately 49-fold preference in catalytic efficiency for OA over OG, indicating that hE1a is specific to the 2-oxoadipate dehydrogenase complex. (iii) The hE1a forms the ThDP-enamine radical from OA according to electron paramagnetic resonance detection in the oxidative half reaction, and could produce superoxide and H2O2 from decarboxylation of OA in the forward physiological direction, as also seen with the 2-oxoglutarate dehydrogenase hE1o component. (iv) Once assembled to complex with the same hE2o and hE3 components, the hE1o and hE1a display strikingly different regulation: both succinyl-CoA and glutaryl-CoA significantly reduced the hE1o activity, but not the activity of hE1a.
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Affiliation(s)
- Natalia S Nemeria
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA.
| | - Gary Gerfen
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461-2304, USA
| | | | - Luying Yang
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA
| | - Xu Zhang
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA
| | - Michal Szostak
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA
| | - Frank Jordan
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA.
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27
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Hsu NS, Wang YL, Lin KH, Chang CF, Lyu SY, Hsu LJ, Liu YC, Chang CY, Wu CJ, Li TL. The Mesomeric Effect of Thiazolium on non-Kekulé Diradicals in Pichia stipitis
Transketolase. Angew Chem Int Ed Engl 2018; 57:1802-1807. [DOI: 10.1002/anie.201709799] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/23/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Ning-Shian Hsu
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
- Institute of Biochemistry and Molecular Biology; National Yang-Ming University; Taipei 112 Taiwan
| | - Yung-Lin Wang
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Kuan-Hung Lin
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
- Institute of Biochemistry and Molecular Biology; National Yang-Ming University; Taipei 112 Taiwan
| | - Chi-Fon Chang
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Syue-Yi Lyu
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Li-Jen Hsu
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Yu-Chen Liu
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Chin-Yuan Chang
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
| | - Chang-Jer Wu
- Department of Food Science; National (Taiwan) Ocean University; Keelung 202 Taiwan
| | - Tsung-Lin Li
- Genomics Research Center; Academia Sinica; Taipei 115 Taiwan
- Biotechnology Center; National Chung Hsing University; Taichung City 402 Taiwan
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28
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Bunik VI, Brand MD. Generation of superoxide and hydrogen peroxide by side reactions of mitochondrial 2-oxoacid dehydrogenase complexes in isolation and in cells. Biol Chem 2018; 399:407-420. [DOI: 10.1515/hsz-2017-0284] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/03/2018] [Indexed: 01/06/2023]
Abstract
Abstract
Mitochondrial 2-oxoacid dehydrogenase complexes oxidize 2-oxoglutarate, pyruvate, branched-chain 2-oxoacids and 2-oxoadipate to the corresponding acyl-CoAs and reduce NAD+ to NADH. The isolated enzyme complexes generate superoxide anion radical or hydrogen peroxide in defined reactions by leaking electrons to oxygen. Studies using isolated mitochondria in media mimicking cytosol suggest that the 2-oxoacid dehydrogenase complexes contribute little to the production of superoxide or hydrogen peroxide relative to other mitochondrial sites at physiological steady states. However, the contributions may increase under pathological conditions, in accordance with the high maximum capacities of superoxide or hydrogen peroxide-generating reactions of the complexes, established in isolated mitochondria. We assess available data on the use of modulations of enzyme activity to infer superoxide or hydrogen peroxide production from particular 2-oxoacid dehydrogenase complexes in cells, and limitations of such methods to discriminate specific superoxide or hydrogen peroxide sources in vivo.
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Affiliation(s)
- Victoria I. Bunik
- A.N. Belozersky Institute of Physicochemical Biology , Lomonosov Moscow State University , 119992 Moscow , Russia
| | - Martin D. Brand
- Buck Institute for Research on Aging , 8001 Redwood Blvd. , Novato, CA 94945 , USA
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29
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Kuksal N, Chalker J, Mailloux RJ. Progress in understanding the molecular oxygen paradox - function of mitochondrial reactive oxygen species in cell signaling. Biol Chem 2017; 398:1209-1227. [PMID: 28675747 DOI: 10.1515/hsz-2017-0160] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 06/27/2017] [Indexed: 11/15/2022]
Abstract
The molecular oxygen (O2) paradox was coined to describe its essential nature and toxicity. The latter characteristic of O2 is associated with the formation of reactive oxygen species (ROS), which can damage structures vital for cellular function. Mammals are equipped with antioxidant systems to fend off the potentially damaging effects of ROS. However, under certain circumstances antioxidant systems can become overwhelmed leading to oxidative stress and damage. Over the past few decades, it has become evident that ROS, specifically H2O2, are integral signaling molecules complicating the previous logos that oxyradicals were unfortunate by-products of oxygen metabolism that indiscriminately damage cell structures. To avoid its potential toxicity whilst taking advantage of its signaling properties, it is vital for mitochondria to control ROS production and degradation. H2O2 elimination pathways are well characterized in mitochondria. However, less is known about how H2O2 production is controlled. The present review examines the importance of mitochondrial H2O2 in controlling various cellular programs and emerging evidence for how production is regulated. Recently published studies showing how mitochondrial H2O2 can be used as a secondary messenger will be discussed in detail. This will be followed with a description of how mitochondria use S-glutathionylation to control H2O2 production.
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30
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Young A, Gardiner D, Brosnan ME, Brosnan JT, Mailloux RJ. Physiological levels of formate activate mitochondrial superoxide/hydrogen peroxide release from mouse liver mitochondria. FEBS Lett 2017; 591:2426-2438. [PMID: 28771687 DOI: 10.1002/1873-3468.12777] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 07/30/2017] [Accepted: 07/31/2017] [Indexed: 11/11/2022]
Abstract
Here, we found that formate, an essential one-carbon metabolite, activates superoxide (O2·-)/hydrogen peroxide (H2 O2 ) release from mitochondria. Sodium formate (30 μm) induces a significant increase in O2·-/H2 O2 production in liver mitochondria metabolizing pyruvate (50 μm). At concentrations deemed to be toxic, formate does not increase O2·-/H2 O2 production further. It was observed that the formate-mediated increase in O2·-/H2 O2 production is not associated with cytochrome c oxidase (COX) inhibition or changes in membrane potential and NAD(P)H levels. Sodium formate supplementation increases phosphorylating respiration without altering proton leaks. Finally, it was observed that the 2-oxoglutarate dehydrogenase (OGDH) inhibitors 3-methyl-2-oxovaleric acid (KMV) and CPI-613 inhibit the formate-induced increase in pyruvate-driven ROS production. The importance of these findings in one-carbon metabolism and physiology are discussed herein.
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Affiliation(s)
- Adrian Young
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Danielle Gardiner
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Margaret E Brosnan
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - John T Brosnan
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Ryan J Mailloux
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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31
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Nemeria NS, Gerfen G, Guevara E, Nareddy PR, Szostak M, Jordan F. The human Krebs cycle 2-oxoglutarate dehydrogenase complex creates an additional source of superoxide/hydrogen peroxide from 2-oxoadipate as alternative substrate. Free Radic Biol Med 2017; 108:644-654. [PMID: 28435050 DOI: 10.1016/j.freeradbiomed.2017.04.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/14/2017] [Accepted: 04/15/2017] [Indexed: 12/19/2022]
Abstract
Recently, we reported that the human 2-oxoglutarate dehydrogenase (hE1o) component of the 2-oxoglutarate dehydrogenase complex (OGDHc) could produce the reactive oxygen species superoxide and hydrogen peroxide (detected by chemical means) from its substrate 2-oxoglutarate (OG), most likely concurrently with one-electron oxidation by dioxygen of the thiamin diphosphate (ThDP)-derived enamine intermediate to a C2α-centered radical (detected by Electron Paramagnetic Resonance) [Nemeria et al., 2014 [17]; Ambrus et al. 2015 [18]]. We here report that hE1o can also utilize the next higher homologue of OG, 2-oxoadipate (OA) as a substrate according to multiple criteria in our toolbox: (i) Both E1o-specific and overall complex activities (NADH production) were detected using OA as a substrate; (ii) Two post-decarboxylation intermediates were formed by hE1o from OA, the ThDP-enamine and the C2α-hydroxyalkyl-ThDP, with nearly identical rates for OG and OA; (iii) Both OG and OA could reductively acylate lipoyl domain created from dihydrolipoyl succinyltransferase (E2o); (iv) Both OG and OA gave α-ketol carboligaton products with glyoxylate, but with opposite chirality; a finding that could be of utility in chiral synthesis; (v) Dioxygen could oxidize the ThDP-derived enamine from both OG and OA, leading to ThDP-enamine radical and generation of superoxide and H2O2. While the observed oxidation-reduction with dioxygen is only a side reaction of the predominant physiological product glutaryl-CoA, the efficiency of superoxide/ H2O2 production was 7-times larger from OA than from OG, making the reaction of OGDHc with OA one of the important superoxide/ H2O2 producers among 2-oxo acid dehydrogenase complexes in mitochondria.
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Affiliation(s)
- Natalia S Nemeria
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA.
| | - Gary Gerfen
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461-2304, USA.
| | - Elena Guevara
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA
| | | | - Michal Szostak
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA
| | - Frank Jordan
- Department of Chemistry, Rutgers University, Newark, NJ 07102-1811, USA.
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32
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Ambrus A, Adam-Vizi V. Human dihydrolipoamide dehydrogenase (E3) deficiency: Novel insights into the structural basis and molecular pathomechanism. Neurochem Int 2017; 117:5-14. [PMID: 28579060 DOI: 10.1016/j.neuint.2017.05.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/22/2017] [Accepted: 05/30/2017] [Indexed: 11/18/2022]
Abstract
This review summarizes our present view on the molecular pathogenesis of human (h) E3-deficiency caused by a variety of genetic alterations with a special emphasis on the moonlighting biochemical phenomena related to the affected (dihydro)lipoamide dehydrogenase (LADH, E3, gene: dld), in particular the generation of reactive oxygen species (ROS). E3-deficiency is a rare autosomal recessive genetic disorder frequently presenting with a neonatal onset and premature death; the highest carrier rate of a single pathogenic dld mutation (1:94-1:110) was found among Ashkenazi Jews. Patients usually die during acute episodes that generally involve severe metabolic decompensation and lactic acidosis leading to neurological, cardiological, and/or hepatological manifestations. The disease owes its severity to the fact that LADH is the common E3 subunit of the alpha-ketoglutarate (KGDHc), pyruvate (PDHc), and branched-chain α-keto acid dehydrogenase complexes and is also part of the glycine cleavage system, hence the malfunctioning of LADH simultaneously incapacitates several central metabolic pathways. Nevertheless, the clinical pictures are usually not unequivocally portrayed through the loss of LADH activities and imply auxiliary mechanisms that exacerbate the symptoms and outcomes of this disorder. Enhanced ROS generation by disease-causing hE3 variants as well as by the E1-E2 subcomplex of the hKGDHc likely contributes to selected pathogeneses of E3-deficiency, which could be targeted by specific drugs or antioxidants; lipoic acid was demonstrated to be a potent inhibitor of ROS generation by hE3 in vitro. Flavin supplementation might prove to be beneficial for those mutations triggering FAD loss in the hE3 component. Selected pathogenic hE3 variants lose their affinity for the E2 component of the hPDHc, a mechanism which warrants scrutiny also for other E3-haboring complexes.
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Affiliation(s)
- Attila Ambrus
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary.
| | - Vera Adam-Vizi
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary.
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33
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Pierce E, Mansoorabadi SO, Can M, Reed GH, Ragsdale SW. Properties of Intermediates in the Catalytic Cycle of Oxalate Oxidoreductase and Its Suicide Inactivation by Pyruvate. Biochemistry 2017; 56:2824-2835. [PMID: 28514140 PMCID: PMC5463272 DOI: 10.1021/acs.biochem.7b00222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxalate:ferredoxin oxidoreductase (OOR) is an unusual member of the thiamine pyrophosphate (TPP)-dependent 2-oxoacid:ferredoxin oxidoreductase (OFOR) family in that it catalyzes the coenzyme A (CoA)-independent conversion of oxalate into 2 equivalents of carbon dioxide. This reaction is surprising because binding of CoA to the acyl-TPP intermediate of other OFORs results in formation of a CoA ester, and in the case of pyruvate:ferredoxin oxidoreductase (PFOR), CoA binding generates the central metabolic intermediate acetyl-CoA and promotes a 105-fold acceleration of the rate of electron transfer. Here we describe kinetic, spectroscopic, and computational results to show that CoA has no effect on catalysis by OOR and describe the chemical rationale for why this cofactor is unnecessary in this enzymatic transformation. Our results demonstrate that, like PFOR, OOR binds pyruvate and catalyzes decarboxylation to form the same hydroxyethylidine-TPP (HE-TPP) intermediate and one-electron transfer to generate the HE-TPP radical. However, in OOR, this intermediate remains stranded at the active site as a covalent inhibitor. These and other results indicate that, like other OFOR family members, OOR generates an oxalate-derived adduct with TPP (oxalyl-TPP) that undergoes decarboxylation and one-electron transfer to form a radical intermediate remaining bound to TPP (dihydroxymethylidene-TPP). However, unlike in PFOR, where CoA binding drives formation of the product, in OOR, proton transfer and a conformational change in the "switch loop" alter the redox potential of the radical intermediate sufficiently to promote the transfer of an electron into the iron-sulfur cluster network, leading directly to a second decarboxylation and completing the catalytic cycle.
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Affiliation(s)
- Elizabeth Pierce
- Department of Biological Chemistry, University of Michigan , Ann Arbor, Michigan 48109-0606, United States
| | - Steven O Mansoorabadi
- Department of Chemistry and Biochemistry, Auburn University , 179 Chemistry Building, Auburn, Alabama 36849, United States
| | - Mehmet Can
- Department of Biological Chemistry, University of Michigan , Ann Arbor, Michigan 48109-0606, United States
| | - George H Reed
- Department of Biochemistry, University of Wisconsin-Madison , 440 Henry Mall, Madison, Wisconsin 53726, United States
| | - Stephen W Ragsdale
- Department of Biological Chemistry, University of Michigan , Ann Arbor, Michigan 48109-0606, United States
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34
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Liu Y, Wang C, Xue D, Xiao M, Liu J, Li C, Xiao J. Reactions Catalysed by a Binuclear Copper Complex: Relay Aerobic Oxidation of N
-Aryl Tetrahydroisoquinolines to Dihydroisoquinolones with a Vitamin B1 Analogue. Chemistry 2017; 23:3062-3066. [PMID: 27880016 DOI: 10.1002/chem.201604750] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Yuxia Liu
- Key Laboratory of Applied Surface and Colloid Chemistry; Ministry of Education and School of Chemistry and Chemical Engineering; Shaanxi Normal University; Xi'an 710062 P. R. China
| | - Chao Wang
- Key Laboratory of Applied Surface and Colloid Chemistry; Ministry of Education and School of Chemistry and Chemical Engineering; Shaanxi Normal University; Xi'an 710062 P. R. China
| | - Dong Xue
- Key Laboratory of Applied Surface and Colloid Chemistry; Ministry of Education and School of Chemistry and Chemical Engineering; Shaanxi Normal University; Xi'an 710062 P. R. China
| | - Miao Xiao
- Key Laboratory of Applied Surface and Colloid Chemistry; Ministry of Education and School of Chemistry and Chemical Engineering; Shaanxi Normal University; Xi'an 710062 P. R. China
| | - Jiao Liu
- Key Laboratory of Applied Surface and Colloid Chemistry; Ministry of Education and School of Chemistry and Chemical Engineering; Shaanxi Normal University; Xi'an 710062 P. R. China
| | - Chaoqun Li
- Key Laboratory of Applied Surface and Colloid Chemistry; Ministry of Education and School of Chemistry and Chemical Engineering; Shaanxi Normal University; Xi'an 710062 P. R. China
| | - Jianliang Xiao
- Key Laboratory of Applied Surface and Colloid Chemistry; Ministry of Education and School of Chemistry and Chemical Engineering; Shaanxi Normal University; Xi'an 710062 P. R. China
- Department of Chemistry; University of Liverpool; Liverpool L69 7ZD UK
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Ambrus A, Wang J, Mizsei R, Zambo Z, Torocsik B, Jordan F, Adam-Vizi V. Structural alterations induced by ten disease-causing mutations of human dihydrolipoamide dehydrogenase analyzed by hydrogen/deuterium-exchange mass spectrometry: Implications for the structural basis of E3 deficiency. Biochim Biophys Acta Mol Basis Dis 2016; 1862:2098-2109. [PMID: 27544700 DOI: 10.1016/j.bbadis.2016.08.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/11/2016] [Accepted: 08/16/2016] [Indexed: 01/06/2023]
Abstract
Pathogenic amino acid substitutions of the common E3 component (hE3) of the human alpha-ketoglutarate dehydrogenase and the pyruvate dehydrogenase complexes lead to severe metabolic diseases (E3 deficiency), which usually manifest themselves in cardiological and/or neurological symptoms and often cause premature death. To date, 14 disease-causing amino acid substitutions of the hE3 component have been reported in the clinical literature. None of the pathogenic protein variants has lent itself to high-resolution structure elucidation by X-ray or NMR. Hence, the structural alterations of the hE3 protein caused by the disease-causing mutations and leading to dysfunction, including the enhanced generation of reactive oxygen species by selected disease-causing variants, could only be speculated. Here we report results of an examination of the effects on the protein structure of ten pathogenic mutations of hE3 using hydrogen/deuterium-exchange mass spectrometry (HDX-MS), a new and state-of-the-art approach of solution structure elucidation. On the basis of the results, putative structural and mechanistic conclusions were drawn regarding the molecular pathogenesis of each disease-causing hE3 mutation addressed in this study.
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Affiliation(s)
- Attila Ambrus
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary.
| | - Junjie Wang
- Department of Chemistry, Rutgers University, Newark, NJ, USA
| | - Reka Mizsei
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary
| | - Zsofia Zambo
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary
| | - Beata Torocsik
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary
| | - Frank Jordan
- Department of Chemistry, Rutgers University, Newark, NJ, USA.
| | - Vera Adam-Vizi
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary.
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Nemeria NS, Shome B, DeColli AA, Heflin K, Begley TP, Meyers CF, Jordan F. Competence of Thiamin Diphosphate-Dependent Enzymes with 2'-Methoxythiamin Diphosphate Derived from Bacimethrin, a Naturally Occurring Thiamin Anti-vitamin. Biochemistry 2016; 55:1135-48. [PMID: 26813608 PMCID: PMC4852132 DOI: 10.1021/acs.biochem.5b01300] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bacimethrin (4-amino-5-hydroxymethyl-2-methoxypyrimidine), a natural product isolated from some bacteria, has been implicated as an inhibitor of bacterial and yeast growth, as well as in inhibition of thiamin biosynthesis. Given that thiamin biosynthetic enzymes could convert bacimethrin to 2'-methoxythiamin diphosphate (MeOThDP), it is important to evaluate the effect of this coenzyme analogue on thiamin diphosphate (ThDP)-dependent enzymes. The potential functions of MeOThDP were explored on five ThDP-dependent enzymes: the human and Escherichia coli pyruvate dehydrogenase complexes (PDHc-h and PDHc-ec, respectively), the E. coli 1-deoxy-D-xylulose 5-phosphate synthase (DXPS), and the human and E. coli 2-oxoglutarate dehydrogenase complexes (OGDHc-h and OGDHc-ec, respectively). Using several mechanistic tools (fluorescence, circular dichroism, kinetics, and mass spectrometry), it was demonstrated that MeOThDP binds in the active centers of ThDP-dependent enzymes, however, with a binding mode different from that of ThDP. While modest activities resulted from addition of MeOThDP to E. coli PDHc (6-11%) and DXPS (9-14%), suggesting that MeOThDP-derived covalent intermediates are converted to the corresponding products (albeit with rates slower than that with ThDP), remarkably strong activity (up to 75%) resulted upon addition of the coenzyme analogue to PDHc-h. With PDHc-ec and PDHc-h, the coenzyme analogue could support all reactions, including communication between components in the complex. No functional substitution of MeOThDP for ThDP was in evidence with either OGDH-h or OGDH-ec, shown to be due to tight binding of ThDP.
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Affiliation(s)
- Natalia S. Nemeria
- Department of Chemistry, Rutgers University, Newark, New Jersey 07102, United States
| | - Brateen Shome
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Alicia A. DeColli
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Kathryn Heflin
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Tadhg P. Begley
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Caren Freel Meyers
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Frank Jordan
- Department of Chemistry, Rutgers University, Newark, New Jersey 07102, United States
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Mailloux RJ, Craig Ayre D, Christian SL. Induction of mitochondrial reactive oxygen species production by GSH mediated S-glutathionylation of 2-oxoglutarate dehydrogenase. Redox Biol 2016; 8:285-97. [PMID: 26928132 PMCID: PMC4776629 DOI: 10.1016/j.redox.2016.02.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 02/01/2016] [Accepted: 02/07/2016] [Indexed: 12/18/2022] Open
Abstract
2-Oxoglutarate dehydrogenase (Ogdh) is an important mitochondria redox sensor that can undergo S-glutathionylation following an increase in H2O2 levels. Although S-glutathionylation is required to protect Ogdh from irreversible oxidation while simultaneously modulating its activity it remains unknown if glutathione can also modulate reactive oxygen species (ROS) production by the complex. We report that reduced (GSH) and oxidized (GSSG) glutathione control O2∙-/H2O2 formation by Ogdh through protein S-glutathionylation reactions. GSSG (1 mM) induced a modest decrease in Ogdh activity which was associated with a significant decrease in O2∙-/H2O2 formation. GSH had the opposite effect, amplifying O2∙-/H2O2 formation by Ogdh. Incubation of purified Ogdh in 2.5 mM GSH led to significant increase in O2∙-/H2O2 formation which also lowered NADH production. Inclusion of enzymatically active glutaredoxin-2 (Grx2) in reaction mixtures reversed the GSH-mediated amplification of O2∙-/H2O2 formation. Similarly pre-incubation of permeabilized liver mitochondria from mouse depleted of GSH showed an approximately ~3.5-fold increase in Ogdh-mediated O2∙-/H2O2 production that was matched by a significant decrease in NADH formation which could be reversed by Grx2. Taken together, our results demonstrate GSH and GSSG modulate ROS production by Ogdh through S-glutathionylation of different subunits. This is also the first demonstration that GSH can work in the opposite direction in mitochondria-amplifying ROS formation instead of quenching it. We propose that this regulatory mechanism is required to modulate ROS emission from Ogdh in response to variations in glutathione redox buffering capacity. ROS formation by Ogdh is controlled by glutathione. GSH amplifies ROS production by Ogdh. Ogdh is S-glutathionylated by GSH. Grx2 deglutathionylates Ogdh.
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Affiliation(s)
- Ryan J Mailloux
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
| | - D Craig Ayre
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Sherri L Christian
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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Ambrus A, Nemeria NS, Torocsik B, Tretter L, Nilsson M, Jordan F, Adam-Vizi V. Formation of reactive oxygen species by human and bacterial pyruvate and 2-oxoglutarate dehydrogenase multienzyme complexes reconstituted from recombinant components. Free Radic Biol Med 2015; 89:642-50. [PMID: 26456061 PMCID: PMC4684775 DOI: 10.1016/j.freeradbiomed.2015.10.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/18/2015] [Accepted: 10/03/2015] [Indexed: 01/25/2023]
Abstract
Individual recombinant components of pyruvate and 2-oxoglutarate dehydrogenase multienzyme complexes (PDHc, OGDHc) of human and Escherichia coli (E. coli) origin were expressed and purified from E. coli with optimized protocols. The four multienzyme complexes were each reconstituted under optimal conditions at different stoichiometric ratios. Binding stoichiometries for the highest catalytic efficiency were determined from the rate of NADH generation by the complexes at physiological pH. Since some of these complexes were shown to possess 'moonlighting' activities under pathological conditions often accompanied by acidosis, activities were also determined at pH 6.3. As reactive oxygen species (ROS) generation by the E3 component of hOGDHc is a pathologically relevant feature, superoxide generation by the complexes with optimal stoichiometry was measured by the acetylated cytochrome c reduction method in both the forward and the reverse catalytic directions. Various known affectors of physiological activity and ROS production, including Ca(2+), ADP, lipoylation status or pH, were investigated. The human complexes were also reconstituted with the most prevalent human pathological mutant of the E3 component, G194C and characterized; isolated human E3 with the G194C substitution was previously reported to have an enhanced ROS generating capacity. It is demonstrated that: i. PDHc, similarly to OGDHc, is able to generate ROS and this feature is displayed by both the E. coli and human complexes, ii. Reconstituted hPDHc generates ROS at a significantly higher rate as compared to hOGDHc in both the forward and the reverse reactions when ROS generation is calculated for unit mass of their common E3 component, iii. The E1 component or E1-E2 subcomplex generates significant amount of ROS only in hOGDHc; iv. Incorporation of the G194C variant of hE3, the result of a disease-causing mutation, into reconstituted hOGDHc and hPDHc indeed leads to a decreased activity of both complexes and higher ROS generation by only hOGDHc and only in its reverse reaction.
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Affiliation(s)
- Attila Ambrus
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, 1094, Hungary
| | - Natalia S Nemeria
- Department of Chemistry, Rutgers, the State University, Newark, NJ 07102, USA
| | - Beata Torocsik
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, 1094, Hungary
| | - Laszlo Tretter
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, 1094, Hungary
| | - Mattias Nilsson
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, 1094, Hungary
| | - Frank Jordan
- Department of Chemistry, Rutgers, the State University, Newark, NJ 07102, USA
| | - Vera Adam-Vizi
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, 1094, Hungary.
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Ambrus A, Mizsei R, Adam-Vizi V. Structural alterations by five disease-causing mutations in the low-pH conformation of human dihydrolipoamide dehydrogenase (hLADH) analyzed by molecular dynamics - Implications in functional loss and modulation of reactive oxygen species generation by pathogenic hLADH forms. Biochem Biophys Rep 2015; 2:50-56. [PMID: 29594200 PMCID: PMC5871931 DOI: 10.1016/j.bbrep.2015.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 04/25/2015] [Accepted: 04/27/2015] [Indexed: 01/12/2023] Open
Abstract
Human dihydrolipoamide dehydrogenase (hLADH) is a flavoenzyme component (E3) of the human alpha-ketoglutarate dehydrogenase complex (α-KGDHc) and few other dehydrogenase complexes. Pathogenic mutations of hLADH cause severe metabolic diseases (atypical forms of E3 deficiency) that often escalate to cardiological or neurological presentations and even premature death; the pathologies are generally accompanied by lactic acidosis. hLADH presents a distinct conformation under acidosis (pH 5.5–6.8) with lower physiological activity and the capacity of generating reactive oxygen species (ROS). It has been shown by our laboratory that selected pathogenic mutations, besides lowering the physiological activity of hLADH, significantly stimulate ROS generation by hLADH, especially at lower pH, which might play a role in the pathogenesis of E3-deficiency in respective cases. Previously, we generated by molecular dynamics (MD) simulation the low-pH hLADH structure and analyzed the structural changes induced in this structure by eight of the pathogenic mutations of hLADH. In the absence of high resolution mutant structures these pieces of information are crucial for the mechanistic investigation of the molecular pathogeneses of the hLADH protein. In the present work we analyzed by molecular dynamics simulation the structural changes induced in the low-pH conformation of hLADH by five pathogenic mutations of hLADH; the structures of these disease-causing mutants of hLADH have never been examined before. 5 disease-causing mutants of hLADH were subjected to MD to reveal structural changes. MD simulations were carried out both in vacuum and in water supplemented with ions. Functional regions significantly affected by mutation were identified. Implicated residues are to be targeted in mechanistic studies of hLADH dysfunction.
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Key Words
- FAD, flavin adenine dinucleotide
- LADH, (dihydro)lipoamide dehydrogenase
- Lipoamide dehydrogenase
- MD, molecular dynamics
- Molecular dynamics
- Mutation
- NAD+/NADH, nicotinamide adenine dinucleotide (oxidized/reduced)
- PDHc, pyruvate dehydrogenase complex
- RMSD, root mean square deviation
- ROS, reactive oxygen species
- Reactive oxygen species
- S.E.M., standard error of the mean
- WT, wild-type
- α-KGDHc, alpha-ketoglutarate dehydrogenase complex
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Affiliation(s)
- Attila Ambrus
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest 1094, Hungary
| | - Reka Mizsei
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest 1094, Hungary
| | - Vera Adam-Vizi
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, 37-47 Tuzolto Street, Budapest 1094, Hungary
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Jordan F, Nemeria NS. Experimental observation of thiamin diphosphate-bound intermediates on enzymes and mechanistic information derived from these observations. Bioorg Chem 2005; 33:190-215. [PMID: 15888311 PMCID: PMC4189838 DOI: 10.1016/j.bioorg.2005.02.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Revised: 02/08/2005] [Accepted: 02/10/2005] [Indexed: 11/27/2022]
Abstract
Thiamin diphosphate (ThDP), the vitamin B1 coenzyme, is an excellent representative of coenzymes, which carry out electrophilic catalysis by forming a covalent complex with their substrates. The function of ThDP is to greatly increase the acidity of two carbon acids by stabilizing their conjugate bases, the ylide/C2-carbanion of the thiazolium ring and the C2alpha-carbanion (or enamine) once the substrate binds to ThDP. In recent years, several ThDP-bound intermediates on such pathways have been characterized by both solution and solid-state (X-ray) methods. Prominent among these advances are X-ray crystallographic results identifying both oxidative and non-oxidative intermediates, rapid chemical quench followed by NMR detection of a several intermediates which are stable under acidic conditions, and circular dichroism detection of the 1',4'-imino tautomer of ThDP in some of the intermediates. Some of these methods also enable the investigator to determine the rate-limiting step in the complex series of steps.
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Affiliation(s)
- Frank Jordan
- Department of Chemistry, Rutgers University, Newark, NJ 07102, USA
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