1
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Li M, Yang Z, Chen S, Liu Z, Tong L, Zheng S, Yang D. Sphaerotilus natans hemoglobins have an NADH oxidation activity and promote the yield of limonene in an engineered E. coli strain. Int J Biol Macromol 2024; 254:128112. [PMID: 37972845 DOI: 10.1016/j.ijbiomac.2023.128112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 11/19/2023]
Abstract
Bacterial hemoglobins play important roles inside the cell. Phylogenetically, they belong to three different families: the single domain hemoglobin, flavohemoglobin and truncated hemoglobin. Vitreoscilla hemoglobin (VHb) is the first characterized bacterial hemoglobin, and belongs to the single domain hemoglobin family. Heterologous expression of VHb promotes the growth of host cells under microaerobic conditions, and enhances the yield of products during fermentation. Although VHb has been widely applied in the biotechnology field, other bacterial hemoglobins have not demonstrated similar applications. In this study, we identified four bacterial hemoglobins from the microaerobic growing bacterium Sphaerotilus natans, including one flavohemoglobins (FHB) and three truncated hemoglobins (THB1, THB2 and THB3). Absorption spectrum studies validate the existent of the Soret peak and Q-band characteristic to heme and suggest heme groups in FHB and THB1 are hexa- or penta-coordinated, respectively. Our studies demonstrate that FHB and all three truncated hemoglobins have NADH oxidation and radical production activities, which is surprising since truncated hemoglobins do not have a reductase domain that could bind NADH. However, the M. tuberculosis HbN does not show these activities, indicating they are not universal among truncated hemoglobins. Docking studies suggest the nicotinamide ring of NADH may bind to the distal heme pocket of THB1, suggesting the direct electron transfer from NADH to heme might be possible. Our truncated hemoglobins also show peroxidase activities that in THB2 and THB3 could be inhibited by FdR, indicating possible interactions between FdR and truncate hemoglobins. Expression of FHB and THB1 in E. coli could promote cell growth. THB1 also enhances the production of limonene in an engineered E. coli strain, while VHb does not have this effect, which suggests that studies on truncated hemoglobins may lead to the discovery of new and more powerful tools that could have profound impact on biotechnology.
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Affiliation(s)
- Mohui Li
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Ziqing Yang
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Sihua Chen
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Zilu Liu
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Li Tong
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Shaokui Zheng
- School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, China.
| | - Dong Yang
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China.
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2
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Yang P, Zhang J. Indoleamine 2,3-Dioxygenase (IDO) Activity: A Perspective Biomarker for Laboratory Determination in Tumor Immunotherapy. Biomedicines 2023; 11:1988. [PMID: 37509627 PMCID: PMC10377333 DOI: 10.3390/biomedicines11071988] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/05/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Indoleamine 2,3-dioxygenase 1 (IDO1) is a heme enzyme involved in catalyzing the conversion of tryptophan (Trp) into kynurenine (Kyn) at the first rate-limiting step in the kynurenine pathway of L-tryptophan metabolism. It has been found to be involved in several biological functions such as aging, immune microorganism, neurodegenerative and infectious diseases, and cancer. IDO1 plays an important role in immune tolerance by depleting tryptophan in the tumor microenvironment and inhibiting the proliferation of effector T cells, which makes it an important emerging biomarker for cancer immunotherapy. Therefore, the research and development of IDO1 inhibitors are of great importance for tumor therapy. Of interest, IDO activity assays are of great value in the screening and evaluation of inhibitors. Herein, we mainly review the biological functions of IDO1, immune regulation, key signaling molecules in the response pathway, and the development of IDO1 inhibitors in clinical trials. Furthermore, this review provides a comprehensive overview and, in particular, a discussion of currently available IDO activity assays for use in the evaluation of IDO inhibitors in human blood. We believe that the IDO activity is a promising biomarker for the immune escape and laboratory evaluation of tumor immunotherapy.
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Affiliation(s)
- Pengbo Yang
- Department of Laboratory Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Junhua Zhang
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing 100730, China
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3
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Bello C, Heinisch PP, Mihalj M, Carrel T, Luedi MM. Indoleamine-2,3-Dioxygenase as a Perioperative Marker of the Immune System. Front Physiol 2021; 12:766511. [PMID: 34819875 PMCID: PMC8606526 DOI: 10.3389/fphys.2021.766511] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 10/14/2021] [Indexed: 12/18/2022] Open
Abstract
Indoleamine-2,3-dioxygenase (IDO) is the “rate-limiting” enzyme in the kynurenine (Kyn) pathway of the tryptophan (Trp) catabolism. By its immune-modulatory effect, IDO initiates changes to the physiologically balanced immune state and plays a key role in the pathogenesis of various diseases, as well as in the perioperative setting during surgery. In autoimmune processes, highly malignant cancers such as glioblastoma or organ transplantation, IDO’s involvement has been studied extensively. However, in severe systemic infections, as present in sepsis, it is not yet completely understood. Hereafter, in this narrative review, we present the current knowledge of IDO’s implication on such complex immune-related processes. Moreover, we address the role of IDO as a predictive biomarker as well as a therapeutic target for immune-mediated diseases. Finally, we discuss IDO in the setting of surgical trauma-induced stress and highlight its promising use as a biomarker in the pre-operative setting for all disciplines involved in the decision-making process and treatment of patients undergoing surgery.
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Affiliation(s)
- Corina Bello
- Department of Anaesthesiology, Spital Grabs, Grabs, Switzerland.,Department of Anaesthesiology and Pain Medicine, Bern University Hospital (Inselspital), University of Bern, Bern, Switzerland
| | - Paul Philipp Heinisch
- Department of Anaesthesiology and Pain Medicine, Bern University Hospital (Inselspital), University of Bern, Bern, Switzerland.,Department of Congenital and Pediatric Heart Surgery, German Heart Center Munich, Technical University, Munich, Germany
| | - Maks Mihalj
- Department of Cardiovascular Surgery, Bern University Hospital (Inselspital), Bern, Switzerland
| | - Thierry Carrel
- Department of Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland
| | - Markus M Luedi
- Department of Anaesthesiology and Pain Medicine, Bern University Hospital (Inselspital), University of Bern, Bern, Switzerland
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4
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Platten M, Friedrich M, Wainwright DA, Panitz V, Opitz CA. Tryptophan metabolism in brain tumors - IDO and beyond. Curr Opin Immunol 2021; 70:57-66. [PMID: 33813026 DOI: 10.1016/j.coi.2021.03.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/27/2021] [Accepted: 03/08/2021] [Indexed: 12/13/2022]
Abstract
Metabolism of the essential amino acid tryptophan is a key metabolic pathway that restricts antitumor immunity and is a drug development target for cancer immunotherapy. Tryptophan metabolism is active in brain tumors including gliomas and promotes a malignant phenotype and contributes to the immunosuppressive tumor microenvironment. In recent years, improved understanding of the regulation and downstream function of tryptophan metabolism has been significantly expanded beyond the initial in vitro observation that the enzyme indoleamine-2,3-dioxygenase 1 (IDO1) promotes the depletion of intracellular tryptophan. Here, we revisit the specific roles of tryptophan metabolites in regulating brain functioning and neuronal integrity as well as in the context of brain tumors. This review summarizes recent developments in identifying key regulators, as well as the cellular and molecular effects of tryptophan metabolism with a particular focus on potential therapeutic targets in glioma.
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Affiliation(s)
- Michael Platten
- Department of Neurology, Medical Faculty Mannheim, MCTN, Heidelberg University, Heidelberg, Germany; DKTK CCU Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Mirco Friedrich
- Department of Neurology, Medical Faculty Mannheim, MCTN, Heidelberg University, Heidelberg, Germany; DKTK CCU Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Derek A Wainwright
- Departments of Neurological Surgery, Medicine - Division of Hematology/Oncology, and Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Verena Panitz
- DKTK Brain Cancer Metabolism Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Department of Neurology and National Center for Tumor Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Christiane A Opitz
- DKTK Brain Cancer Metabolism Group, German Cancer Research Center (DKFZ), Heidelberg, Germany; Department of Neurology and National Center for Tumor Diseases, Heidelberg University Hospital, Heidelberg, Germany.
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5
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Yuasa HJ, Stocker R. Methylene blue and ascorbate interfere with the accurate determination of the kinetic properties of IDO2. FEBS J 2021; 288:4892-4904. [PMID: 33686747 DOI: 10.1111/febs.15806] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 02/16/2021] [Accepted: 03/08/2021] [Indexed: 11/30/2022]
Abstract
Indoleamine 2,3-dioxygenases (IDOs) catalyze the oxidative cleavage of L-tryptophan (Trp) to N-formylkynurenine. Two IDOs, IDO1 and IDO2, are present in vertebrates. IDO1 is a high-affinity Trp-degrading enzyme involved in several physiological processes. By comparison, IDO2 generally has been reported to have low affinity (high Km -value) for Trp, and the enzyme's in vivo function remains unclear. Using IDOs from different species, we show that compared with ferrous-oxy (Fe2+ -O2 ) IDO1, Fe2+ -O2 IDO2 is substantially more stable and engages in multiple turnovers of the reaction in the absence of a reductant. Without reductant, Fe2+ -O2 IDO2 showed Km -values in the range of 80-356 μM, that is, values substantially lower than reported previously and close to the physiological concentrations of Trp. Methylene blue and ascorbate (Asc), used commonly as the reducing system for IDO activity determination, significantly affected the enzymatic activity of IDO2: In combination, the two reductants increased the apparent Km - and kcat -values 8- to 117-fold and 2-fold, respectively. Asc alone both activated and inhibited IDO2 by acting as a source of electrons and as a weak competitive inhibitor, respectively. In addition, ferric (Fe3+ ) IDO1 and IDO2 exhibited weak dioxygenase activity, similar to tryptophan 2,3-dioxygenase. Our results shed new light in the enzymatic activity of IDO2, and they support the view that this isoform of IDO also participates in the metabolism of Trp in vivo.
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Affiliation(s)
- Hajime J Yuasa
- Laboratory of Biochemistry, Department of Chemistry and Biotechnology, Faculty of Science and Technology, National University Corporation Kochi University, Japan
| | - Roland Stocker
- Arterial Inflammation and Redox Biology Group, Heart Research Institute, Newtown, NSW, Australia
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6
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Nguyen DJM, Theodoropoulos G, Li YY, Wu C, Sha W, Feun LG, Lampidis TJ, Savaraj N, Wangpaichitr M. Targeting the Kynurenine Pathway for the Treatment of Cisplatin-Resistant Lung Cancer. Mol Cancer Res 2019; 18:105-117. [PMID: 31628200 DOI: 10.1158/1541-7786.mcr-19-0239] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/09/2019] [Accepted: 10/15/2019] [Indexed: 01/02/2023]
Abstract
Cisplatin resistance is a major barrier in the effective treatment of lung cancer. Cisplatin-resistant (CR) lung cancer cells do not primarily use glucose but rather consume amino acids such as glutamine and tryptophan (Trp) for survival. CR cells activate the kynurenine (KYN) pathway (KP) to cope with excessive reactive oxygen species (ROS) and maintain homeostasis for growth and proliferation. Consequently, indoleamine 2,3-dioxygenase-1 (IDO1) becomes an essential enzyme for CR cells' survival because it initiates and regulates the first step in the KP. Increased IDO1 activities and ROS levels are found in CR cells versus cisplatin-sensitive lung cancer. Importantly, significantly greater KYN/Trp ratio (P = 0.005) is detected in serum of patients who fail cisplatin when compared with naïve treatment. Knocking down IDO1 using shRNA or IDO1 inhibitors heightens ROS levels and results in a significant growth inhibitory effect only on CR cells and not on cisplatin-sensitive cells. Exposing CR cells to antioxidant (TIRON) results in suppression of IDO1 activity and confers resistance to IDO1 inhibition, indicating an interrelationship between ROS and IDO1. Because KYN plays a critical role in reprogramming naïve T cells to the immune-suppressive regulatory T-cell (T-reg) phenotype, we observed higher expression of TGFβ, FoxP3, and CD4+CD25+ in mice bearing CR tumors compared with tumors from cisplatin-sensitive counterparts. IMPLICATIONS: Findings suggest that the enzyme-inhibitory activity and antitumor efficacy of IDO1 inhibitors rely in part on ROS levels, arguing that IDO1 expression alone may be insufficient to determine the clinical benefits for this class of experimental cancer drugs. Importantly, IDO1 inhibitors may be more suitable to treat patients with lung cancer who failed cisplatin therapy than naïve treatment patients.
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Affiliation(s)
- Dan J M Nguyen
- Department of Veterans Affairs, Miami VA Healthcare System, Research Service, Miami, Florida
| | - George Theodoropoulos
- Department of Veterans Affairs, Miami VA Healthcare System, Research Service, Miami, Florida
| | - Ying-Ying Li
- Department of Veterans Affairs, Miami VA Healthcare System, Research Service, Miami, Florida
| | - Chunjing Wu
- Department of Veterans Affairs, Miami VA Healthcare System, Research Service, Miami, Florida
| | - Wei Sha
- Department of Veterans Affairs, Miami VA Healthcare System, Research Service, Miami, Florida
| | - Lynn G Feun
- Department of Medicine, Hematology/Oncology, Miller School of Medicine, University of Miami, Miami, Florida
| | - Theodore J Lampidis
- Department of Cell Biology, Miller School of Medicine, University of Miami, Miami, Florida
| | - Niramol Savaraj
- Department of Veterans Affairs, Miami VA Healthcare System, Research Service, Miami, Florida. .,Department of Medicine, Hematology/Oncology, Miller School of Medicine, University of Miami, Miami, Florida
| | - Medhi Wangpaichitr
- Department of Veterans Affairs, Miami VA Healthcare System, Research Service, Miami, Florida. .,Department of Surgery, Cardiothoracic Surgery, Miller School of Medicine, University of Miami, Miami, Florida
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7
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Yuasa HJ. A comprehensive comparison of the metazoan tryptophan degrading enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1868:140247. [PMID: 31276825 DOI: 10.1016/j.bbapap.2019.06.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 06/28/2019] [Accepted: 06/30/2019] [Indexed: 01/15/2023]
Abstract
Tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO) have an independent origin; however, they have distinctly evolved to catalyze the same reaction. In general, TDO is a single-copy gene in each metazoan species, and TDO enzymes demonstrate similar enzyme activity regardless of their biological origin. In contrast, multiple IDO paralogues are observed in many species, and they display various enzymatic properties. Similar to vertebrate IDO2, invertebrate IDOs generally show low affinity/catalytic efficiency for L-Trp. Meanwhile, two IDO isoforms from scallop (IDO-I and -III) and sponge IDOs show high L-Trp catalytic activity, which is comparable to vertebrate IDO1. Site-directed mutagenesis experiments have revealed that primarily two residues, Tyr located at the 2nd residue on the F-helix (F2nd) and His located at the 9th residue on the G-helix (G9th), are crucial for the high affinity/catalytic efficiency of these 'high performance' invertebrate IDOs. Conversely, those two amino acid substitutions (F2nd/Tyr and G9th/His) resulted in high affinity and catalytic activity in other molluscan 'low performance' IDOs. In human IDO1, G9th is Ser167, whereas the counterpart residue of G9th in human TDO is His76. Previous studies have shown that Ser167 could not be substituted by His because the human IDO1 Ser167His variant showed significantly low catalytic activity. However, this may be specific for human IDO1 because G9th/His was demonstrated to be very effective in increasing the L-Trp affinity even in vertebrate IDOs. Therefore, these findings indicate that the active sites of TDO and IDO are more similar to each other than previously expected.
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Affiliation(s)
- Hajime Julie Yuasa
- Laboratory of Biochemistry, Department of Applied Science, Faculty of Science and Technology, National University Corporation Kochi University, Kochi 780-8520, Japan.
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8
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Bartosiewicz J, Kaminski T, Pawlak K, Karbowska M, Tankiewicz-Kwedlo A, Pawlak D. The activation of the kynurenine pathway in a rat model with renovascular hypertension. Exp Biol Med (Maywood) 2017; 242:750-761. [PMID: 28165296 PMCID: PMC5363689 DOI: 10.1177/1535370217693114] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 01/09/2017] [Indexed: 01/23/2023] Open
Abstract
Hypertension is a serious condition that can lead to many health problems. The mechanisms underlying this process are still not fully understood. The kynurenine pathway may be involved in the occurrence and progression of hypertension. The purpose of this study was to examine the activity of peripheral kynurenine pathway in rats with renovascular hypertension in Goldblatt 2K1C model. Hypertension was induced in the experimental groups by constricting the renal artery of the left kidney of the rats. Determination of tryptophan (Trp) and kynurenine pathway metabolites was assessed by high-performance liquid chromatography in plasma and tissues obtained at 4, 8, and 16 weeks after the surgical intervention or sham surgery. Levels of Ang II were evaluated using commercial immuno-enzymatic ELISA kits. Surgical treatment led to increased values of mean blood pressure and systolic blood pressure, whereas Trp concentrations were decreased in experimental animals compared to appropriate controls. Simultaneously, the considerable increment of kynurenine pathway components and a significant increase in the activity of tryptophan 2,3-dioxygenase were observed in rats with developed hypertension in comparison with controls. There were no differences between Ang II levels in controls and experimental groups. The inverse relationship was between plasma Trp and both SBP and Ang II values, and Trp independently affected Ang II concentrations in hypertensive rats. In contrast, tryptophan 2,3-dioxygenase activity and plasma kynurenine metabolites positively correlated with blood pressure values as well as with Ang II levels in these animals. Moreover, kynurenine was independently connected with MBP. Renovascular hypertension influences kynurenine pathway and leads to an imbalance in Trp and its metabolite levels. Tryptophan 2,3-dioxygenase and part of the kynurenine metabolites in plasma and tissues positively correlated with blood pressure values and Ang II levels. Although the mechanisms underlying this phenomenon are unclear, our experiment showed a link between renovascular hypertension and activation of kynurenine pathway. Impact statement As hypertension is a major health problem, our research has focused on the connection between the kynurenine pathway and hypertension. We assessed the levels of the main metabolites of dietary tryptophan and analyzed its levels in terms of high blood pressure. The results of our work indicated that in the renovascular rat's model of hypertension, an alteration of the kynurenine pathway occurred. According to our knowledge, this is the first study that has investigated in a comprehensive manner the alteration of the kynurenine pathway under the condition of elevated blood pressure. On the one hand, the work supports a better understanding of pathophysiological basics of the occurrence of hypertension, and on the other hand it provides potential opportunities to treat this disease.
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Affiliation(s)
- Jacek Bartosiewicz
- Department of Pharmacodynamics, Medical University of Bialystok, 15-222 Bialystok, Poland
| | - Tomasz Kaminski
- Department of Pharmacodynamics, Medical University of Bialystok, 15-222 Bialystok, Poland
| | - Krystyna Pawlak
- Department of Monitored Pharmacotherapy, Medical University of Bialystok, 15-222 Bialystok, Poland
| | - Malgorzata Karbowska
- Department of Pharmacodynamics, Medical University of Bialystok, 15-222 Bialystok, Poland
| | - Anna Tankiewicz-Kwedlo
- Department of Monitored Pharmacotherapy, Medical University of Bialystok, 15-222 Bialystok, Poland
| | - Dariusz Pawlak
- Department of Pharmacodynamics, Medical University of Bialystok, 15-222 Bialystok, Poland
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9
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Basran J, Booth ES, Lee M, Handa S, Raven EL. Analysis of Reaction Intermediates in Tryptophan 2,3-Dioxygenase: A Comparison with Indoleamine 2,3-Dioxygenase. Biochemistry 2016; 55:6743-6750. [PMID: 27951658 DOI: 10.1021/acs.biochem.6b01005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) are heme-containing enzymes that catalyze the O2-dependent oxidation of l-tryptophan (l-Trp) in biological systems. Although many decades have passed since their discovery, the mechanism of tryptophan oxidation has not been established. It has been widely assumed that IDO and TDO react using the same mechanism, although there is no evidence that they do. For IDO, a Compound II (ferryl) species accumulates in the steady state and is implicated in the mechanism; in TDO, no such species has ever been observed. In this paper, we examine the kinetics of tryptophan oxidation in TDO. We find no evidence for the accumulation of Compound II during TDO catalysis. Instead, a ternary [Fe(II)-O2, l-Trp] complex is detected under steady state conditions. The absence of a Compound II species in the steady state in TDO is not due to an intrinsic inability of the TDO enzyme to form ferryl heme, because Compound II can be formed directly through a different route in which ferrous heme is reacted with peroxide. We interpret the data to mean that the rate-limiting step in the IDO and TDO mechanisms is not the same.
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Affiliation(s)
- Jaswir Basran
- Department of Molecular and Cellular Biology and Henry Wellcome Laboratories for Structural Biology, Henry Wellcome Building, University of Leicester , Lancaster Road, Leicester LE1 7RH, England, U.K
| | - Elizabeth S Booth
- Department of Chemistry, University of Leicester , University Road, Leicester LE1 7RH, England, U.K
| | - Michael Lee
- Department of Molecular and Cellular Biology and Henry Wellcome Laboratories for Structural Biology, Henry Wellcome Building, University of Leicester , Lancaster Road, Leicester LE1 7RH, England, U.K
| | - Sandeep Handa
- Department of Chemistry, University of Leicester , University Road, Leicester LE1 7RH, England, U.K
| | - Emma L Raven
- Department of Chemistry, University of Leicester , University Road, Leicester LE1 7RH, England, U.K
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10
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Raven EL. A short history of heme dioxygenases: rise, fall and rise again. J Biol Inorg Chem 2016; 22:175-183. [PMID: 27909919 PMCID: PMC5350241 DOI: 10.1007/s00775-016-1412-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 11/10/2016] [Indexed: 01/20/2023]
Abstract
It is well established that there are two different classes of enzymes—tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO)—that catalyse the O2-dependent oxidation of l-tryptophan to N-formylkynurenine. But it was not always so. This perspective presents a short history of the early TDO and IDO literature, the people that were involved in creating it, and the legacy that this left for the future.
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Affiliation(s)
- Emma L Raven
- Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, UK.
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11
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Booth ES, Basran J, Lee M, Handa S, Raven EL. Substrate Oxidation by Indoleamine 2,3-Dioxygenase: EVIDENCE FOR A COMMON REACTION MECHANISM. J Biol Chem 2015; 290:30924-30. [PMID: 26511316 PMCID: PMC4692220 DOI: 10.1074/jbc.m115.695684] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Indexed: 11/06/2022] Open
Abstract
The kynurenine pathway is the major route of l-tryptophan (l-Trp) catabolism in biology, leading ultimately to the formation of NAD+. The initial and rate-limiting step of the kynurenine pathway involves oxidation of l-Trp to N-formylkynurenine. This is an O2-dependent process and catalyzed by indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase. More than 60 years after these dioxygenase enzymes were first isolated (Kotake, Y., and Masayama, I. (1936) Z. Physiol. Chem. 243, 237–244), the mechanism of the reaction is not established. We examined the mechanism of substrate oxidation for a series of substituted tryptophan analogues by indoleamine 2,3-dioxygenase. We observed formation of a transient intermediate, assigned as a Compound II (ferryl) species, during oxidation of l-Trp, 1-methyl-l-Trp, and a number of other substrate analogues. The data are consistent with a common reaction mechanism for indoleamine 2,3-dioxygenase-catalyzed oxidation of tryptophan and other tryptophan analogues.
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Affiliation(s)
- Elizabeth S Booth
- From the Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, Great Britain, United Kingdom and
| | - Jaswir Basran
- Department of Molecular and Cellular Biology and Henry Wellcome Laboratories for Structural Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 9HN, Great Britain, United Kingdom
| | - Michael Lee
- From the Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, Great Britain, United Kingdom and
| | - Sandeep Handa
- From the Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, Great Britain, United Kingdom and
| | - Emma L Raven
- From the Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, Great Britain, United Kingdom and
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Abstract
IDO1 (indoleamine 2,3-dioxygenase 1) is a member of a unique class of mammalian haem dioxygenases that catalyse the oxidative catabolism of the least-abundant essential amino acid, L-Trp (L-tryptophan), along the kynurenine pathway. Significant increases in knowledge have been recently gained with respect to understanding the fundamental biochemistry of IDO1 including its catalytic reaction mechanism, the scope of enzyme reactions it catalyses, the biochemical mechanisms controlling IDO1 expression and enzyme activity, and the discovery of enzyme inhibitors. Major advances in understanding the roles of IDO1 in physiology and disease have also been realised. IDO1 is recognised as a prominent immune regulatory enzyme capable of modulating immune cell activation status and phenotype via several molecular mechanisms including enzyme-dependent deprivation of L-Trp and its conversion into the aryl hydrocarbon receptor ligand kynurenine and other bioactive kynurenine pathway metabolites, or non-enzymatic cell signalling actions involving tyrosine phosphorylation of IDO1. Through these different modes of biochemical signalling, IDO1 regulates certain physiological functions (e.g. pregnancy) and modulates the pathogenesis and severity of diverse conditions including chronic inflammation, infectious disease, allergic and autoimmune disorders, transplantation, neuropathology and cancer. In the present review, we detail the current understanding of IDO1’s catalytic actions and the biochemical mechanisms regulating IDO1 expression and activity. We also discuss the biological functions of IDO1 with a focus on the enzyme's immune-modulatory function, its medical implications in diverse pathological settings and its utility as a therapeutic target.
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Kolawole AO, Hixon BP, Dameron LS, Chrisman IM, Smirnov VV. Catalytic activity of human indoleamine 2,3-dioxygenase (hIDO1) at low oxygen. Arch Biochem Biophys 2015; 570:47-57. [PMID: 25712221 PMCID: PMC4412315 DOI: 10.1016/j.abb.2015.02.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/12/2015] [Accepted: 02/15/2015] [Indexed: 11/30/2022]
Abstract
A cytokine-inducible extrahepatic human indoleamine 2,3-dioxygenase (hIDO1) catalyzes the first step of the kynurenine pathway. Immunosuppressive activity of hIDO1 in tumor cells weakens host T-cell immunity, contributing to the progression of cancer. Here we report on enzyme kinetics and catalytic mechanism of hIDO1, studied at varied levels of dioxygen (O2) and L-tryptophan (L-Trp). Using a cytochrome b5-based activating system, we measured the initial rates of O2 decay with a Clark-type oxygen electrode at physiologically-relevant levels of both substrates. Kinetics was also studied in the presence of two substrate analogs: 1-methyl-L-tryptophan and norharmane. Quantitative analysis supports a steady-state rather than a rapid equilibrium kinetic mechanism, where the rates of individual pathways, leading to a ternary complex, are significantly different, and the overall rate of catalysis depends on contributions of both routes. One path, where O2 binds to ferrous hIDO1 first, is faster than the second route, which starts with the binding of L-Trp. However, L-Trp complexation with free ferrous hIDO1 is more rapid than that of O2. As the level of L-Trp increases, the slower route becomes a significant contributor to the overall rate, resulting in observed substrate inhibition.
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Affiliation(s)
- Ayodele O Kolawole
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, United States
| | - Brian P Hixon
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, United States
| | - Laura S Dameron
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, United States
| | - Ian M Chrisman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, United States
| | - Valeriy V Smirnov
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812, United States.
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Geng J, Liu A. Heme-dependent dioxygenases in tryptophan oxidation. Arch Biochem Biophys 2013; 544:18-26. [PMID: 24295960 DOI: 10.1016/j.abb.2013.11.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 12/29/2022]
Abstract
L-Tryptophan is an essential amino acid for mammals. It is utilized not only for protein synthesis but also for the biosynthesis of serotonin and melatonin by the serotonin pathway as well as nicotinamide adenine dinucleotide by the kynurenine pathway. Although the kynurenine pathway is responsible for the catabolism of over 90% of l-tryptophan in the mammalian intracellular and extracellular pools, the scientific field was dominated in the last century by studies of the serotonin pathway, due to the physiological significance of the latter's catabolic intermediates and products. However, in the past decade, the focus gradually reversed as the link between the kynurenine pathway and various neurodegenerative disorders and immune diseases is increasingly highlighted. Notably, the first step of this pathway, which is catalyzed by heme-dependent dioxygenases, has been proven to be a potential target for immune regulation and cancer treatment. A thorough understanding of the intriguing chemistry of the heme-dependent dioxygenases may yield insight for the drug discovery of these prevalent illnesses. In this review, we survey enzymatic and mechanistic studies, initially started by Kotake and Masayama over 70 years ago, at the molecular level on the heme-dependent tryptophan dioxygenation reactions.
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Affiliation(s)
- Jiafeng Geng
- Department of Chemistry, Georgia State University, 50 Decatur Street SE, Atlanta, GA 30303, United States
| | - Aimin Liu
- Department of Chemistry, Georgia State University, 50 Decatur Street SE, Atlanta, GA 30303, United States.
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Valladares R, Bojilova L, Potts AH, Cameron E, Gardner C, Lorca G, Gonzalez CF. Lactobacillus johnsonii
inhibits indoleamine 2,3‐dioxygenase and alters tryptophan metabolite levels in BioBreeding rats. FASEB J 2013; 27:1711-20. [DOI: 10.1096/fj.12-223339] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Ricardo Valladares
- Department of Microbiology and Cell ScienceGenetics InstituteInstitute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
| | - Lora Bojilova
- Department of Microbiology and Cell ScienceGenetics InstituteInstitute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
| | - Anastasia H. Potts
- Department of Microbiology and Cell ScienceGenetics InstituteInstitute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
| | - Evan Cameron
- Department of Microbiology and Cell ScienceGenetics InstituteInstitute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
| | - Christopher Gardner
- Department of Microbiology and Cell ScienceGenetics InstituteInstitute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
| | - Graciela Lorca
- Department of Microbiology and Cell ScienceGenetics InstituteInstitute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
| | - Claudio F. Gonzalez
- Department of Microbiology and Cell ScienceGenetics InstituteInstitute of Food and Agricultural SciencesUniversity of FloridaGainesvilleFloridaUSA
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Freewan M, Rees MD, Plaza TSS, Glaros E, Lim YJ, Wang XS, Yeung AWS, Witting PK, Terentis AC, Thomas SR. Human indoleamine 2,3-dioxygenase is a catalyst of physiological heme peroxidase reactions: implications for the inhibition of dioxygenase activity by hydrogen peroxide. J Biol Chem 2012; 288:1548-67. [PMID: 23209301 DOI: 10.1074/jbc.m112.410993] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The heme enzyme indoleamine 2,3-dioxygenase (IDO) is a key regulator of immune responses through catalyzing l-tryptophan (l-Trp) oxidation. Here, we show that hydrogen peroxide (H(2)O(2)) activates the peroxidase function of IDO to induce protein oxidation and inhibit dioxygenase activity. Exposure of IDO-expressing cells or recombinant human IDO (rIDO) to H(2)O(2) inhibited dioxygenase activity in a manner abrogated by l-Trp. Dioxygenase inhibition correlated with IDO-catalyzed H(2)O(2) consumption, compound I-mediated formation of protein-centered radicals, altered protein secondary structure, and opening of the distal heme pocket to promote nonproductive substrate binding; these changes were inhibited by l-Trp, the heme ligand cyanide, or free radical scavengers. Protection by l-Trp coincided with its oxidation into oxindolylalanine and kynurenine and the formation of a compound II-type ferryl-oxo heme. Physiological peroxidase substrates, ascorbate or tyrosine, enhanced rIDO-mediated H(2)O(2) consumption and attenuated H(2)O(2)-induced protein oxidation and dioxygenase inhibition. In the presence of H(2)O(2), rIDO catalytically consumed nitric oxide (NO) and utilized nitrite to promote 3-nitrotyrosine formation on IDO. The promotion of H(2)O(2) consumption by peroxidase substrates, NO consumption, and IDO nitration was inhibited by l-Trp. This study identifies IDO as a heme peroxidase that, in the absence of substrates, self-inactivates dioxygenase activity via compound I-initiated protein oxidation. l-Trp protects against dioxygenase inactivation by reacting with compound I and retarding compound II reduction to suppress peroxidase turnover. Peroxidase-mediated dioxygenase inactivation, NO consumption, or protein nitration may modulate the biological actions of IDO expressed in inflammatory tissues where the levels of H(2)O(2) and NO are elevated and l-Trp is low.
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Affiliation(s)
- Mohammed Freewan
- Centre for Vascular Research and School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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Abstract
The heme enzyme indoleamine 2,3-dioxygenase (IDO) was found to catalyze the oxidation of indole by H(2)O(2), with generation of 2- and 3-oxoindole as the major products. This reaction occurred in the absence of O(2) and reducing agents and was not inhibited by superoxide dismutase or hydroxyl radical scavengers, although it was strongly inhibited by L-Trp. The stoichiometry of the reaction indicated a one-to-one correspondence for the consumption of indole and H(2)O(2). The (18)O-labeling experiments indicated that the oxygen incorporated into the monooxygenated products was derived almost exclusively from H(2)(18)O(2), suggesting that electron transfer was coupled to the transfer of oxygen from a ferryl intermediate of IDO. These results demonstrate that IDO oxidizes indole by means of a previously unrecognized peroxygenase activity. We conclude that IDO inserts oxygen into indole in a reaction that is mechanistically analogous to the "peroxide shunt" pathway of cytochrome P450.
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Millett ES, Efimov I, Basran J, Handa S, Mowat CG, Raven EL. Heme-containing dioxygenases involved in tryptophan oxidation. Curr Opin Chem Biol 2012; 16:60-6. [DOI: 10.1016/j.cbpa.2012.01.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 01/18/2012] [Accepted: 01/25/2012] [Indexed: 10/28/2022]
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