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Behlendorf C, Diwo M, Neumann-Schaal M, Fuchs M, Körner D, Jänsch L, Faber F, Blankenfeldt W. Formation of the pyruvoyl-dependent proline reductase Prd from Clostridioides difficile requires the maturation enzyme PrdH. PNAS NEXUS 2024; 3:pgae249. [PMID: 38979079 PMCID: PMC11229817 DOI: 10.1093/pnasnexus/pgae249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 06/09/2024] [Indexed: 07/10/2024]
Abstract
Stickland fermentation, the coupled oxidation and reduction of amino acid pairs, is a major pathway for obtaining energy in the nosocomial bacterium Clostridioides difficile. D-proline is the preferred substrate for the reductive path, making it not only a key component of the general metabolism but also impacting on the expression of the clostridial toxins TcdA and TcdB. D-proline reduction is catalyzed by the proline reductase Prd, which belongs to the pyruvoyl-dependent enzymes. These enzymes are translated as inactive proenzymes and require subsequent processing to install the covalently bound pyruvate. Whereas pyruvoyl formation by intramolecular serinolysis has been studied in unrelated enzymes, details about pyruvoyl generation by cysteinolysis as in Prd are lacking. Here, we show that Prd maturation requires a small dimeric protein that we have named PrdH. PrdH (CD630_32430) is co-encoded with the PrdA and PrdB subunits of Prd and also found in species producing similar reductases. By producing stable variants of PrdA and PrdB, we demonstrate that PrdH-mediated cleavage and pyruvoyl formation in the PrdA subunit requires PrdB, which can be harnessed to produce active recombinant Prd for subsequent analyses. We further created PrdA- and PrdH-mutants to get insight into the interaction of the components and into the processing reaction itself. Finally, we show that deletion of prdH renders C. difficile insensitive to proline concentrations in culture media, suggesting that this processing factor is essential for proline utilization. Due to the link between Stickland fermentation and pathogenesis, we suggest PrdH may be an attractive target for drug development.
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Affiliation(s)
- Christian Behlendorf
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Maurice Diwo
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Meina Neumann-Schaal
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, 38124 Braunschweig, Germany
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Manuela Fuchs
- Helmholtz Centre for Infection Research (HZI), Helmholtz Institute for RNA-based Infection Research (HIRI), 97080 Würzburg, Germany
- Faculty of Medicine, Institute for Molecular Infection Biology (IMIB), Julius-Maximilians-University of Würzburg (JMU), 97080 Würzburg, Germany
| | - Dominik Körner
- Cellular Proteomics, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Lothar Jänsch
- Cellular Proteomics, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Franziska Faber
- Helmholtz Centre for Infection Research (HZI), Helmholtz Institute for RNA-based Infection Research (HIRI), 97080 Würzburg, Germany
- Faculty of Medicine, Institute for Molecular Infection Biology (IMIB), Julius-Maximilians-University of Würzburg (JMU), 97080 Würzburg, Germany
| | - Wulf Blankenfeldt
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, 38106 Braunschweig, Germany
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2
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Vasseur CM, Karunasegaram D, Seebeck FP. Structure and Substrate Specificity of S-Methyl Thiourocanate Hydratase. ACS Chem Biol 2024; 19:718-724. [PMID: 38389448 DOI: 10.1021/acschembio.3c00745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Nicotinamide adenine dinucleotide (NAD+) is a common cofactor in enzyme-catalyzed reactions that involve hydride transfers. In contrast, urocanase and urocanase-like enzymes use NAD+ for covalent electrophilic catalysis. Deciphering avenues by which this unusual catalytic strategy has diversified by evolution may point to approaches for the design of novel enzymes. In this report, we describe the S-methyl thiourocanate hydratase (S-Me-TUC) from Variovorax sp. RA8 as a novel member of this small family of NAD+-dependent hydratases. This enzyme catalyzes the 1,4-addition of water to S-methyl thiourocanate as the second step in the catabolism of S-methyl ergothioneine. The crystal structure of this enzyme in complex with the cofactor and a product analogue identifies critical sequence motifs that explain the narrow and nonoverlapping substrate scopes of S-methyl thiourocanate-, urocanate-, thiourocanate-, and Nτ-methyl urocanate-specific hydratases. The discovery of a S-methyl ergothioneine catabolic pathway also suggests that S-methylation or alkylation may be a significant activity in the biology of ergothioneine.
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Affiliation(s)
- Camille M Vasseur
- Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 22, Basel 4002, Switzerland
| | - Dishani Karunasegaram
- Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 22, Basel 4002, Switzerland
| | - Florian P Seebeck
- Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 22, Basel 4002, Switzerland
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3
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Dumont R, Dowdell J, Song J, Li J, Wang S, Kang W, Li B. Control of charge transport in electronically active systems towards integrated biomolecular circuits (IbC). J Mater Chem B 2023; 11:8302-8314. [PMID: 37464922 DOI: 10.1039/d3tb00701d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
The miniaturization of traditional silicon-based electronics will soon reach its limitation as quantum tunneling and heat become serious problems at the several-nanometer scale. Crafting integrated circuits via self-assembly of electronically active molecules using a "bottom-up" paradigm provides a potential solution to these technological challenges. In particular, integrated biomolecular circuits (IbC) offer promising advantages to achieve this goal, as nature offers countless examples of functionalities entailed by self-assembly and examples of controlling charge transport at the molecular level within the self-assembled structures. To this end, the review summarizes the progress in understanding how charge transport is regulated in biosystems and the key redox-active amino acids that enable the charge transport. In addition, charge transport mechanisms at different length scales are also reviewed, offering key insights for controlling charge transport in IbC in the future.
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Affiliation(s)
- Ryan Dumont
- Department of Mechanical Engineering, Kennesaw State University, Marietta, GA, USA.
| | - Juwaan Dowdell
- Department of Mechanical Engineering, Kennesaw State University, Marietta, GA, USA.
| | - Jisoo Song
- Department of Mechanical Engineering, Kennesaw State University, Marietta, GA, USA.
| | - Jiani Li
- State Key Laboratory of Fine Chemicals, Frontiers Science Centre for Smart Materials Oriented Chemical Engineering, School of Bioengineering, Dalian University of Technology, Dalian, China.
| | - Suwan Wang
- State Key Laboratory of Fine Chemicals, Frontiers Science Centre for Smart Materials Oriented Chemical Engineering, School of Bioengineering, Dalian University of Technology, Dalian, China.
| | - Wei Kang
- State Key Laboratory of Fine Chemicals, Frontiers Science Centre for Smart Materials Oriented Chemical Engineering, School of Bioengineering, Dalian University of Technology, Dalian, China.
- Ningbo Institute of Dalian University of Technology, Ningbo, China
| | - Bo Li
- Department of Mechanical Engineering, Kennesaw State University, Marietta, GA, USA.
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4
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Wang L, Jiang Y, Yu Q, Xiao C, Sun J, Weng L, Qiu Y. Gentiopicroside improves high-fat diet-induced NAFLD in association with modulation of host serum metabolome and gut microbiome in mice. Front Microbiol 2023; 14:1145430. [PMID: 37614606 PMCID: PMC10443917 DOI: 10.3389/fmicb.2023.1145430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 07/24/2023] [Indexed: 08/25/2023] Open
Abstract
Objective The incidence of non-alcoholic fatty liver disease is increasing every year, and there is growing evidence that metabolites and intestinal bacteria play a causal role in NAFLD. Gentiopicroside, a major iridoids compound in gentian, has been reported to reduce hepatic lipid accumulation. However to date, no studies have confirmed whether the predominance of Gentiopicroside is related to metabolites and intestinal bacteria. Therefore, we sought to study whether the hypolipidemic effect of Gentiopicroside is related to metabolic function and intestinal flora regulation. Methods In the present study, C57BL/6J mice were fed a high-fat diet for 12 weeks, followed by a high-fat diet with or without Gentiopicroside for 8 weeks, respectively. The Gentiopicroside intervention reduced body weight gain, liver index, and decreased serum biochemical parameters such as alanine aminotransferase, aspartate aminotransferase, and triglycerides in high-fat fed mice. The effect of Gentiopicroside on non-alcoholic fatty liver disease was studied using serum untargeted metabolomics and 16S rDNA assay. Results Metabolomic analysis showed that the addition of Gentiopicroside significantly altered the levels of amino acids, unmetabolized Gentiopicroside after administration, and metabolites such as Cinnoline, Galabiosylceramide, and Tryptophyl-Tyrosine, which are involved in the pathways regulating bile secretion, tryptophan metabolism, and lipid metabolism. Analysis of intestinal bacteria showed that Gentiopicrosides altered the community composition structure of intestinal bacteria, characterized by an increase and a decrease in beneficial and harmful bacteria, respectively. In addition, correlation analysis showed that the effect of Gentiopicroside on metabolites was positively correlated with intestinal flora Bacteroides, Lactobacillus, Muribaculum, and Prevotellaceae_UCG_001. Finally, the combined analysis revealed that metabolites were associated with the regulation of Firmicutes and Actinobacteria and positively correlated with lipid levels. Conclusion These results suggest that Gentiopicroside may be a potential agent for the prevention of intestinal disorders and the alleviation of non-alcoholic fatty liver disease.
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Affiliation(s)
| | | | | | | | | | - Lili Weng
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Ye Qiu
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
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Li B, Liang J, Phillips MA, Michael AJ. Neofunctionalization of S-adenosylmethionine decarboxylase into pyruvoyl-dependent L-ornithine and L-arginine decarboxylases is widespread in bacteria and archaea. J Biol Chem 2023; 299:105005. [PMID: 37399976 PMCID: PMC10407285 DOI: 10.1016/j.jbc.2023.105005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/12/2023] [Accepted: 06/28/2023] [Indexed: 07/05/2023] Open
Abstract
S-adenosylmethionine decarboxylase (AdoMetDC/SpeD) is a key polyamine biosynthetic enzyme required for conversion of putrescine to spermidine. Autocatalytic self-processing of the AdoMetDC/SpeD proenzyme generates a pyruvoyl cofactor from an internal serine. Recently, we discovered that diverse bacteriophages encode AdoMetDC/SpeD homologs that lack AdoMetDC activity and instead decarboxylate L-ornithine or L-arginine. We reasoned that neofunctionalized AdoMetDC/SpeD homologs were unlikely to have emerged in bacteriophages and were probably acquired from ancestral bacterial hosts. To test this hypothesis, we sought to identify candidate AdoMetDC/SpeD homologs encoding L-ornithine and L-arginine decarboxylases in bacteria and archaea. We searched for the anomalous presence of AdoMetDC/SpeD homologs in the absence of its obligatory partner enzyme spermidine synthase, or the presence of two AdoMetDC/SpeD homologs encoded in the same genome. Biochemical characterization of candidate neofunctionalized genes confirmed lack of AdoMetDC activity, and functional presence of L-ornithine or L-arginine decarboxylase activity in proteins from phyla Actinomycetota, Armatimonadota, Planctomycetota, Melainabacteria, Perigrinibacteria, Atribacteria, Chloroflexota, Sumerlaeota, Omnitrophota, Lentisphaerota, and Euryarchaeota, the bacterial candidate phyla radiation and DPANN archaea, and the δ-Proteobacteria class. Phylogenetic analysis indicated that L-arginine decarboxylases emerged at least three times from AdoMetDC/SpeD, whereas L-ornithine decarboxylases arose only once, potentially from the AdoMetDC/SpeD-derived L-arginine decarboxylases, revealing unsuspected polyamine metabolic plasticity. Horizontal transfer of the neofunctionalized genes appears to be the more prevalent mode of dissemination. We identified fusion proteins of bona fide AdoMetDC/SpeD with homologous L-ornithine decarboxylases that possess two, unprecedented internal protein-derived pyruvoyl cofactors. These fusion proteins suggest a plausible model for the evolution of the eukaryotic AdoMetDC.
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Affiliation(s)
- Bin Li
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Jue Liang
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Margaret A Phillips
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Anthony J Michael
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA.
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6
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Bustin KA, Abbas A, Wang X, Abt MC, Zackular JP, Matthews ML. Characterizing metabolic drivers of Clostridioides difficile infection with activity-based hydrazine probes. Front Pharmacol 2023; 14:1074619. [PMID: 36778002 PMCID: PMC9908766 DOI: 10.3389/fphar.2023.1074619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 01/05/2023] [Indexed: 01/27/2023] Open
Abstract
Many enzymes require post-translational modifications or cofactor machinery for primary function. As these catalytically essential moieties are highly regulated, they act as dual sensors and chemical handles for context-dependent metabolic activity. Clostridioides difficile is a major nosocomial pathogen that infects the colon. Energy generating metabolism, particularly through amino acid Stickland fermentation, is central to colonization and persistence of this pathogen during infection. Here using activity-based protein profiling (ABPP), we revealed Stickland enzyme activity is a biomarker for C. difficile infection (CDI) and annotated two such cofactor-dependent Stickland reductases. We structurally characterized the cysteine-derived pyruvoyl cofactors of D-proline and glycine reductase in C. difficile cultures and showed through cofactor monitoring that their activity is regulated by their respective amino acid substrates. Proline reductase was consistently active in toxigenic C. difficile, confirming the enzyme to be a major metabolic driver of CDI. Further, activity-based hydrazine probes were shown to be active site-directed inhibitors of proline reductase. As such, this enzyme activity, via its druggable cofactor modality, is a promising therapeutic target that could allow for the repopulation of bacteria that compete with C. difficile for proline and therefore restore colonization resistance against C. difficile in the gut.
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Affiliation(s)
- Katelyn A. Bustin
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Arwa Abbas
- Division of Protective Immunity, Children’s Hospital of Pennsylvania, Philadelphia, PA, United States
| | - Xie Wang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Michael C. Abt
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Joseph P. Zackular
- Division of Protective Immunity, Children’s Hospital of Pennsylvania, Philadelphia, PA, United States,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Megan L. Matthews
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States,*Correspondence: Megan L. Matthews,
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7
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Wang X, Lin Z, Bustin KA, McKnight NR, Parsons WH, Matthews ML. Discovery of Potent and Selective Inhibitors against Protein-Derived Electrophilic Cofactors. J Am Chem Soc 2022; 144:5377-5388. [PMID: 35235319 PMCID: PMC10159212 DOI: 10.1021/jacs.1c12748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Electrophilic cofactors are widely distributed in nature and play important roles in many physiological and disease processes, yet they have remained blind spots in traditional activity-based protein profiling (ABPP) approaches that target nucleophiles. More recently, reverse-polarity (RP)-ABPP using hydrazine probes identified an electrophilic N-terminal glyoxylyl (Glox) group for the first time in secernin-3 (SCRN3). The biological function(s) of both the protein and Glox as a cofactor has not yet been pharmacologically validated because of the lack of selective inhibitors that could disrupt and therefore identify its activity. Here, we present the first platform for analyzing the reactivity and selectivity of an expanded nucleophilic probe library toward main-chain carbonyl cofactors such as Glox and pyruvoyl (Pyvl) groups. We first applied the library proteome-wide to profile and confirm engagement with various electrophilic protein targets, including secernin-2 (SCRN2), shown here also to possess a Glox group. A broadly reactive indole ethylhydrazine probe was used for a competitive in vitro RP-ABPP assay to screen for selective inhibitors against such cofactors from a set of commercially available nucleophilic fragments. Using Glox-containing SCRN proteins as a case study, naphthyl hydrazine was identified as a potent and selective SCRN3 inhibitor, showing complete inhibition in cell lysates with no significant cross-reactivity detected for other enzymes. Moving forward, this platform provides the fundamental basis for the development of selective Glox inhibitors and represents a starting point to advance small molecules that modulate electrophile-dependent function.
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Affiliation(s)
- Xie Wang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Zongtao Lin
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Katelyn A Bustin
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Nate R McKnight
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - William H Parsons
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074, United States
| | - Megan L Matthews
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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Widespread occurrence of covalent lysine–cysteine redox switches in proteins. Nat Chem Biol 2022; 18:368-375. [PMID: 35165445 PMCID: PMC8964421 DOI: 10.1038/s41589-021-00966-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022]
Abstract
We recently reported the discovery of a lysine–cysteine redox switch in proteins with a covalent nitrogen–oxygen–sulfur (NOS) bridge. Here, a systematic survey of the whole protein structure database discloses that NOS bridges are ubiquitous redox switches in proteins of all domains of life and are found in diverse structural motifs and chemical variants. In several instances, lysines are observed in simultaneous linkage with two cysteines, forming a sulfur–oxygen–nitrogen–oxygen–sulfur (SONOS) bridge with a trivalent nitrogen, which constitutes an unusual native branching cross-link. In many proteins, the NOS switch contains a functionally essential lysine with direct roles in enzyme catalysis or binding of substrates, DNA or effectors, linking lysine chemistry and redox biology as a regulatory principle. NOS/SONOS switches are frequently found in proteins from human and plant pathogens, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and also in many human proteins with established roles in gene expression, redox signaling and homeostasis in physiological and pathophysiological conditions. ![]()
A survey of protein structures identifies widespread lysine–cysteine cross-links in functionally diverse proteins across all domains of life and in various structural motifs, where these redox switches control enzyme catalysis and/or ligand binding.
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ATP7A-Regulated Enzyme Metalation and Trafficking in the Menkes Disease Puzzle. Biomedicines 2021; 9:biomedicines9040391. [PMID: 33917579 PMCID: PMC8067471 DOI: 10.3390/biomedicines9040391] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 12/12/2022] Open
Abstract
Copper is vital for numerous cellular functions affecting all tissues and organ systems in the body. The copper pump, ATP7A is critical for whole-body, cellular, and subcellular copper homeostasis, and dysfunction due to genetic defects results in Menkes disease. ATP7A dysfunction leads to copper deficiency in nervous tissue, liver, and blood but accumulation in other tissues. Site-specific cellular deficiencies of copper lead to loss of function of copper-dependent enzymes in all tissues, and the range of Menkes disease pathologies observed can now be explained in full by lack of specific copper enzymes. New pathways involving copper activated lysosomal and steroid sulfatases link patient symptoms usually related to other inborn errors of metabolism to Menkes disease. Additionally, new roles for lysyl oxidase in activation of molecules necessary for the innate immune system, and novel adapter molecules that play roles in ERGIC trafficking of brain receptors and other proteins, are emerging. We here summarize the current knowledge of the roles of copper enzyme function in Menkes disease, with a focus on ATP7A-mediated enzyme metalation in the secretory pathway. By establishing mechanistic relationships between copper-dependent cellular processes and Menkes disease symptoms in patients will not only increase understanding of copper biology but will also allow for the identification of an expanding range of copper-dependent enzymes and pathways. This will raise awareness of rare patient symptoms, and thus aid in early diagnosis of Menkes disease patients.
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10
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The Autotrophic Core: An Ancient Network of 404 Reactions Converts H 2, CO 2, and NH 3 into Amino Acids, Bases, and Cofactors. Microorganisms 2021; 9:microorganisms9020458. [PMID: 33672143 PMCID: PMC7926472 DOI: 10.3390/microorganisms9020458] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/11/2021] [Accepted: 02/19/2021] [Indexed: 01/03/2023] Open
Abstract
The metabolism of cells contains evidence reflecting the process by which they arose. Here, we have identified the ancient core of autotrophic metabolism encompassing 404 reactions that comprise the reaction network from H2, CO2, and ammonia (NH3) to amino acids, nucleic acid monomers, and the 19 cofactors required for their synthesis. Water is the most common reactant in the autotrophic core, indicating that the core arose in an aqueous environment. Seventy-seven core reactions involve the hydrolysis of high-energy phosphate bonds, furthermore suggesting the presence of a non-enzymatic and highly exergonic chemical reaction capable of continuously synthesizing activated phosphate bonds. CO2 is the most common carbon-containing compound in the core. An abundance of NADH and NADPH-dependent redox reactions in the autotrophic core, the central role of CO2, and the circumstance that the core’s main products are far more reduced than CO2 indicate that the core arose in a highly reducing environment. The chemical reactions of the autotrophic core suggest that it arose from H2, inorganic carbon, and NH3 in an aqueous environment marked by highly reducing and continuously far from equilibrium conditions. Such conditions are very similar to those found in serpentinizing hydrothermal systems.
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11
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Oozeki T, Nakai T, Kozakai K, Okamoto K, Kuroda S, Kobayashi K, Tanizawa K, Okajima T. Functional and structural characterization of a flavoprotein monooxygenase essential for biogenesis of tryptophylquinone cofactor. Nat Commun 2021; 12:933. [PMID: 33568660 PMCID: PMC7876137 DOI: 10.1038/s41467-021-21200-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/14/2021] [Indexed: 01/07/2023] Open
Abstract
Bioconversion of peptidyl amino acids into enzyme cofactors is an important post-translational modification. Here, we report a flavoprotein, essential for biosynthesis of a protein-derived quinone cofactor, cysteine tryptophylquinone, contained in a widely distributed bacterial enzyme, quinohemoprotein amine dehydrogenase. The purified flavoprotein catalyzes the single-turnover dihydroxylation of the tryptophylquinone-precursor, tryptophan, in the protein substrate containing triple intra-peptidyl crosslinks that are pre-formed by a radical S-adenosylmethionine enzyme within the ternary complex of these proteins. Crystal structure of the peptidyl tryptophan dihydroxylase reveals a large pocket that may dock the protein substrate with the bound flavin adenine dinucleotide situated close to the precursor tryptophan. Based on the enzyme-protein substrate docking model, we propose a chemical reaction mechanism of peptidyl tryptophan dihydroxylation catalyzed by the flavoprotein monooxygenase. The diversity of the tryptophylquinone-generating systems suggests convergent evolution of the peptidyl tryptophan-derived cofactors in different proteins.
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Affiliation(s)
- Toshinori Oozeki
- grid.136593.b0000 0004 0373 3971Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Tadashi Nakai
- grid.136593.b0000 0004 0373 3971Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan ,grid.417545.60000 0001 0665 883XFaculty of Life Sciences, Hiroshima Institute of Technology, Hiroshima, Japan
| | - Kazuki Kozakai
- grid.136593.b0000 0004 0373 3971Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Kazuki Okamoto
- grid.136593.b0000 0004 0373 3971Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Shun’ichi Kuroda
- grid.136593.b0000 0004 0373 3971Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Kazuo Kobayashi
- grid.136593.b0000 0004 0373 3971Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Katsuyuki Tanizawa
- grid.136593.b0000 0004 0373 3971Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Toshihide Okajima
- grid.136593.b0000 0004 0373 3971Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
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12
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Shin I, Davis I, Nieves-Merced K, Wang Y, McHardy S, Liu A. A novel catalytic heme cofactor in SfmD with a single thioether bond and a bis-His ligand set revealed by a de novo crystal structural and spectroscopic study. Chem Sci 2021; 12:3984-3998. [PMID: 34163669 PMCID: PMC8179489 DOI: 10.1039/d0sc06369j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/21/2021] [Indexed: 12/13/2022] Open
Abstract
SfmD is a heme-dependent enzyme in the biosynthetic pathway of saframycin A. Here, we present a 1.78 Å resolution de novo crystal structure of SfmD, which unveils a novel heme cofactor attached to the protein with an unusual Hx n HxxxC motif (n ∼ 38). This heme cofactor is unique in two respects. It contains a single thioether bond in a cysteine-vinyl link with Cys317, and the ferric heme has two axial protein ligands, i.e., His274 and His313. We demonstrated that SfmD heme is catalytically active and can utilize dioxygen and ascorbate for a single-oxygen insertion into 3-methyl-l-tyrosine. Catalytic assays using ascorbate derivatives revealed the functional groups of ascorbate essential to its function as a cosubstrate. Abolishing the thioether linkage through mutation of Cys317 resulted in catalytically inactive SfmD variants. EPR and optical data revealed that the heme center undergoes a substantial conformational change with one axial histidine ligand dissociating from the iron ion in response to substrate 3-methyl-l-tyrosine binding or chemical reduction by a reducing agent, such as the cosubstrate ascorbate. The labile axial ligand was identified as His274 through redox-linked structural determinations. Together, identifying an unusual heme cofactor with a previously unknown heme-binding motif for a monooxygenase activity and the structural similarity of SfmD to the members of the heme-based tryptophan dioxygenase superfamily will broaden understanding of heme chemistry.
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Affiliation(s)
- Inchul Shin
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Ian Davis
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Karinel Nieves-Merced
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
- Center for Innovative Drug Discovery, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Yifan Wang
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Stanton McHardy
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
- Center for Innovative Drug Discovery, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
| | - Aimin Liu
- Department of Chemistry, The University of Texas at San Antonio One UTSA Circle Texas 78249 USA
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13
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The Uniqueness of Tryptophan in Biology: Properties, Metabolism, Interactions and Localization in Proteins. Int J Mol Sci 2020; 21:ijms21228776. [PMID: 33233627 PMCID: PMC7699789 DOI: 10.3390/ijms21228776] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022] Open
Abstract
Tryptophan (Trp) holds a unique place in biology for a multitude of reasons. It is the largest of all twenty amino acids in the translational toolbox. Its side chain is indole, which is aromatic with a binuclear ring structure, whereas those of Phe, Tyr, and His are single-ring aromatics. In part due to these elaborate structural features, the biosynthetic pathway of Trp is the most complex and the most energy-consuming among all amino acids. Essential in the animal diet, Trp is also the least abundant amino acid in the cell, and one of the rarest in the proteome. In most eukaryotes, Trp is the only amino acid besides Met, which is coded for by a single codon, namely UGG. Due to the large and hydrophobic π-electron surface area, its aromatic side chain interacts with multiple other side chains in the protein, befitting its strategic locations in the protein structure. Finally, several Trp derivatives, namely tryptophylquinone, oxitriptan, serotonin, melatonin, and tryptophol, have specialized functions. Overall, Trp is a scarce and precious amino acid in the cell, such that nature uses it parsimoniously, for multiple but selective functions. Here, the various aspects of the uniqueness of Trp are presented in molecular terms.
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14
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Sahrmann PG, Donnan PH, Merz KM, Mansoorabadi SO, Goodwin DC. MRP.py: A Parametrizer of Post-Translationally Modified Residues. J Chem Inf Model 2020; 60:4424-4428. [PMID: 32672967 DOI: 10.1021/acs.jcim.0c00472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
MRP.py is a Python-based parametrization program for covalently modified amino acid residues for molecular dynamics simulations. Charge derivation is performed via an RESP charge fit, and force constants are obtained through rewriting of either protein or GAFF database parameters. This allows for the description of interfacial interactions between the modifed residue and protein. MRP.py is capable of working with a variety of protein databases. MRP.py's highly general and systematic method of obtaining parameters allows the user to circumvent the process of parametrizing the modified residue-protein interface. Two examples, a covalently bound inhibitor and covalent adduct consisting of modified residues, are provided in the Supporting Information.
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Affiliation(s)
- Patrick G Sahrmann
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849-5312, United States
| | - Patrick H Donnan
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849-5312, United States
| | - Kenneth M Merz
- Department of Chemistry and the Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824-1312, United States
| | - Steven O Mansoorabadi
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849-5312, United States
| | - Douglas C Goodwin
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849-5312, United States
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15
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Mamounis KJ, Yukl ET, Davidson VL. Roles of active-site residues in catalysis, substrate binding, cooperativity, and the reaction mechanism of the quinoprotein glycine oxidase. J Biol Chem 2020; 295:6472-6481. [PMID: 32234764 DOI: 10.1074/jbc.ra120.013198] [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: 02/24/2020] [Revised: 03/30/2020] [Indexed: 11/06/2022] Open
Abstract
The quinoprotein glycine oxidase from the marine bacterium Pseudoalteromonas luteoviolacea (PlGoxA) uses a protein-derived cysteine tryptophylquinone (CTQ) cofactor to catalyze conversion of glycine to glyoxylate and ammonia. This homotetrameric enzyme exhibits strong cooperativity toward glycine binding. It is a good model for studying enzyme kinetics and cooperativity, specifically for being able to separate those aspects of protein function through directed mutagenesis. Variant proteins were generated with mutations in four active-site residues, Phe-316, His-583, Tyr-766, and His-767. Structures for glycine-soaked crystals were obtained for each. Different mutations had differential effects on k cat and K 0.5 for catalysis, K 0.5 for substrate binding, and the Hill coefficients describing the steady-state kinetics or substrate binding. Phe-316 and Tyr-766 variants retained catalytic activity, albeit with altered kinetics and cooperativity. Substitutions of His-583 revealed that it is essential for glycine binding, and the structure of H583C PlGoxA had no active-site glycine present in glycine-soaked crystals. The structure of H767A PlGoxA revealed a previously undetected reaction intermediate, a carbinolamine product-reduced CTQ adduct, and exhibited only negligible activity. The results of these experiments, as well as those with the native enzyme and previous variants, enabled construction of a detailed mechanism for the reductive half-reaction of glycine oxidation. This proposed mechanism includes three discrete reaction intermediates that are covalently bound to CTQ during the reaction, two of which have now been structurally characterized by X-ray crystallography.
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Affiliation(s)
- Kyle J Mamounis
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32827
| | - Erik T Yukl
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Victor L Davidson
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32827
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16
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Shao X, Zhang H, Yang Z, Zhu L, Cai Z. Quantitative Profiling of Protein-Derived Electrophilic Cofactors in Bacterial Cells with a Hydrazine-Derived Probe. Anal Chem 2020; 92:4484-4490. [PMID: 32093472 DOI: 10.1021/acs.analchem.9b05607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Post-translational modification of proteins can form electrophilic cofactors that serve as a catalytic center. The derived electrophilic cofactors greatly expand protein activities and functions. However, there are few studies concerning how to profile the electrophiles in bacteria. Herein, we utilized a clickable probe called propargyl hydrazine to profile the protein-derived electrophilic cofactors in Escherichia coli (E. coli) cells. Since the cofactors are mostly carbonyl groups, the hydrazine-based probe can specifically react with the cofactors to form a Schiff base. The labeled proteins were then pulled down for mass spectrometry (MS) analysis. Fourteen proteins were shown to undergo enrichment by the probe and competitive binding by its analogue, propyl hydrazine. The identified proteins were further analyzed with targeted proteomics based on parallel reaction monitoring (PRM). Using this strategy, we obtained a global portrait of protein electrophiles in bacterial cells, among which the proteins of speD and panD were previously reported to derive pyruvoyl group as an electrophilic center while lpp can retain N-terminal formyl methionine. This quantitative chemical proteomics strategy can be used to find out protein electrophiles in bacteria and holds great potential to further characterize the protein functions.
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Affiliation(s)
- Xiaojian Shao
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Hailei Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Zhu Yang
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Lin Zhu
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
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17
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Ren Y, Forté J, Cheaib K, Vanthuyne N, Fensterbank L, Vezin H, Orio M, Blanchard S, Desage-El Murr M. Optimizing Group Transfer Catalysis by Copper Complex with Redox-Active Ligand in an Entatic State. iScience 2020; 23:100955. [PMID: 32199288 PMCID: PMC7083792 DOI: 10.1016/j.isci.2020.100955] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/14/2020] [Accepted: 02/25/2020] [Indexed: 01/07/2023] Open
Abstract
Metalloenzymes use earth-abundant non-noble metals to perform high-fidelity transformations in the biological world. To ensure chemical efficiency, metalloenzymes have acquired evolutionary reactivity-enhancing tools. Among these, the entatic state model states that a strongly distorted geometry induced by ligands around a metal center gives rise to an energized structure called entatic state, strongly improving the reactivity. However, the original definition refers both to the transfer of electrons or chemical groups, whereas the chemical application of this concept in synthetic systems has mostly focused on electron transfer, therefore eluding chemical transformations. Here we report that a highly strained redox-active ligand enables a copper complex to perform catalytic nitrogen- and carbon-group transfer in as fast as 2 min, thus exhibiting a strong increase in reactivity compared with its unstrained analogue. This report combines two reactivity-enhancing features from metalloenzymes, entasis and redox cofactors, applied to group-transfer catalysis. We design a catalyst interfacing two reactivity-enhancing tools from metalloenzymes This work merges redox-active cofactors and entatic state reactivity The modifications in the coordination sphere lead to enhanced catalytic behavior These results open perspectives in bioinspired catalysis and group-transfer reactions
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Affiliation(s)
- Yufeng Ren
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 75005 Paris, France
| | - Jeremy Forté
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 75005 Paris, France
| | - Khaled Cheaib
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 75005 Paris, France
| | - Nicolas Vanthuyne
- Aix Marseille Université, CNRS, Centrale Marseille, iSm2, UMR CNRS 7313, 13397 Marseille, France
| | - Louis Fensterbank
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 75005 Paris, France
| | - Hervé Vezin
- Université des Sciences et Technologies de Lille, LASIR, UMR CNRS 8516, 59655 Villeneuve d'Ascq Cedex, France
| | - Maylis Orio
- Aix Marseille Université, CNRS, Centrale Marseille, iSm2, UMR CNRS 7313, 13397 Marseille, France
| | - Sébastien Blanchard
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 75005 Paris, France
| | - Marine Desage-El Murr
- Université de Strasbourg, Institut de Chimie, UMR CNRS 7177, 67000 Strasbourg, France.
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18
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Kim H, Sharma SK, Schaefer AW, Solomon EI, Karlin KD. Heme-Cu Binucleating Ligand Supports Heme/O 2 and Fe II-Cu I/O 2 Reactivity Providing High- and Low-Spin Fe III-Peroxo-Cu II Complexes. Inorg Chem 2019; 58:15423-15432. [PMID: 31657921 DOI: 10.1021/acs.inorgchem.9b02521] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The focus of this study is in the description of synthetic heme/copper/O2 chemistry employing a heme-containing binucleating ligand which provides a tridentate chelate for copper ion binding. The addition of O2 (-80 °C, tetrahydrofuran (THF) solvent) to the reduced heme compound (PImH)FeII (1), gives the oxy-heme adduct, formally a heme-superoxide complex FeIII-(O2•-) (2) (resonance Raman spectroscopy (rR): νO-O, 1171 cm-1 (Δ18O2, -61 cm-1); νFe-O, 575 cm-1 (Δ18O2, -24 cm-1)). Simple warming of 2 to room temperature regenerates reduced complex 1; this reaction is reversible, as followed by UV-vis spectroscopy. Complex 2 is electron paramagnetic resonance (EPR)-silent and exhibits upfield-shifted pyrrole resonances (δ 9.12 ppm) in 2H NMR spectroscopy, indicative of a six-coordinate low-spin heme. The coordination of the tethered imidazolyl arm to the heme-superoxide complex as an axial base ligand is suggested. We also report the new fully reduced heme-copper complex [(PImH)FeIICuI]+ (3), where the copper ion is bound to the tethered tridentate portion of PImH. This reacts with O2 to give a distinctive low-temperature-stable, high-spin (S = 2, overall) peroxo-bridged complex [(PImH)FeIII-(O22-)-CuII]+ (3a): λmax, 420 (Soret), 545, 565 nm; δpyrr, 93 ppm; νO-O, 799 cm-1 (Δ18O2, -48 cm-1); νFe-O, 524 cm-1 (Δ18O2, -23 cm-1). To 3a, the addition of dicyclohexylimidazole (DCHIm), which serves as a heme axial base, leads to low-spin (S = 0 overall) species complex [(DCHIm)(PImH)FeIII-(O22-)-CuII]+ (3b): λmax, 425 (Soret), 538 nm; δpyrr, 10.2 ppm; νO-O, 817 cm-1 (Δ18O2, -55 cm-1); νFe-O, 610 cm-1 (Δ18O2, -26 cm-1). These investigations into the characterization of the O2-adducts from (PImH)FeII (1) with/without additional copper chelation advance our understanding of the dioxygen reactivity of heme-only and heme/Cu-ligand heterobinuclear system, thus potentially relevant to O2 reduction in heme-copper oxidases or fuel-cell chemistry.
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Affiliation(s)
- Hyun Kim
- Department of Chemistry , Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - Savita K Sharma
- Department of Chemistry , Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - Andrew W Schaefer
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Edward I Solomon
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Kenneth D Karlin
- Department of Chemistry , Johns Hopkins University , Baltimore , Maryland 21218 , United States
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19
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Desage‐El Murr M. Nature is the Cure: Engineering Natural Redox Cofactors for Biomimetic and Bioinspired Catalysis. ChemCatChem 2019. [DOI: 10.1002/cctc.201901642] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Marine Desage‐El Murr
- Institut de Chimie UMR 7177Université de Strasbourg 1 rue Blaise Pascal Strasbourg 67000 France
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20
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Characterization of PlGoxB, a flavoprotein required for cysteine tryptophylquinone biosynthesis in glycine oxidase from Pseudoalteromonas luteoviolacea. Arch Biochem Biophys 2019; 674:108110. [PMID: 31541619 DOI: 10.1016/j.abb.2019.108110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/13/2019] [Accepted: 09/17/2019] [Indexed: 11/23/2022]
Abstract
LodA-like proteins are oxidases with a protein-derived cysteine tryptophylquinone (CTQ) prosthetic group. In Pseudoalteromonas luteoviolacea glycine oxidase (PlGoxA), CTQ biosynthesis requires post-translational modifications catalyzed by a modifying enzyme encoded by PlgoxB. The PlGoxB protein was expressed and shown to possess a flavin cofactor. PlGoxB was unstable in solution as it readily lost the flavin and precipitated. PlGoxB precipitation was significantly reduced by incubation with either excess FAD or an equal concentration of prePlGoxA, the precursor protein that is its substrate. In contrast, the mature CTQ-bearing PlGoxA had no stabilizing effect. A homology model of PlGoxB was generated using the structure of Alkylhalidase CmIS. The FAD-binding site of PlGoxB in the model was nearly identical to that of the template structure. The bound FAD in PlGoxB had significant solvent exposure, consistent with the observed tendency to lose FAD. This also suggested that interaction of prePlGoxA with PlGoxB at the exposed FAD-binding site could prevent the observed loss of FAD and subsequent precipitation of PlGoxB. A docking model of the putative PlGoxB-prePlGoxA complex was consistent with these hypotheses. The experimental results and computational analysis implicate structural features of PlGoxB that contribute to its stability and function.
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21
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Ehudin MA, Senft L, Franke A, Ivanović-Burmazović I, Karlin KD. Formation and Reactivity of New Isoporphyrins: Implications for Understanding the Tyr-His Cross-Link Cofactor Biogenesis in Cytochrome c Oxidase. J Am Chem Soc 2019; 141:10632-10643. [PMID: 31150209 DOI: 10.1021/jacs.9b01791] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cytochrome c oxidase (CcO) catalyzes the reduction of dioxygen to water utilizing a heterobinuclear active site composed of a heme moiety and a mononuclear copper center coordinated to three histidine residues, one of which is covalently cross-linked to a tyrosine residue via a post-translational modification (PTM). Although this tyrosine-histidine moiety has functional and structural importance, the pathway behind this net oxidative C-N bond coupling is still unknown. A novel route employing an iron(III) meso-substituted isoporphyrin derivative, isoelectronic with Cmpd-I ((Por•+)FeIV═O), is for the first time proposed to be a key intermediate in the Tyr-His cofactor biogenesis. Newly synthesized iron(III) meso-substituted isoporphyrins were prepared with azide, cyanide, and substituted imidazole functionalities, by adding nucleophiles to an iron(III) π-dication species formed via addition of trifluoroacetic acid to F8Cmpd-I (F8 = (tetrakis(2,6-difluorophenyl)porphyrinate)). Isoporphyrin derivatives were characterized at cryogenic temperatures via ESI-MS and UV-vis, 2H NMR, and EPR spectroscopies. Addition of 1,3,5-trimethoxybenzene or 4-methoxyphenol to the imidazole-substituted isoporphyrin led to formation of the organic product containing the imidazole coupled to aromatic substrate via a new C-N bond, as detected via cryo-ESI-MS. Experimental evidence for the formation of an imidazole-substituted isoporphyrin and its promising reactivity to form the imidazole-phenol coupled product yields viability to the herein proposed pathway behind the PTM (i.e., biogenesis) leading to the key covalent Tyr-His cross-link in CcO.
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Affiliation(s)
- Melanie A Ehudin
- Department of Chemistry , Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - Laura Senft
- Department of Chemistry and Pharmacy , Friedrich-Alexander University Erlangen-Nuremberg , 91058 Erlangen , Germany
| | - Alicja Franke
- Department of Chemistry and Pharmacy , Friedrich-Alexander University Erlangen-Nuremberg , 91058 Erlangen , Germany
| | - Ivana Ivanović-Burmazović
- Department of Chemistry and Pharmacy , Friedrich-Alexander University Erlangen-Nuremberg , 91058 Erlangen , Germany
| | - Kenneth D Karlin
- Department of Chemistry , Johns Hopkins University , Baltimore , Maryland 21218 , United States
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22
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Ma Z, Davidson VL. The Redox Properties of a Cysteine Tryptophylquinone-Dependent Glycine Oxidase Are Distinct from Those of Tryptophylquinone-Dependent Dehydrogenases. Biochemistry 2019; 58:2243-2249. [PMID: 30945853 DOI: 10.1021/acs.biochem.9b00104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
GoxA is a cysteine tryptophylquinone (CTQ)-dependent glycine oxidase that is a member of a family of LodA-like proteins. The electrochemical midpoint potential ( Em) values for the quinone/semiquinone couple and the semiquinone/quinol couple were determined to be 111 and 21, respectively. The Em value for the overall two-electron quinone/quinol couple was similar to those of CTQ- and tryptophan tryptophylquinone (TTQ)-bearing dehydrogenases. However, for the well-studied TTQ-dependent methylamine dehydrogenase, the quinone/semiquinone couple is more negative than the semiquinone/quinol couple, the opposite of what was determined for GoxA. The change in Em value for the two-electron quinone/quinol couple of CTQ in GoxA with pH indicates that the overall two-electron transfer process is associated with the transfer of one proton. Thus, the quinol is anionic. The data reported herein further suggest that in GoxA the CTQ semiquinone is neutral, in contrast to the TTQ-dependent dehydrogenases, in which it is an anionic TTQ semiquinone. These results are discussed in the context of the structure and function of this glycine oxidase, compared to that of the tryptophylquinone-dependent dehydrogenases.
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Affiliation(s)
- Zhongxin Ma
- Burnett School of Biomedical Sciences, College of Medicine , University of Central Florida , Orlando , Florida 32827 , United States
| | - Victor L Davidson
- Burnett School of Biomedical Sciences, College of Medicine , University of Central Florida , Orlando , Florida 32827 , United States
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23
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Guengerich FP, Yoshimoto FK. Formation and Cleavage of C-C Bonds by Enzymatic Oxidation-Reduction Reactions. Chem Rev 2018; 118:6573-6655. [PMID: 29932643 DOI: 10.1021/acs.chemrev.8b00031] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Many oxidation-reduction (redox) enzymes, particularly oxygenases, have roles in reactions that make and break C-C bonds. The list includes cytochrome P450 and other heme-based monooxygenases, heme-based dioxygenases, nonheme iron mono- and dioxygenases, flavoproteins, radical S-adenosylmethionine enzymes, copper enzymes, and peroxidases. Reactions involve steroids, intermediary metabolism, secondary natural products, drugs, and industrial and agricultural chemicals. Many C-C bonds are formed via either (i) coupling of diradicals or (ii) generation of unstable products that rearrange. C-C cleavage reactions involve several themes: (i) rearrangement of unstable oxidized products produced by the enzymes, (ii) oxidation and collapse of radicals or cations via rearrangement, (iii) oxygenation to yield products that are readily hydrolyzed by other enzymes, and (iv) activation of O2 in systems in which the binding of a substrate facilitates O2 activation. Many of the enzymes involve metals, but of these, iron is clearly predominant.
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Affiliation(s)
- F Peter Guengerich
- Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , Tennessee 37232-0146 , United States.,Department of Chemistry , University of Texas-San Antonio , San Antonio , Texas 78249-0698 , United States
| | - Francis K Yoshimoto
- Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , Tennessee 37232-0146 , United States.,Department of Chemistry , University of Texas-San Antonio , San Antonio , Texas 78249-0698 , United States
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