1
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Kang Y, Yeo M, Choi H, Jun H, Eom S, Park SG, Yoon H, Kim E, Kang S. Lactate oxidase/vSIRPα conjugates efficiently consume tumor-produced lactates and locally produce tumor-necrotic H 2O 2 to suppress tumor growth. Int J Biol Macromol 2023; 231:123577. [PMID: 36758763 DOI: 10.1016/j.ijbiomac.2023.123577] [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: 12/08/2022] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 02/11/2023]
Abstract
Aggressive tumor formation often leads to excessive anaerobic glycolysis and massive production and accumulation of lactate in the tumor microenvironment (TME). To significantly curb lactate accumulation in TME, in this study, lactate oxidase (LOX) was used as a potential therapeutic enzyme and signal regulatory protein α variant (vSIRPα) as a tumor cell targeting ligand. SpyCatcher protein and SpyTag peptide were genetically fused to LOX and vSIRPα, respectively, to form SC-LOX and ST-vSIRPα and tumor-targeting LOX/vSIRPα conjugates were constructed via a SpyCatcher/SpyTag protein ligation system. LOX/vSIRPα conjugates selectively bound to the CD47-overexpressing mouse melanoma B16-F10 cells and effectively consumed lactate produced by the B16-F10 cells, generating adequate amounts of hydrogen peroxide (H2O2), which induces drastic necrotic tumor cell death. Local treatments of B16-F10 tumor-bearing mice with LOX/vSIRPα conjugates significantly suppressed B16-F10 tumor growth in vivo without any severe side effects. Tumor-targeting vSIRPα may allow longer retention of LOX in tumor sites, effectively consuming surrounding lactate in TME and locally generating adequate amounts of cytotoxic H2O2 to suppress tumor growth. The approach restraining the local lactate concentration and H2O2 in TME using LOX and vSIRPα could offer new opportunities for developing enzyme/targeting ligand conjugate-based therapeutic tools for tumor treatment.
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Affiliation(s)
- Yujin Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Mirae Yeo
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Hyukjun Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Heejin Jun
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Soomin Eom
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Seong Guk Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Haejin Yoon
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Eunhee Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
| | - Sebyung Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
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2
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His-tagged lactate oxidase production for industrial applications using fed-batch fermentation. J Biotechnol 2023; 363:1-7. [PMID: 36608873 DOI: 10.1016/j.jbiotec.2022.12.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 12/28/2022] [Accepted: 12/30/2022] [Indexed: 01/05/2023]
Abstract
L-lactate oxidase (LOX) is a biotechnologically important enzyme used in biosensors and colorimetric kits to detect lactate, a key biomarker in clinical diagnostics, sports medicine and the food industry. In this work, we produced a recombinant His-tagged Aerococcus viridans LOX (rLOX) in Escherichia coli and carried out its functional characterization for industrial applications. Our rLOX was evaluated in a colorimetric kit for human diagnostics and in an amperometric biosensor to measure the lactic acid in food products. The rLOX was fully functional for both applications, with a performance comparable to commercial untagged LOXs. As the industrial use of LOX enzyme requires a large-scale production, we scaled up the rLOX production in a fed-batch bioreactor culture and obtained a yield approximately ten times higher than that of the Erlenmeyer scale. The His-tag allowed an easy and highly efficient purification process, and a high-purity rLOX was recovered after this one-step affinity purification. In this study, we described a simple, rapid and cost-competitive approach for the production of a recombinant His-tagged LOX enzyme suitable for industrial use.
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3
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Choi H, Yeo M, Kang Y, Kim HJ, Park SG, Jang E, Park SH, Kim E, Kang S. Lactate oxidase/catalase-displaying nanoparticles efficiently consume lactate in the tumor microenvironment to effectively suppress tumor growth. J Nanobiotechnology 2023; 21:5. [PMID: 36597089 PMCID: PMC9811728 DOI: 10.1186/s12951-022-01762-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
The aggressive proliferation of tumor cells often requires increased glucose uptake and excessive anaerobic glycolysis, leading to the massive production and secretion of lactate to form a unique tumor microenvironment (TME). Therefore, regulating appropriate lactate levels in the TME would be a promising approach to control tumor cell proliferation and immune suppression. To effectively consume lactate in the TME, lactate oxidase (LOX) and catalase (CAT) were displayed onto Aquifex aeolicus lumazine synthase protein nanoparticles (AaLS) to form either AaLS/LOX or AaLS/LOX/CAT. These complexes successfully consumed lactate produced by CT26 murine colon carcinoma cells under both normoxic and hypoxic conditions. Specifically, AaLS/LOX generated a large amount of H2O2 with complete lactate consumption to induce drastic necrotic cell death regardless of culture condition. However, AaLS/LOX/CAT generated residual H2O2, leading to necrotic cell death only under hypoxic condition similar to the TME. While the local administration of AaLS/LOX to the tumor site resulted in mice death, that of AaLS/LOX/CAT significantly suppressed tumor growth without any severe side effects. AaLS/LOX/CAT effectively consumed lactate to produce adequate amounts of H2O2 which sufficiently suppress tumor growth and adequately modulate the TME, transforming environments that are favorable to tumor suppressive neutrophils but adverse to tumor-supportive tumor-associated macrophages. Collectively, these findings showed that the modular functionalization of protein nanoparticles with multiple metabolic enzymes may offer the opportunity to develop new enzyme complex-based therapeutic tools that can modulate the TME by controlling cancer metabolism.
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Affiliation(s)
- Hyukjun Choi
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
| | - Mirae Yeo
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
| | - Yujin Kang
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
| | - Hyo Jeong Kim
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
| | - Seong Guk Park
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
| | - Eunjung Jang
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
| | - Sung Ho Park
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
| | - Eunhee Kim
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
| | - Sebyung Kang
- grid.42687.3f0000 0004 0381 814XDepartment of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 South Korea
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4
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Tsvik L, Steiner B, Herzog P, Haltrich D, Sützl L. Flavin Mononucleotide-Dependent l-Lactate Dehydrogenases: Expanding the Toolbox of Enzymes for l-Lactate Biosensors. ACS OMEGA 2022; 7:41480-41492. [PMID: 36406534 PMCID: PMC9670274 DOI: 10.1021/acsomega.2c05257] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
The development of L-lactate biosensors has been hampered in recent years by the lack of availability and knowledge about a wider range and diversity of L-lactate-oxidizing enzymes that can be used as bioelements in these sensors. For decades, L-lactate oxidase of Aerococcus viridans (AvLOx) has been used almost exclusively in the field of L-lactate biosensor development and has achieved somewhat like a monopoly status as a biocatalyst for these applications. Studies on other L-lactate-oxidizing enzymes are sparse and are often missing biochemical data. In this work, we made use of the vast amount of sequence information that is currently available on protein databases to investigate the naturally occurring diversity of L-lactate-utilizing enzymes of the flavin mononucleotide (FMN)-dependent α-hydroxy acid oxidoreductase (HAOx) family. We identified the HAOx sequence space specific for L-lactate oxidation and additionally discovered a not-yet described class of soluble and FMN-dependent L-lactate dehydrogenases, which are promising for the construction of second-generation biosensors or other biotechnological applications. Our work paves the way for new studies on α-hydroxy acid biosensors and proves that there is more to the HAOx family than AvLOx.
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Affiliation(s)
- Lidiia Tsvik
- Laboratory
of Food Biotechnology, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 11, A-1190 Wien, Vienna, Austria
| | - Beate Steiner
- DirectSens
Biosensors GmbH, Am Rosenbühel
38, 3400 Klosterneuburg, Austria
| | - Peter Herzog
- DirectSens
Biosensors GmbH, Am Rosenbühel
38, 3400 Klosterneuburg, Austria
| | - Dietmar Haltrich
- Laboratory
of Food Biotechnology, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 11, A-1190 Wien, Vienna, Austria
| | - Leander Sützl
- Laboratory
of Food Biotechnology, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 11, A-1190 Wien, Vienna, Austria
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5
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An Oxygen-Insensitive Biosensor and a Biofuel Cell Device based on FMN L-lactate Dehydrogenase. Bioelectrochemistry 2022; 149:108316. [DOI: 10.1016/j.bioelechem.2022.108316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/22/2022] [Accepted: 10/26/2022] [Indexed: 11/08/2022]
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6
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Unusual reactivity of a flavin in a bifurcating electron-transferring flavoprotein leads to flavin modification and a charge-transfer complex. J Biol Chem 2022; 298:102606. [PMID: 36257407 PMCID: PMC9713284 DOI: 10.1016/j.jbc.2022.102606] [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: 07/17/2022] [Revised: 10/08/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022] Open
Abstract
From the outset, canonical electron transferring flavoproteins (ETFs) earned a reputation for containing modified flavin. We now show that modification occurs in the recently recognized bifurcating (Bf) ETFs as well. In Bf ETFs, the 'electron transfer' (ET) flavin mediates single electron transfer via a stable anionic semiquinone state, akin to the FAD of canonical ETFs, whereas a second flavin mediates bifurcation (the Bf FAD). We demonstrate that the ET FAD undergoes transformation to two different modified flavins by a sequence of protein-catalyzed reactions that occurs specifically in the ET site, when the enzyme is maintained at pH 9 in an amine-based buffer. Our optical and mass spectrometric characterizations identify 8-formyl flavin early in the process and 8-amino flavins (8AFs) at later times. The latter have not previously been documented in an ETF to our knowledge. Mass spectrometry of flavin products formed in Tris or bis-tris-aminopropane solutions demonstrates that the source of the amine adduct is the buffer. Stepwise reduction of the 8AF demonstrates that it can explain a charge transfer band observed near 726 nm in Bf ETF, as a complex involving the hydroquinone state of the 8AF in the ET site with the oxidized state of unmodified flavin in the Bf site. This supports the possibility that Bf ETF can populate a conformation enabling direct electron transfer between its two flavins, as has been proposed for cofactors brought together in complexes between ETF and its partner proteins.
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7
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Hiraka K, Yoshida H, Tsugawa W, Asano R, La Belle JT, Ikebukuro K, Sode K. Structure of lactate oxidase from Enterococcus hirae revealed new aspects of active site loop function: Product-inhibition mechanism and oxygen gatekeeper. Protein Sci 2022; 31:e4434. [PMID: 36173159 PMCID: PMC9490804 DOI: 10.1002/pro.4434] [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: 05/19/2022] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/09/2022]
Abstract
l-Lactate oxidase (LOx) is a flavin mononucleotide (FMN)-dependent triose phosphate isomerase (TIM) barrel fold enzyme that catalyzes the oxidation of l-lactate using oxygen as a primary electron acceptor. Although reductive half-reaction mechanism of LOx has been studied by structure-based kinetic studies, oxidative half-reaction and substrate/product-inhibition mechanisms were yet to be elucidated. In this study, the structure and enzymatic properties of wild-type and mutant LOxs from Enterococcus hirae (EhLOx) were investigated. EhLOx structure showed the common TIM-barrel fold with flexible loop region. Noteworthy observations were that the EhLOx crystal structures prepared by co-crystallization with product, pyruvate, revealed the complex structures with "d-lactate form ligand," which was covalently bonded with a Tyr211 side chain. This observation provided direct evidence to suggest the product-inhibition mode of EhLOx. Moreover, this structure also revealed a flip motion of Met207 side chain, which is located on the flexible loop region as well as Tyr211. Through a saturation mutagenesis study of Met207, one of the mutants Met207Leu showed the drastically decreased oxidase activity but maintained dye-mediated dehydrogenase activity. The structure analysis of EhLOx Met207Leu revealed the absence of flipping in the vicinity of FMN, unlike the wild-type Met207 side chain. Together with the simulation of the oxygen-accessible channel prediction, Met207 may play as an oxygen gatekeeper residue, which contributes oxygen uptake from external enzyme to FMN. Three clades of LOxs are proposed based on the difference of the Met207 position and they have different oxygen migration pathway from external enzyme to active center FMN.
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Affiliation(s)
- Kentaro Hiraka
- Department of Biotechnology and Life Science, Graduate School of EngineeringTokyo University of Agriculture and TechnologyTokyoJapan
- College of Science, Engineering and TechnologyGrand Canyon UniversityPhoenixArizonaUSA
| | - Hiromi Yoshida
- Department of Basic Life Science, Faculty of MedicineKagawa UniversityKagawaJapan
| | - Wakako Tsugawa
- Department of Biotechnology and Life Science, Graduate School of EngineeringTokyo University of Agriculture and TechnologyTokyoJapan
| | - Ryutaro Asano
- Department of Biotechnology and Life Science, Graduate School of EngineeringTokyo University of Agriculture and TechnologyTokyoJapan
| | - Jeffrey T. La Belle
- College of Science, Engineering and TechnologyGrand Canyon UniversityPhoenixArizonaUSA
| | - Kazunori Ikebukuro
- Department of Biotechnology and Life Science, Graduate School of EngineeringTokyo University of Agriculture and TechnologyTokyoJapan
| | - Koji Sode
- Joint Department of Biomedical EngineeringThe University of North Carolina at Chapel Hill and North Carolina State UniversityChapel HillNorth CarolinaUSA
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8
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Trisrivirat D, Sutthaphirom C, Pimviriyakul P, Chaiyen P. Dual activities of oxidation and oxidative decarboxylation by flavoenzymes. Chembiochem 2022; 23:e202100666. [PMID: 35040514 DOI: 10.1002/cbic.202100666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/17/2022] [Indexed: 11/07/2022]
Abstract
Specific flavoenzyme oxidases catalyze oxidative decarboxylation in addition to their classical oxidation reactions in the same active sites. The mechanisms underlying oxidative decarboxylation by these enzymes and how they control their two activities are not clearly known. This article reviews the current state of knowledge of four enzymes from the l-amino acid oxidase and l-hydroxy acid oxidase families, including l-tryptophan 2-monooxygenase, l-phenylalanine 2-oxidase and l-lysine oxidase/monooxygenase and lactate monooxygenase which catalyze substrate oxidation and oxidative decarboxylation. Apart from specific interactions to allow substrate oxidation by the flavin cofactor, specific binding of oxidized product in the active sites appears to be important for enabling subsequent decarboxylation by these enzymes. Based on recent findings of l-lysine oxidase/monooxygenase, we propose that nucleophilic attack of H2O2 on the imino acid product is the mechanism enabling oxidative decarboxylation.
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Affiliation(s)
- Duangthip Trisrivirat
- VISTEC: Vidyasirimedhi Institute of Science and Technology, Biomolecular Science and Engineering, THAILAND
| | - Chalermroj Sutthaphirom
- VISTEC: Vidyasirimedhi Institute of Science and Technology, Biomolecular Science and Engineering, THAILAND
| | | | - Pimchai Chaiyen
- Vidyasirimedhi Institute of Science and Technology (VISTEC), School of Biomolecular Science and Engineering, 555 Moo 1 Payupnai, 21210, Wangchan District, THAILAND
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9
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Experimental and computational investigation of enzyme functional annotations uncovers misannotation in the EC 1.1.3.15 enzyme class. PLoS Comput Biol 2021; 17:e1009446. [PMID: 34555022 PMCID: PMC8491902 DOI: 10.1371/journal.pcbi.1009446] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 10/05/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Only a small fraction of genes deposited to databases have been experimentally characterised. The majority of proteins have their function assigned automatically, which can result in erroneous annotations. The reliability of current annotations in public databases is largely unknown; experimental attempts to validate the accuracy within individual enzyme classes are lacking. In this study we performed an overview of functional annotations to the BRENDA enzyme database. We first applied a high-throughput experimental platform to verify functional annotations to an enzyme class of S-2-hydroxyacid oxidases (EC 1.1.3.15). We chose 122 representative sequences of the class and screened them for their predicted function. Based on the experimental results, predicted domain architecture and similarity to previously characterised S-2-hydroxyacid oxidases, we inferred that at least 78% of sequences in the enzyme class are misannotated. We experimentally confirmed four alternative activities among the misannotated sequences and showed that misannotation in the enzyme class increased over time. Finally, we performed a computational analysis of annotations to all enzyme classes in the BRENDA database, and showed that nearly 18% of all sequences are annotated to an enzyme class while sharing no similarity or domain architecture to experimentally characterised representatives. We showed that even well-studied enzyme classes of industrial relevance are affected by the problem of functional misannotation. Correct annotation of genomes is crucial for our understanding and utilization of functional gene diversity, yet the reliability of current protein annotations in public databases is largely unknown. In our work we validated annotations to an S-2-hydroxyacid oxidase enzyme class (EC 1.1.3.15) by assessing activity of 122 representative sequences in a high-throughput screening experiment. From this dataset we inferred that at least 78% of the sequences in the enzyme class are misannotated, and confirmed four alternative activities among the misannotated sequences. We showed that the misannotation is widespread throughout enzyme classes, affecting even well-studied classes of industrial relevance. Overall, our study highlights the value of experimental and computational validation of predicted functions within individual enzyme classes.
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10
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Dynamic interactions in the l-lactate oxidase active site facilitate substrate binding at pH4.5. Biochem Biophys Res Commun 2021; 568:131-135. [PMID: 34214876 DOI: 10.1016/j.bbrc.2021.06.078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 11/23/2022]
Abstract
The crystal structure of l-lactate oxidase in complex with l-lactate was solved at a 1.33 Å resolution. The electron density of the bound l-lactate was clearly shown and comparisons of the free form and substrate bound complexes demonstrated that l-lactate was bound to the FMN and an additional active site within the enzyme complex. l-lactate interacted with the related side chains, which play an important role in enzymatic catalysis and especially the coupled movement of H265 and D174, which may be essential to activity. These observations not only reveal the enzymatic mechanism for l-lactate binding but also demonstrate the dynamic motion of these enzyme structures in response to substrate binding and enzymatic reaction progression.
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11
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Pollegioni L, Molla G, Sacchi S, Murtas G. Human D-aspartate Oxidase: A Key Player in D-aspartate Metabolism. Front Mol Biosci 2021; 8:689719. [PMID: 34250021 PMCID: PMC8260693 DOI: 10.3389/fmolb.2021.689719] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/09/2021] [Indexed: 11/15/2022] Open
Abstract
In recent years, the D-enantiomers of amino acids have been recognized as natural molecules present in all kingdoms, playing a variety of biological roles. In humans, d-serine and d-aspartate attracted attention for their presence in the central nervous system. Here, we focus on d-aspartate, which is involved in glutamatergic neurotransmission and the synthesis of various hormones. The biosynthesis of d-aspartate is still obscure, while its degradation is due to the peroxisomal flavin adenine dinucleotide (FAD)-containing enzyme d-aspartate oxidase. d-Aspartate emergence is strictly controlled: levels decrease in brain within the first days of life while increasing in endocrine glands postnatally and through adulthood. The human d-aspartate oxidase (hDASPO) belongs to the d-amino acid oxidase-like family: its tertiary structure closely resembles that of human d-amino acid oxidase (hDAAO), the enzyme that degrades neutral and basic d-amino acids. The structure-function relationships of the physiological isoform of hDASPO (named hDASPO_341) and the regulation of gene expression and distribution and properties of the longer isoform hDASPO_369 have all been recently elucidated. Beyond the substrate preference, hDASPO and hDAAO also differ in kinetic efficiency, FAD-binding affinity, pH profile, and oligomeric state. Such differences suggest that evolution diverged to create two different ways to modulate d-aspartate and d-serine levels in the human brain. Current knowledge about hDASPO is shedding light on the molecular mechanisms underlying the modulation of d-aspartate levels in human tissues and is pushing novel, targeted therapeutic strategies. Now, it has been proposed that dysfunction in NMDA receptor-mediated neurotransmission is caused by disrupted d-aspartate metabolism in the nervous system during the onset of various disorders (such as schizophrenia): the design of suitable hDASPO inhibitors aimed at increasing d-aspartate levels thus represents a novel and useful form of therapy.
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Affiliation(s)
- Loredano Pollegioni
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Gianluca Molla
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Silvia Sacchi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Giulia Murtas
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
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12
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Ferreira M, Sharma SK, Paudyal S, Leblanc RM. Interfacial behavior of Lactate Oxidase at Air-Subphase interface. J Colloid Interface Sci 2021; 589:173-178. [PMID: 33460849 DOI: 10.1016/j.jcis.2020.12.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/27/2020] [Accepted: 12/30/2020] [Indexed: 11/25/2022]
Abstract
This article investigates the main aspects of the surface chemistry properties of the lactate oxidase (LacOx) enzyme monolayer at the air-subphase interface. Surface chemistry study determined the important properties like the surface packing and stability of the formed layer, whereas the spectroscopic experiments provided information regarding its secondary structure conformation of the enzyme. We have demonstrated that the LacOx in the monolayer form remained active for extended time period. In accordance to the data obtained from the isotherm it was also found that LacOx forms a stable monolayer that does not aggregate at the air-subphase interface. The stability of the monolayer at the air-subphase interface was studied by using compression-decompression cycles which revealed the stability with no significant evidence of aggregates or irreversible domains. This was further confirmed by UV-vis absorption and fluorescence measurements. Spectra from circular dichroism (CD) showed that the LB film retains the characteristic of an α-helix conformation.
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Affiliation(s)
- Marystela Ferreira
- Department of Mathematic, Physical, Chemistry, Federal University of São Paulo, Sorocaba, São Paulo, 18052-720, Brazil
| | - Shiv K Sharma
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, United States
| | - Suraj Paudyal
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, United States
| | - Roger M Leblanc
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, United States.
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13
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Yan J, Tan YL, Lin MJ, Xing H, Jiang JH. A DNA-mediated crosslinking strategy to enhance cellular delivery and sensor performance of protein spherical nucleic acids. Chem Sci 2020; 12:1803-1809. [PMID: 34163943 PMCID: PMC8179099 DOI: 10.1039/d0sc04977h] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Intracellular delivery of enzymes is essential for protein-based diagnostic and therapeutic applications. Protein-spherical nucleic acids (ProSNAs) defined by protein core and dense shell of oligonucleotides have been demonstrated as a promising vehicle-free enzyme delivery platform. In this work, we reported a crosslinking strategy to vastly improve both delivery efficiency and intracellular sensor performance of ProSNA. By assembling individual ProSNA with lactate oxidase (LOX) core into a nanoscale particle, termed as crosslinked SNA (X-SNA), the enzyme delivery efficiency increased up to 5-6 times higher. The LOX X-SNA was later demonstrated as a ratiometric probe for quantitative detection of lactate in living cells. More importantly, X-SNA probe showed significantly improved sensor performance with signal-to-noise ratio 4 times as high as ProSNA when detecting intracellular lactate.
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Affiliation(s)
- Jing Yan
- Institute of Chemical Biology and Nanomedicine, Hunan University Changsha 410082 P. R. China .,State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University Changsha 410082 P. R. China
| | - Ya-Ling Tan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University Changsha 410082 P. R. China
| | - Min-Jie Lin
- Institute of Chemical Biology and Nanomedicine, Hunan University Changsha 410082 P. R. China .,State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University Changsha 410082 P. R. China
| | - Hang Xing
- Institute of Chemical Biology and Nanomedicine, Hunan University Changsha 410082 P. R. China .,State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University Changsha 410082 P. R. China
| | - Jian-Hui Jiang
- Institute of Chemical Biology and Nanomedicine, Hunan University Changsha 410082 P. R. China .,State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University Changsha 410082 P. R. China
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14
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Abstract
This chapter represents a journey through flavoprotein oxidases. The purpose is to excite the reader curiosity regarding this class of enzymes by showing their diverse applications. We start with a brief overview on oxidases to then introduce flavoprotein oxidases and elaborate on the flavin cofactors, their redox and spectroscopic characteristics, and their role in the catalytic mechanism. The six major flavoprotein oxidase families will be described, giving examples of their importance in biology and their biotechnological uses. Specific attention will be given to a few selected flavoprotein oxidases that are not extensively discussed in other chapters of this book. Glucose oxidase, cholesterol oxidase, 5-(hydroxymethyl)furfural (HMF) oxidase and methanol oxidase are four examples of oxidases belonging to the GMC-like flavoprotein oxidase family and that have been shown to be valuable biocatalysts. Their structural and mechanistic features and recent enzyme engineering will be discussed in details. Finally we give a look at the current trend in research and conclude with a future outlook.
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Affiliation(s)
- Caterina Martin
- Molecular Enzymology Group, University of Groningen, Groningen, The Netherlands
| | - Claudia Binda
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Marco W Fraaije
- Molecular Enzymology Group, University of Groningen, Groningen, The Netherlands.
| | - Andrea Mattevi
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
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15
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Employment of 1-Methoxy-5-Ethyl Phenazinium Ethyl Sulfate as a Stable Electron Mediator in Flavin Oxidoreductases-Based Sensors. SENSORS 2020; 20:s20102825. [PMID: 32429321 PMCID: PMC7284575 DOI: 10.3390/s20102825] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/10/2020] [Accepted: 05/13/2020] [Indexed: 11/20/2022]
Abstract
In this paper, a novel electron mediator, 1-methoxy-5-ethyl phenazinium ethyl sulfate (mPES), was introduced as a versatile mediator for disposable enzyme sensor strips, employing representative flavin oxidoreductases, lactate oxidase (LOx), glucose dehydrogenase (GDH), and fructosyl peptide oxidase (FPOx). A disposable lactate enzyme sensor with oxygen insensitive Aerococcus viridans-derived engineered LOx (AvLOx), with A96L mutant as the enzyme, was constructed. The constructed lactate sensor exhibited a high sensitivity (0.73 ± 0.12 μA/mM) and wide linear range (0–50 mM lactate), showings that mPES functions as an effective mediator for AvLOx. Employing mPES as mediator allowed this amperometric lactate sensor to be operated at a relatively low potential of +0.2 V to 0 V vs. Ag/AgCl, thus avoiding interference from uric acid and acetaminophen. The lactate sensors were adequately stable for at least 48 days of storage at 25 °C. These results indicated that mPES can be replaced with 1-methoxy-5-methyl phenazinium methyl sulfate (mPMS), which we previously reported as the best mediator for AvLOx-based lactate sensors. Furthermore, this study revealed that mPES can be used as an effective electron mediator for the enzyme sensors employing representative flavin oxidoreductases, GDH-based glucose sensors, and FPOx-based hemoglobin A1c (HbA1c) sensors.
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16
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Rational engineering of Aerococcus viridansl-lactate oxidase for the mediator modification to achieve quasi-direct electron transfer type lactate sensor. Biosens Bioelectron 2019; 151:111974. [PMID: 31999581 DOI: 10.1016/j.bios.2019.111974] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 11/23/2022]
Abstract
The l-lactate oxidase (LOx) based lactate sensors are widely used for clinical diagnostics, sports medicine, and food quality control. However, dissolved oxygen interference and electroactive interferent effects are inherent issues of current lactate sensors. In this paper, a quasi-direct electron transfer (quasi-DET) type lactate sensor was developed using rationally engineered Aerococcus viridans LOx (AvLOx) modified with amine-reactive phenazine ethosulfate (PES). Since the modification of wild type AvLOx by PES did not result quasi-DET, engineered AvLOx with additional Lys residue was designed. The additional Lys residue was introduced by substituting residue locating on the surface of AvLOx, and within 20 Å of the isoalloxazine ring of FMN. Among several constructed mutants, Ala96Leu/Asn212Lys double mutant showed the highest dye-mediated dehydrogenase activity with negligible oxidase activity, showing quasi-DET properties after PES modification, when the enzyme was immobilized on screen printed carbon electrode. The constructed electrode did not show oxygen interference in cyclic voltammetric analysis and distinct catalytic current with 20 mM l-lactate. The sensor performance of a chronoamperometric l-lactate sensor employing PES modified Ala96Leu/Asn212Lys AvLOx, marked with linear range between 0 and 1 mM, with sensitivity of 13 μA/mM∙cm2, and a limit of detection of 25 μM for l-lactate. By applying -200 mV vs. Ag/AgCl, l-lactate could be monitored with negligible interference from 170 μM ascorbic acid, 1.3 mM acetaminophen, 1.4 mM uric acid or 20 mM glucose. These results indicated that a quasi-DET type lactate sensor was developed that did not suffer from the interference of oxygen and representative electroactive ingredient compounds.
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17
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Cunha-Silva H, Pires F, Dias-Cabral AC, Arcos-Martinez MJ. Inhibited enzymatic reaction of crosslinked lactate oxidase through a pH-dependent mechanism. Colloids Surf B Biointerfaces 2019; 184:110490. [PMID: 31536937 DOI: 10.1016/j.colsurfb.2019.110490] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/12/2019] [Accepted: 09/04/2019] [Indexed: 12/01/2022]
Abstract
Lactate oxidase (LOx), recognized to selectively catalyze the lactate oxidation in complex matrices, has been highlighted as preferable biorecognition element for the development of lactate biosensors. In a previous work, we have demonstrated that LOx crosslinking on a modified screen-printed electrode results in a dual range lactate biosensor, with one of the analysis linear range (4 to 50 mM) compatible with lactate sweat levels. It was advanced that such behavior results from an atypical substrate inhibition process. To understand such inhibition phenomena, this work relies in the study of LOx structure when submitted to increased substrate concentrations. The results found by fluorescence spectroscopy and dynamic light scattering of LOx solutions, evidenced conformational changes of the enzyme, occurring in presence of inhibitory substrate concentrations. Therefore, the inhibition behavior found at the biosensor, is an outcome of LOx structural alterations as result of a pH-dependent mechanism promoted at high substrate concentrations.
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Affiliation(s)
- Hugo Cunha-Silva
- Departmento de Química, Facultad de Ciencias, Universidad de Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
| | - F Pires
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal; Department of Chemistry, University of Beira Interior, 6200-001 Covilhã, Portugal
| | - A C Dias-Cabral
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal; Department of Chemistry, University of Beira Interior, 6200-001 Covilhã, Portugal
| | - M Julia Arcos-Martinez
- Departmento de Química, Facultad de Ciencias, Universidad de Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain
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18
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Bollella P, Sharma S, Cass AEG, Antiochia R. Minimally-invasive Microneedle-based Biosensor Array for Simultaneous Lactate and Glucose Monitoring in Artificial Interstitial Fluid. ELECTROANAL 2019. [DOI: 10.1002/elan.201800630] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Paolo Bollella
- Department of Chemistry and Drug Technologies; Sapienza University of Rome; Rome Italy
| | - Sanjiv Sharma
- College of Engineering; Swansea University; Swansea Wales
| | | | - Riccarda Antiochia
- Department of Chemistry and Drug Technologies; Sapienza University of Rome; Rome Italy
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19
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Microneedle-based biosensor for minimally-invasive lactate detection. Biosens Bioelectron 2019; 123:152-159. [DOI: 10.1016/j.bios.2018.08.010] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/03/2018] [Accepted: 08/07/2018] [Indexed: 01/27/2023]
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20
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Kean KM, Karplus PA. Structure and role for active site lid of lactate monooxygenase from Mycobacterium smegmatis. Protein Sci 2018; 28:135-149. [PMID: 30207005 DOI: 10.1002/pro.3506] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/30/2018] [Accepted: 09/05/2018] [Indexed: 12/17/2022]
Abstract
Lactate monooxygenase (LMO) catalyzes the FMN-dependent "coupled" oxidation of lactate and O2 to acetate, carbon dioxide, and water, involving pyruvate and hydrogen peroxide as enzyme-bound intermediates. Other α-hydroxy acid oxidase family members follow an "uncoupled pathway," wherein the α-keto acid product quickly dissociates before the reduced flavin reacts with oxygen. Here, we report the structures of Mycobacterium smegmatis wild-type LMO and a wild-type-like C203A variant at 2.1 Å and 1.7 Å resolution, respectively. The overall LMO fold and active site organization, including a bound sulfate mimicking substrate, resemble those of other α-hydroxy acid oxidases. Based on structural similarity, LMO is similarly distant from lactate oxidase, glycolate oxidase, mandelate dehydrogenase, and flavocytochrome b2 and is the first representative enzyme of its type. Comparisons with other α-hydroxy acid oxidases reveal that LMO has a longer and more compact folded active site loop (Loop 4), which is known in related flavoenzymes to undergo order/disorder transitions to allow substrate/product binding and release. We propose that LMO's Loop 4 has an enhanced stability that is responsible for the slow product release requisite for the coupled pathway. We also note electrostatic features of the LMO active site that promote substrate binding. Whereas the physiological role of LMO remains unknown, we document what can currently be assessed of LMO's distribution in nature, including its unexpected occurrence, presumably through horizontal gene transfer, in halophilic archaea and in a limited group of fungi of the genus Beauveria. BROAD STATEMENT OF IMPACT: This first crystal structure of the FMN-dependent α-hydroxy acid oxidase family member lactate monooxygenase (LMO) reveals it has a uniquely large active site lid that we hypothesize is stable enough to explain the slow dissociation of pyruvate that leads to its "coupled" oxidation of lactate and O2 to produce acetate, carbon dioxide, and water. Also, the relatively widespread distribution of putative LMOs supports their importance and provides new motivation for their further study.
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Affiliation(s)
- Kelsey M Kean
- Department of Biochemistry and Biophysics, 2011 Agriculture and Life Sciences Building, Oregon State University, Corvallis, Oregon 97331
| | - P Andrew Karplus
- Department of Biochemistry and Biophysics, 2011 Agriculture and Life Sciences Building, Oregon State University, Corvallis, Oregon 97331
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21
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Hiraka K, Kojima K, Lin CE, Tsugawa W, Asano R, La Belle JT, Sode K. Minimizing the effects of oxygen interference on l -lactate sensors by a single amino acid mutation in Aerococcus viridans l -lactate oxidase. Biosens Bioelectron 2018; 103:163-170. [DOI: 10.1016/j.bios.2017.12.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/17/2017] [Accepted: 12/13/2017] [Indexed: 01/26/2023]
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22
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Elhoul MB, Machillot P, Benoît M, Lederer F. Translational misreading, amino acid misincorporation and misinterpretations. The case of the flavocytochrome b 2 H373Q variant. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1865:353-358. [PMID: 28007443 DOI: 10.1016/j.bbapap.2016.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/24/2016] [Accepted: 12/16/2016] [Indexed: 11/19/2022]
Abstract
Amino acid misincorporation during protein synthesis occurs naturally at a low level. Protein sequence errors, depending on the level and the nature of the misincorporation, can have various consequences. When site-directed mutagenesis is used as a tool for understanding the role of a side chain in enzyme catalysis, misincorporation in a variant with intrinsically low activity may lead to misinterpretations concerning the enzyme mechanism. We report here one more example of such a problem, dealing with flavocytochrome b2 (Fcb2), a lactate dehydrogenase, member of a family of FMN-dependent L-2-hydroxy acid oxidizing enzymes. Two papers have described the properties of the Fcb2 catalytic base H373Q variant, each one using a different expression system with the same base change for the mutation. The two papers found similar apparent kinetic parameters. But the first one demonstrated the existence of a low level of histidine misincorporation, which led to an important correction of the variant residual activity (Gaume et al. (1995) Biochimie, 77, 621). The second paper did not investigate the possibility of a misincorporation (Tsai et al. (2007) Biochemistry, 46, 7844). The two papers had different mechanistic conclusions. We show here that in this case the misincorporation does not depend on the expression system. We bring the proof that Tsai et al. (2007) were led to an erroneous mechanistic conclusion for having missed the phenomenon as well as for having misinterpreted the crystal structure of the variant. This work is another illustration of the caution one should exercise when characterizing enzyme variants with low activity.
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Affiliation(s)
- Mouna Ben Elhoul
- Laboratoire de Chimie Physique, CNRS UMR 8000, Faculté des Sciences, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Paul Machillot
- Laboratoire de Chimie Physique, CNRS UMR 8000, Faculté des Sciences, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Mireille Benoît
- Laboratoire de Chimie Physique, CNRS UMR 8000, Faculté des Sciences, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Florence Lederer
- Laboratoire de Chimie Physique, CNRS UMR 8000, Faculté des Sciences, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France.
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23
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Conformational flexibility related to enzyme activity: evidence for a dynamic active-site gatekeeper function of Tyr(215) in Aerococcus viridans lactate oxidase. Sci Rep 2016; 6:27892. [PMID: 27302031 PMCID: PMC4908395 DOI: 10.1038/srep27892] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 05/26/2016] [Indexed: 01/15/2023] Open
Abstract
L-Lactate oxidase (LOX) belongs to a large family of flavoenzymes that catalyze oxidation of α-hydroxy acids. How in these enzymes the protein structure controls reactivity presents an important but elusive problem. LOX contains a prominent tyrosine in the substrate binding pocket (Tyr(215) in Aerococcus viridans LOX) that is partially responsible for securing a flexible loop which sequesters the active site. To characterize the role of Tyr(215), effects of substitutions of the tyrosine (Y215F, Y215H) were analyzed kinetically, crystallographically and by molecular dynamics simulations. Enzyme variants showed slowed flavin reduction and oxidation by up to 33-fold. Pyruvate release was also decelerated and in Y215F, it was the slowest step overall. A 2.6-Å crystal structure of Y215F in complex with pyruvate shows the hydrogen bond between the phenolic hydroxyl and the keto oxygen in pyruvate is replaced with a potentially stronger hydrophobic interaction between the phenylalanine and the methyl group of pyruvate. Residues 200 through 215 or 216 appear to be disordered in two of the eight monomers in the asymmetric unit suggesting that they function as a lid controlling substrate entry and product exit from the active site. Substitutions of Tyr(215) can thus lead to a kinetic bottleneck in product release.
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24
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Lederer F, Vignaud C, North P, Bodevin S. Trifluorosubstrates as mechanistic probes for an FMN-dependent l-2-hydroxy acid-oxidizing enzyme. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1215-1221. [PMID: 27155230 DOI: 10.1016/j.bbapap.2016.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 04/17/2016] [Accepted: 05/03/2016] [Indexed: 11/29/2022]
Abstract
A controversy exists with respect to the mechanism of l-2-hydroxy acid oxidation by members of a family of FMN-dependent enzymes. A so-called carbanion mechanism was initially proposed, in which the active site histidine abstracts the substrate α-hydrogen as a proton, followed by electron transfer from the carbanion to the flavin. But an alternative mechanism was not incompatible with some results, a mechanism in which the active site histidine instead picks up the substrate hydroxyl proton and a hydride transfer occurs. Even though more recent experiments ruling out such a mechanism were published (Rao & Lederer (1999) Protein Science 7, 1531-1537), a few authors have subsequently interpreted their results with variant enzymes in terms of a hydride transfer. In the present work, we analyse the reactivity of trifluorolactate, a substrate analogue, with the flavocytochrome b2 (Fcb2) flavodehydrogenase domain, compared to its reactivity with an NAD-dependent lactate dehydrogenase (LDH), for which this compound is known to be an inhibitor (Pogolotti & Rupley (1973) Biochem. Biophys. Res. Commun, 55, 1214-1219). Indeed, electron attraction by the three fluorine atoms should make difficult the removal of the α-H as a hydride. We also analyse the reactivity of trifluoropyruvate with the FMN- and NAD-dependent enzymes. The results substantiate a different effect of the fluorine substituents on the two enzymes compared to their normal substrates. In the discussion we analyse the conclusions of recent papers advocating a hydride transfer mechanism for the family of l-2-hydroxy acid oxidizing FMN-dependent enzymes.
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Affiliation(s)
- Florence Lederer
- Laboratoire d'Enzymologie, UPR 9063, CNRS, 91198 Gif-sur-Yvette Cedex, France; Laboratoire de Chimie Physique, CNRS UMR 8000, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France.
| | - Caroline Vignaud
- Laboratoire d'Enzymologie, UPR 9063, CNRS, 91198 Gif-sur-Yvette Cedex, France
| | - Paul North
- Laboratoire d'Enzymologie, UPR 9063, CNRS, 91198 Gif-sur-Yvette Cedex, France
| | - Sabrina Bodevin
- Laboratoire d'Enzymologie, UPR 9063, CNRS, 91198 Gif-sur-Yvette Cedex, France
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25
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Stoisser T, Klimacek M, Wilson DK, Nidetzky B. Speeding up the product release: a second-sphere contribution from Tyr191 to the reactivity of L-lactate oxidase revealed in crystallographic and kinetic studies of site-directed variants. FEBS J 2015; 282:4130-40. [PMID: 26260739 DOI: 10.1111/febs.13409] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 08/03/2015] [Accepted: 08/06/2015] [Indexed: 11/26/2022]
Abstract
Among α-hydroxy acid-oxidizing flavoenzymes l-lactate oxidase (LOX) is unique in featuring a second-sphere tyrosine (Tyr191 in Aerococcus viridans LOX; avLOX) at the binding site for the substrate's carboxylate group. Y191F, Y191L and Y191A variants of avLOX were constructed to affect a hydrogen-bond network connecting Tyr191 to the carboxylate of the bound ligand via the conserved Tyr40 and to examine consequent effects on enzymatic reactivity. Kinetic studies at 20 °C and pH 6.5 revealed that release of pyruvate product was decreased 4.7-fold (Y191F), 19-fold (Y191L) and 28-fold (Y191A) compared with wild-type enzyme (~ 141 s(-1)) and thus became mainly rate limiting for l-lactate oxidation by the variants at a steady-state under air-saturated conditions. In the Y191L and the Y191A variants, but not in the Y191F variant, l-lactate binding was also affected strongly by the site-directed substitution. Reduction of the flavin cofactor by l-lactate and its reoxidation by molecular oxygen were, however, comparatively weakly affected by the replacements of Tyr191. Unlike the related lactate monooxygenase, which prevents the fast dissociation of pyruvate to promote its oxidative decarboxylation by H2 O2 into acetate, CO2 and water as final reaction products, all avLOX variants retained their native oxidase activity where catalytic turnover results in the equivalent formation of H2O2. The 1.9 Å crystal structure of the Y191F variant bound with FMN and pyruvate revealed a strictly locally disruptive effect of the site-directed substitution. Product off-rates appear to be dictated by partitioning of residues including Tyr191 from an active-site lid loop into bulk solvent and modulation of the hydrogen bond strength that links Tyr40 with the pyruvate's carboxylate group. Overall, this study emphasizes the possibly high importance of contributions from second-sphere substrate-binding residues to the fine-tuning of reactivity in α-hydroxy acid-oxidizing flavoenzymes, requiring that the catalytic steps of flavin reduction and oxidation are properly timed with the physical step of α-keto acid product release.
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Affiliation(s)
- Thomas Stoisser
- Research Center Pharmaceutical Engineering, Graz, Austria.,Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Austria
| | - Mario Klimacek
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Austria
| | - David K Wilson
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Bernd Nidetzky
- Research Center Pharmaceutical Engineering, Graz, Austria.,Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Austria.,Austrian Centre of Industrial Biotechnology, Graz, Austria
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26
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Stoisser T, Rainer D, Leitgeb S, Wilson DK, Nidetzky B. The Ala95-to-Gly substitution in Aerococcus viridans l-lactate oxidase revisited - structural consequences at the catalytic site and effect on reactivity with O2 and other electron acceptors. FEBS J 2014; 282:562-78. [PMID: 25423902 DOI: 10.1111/febs.13162] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/19/2014] [Accepted: 11/24/2014] [Indexed: 01/05/2023]
Abstract
Aerococcus viridansl-lactate oxidase (avLOX) is a biotechnologically important flavoenzyme that catalyzes the conversion of L-lactate and O₂ into pyruvate and H₂O₂. The enzymatic reaction underlies different biosensor applications of avLOX for blood L-lactate determination. The ability of avLOX to replace O₂ with other electron acceptors such as 2,6-dichlorophenol-indophenol (DCIP) allows the possiblity of analytical and practical applications. The A95G variant of avLOX was previously shown to exhibit lowered reactivity with O₂ compared to wild-type enzyme and therefore was employed in a detailed investigation with respect to the specificity for different electron acceptor substrates. From stopped-flow experiments performed at 20 °C (pH 6.5), we determined that the A95G variant (fully reduced by L-lactate) was approximately three-fold more reactive towards DCIP (1.0 ± 0.1 × 10(6) M(-1) ·s(-1) ) than O₂, whereas avLOX wild-type under the same conditions was 14-fold more reactive towards O₂(1.8 ± 0.1 × 10(6) m(-1) ·s(-1)) than DCIP. Substituted 1,4-benzoquinones were up to five-fold better electron acceptors for reaction with L-lactate-reduced A95G variant than wild-type. A 1.65-Å crystal structure of oxidized A95G variant bound with pyruvate was determined and revealed that the steric volume created by removal of the methyl side chain of Ala95 and a slight additional shift in the main chain at position Gly95 together enable the accomodation of a new active-site water molecule within hydrogen-bond distance to the N5 of the FMN cofactor. The increased steric volume available in the active site allows the A95G variant to exhibit a similar trend with the related glycolate oxidase in electron acceptor substrate specificities, despite the latter containing an alanine at the analogous position.
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Affiliation(s)
- Thomas Stoisser
- Research Center Pharmaceutical Engineering, Graz, Austria; Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Graz, Austria
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27
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Jiang T, Gao C, Ma C, Xu P. Microbial lactate utilization: enzymes, pathogenesis, and regulation. Trends Microbiol 2014; 22:589-99. [PMID: 24950803 DOI: 10.1016/j.tim.2014.05.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 05/21/2014] [Accepted: 05/23/2014] [Indexed: 11/17/2022]
Abstract
Lactate utilization endows microbes with the ability to use lactate as a carbon source. Lactate oxidizing enzymes play key roles in the lactate utilization pathway. Various types of these enzymes have been characterized, but novel ones remain to be identified. Lactate determination techniques and biocatalysts have been developed based on these enzymes. Lactate utilization has also been found to induce pathogenicity of several microbes, and the mechanisms have been investigated. More recently, studies on the structure and organization of operons of lactate utilization have been carried out. This review focuses on the recent progress and future perspectives in understanding microbial lactate utilization.
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Affiliation(s)
- Tianyi Jiang
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China; State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China; School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, People's Republic of China
| | - Chao Gao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Cuiqing Ma
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China.
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
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28
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Pribil MM, Laptev GU, Karyakina EE, Karyakin AA. Noninvasive hypoxia monitor based on gene-free engineering of lactate oxidase for analysis of undiluted sweat. Anal Chem 2014; 86:5215-9. [PMID: 24837858 DOI: 10.1021/ac501547u] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report on the Prussian Blue based lactate biosensor with the remarkably increased upper detection limit suitable for analysis of undiluted sweat. Engineering of the enzyme lactate oxidase has been carried out upon its immobilization from water-isopropanol mixtures with the high (90%) content of organic solvent. To decrease the enzyme binding constant, we propose to shield the substrate binding sites in its active center with negatively charged polyelectrolyte. The biosensor made from the optimal mixture (3% γ- aminopropyltriethoxysilane and 5% perfluorosulfonated ionomer) is characterized by the calibration graph, which even in batch mode is shifted for 2 orders of magnitude toward high analyte concentrations as compared to it of lactate sensitive electrode made without Nafion analogue. In flow-injection mode, the biosensor allows lactate detection up to 0.5 M. The biosensor displays stable response for 4 h of continuous operation. The achieved analytical performance characteristics allow the monitoring of lactate content in undiluted sweat. A successful validation of the elaborated flow-through monitor with the integrated biosensor opens new horizons for noninvasive diagnostics of hypoxia-related conditions.
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Affiliation(s)
- Medeya M Pribil
- Chemistry Faculty, M.V. Lomonosov Moscow State University , 119991, Moscow, Russia
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29
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Esser C, Kuhn A, Groth G, Lercher MJ, Maurino VG. Plant and animal glycolate oxidases have a common eukaryotic ancestor and convergently duplicated to evolve long-chain 2-hydroxy acid oxidases. Mol Biol Evol 2014; 31:1089-101. [PMID: 24408912 DOI: 10.1093/molbev/msu041] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Glycolate oxidase (GOX) is a crucial enzyme of plant photorespiration. The encoding gene is thought to have originated from endosymbiotic gene transfer between the eukaryotic host and the cyanobacterial endosymbiont at the base of plantae. However, animals also possess GOX activities. Plant and animal GOX belong to the gene family of (L)-2-hydroxyacid-oxidases ((L)-2-HAOX). We find that all (L)-2-HAOX proteins in animals and archaeplastida go back to one ancestral eukaryotic sequence; the sole exceptions are green algae of the chlorophyta lineage. Chlorophyta replaced the ancestral eukaryotic (L)-2-HAOX with a bacterial ortholog, a lactate oxidase that may have been obtained through the primary endosymbiosis at the base of plantae; independent losses of this gene may explain its absence in other algal lineages (glaucophyta, rhodophyta, and charophyta). We also show that in addition to GOX, plants possess (L)-2-HAOX proteins with different specificities for medium- and long-chain hydroxyacids (lHAOX), likely involved in fatty acid and protein catabolism. Vertebrates possess lHAOX proteins acting on similar substrates as plant lHAOX; however, the existence of GOX and lHAOX subfamilies in both plants and animals is not due to shared ancestry but is the result of convergent evolution in the two most complex eukaryotic lineages. On the basis of targeting sequences and predicted substrate specificities, we conclude that the biological role of plantae (L)-2-HAOX in photorespiration evolved by co-opting an existing peroxisomal protein.
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Affiliation(s)
- Christian Esser
- Institute for Computer Science, Heinrich-Heine-University, Düsseldorf, Germany
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Koziol L, Kumar N, Wong SE, Lightstone FC. Molecular recognition of aromatic rings by flavin: electrostatics and dispersion determine ring positioning above isoalloxazine. J Phys Chem A 2013; 117:12946-52. [PMID: 24229368 DOI: 10.1021/jp407193c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Aromatic stacking interactions between isoalloxazine (ISA) of flavin and three prototypical aromatics (benzene, pyridine, chlorobenzene) were investigated using electronic structure calculations with Monte Carlo simulated annealing. The Effective Fragment Potential (EFP) method was used to locate the low-energy equilibrium configurations for the three dimer systems. These structures were further characterized through DFT (M06-2X) and MP2 calculations. One equilibrium configuration exists for ISA-benzene; characterizing the stacked dimer surface revealed a steep, single-welled potential that funnels benzene directly between rings II and III, positioning a substituent hydrogen adjacent to the redox-active N5. ISA-pyridine and ISA-chlorobenzene minimum-energy structures contain the aromatic ring in very similar position to that in ISA-benzene. However, the added rotational degree of freedom leads to two distinct binding motifs, having approximately antiparallel or parallel dipole moment alignment with ISA. The existence of the latter binding configuration was unexpected but is explained by the shape of the ISA electrostatic potential. Dispersion is the primary noncovalent interaction driving the positioning of aromatic rings above ISA, while electrostatics determine the orientation in dipole-containing substituted benzenes. The interplay of these interactions can be used to tune molecular recognition properties of synthetic redox cofactors, including positioning desired functional groups adjacent to the redox-active N5.
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Affiliation(s)
- Lucas Koziol
- Physical and Life Sciences Division, Lawrence Livermore National Laboratory , 7000 East Avenue, Livermore, California 94550, United States
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Taurino I, Reiss R, Richter M, Fairhead M, Thöny-Meyer L, De Micheli G, Carrara S. Comparative study of three lactate oxidases from Aerococcus viridans for biosensing applications. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.01.080] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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High resolution crystal structure of rat long chain hydroxy acid oxidase in complex with the inhibitor 4-carboxy-5-[(4-chlorophenyl)sulfanyl]-1, 2, 3-thiadiazole. Implications for inhibitor specificity and drug design. Biochimie 2012; 94:1172-9. [PMID: 22342614 DOI: 10.1016/j.biochi.2012.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 02/02/2012] [Indexed: 11/23/2022]
Abstract
Long chain hydroxy acid oxidase (LCHAO) is responsible for the formation of methylguanidine, a toxic compound with elevated serum levels in patients with chronic renal failure. Its isozyme glycolate oxidase (GOX), has a role in the formation of oxalate, which can lead to pathological deposits of calcium oxalate, in particular in the disease primary hyperoxaluria. Inhibitors of these two enzymes may have therapeutic value. These enzymes are the only human members of the family of FMN-dependent l-2-hydroxy acid-oxidizing enzymes, with yeast flavocytochrome b(2) (Fcb2) among its well studied members. We screened a chemical library for inhibitors, using in parallel rat LCHAO, human GOX and the Fcb2 flavodehydrogenase domain (FDH). Among the hits was an inhibitor, CCPST, with an IC(50) in the micromolar range for all three enzymes. We report here the crystal structure of a complex between this compound and LCHAO at 1.3 Å resolution. In comparison with a lower resolution structure of this enzyme, binding of the inhibitor induces a conformational change in part of the TIM barrel loop 4, as well as protonation of the active site histidine. The CCPST interactions are compared with those it forms with human GOX and those formed by two other inhibitors with human GOX and spinach GOX. These compounds differ from CCPST in having the sulfur replaced with a nitrogen in the five-membered ring as well as different hydrophobic substituents. The possible reason for the ∼100-fold difference in affinity between these two series of inhibitors is discussed. The present results indicate that specificity is an issue in the quest for therapeutic inhibitors of either LCHAO or GOX, but they may give leads for this quest.
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Bourhis JM, Vignaud C, Pietrancosta N, Guéritte F, Guénard D, Lederer F, Lindqvist Y. Structure of human glycolate oxidase in complex with the inhibitor 4-carboxy-5-[(4-chlorophenyl)sulfanyl]-1,2,3-thiadiazole. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:1246-53. [PMID: 20054120 PMCID: PMC2802872 DOI: 10.1107/s1744309109041670] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 10/12/2009] [Indexed: 11/10/2022]
Abstract
Glycolate oxidase, a peroxisomal flavoenzyme, generates glyoxylate at the expense of oxygen. When the normal metabolism of glyoxylate is impaired by the mutations that are responsible for the genetic diseases hyperoxaluria types 1 and 2, glyoxylate yields oxalate, which forms insoluble calcium deposits, particularly in the kidneys. Glycolate oxidase could thus be an interesting therapeutic target. The crystal structure of human glycolate oxidase (hGOX) in complex with 4-carboxy-5-[(4-chlorophenyl)sulfanyl]-1,2,3-thiadiazole (CCPST) has been determined at 2.8 A resolution. The inhibitor heteroatoms interact with five active-site residues that have been implicated in catalysis in homologous flavodehydrogenases of L-2-hydroxy acids. In addition, the chlorophenyl substituent is surrounded by nonconserved hydrophobic residues. The present study highlights the role of mobility in ligand binding by glycolate oxidase. In addition, it pinpoints several structural differences between members of the highly conserved family of flavodehydrogenases of L-2-hydroxy acids.
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Affiliation(s)
- Jean-Marie Bourhis
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm, Sweden
| | - Caroline Vignaud
- Laboratoire d’Enzymologie et Biochimie Structurales, CNRS FRE 2930, Gif-sur-Yvette, France
| | - Nicolas Pietrancosta
- Laboratoire d’Enzymologie et Biochimie Structurales, CNRS FRE 2930, Gif-sur-Yvette, France
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Gif-sur-Yvette, France
| | - Françoise Guéritte
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Gif-sur-Yvette, France
| | - Daniel Guénard
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Gif-sur-Yvette, France
| | - Florence Lederer
- Laboratoire de Chimie Physique, CNRS UMR 8000, Université Paris-Sud, Orsay, France
| | - Ylva Lindqvist
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm, Sweden
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Host-directed evolution of a novel lactate oxidase in Streptococcus iniae isolates from barramundi (Lates calcarifer). Appl Environ Microbiol 2009; 75:2908-19. [PMID: 19270123 DOI: 10.1128/aem.02147-08] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Streptococcus iniae, lactate metabolism is dependent upon two proteins, lactate permease that mediates uptake and lactate oxidase, a flavin mononucleotide-dependent enzyme that catalyzes oxidation of alpha-hydroxyacids. A novel variant of the lactate oxidase gene, lctO, in Australian isolates of S. iniae from diseased barramundi was found during a diagnostic screen using LOX-1 and LOX-2 primers, yielding amplicons of 920 bp instead of the expected 869 bp. Sequencing of the novel gene variant (type 2) revealed a 51-nucleotide insertion in lctO, resulting in a 17-amino-acid repeat in the gene product, and three-dimensional modeling indicated formation of an extra loop in the monomeric protein structure. The activities of the lactate oxidase enzyme variants expressed in Escherichia coli were examined, indicating that the higher-molecular-weight type 2 enzyme exhibited higher activity. Growth rates of S. iniae expressing the novel type 2 enzyme were not reduced at lactate concentrations of 0.3% and 0.5%, whereas a strain expressing the type 1 enzyme exhibited reduced growth rates at these lactate concentrations. During a retrospective screen of 105 isolates of S. iniae from Australia, the United States, Canada, Israel, Réunion Island, and Thailand, the type 2 variant arose only in isolates from a single marine farm with unusually high tidal flow in the Northern Territory, Australia. Elevated plasma lactate levels in the fish, resulting from the effort of swimming in tidal flows of up to 3 knots, may exert sufficient selective pressure to maintain the novel, high-molecular-weight enzyme variant.
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Furuichi M, Suzuki N, Dhakshnamoorhty B, Minagawa H, Yamagishi R, Watanabe Y, Goto Y, Kaneko H, Yoshida Y, Yagi H, Waga I, Kumar PK, Mizuno H. X-ray Structures of Aerococcus viridans Lactate Oxidase and Its Complex with d-Lactate at pH 4.5 Show an α-Hydroxyacid Oxidation Mechanism. J Mol Biol 2008; 378:436-46. [DOI: 10.1016/j.jmb.2008.02.062] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Revised: 02/22/2008] [Accepted: 02/27/2008] [Indexed: 11/25/2022]
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Murray MS, Holmes RP, Lowther WT. Active site and loop 4 movements within human glycolate oxidase: implications for substrate specificity and drug design. Biochemistry 2008; 47:2439-49. [PMID: 18215067 DOI: 10.1021/bi701710r] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human glycolate oxidase (GO) catalyzes the FMN-dependent oxidation of glycolate to glyoxylate and glyoxylate to oxalate, a key metabolite in kidney stone formation. We report herein the structures of recombinant GO complexed with sulfate, glyoxylate, and an inhibitor, 4-carboxy-5-dodecylsulfanyl-1,2,3-triazole (CDST), determined by X-ray crystallography. In contrast to most alpha-hydroxy acid oxidases including spinach glycolate oxidase, a loop region, known as loop 4, is completely visible when the GO active site contains a small ligand. The lack of electron density for this loop in the GO-CDST complex, which mimics a large substrate, suggests that a disordered to ordered transition may occur with the binding of substrates. The conformational flexibility of Trp110 appears to be responsible for enabling GO to react with alpha-hydroxy acids of various chain lengths. Moreover, the movement of Trp110 disrupts a hydrogen-bonding network between Trp110, Leu191, Tyr134, and Tyr208. This loss of interactions is the first indication that active site movements are directly linked to changes in the conformation of loop 4. The kinetic parameters for the oxidation of glycolate, glyoxylate, and 2-hydroxy octanoate indicate that the oxidation of glycolate to glyoxylate is the primary reaction catalyzed by GO, while the oxidation of glyoxylate to oxalate is most likely not relevant under normal conditions. However, drugs that exploit the unique structural features of GO may ultimately prove to be useful for decreasing glycolate and glyoxylate levels in primary hyperoxaluria type 1 patients who have the inability to convert peroxisomal glyoxylate to glycine.
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Affiliation(s)
- Michael S Murray
- Center for Structural Biology and Department of Biochemistry, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, North Carolina 27157, USA
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Li SJ, Umena Y, Yorita K, Matsuoka T, Kita A, Fukui K, Morimoto Y. Crystallographic study on the interaction of l-lactate oxidase with pyruvate at 1.9 Å resolution. Biochem Biophys Res Commun 2007; 358:1002-7. [PMID: 17517371 DOI: 10.1016/j.bbrc.2007.05.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Accepted: 05/02/2007] [Indexed: 11/29/2022]
Abstract
L-Lactate oxidase (LOX) from Aerococcus viridans catalyzes the oxidation of L-lactate to pyruvate by the molecular oxygen and belongs to a large family of 2-hydroxy acid-dependent flavoenzymes. To investigate the interaction of LOX with pyruvate in structural details and understand the chemical mechanism of flavin-dependent L-lactate dehydrogenation, the LOX-pyruvate complex was crystallized and the crystal structure of the complex has been solved at a resolution of 1.90 Angstrom. One pyruvate molecule bound to the active site and located near N5 position of FMN for subunits, A, B, and D in the asymmetric unit, were identified. The pyruvate molecule is stabilized by the interaction of its carboxylate group with the side-chain atoms of Tyr40, Arg181, His265, and Arg268, and of its keto-oxygen atom with the side-chain atoms of Tyr146, Tyr215, and His265. The alpha-carbon of pyruvate is found to be 3.13 Angstrom from the N5 atom of FMN at an angle of 105.4 degrees from the flavin N5-N10 axis.
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Affiliation(s)
- Shu Jie Li
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
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Vignaud C, Pietrancosta N, Williams EL, Rumsby G, Lederer F. Purification and characterization of recombinant human liver glycolate oxidase. Arch Biochem Biophys 2007; 465:410-6. [PMID: 17669354 DOI: 10.1016/j.abb.2007.06.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Revised: 06/19/2007] [Accepted: 06/23/2007] [Indexed: 11/25/2022]
Abstract
Glycolate oxidase, an FMN-dependent peroxisomal oxidase, plays an important role in plants, related to photorespiration, and in animals, where it can contribute to the production of oxalate with formation of kidney stones. The best studied plant glycolate oxidase is that of spinach; it has been expressed as a recombinant enzyme, and its crystal structure is known. With respect to animals, the enzyme purified from pig liver has been characterized in detail in terms of activity and inhibition, the enzyme from human liver in less detail. We describe here the purification and initial characterization of the recombinant human glycolate oxidase. Its substrate specificity and the inhibitory effects of a number of anions are in agreement with the properties expected from previous work on glycolate oxidases from diverse sources. The recombinant enzyme presents an inhibition by excess glycolate and by excess DCIP, which has not been documented before. These inhibitions suggest that glycolate binds to the active site of the reduced enzyme, and that DCIP also has affinity for the oxidized enzyme. Glycolate oxidase belongs to a family of l-2-hydroxy-acid-oxidizing flavoenzymes, with strongly conserved active-site residues. A comparison of some of the present results with studies dealing with other family members suggests that residues outside the active site influence the binding of a number of ligands, in particular sulfite.
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Affiliation(s)
- Caroline Vignaud
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS FRE2930, 91198 Gif-sur-Yvette Cedex, France
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