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Alves LDF, Moore JB, Kell DB. The Biology and Biochemistry of Kynurenic Acid, a Potential Nutraceutical with Multiple Biological Effects. Int J Mol Sci 2024; 25:9082. [PMID: 39201768 PMCID: PMC11354673 DOI: 10.3390/ijms25169082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Revised: 08/16/2024] [Accepted: 08/19/2024] [Indexed: 09/03/2024] Open
Abstract
Kynurenic acid (KYNA) is an antioxidant degradation product of tryptophan that has been shown to have a variety of cytoprotective, neuroprotective and neuronal signalling properties. However, mammalian transporters and receptors display micromolar binding constants; these are consistent with its typically micromolar tissue concentrations but far above its serum/plasma concentration (normally tens of nanomolar), suggesting large gaps in our knowledge of its transport and mechanisms of action, in that the main influx transporters characterized to date are equilibrative, not concentrative. In addition, it is a substrate of a known anion efflux pump (ABCC4), whose in vivo activity is largely unknown. Exogeneous addition of L-tryptophan or L-kynurenine leads to the production of KYNA but also to that of many other co-metabolites (including some such as 3-hydroxy-L-kynurenine and quinolinic acid that may be toxic). With the exception of chestnut honey, KYNA exists at relatively low levels in natural foodstuffs. However, its bioavailability is reasonable, and as the terminal element of an irreversible reaction of most tryptophan degradation pathways, it might be added exogenously without disturbing upstream metabolism significantly. Many examples, which we review, show that it has valuable bioactivity. Given the above, we review its potential utility as a nutraceutical, finding it significantly worthy of further study and development.
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Affiliation(s)
- Luana de Fátima Alves
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Building 220, Søltofts Plads, 2800 Kongens Lyngby, Denmark
| | - J. Bernadette Moore
- School of Food Science & Nutrition, University of Leeds, Leeds LS2 9JT, UK;
- Department of Biochemistry, Cell & Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
| | - Douglas B. Kell
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Building 220, Søltofts Plads, 2800 Kongens Lyngby, Denmark
- Department of Biochemistry, Cell & Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
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Koper K, Han SW, Kothadia R, Salamon H, Yoshikuni Y, Maeda HA. Multisubstrate specificity shaped the complex evolution of the aminotransferase family across the tree of life. Proc Natl Acad Sci U S A 2024; 121:e2405524121. [PMID: 38885378 PMCID: PMC11214133 DOI: 10.1073/pnas.2405524121] [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: 04/02/2024] [Accepted: 05/14/2024] [Indexed: 06/20/2024] Open
Abstract
Aminotransferases (ATs) are an ancient enzyme family that play central roles in core nitrogen metabolism, essential to all organisms. However, many of the AT enzyme functions remain poorly defined, limiting our fundamental understanding of the nitrogen metabolic networks that exist in different organisms. Here, we traced the deep evolutionary history of the AT family by analyzing AT enzymes from 90 species spanning the tree of life (ToL). We found that each organism has maintained a relatively small and constant number of ATs. Mapping the distribution of ATs across the ToL uncovered that many essential AT reactions are carried out by taxon-specific AT enzymes due to wide-spread nonorthologous gene displacements. This complex evolutionary history explains the difficulty of homology-based AT functional prediction. Biochemical characterization of diverse aromatic ATs further revealed their broad substrate specificity, unlike other core metabolic enzymes that evolved to catalyze specific reactions today. Interestingly, however, we found that these AT enzymes that diverged over billion years share common signatures of multisubstrate specificity by employing different nonconserved active site residues. These findings illustrate that AT family enzymes had leveraged their inherent substrate promiscuity to maintain a small yet distinct set of multifunctional AT enzymes in different taxa. This evolutionary history of versatile ATs likely contributed to the establishment of robust and diverse nitrogen metabolic networks that exist throughout the ToL. The study provides a critical foundation to systematically determine diverse AT functions and underlying nitrogen metabolic networks across the ToL.
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Affiliation(s)
- Kaan Koper
- Department of Botany, University of Wisconsin-Madison, Madison, WI53706
| | - Sang-Woo Han
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Biotechnology, Konkuk University, Chungju27478, South Korea
| | - Ramani Kothadia
- The US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Hugh Salamon
- The US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Yasuo Yoshikuni
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- The US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Center for Advanced Bioenergy and Bioproducts Innovation, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Global Center for Food, Land, and Water Resources, Research Faculty of Agriculture, Hokkaido University, Hokkaido, Japan 060-8589
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Tokyo183-8538, Japan
| | - Hiroshi A. Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI53706
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Sathyasaikumar KV, Blanco-Ayala T, Zheng Y, Schwieler L, Erhardt S, Tufvesson-Alm M, Poeggeler B, Schwarcz R. The Tryptophan Metabolite Indole-3-Propionic Acid Raises Kynurenic Acid Levels in the Rat Brain In Vivo. Int J Tryptophan Res 2024; 17:11786469241262876. [PMID: 38911967 PMCID: PMC11191616 DOI: 10.1177/11786469241262876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 05/22/2024] [Indexed: 06/25/2024] Open
Abstract
Alterations in the composition of the gut microbiota may be causally associated with several brain diseases. Indole-3-propionic acid (IPrA) is a tryptophan-derived metabolite, which is produced by intestinal commensal microbes, rapidly enters the circulation, and crosses the blood-brain barrier. IPrA has neuroprotective properties, which have been attributed to its antioxidant and bioenergetic effects. Here, we evaluate an alternative and/or complementary mechanism, linking IPrA to kynurenic acid (KYNA), another neuroprotective tryptophan metabolite. Adult Sprague-Dawley rats received an oral dose of IPrA (200 mg/kg), and both IPrA and KYNA were measured in plasma and frontal cortex 90 minutes, 6 or 24 hours later. IPrA and KYNA levels increased after 90 minutes and 6 hours (brain IPrA: ~56- and ~7-fold; brain KYNA: ~4- and ~3-fold, respectively). In vivo microdialysis, performed in the medial prefrontal cortex and in the striatum, revealed increased KYNA levels (~2.5-fold) following the administration of IPrA (200 mg/kg, p.o), but IPrA failed to affect extracellular KYNA when applied locally. Finally, treatment with 100 or 350 mg IPrA, provided daily to the animals in the chow for a week, resulted in several-fold increases of IPrA and KYNA levels in both plasma and brain. These results suggest that exogenously supplied IPrA may provide a novel strategy to affect the function of KYNA in the mammalian brain.
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Affiliation(s)
- Korrapati V Sathyasaikumar
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, USA
| | - Tonali Blanco-Ayala
- Neurobiochemistry and Behavior Laboratory, National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez,” Mexico City, Mexico
| | - Yiran Zheng
- Departments of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Lilly Schwieler
- Departments of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Sophie Erhardt
- Departments of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | | | - Burkhard Poeggeler
- Department of Physiology, Johann-Friedrich-Blumenbach-Institute for Zoology and Anthropology, Georg-August-Universität Göttingen, Germany
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, USA
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León-Letelier RA, Dou R, Vykoukal J, Sater AHA, Ostrin E, Hanash S, Fahrmann JF. The kynurenine pathway presents multi-faceted metabolic vulnerabilities in cancer. Front Oncol 2023; 13:1256769. [PMID: 37876966 PMCID: PMC10591110 DOI: 10.3389/fonc.2023.1256769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/22/2023] [Indexed: 10/26/2023] Open
Abstract
The kynurenine pathway (KP) and associated catabolites play key roles in promoting tumor progression and modulating the host anti-tumor immune response. To date, considerable focus has been on the role of indoleamine 2,3-dioxygenase 1 (IDO1) and its catabolite, kynurenine (Kyn). However, increasing evidence has demonstrated that downstream KP enzymes and their associated metabolite products can also elicit tumor-microenvironment immune suppression. These advancements in our understanding of the tumor promotive role of the KP have led to the conception of novel therapeutic strategies to target the KP pathway for anti-cancer effects and reversal of immune escape. This review aims to 1) highlight the known biological functions of key enzymes in the KP, and 2) provide a comprehensive overview of existing and emerging therapies aimed at targeting discrete enzymes in the KP for anti-cancer treatment.
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Affiliation(s)
- Ricardo A. León-Letelier
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Rongzhang Dou
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Jody Vykoukal
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Ali Hussein Abdel Sater
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Edwin Ostrin
- Department of General Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Samir Hanash
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Johannes F. Fahrmann
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
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Nordin E, Hellström PM, Vuong E, Ribbenstedt A, Brunius C, Landberg R. IBS randomized study: FODMAPs alter bile acids, phenolic- and tryptophan metabolites, while gluten modifies lipids. Am J Physiol Regul Integr Comp Physiol 2023; 325:R248-R259. [PMID: 37399002 DOI: 10.1152/ajpregu.00016.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 05/10/2023] [Accepted: 06/17/2023] [Indexed: 07/04/2023]
Abstract
Diet is considered a culprit for symptoms in irritable bowel syndrome (IBS), although the mechanistic understanding of underlying causes is lacking. Metabolomics, i.e., the analysis of metabolites in biological samples may offer a diet-responsive fingerprint for IBS. Our aim was to explore alterations in the plasma metabolome after interventions with fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) or gluten versus control in IBS, and to relate such alterations to symptoms. People with IBS (n = 110) were included in a double-blind, randomized, crossover study with 1-wk provocations of FODMAPs, gluten, or placebo. Symptoms were evaluated with the IBS severity scoring system (IBS-SSS). Untargeted metabolomics was performed on plasma samples using LC-qTOF-MS. Discovery of metabolite alterations by treatment was performed using random forest followed by linear mixed modeling. Associations were studied using Spearman correlation. The metabolome was affected by FODMAP [classification rate (CR) 0.88, P < 0.0001], but less by gluten intake CR 0.72, P = 0.01). FODMAP lowered bile acids, whereas phenolic-derived metabolites and 3-indolepropionic acid (IPA) were higher compared with placebo. IPA and some unidentified metabolites correlated weakly to abdominal pain and quality of life. Gluten affected lipid metabolism weakly, but with no interpretable relationship to IBS. FODMAP affected gut microbial-derived metabolites relating to positive health outcomes. IPA and unknown metabolites correlated weakly to IBS severity. Minor symptom worsening by FODMAP intake must be weighed against general positive health aspects of FODMAP. The gluten intervention affected lipid metabolism weakly with no interpretable association to IBS severity. Registration: www.clinicaltrials.gov as NCT03653689.NEW & NOTEWORTHY In irritable bowel syndrome (IBS), fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) affected microbial-derived metabolites relating to positive health outcomes such as reduced risk of colon cancer, inflammation, and type 2 diabetes, as shown in previous studies. The minor IBS symptom induction by FODMAP intake must be weighed against the positive health aspects of FODMAP consumption. Gluten affected lipids weakly with no association to IBS severity.
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Affiliation(s)
- Elise Nordin
- Department of Biology and Biological Engineering, Food and Nutrition Science, Chalmers University of Technology, Gothenburg, Sweden
| | - Per M Hellström
- Department of Medical Sciences, Gastroenterology/Hepatology, Uppsala University, Uppsala, Sweden
| | - Eddie Vuong
- Department of Biology and Biological Engineering, Food and Nutrition Science, Chalmers University of Technology, Gothenburg, Sweden
| | - Anton Ribbenstedt
- Department of Biology and Biological Engineering, Food and Nutrition Science, Chalmers University of Technology, Gothenburg, Sweden
| | - Carl Brunius
- Department of Biology and Biological Engineering, Food and Nutrition Science, Chalmers University of Technology, Gothenburg, Sweden
| | - Rikard Landberg
- Department of Biology and Biological Engineering, Food and Nutrition Science, Chalmers University of Technology, Gothenburg, Sweden
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Nordin E, Hellström PM, Dicksved J, Pelve E, Landberg R, Brunius C. Effects of FODMAPs and Gluten on Gut Microbiota and Their Association with the Metabolome in Irritable Bowel Syndrome: A Double-Blind, Randomized, Cross-Over Intervention Study. Nutrients 2023; 15:3045. [PMID: 37447371 DOI: 10.3390/nu15133045] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/30/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
BACKGROUND A mechanistic understanding of the effects of dietary treatment in irritable bowel syndrome (IBS) is lacking. Our aim was therefore to investigate how fermentable oligo- di-, monosaccharides, and polyols (FODMAPs) and gluten affected gut microbiota and circulating metabolite profiles, as well as to investigate potential links between gut microbiota, metabolites, and IBS symptoms. METHODS We used data from a double-blind, randomized, crossover study with week-long provocations of FODMAPs, gluten, and placebo in participants with IBS. To study the effects of the provocations on fecal microbiota, fecal and plasma short-chain fatty acids, the untargeted plasma metabolome, and IBS symptoms, we used Random Forest, linear mixed model and Spearman correlation analysis. RESULTS FODMAPs increased fecal saccharolytic bacteria, plasma phenolic-derived metabolites, 3-indolepropionate, and decreased isobutyrate and bile acids. Gluten decreased fecal isovalerate and altered carnitine derivatives, CoA, and fatty acids in plasma. For FODMAPs, modest correlations were observed between microbiota and phenolic-derived metabolites and 3-indolepropionate, previously associated with improved metabolic health, and reduced inflammation. Correlations between molecular data and IBS symptoms were weak. CONCLUSIONS FODMAPs, but not gluten, altered microbiota composition and correlated with phenolic-derived metabolites and 3-indolepropionate, with only weak associations with IBS symptoms. Thus, the minor effect of FODMAPs on IBS symptoms must be weighed against the effect on microbiota and metabolites related to positive health factors.
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Affiliation(s)
- Elise Nordin
- Department of Life Sciences, Food and Nutrition Science, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
| | - Per M Hellström
- Department of Medical Sciences, Gastroenterology/Hepatology, Uppsala University, SE-75185 Uppsala, Sweden
| | - Johan Dicksved
- Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Erik Pelve
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Rikard Landberg
- Department of Life Sciences, Food and Nutrition Science, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
| | - Carl Brunius
- Department of Life Sciences, Food and Nutrition Science, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
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Shen H, Xu X, Bai Y, Wang X, Wu Y, Zhong J, Wu Q, Luo Y, Shang T, Shen R, Xi M, Sun H. Therapeutic potential of targeting kynurenine pathway in neurodegenerative diseases. Eur J Med Chem 2023; 251:115258. [PMID: 36917881 DOI: 10.1016/j.ejmech.2023.115258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/17/2023] [Accepted: 03/07/2023] [Indexed: 03/11/2023]
Abstract
Kynurenine pathway (KP), the primary pathway of L-tryptophan (Trp) metabolism in mammals, contains several neuroactive metabolites such as kynurenic acid (KA) and quinolinic acid (QA). Its imbalance involved in aging and neurodegenerative diseases (NDs) has attracted much interest in therapeutically targeting KP enzymes and KP metabolite-associated receptors, especially kynurenine monooxygenase (KMO). Currently, many agents have been discovered with significant improvement in animal models but only one aryl hydrocarbon receptor (AHR) agonist 30 (laquinimod) has entered clinical trials for treating Huntington's disease (HD). In this review, we describe neuroactive KP metabolites, discuss the dysregulation of KP in aging and NDs and summarize the development of KP regulators in preclinical and clinical studies, offering an outlook of targeting KP for NDs treatment in future.
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Affiliation(s)
- Hualiang Shen
- Zhejiang Engineering Research Center of Fat-soluble Vitamin, Shaoxing University, Shaoxing, 312000, China; College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, 312000, China
| | - Xinde Xu
- Zhejiang Medicine Co. Ltd., Shaoxing, 312500, China
| | - Yalong Bai
- Zhejiang Medicine Co. Ltd., Shaoxing, 312500, China
| | | | - Yibin Wu
- College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, 312000, China
| | - Jia Zhong
- College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, 312000, China
| | - Qiyi Wu
- College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, 312000, China
| | - Yanjuan Luo
- Zhejiang Engineering Research Center of Fat-soluble Vitamin, Shaoxing University, Shaoxing, 312000, China; College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, 312000, China
| | - Tianbo Shang
- Zhejiang Engineering Research Center of Fat-soluble Vitamin, Shaoxing University, Shaoxing, 312000, China; College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, 312000, China
| | - Runpu Shen
- Zhejiang Engineering Research Center of Fat-soluble Vitamin, Shaoxing University, Shaoxing, 312000, China; College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, 312000, China
| | - Meiyang Xi
- Zhejiang Engineering Research Center of Fat-soluble Vitamin, Shaoxing University, Shaoxing, 312000, China; College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, 312000, China.
| | - Haopeng Sun
- Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, 210009, China.
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Koper K, Han SW, Pastor DC, Yoshikuni Y, Maeda HA. Evolutionary Origin and Functional Diversification of Aminotransferases. J Biol Chem 2022; 298:102122. [PMID: 35697072 PMCID: PMC9309667 DOI: 10.1016/j.jbc.2022.102122] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/30/2022] Open
Abstract
Aminotransferases (ATs) are pyridoxal 5′-phosphate–dependent enzymes that catalyze the transamination reactions between amino acid donor and keto acid acceptor substrates. Modern AT enzymes constitute ∼2% of all classified enzymatic activities, play central roles in nitrogen metabolism, and generate multitude of primary and secondary metabolites. ATs likely diverged into four distinct AT classes before the appearance of the last universal common ancestor and further expanded to a large and diverse enzyme family. Although the AT family underwent an extensive functional specialization, many AT enzymes retained considerable substrate promiscuity and multifunctionality because of their inherent mechanistic, structural, and functional constraints. This review summarizes the evolutionary history, diverse metabolic roles, reaction mechanisms, and structure–function relationships of the AT family enzymes, with a special emphasis on their substrate promiscuity and multifunctionality. Comprehensive characterization of AT substrate specificity is still needed to reveal their true metabolic functions in interconnecting various branches of the nitrogen metabolic network in different organisms.
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Affiliation(s)
- Kaan Koper
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Sang-Woo Han
- The US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | - Yasuo Yoshikuni
- The US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Global Center for Food, Land, and Water Resources, Research Faculty of Agriculture, Hokkaido University, Hokkaido 060-8589, Japan
| | - Hiroshi A Maeda
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, USA
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Selvam AK, Jawad R, Gramignoli R, Achour A, Salter H, Björnstedt M. A Novel mRNA-Mediated and MicroRNA-Guided Approach to Specifically Eradicate Drug-Resistant Hepatocellular Carcinoma Cell Lines by Se-Methylselenocysteine. Antioxidants (Basel) 2021; 10:1094. [PMID: 34356326 PMCID: PMC8301172 DOI: 10.3390/antiox10071094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 01/25/2023] Open
Abstract
Despite progress in the treatment of non-visceral malignancies, the prognosis remains poor for malignancies of visceral organs and novel therapeutic approaches are urgently required. We evaluated a novel therapeutic regimen based on treatment with Se-methylselenocysteine (MSC) and concomitant tumor-specific induction of Kynurenine aminotransferase 1 (KYAT1) in hepatocellular carcinoma (HCC) cell lines, using either vector-based and/or lipid nanoparticle-mediated delivery of mRNA. Supplementation of MSC in KYAT1 overexpressed cells resulted in significantly increased cytotoxicity, due to ROS formation, as compared to MSC alone. Furthermore, microRNA antisense-targeted sites for miR122, known to be widely expressed in normal hepatocytes while downregulated in hepatocellular carcinoma, were added to specifically limit cytotoxicity in HCC cells, thereby limiting the off-target effects. KYAT1 expression was significantly reduced in cells with high levels of miR122 supporting the concept of miR-guided induction of tumor-specific cytotoxicity. The addition of alpha-ketoacid favored the production of methylselenol, enhancing the cytotoxic efficacy of MSC in HCC cells, with no effects on primary human hepatocytes. Altogether, the proposed regimen offers great potential to safely and specifically target hepatic tumors that are currently untreatable.
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Affiliation(s)
- Arun Kumar Selvam
- Department of Laboratory Medicine, Division of Pathology, Karolinska Institutet, Karolinska University Hospital, S-141 86 Stockholm, Sweden; (A.K.S.); (R.J.); (R.G.); (H.S.)
| | - Rim Jawad
- Department of Laboratory Medicine, Division of Pathology, Karolinska Institutet, Karolinska University Hospital, S-141 86 Stockholm, Sweden; (A.K.S.); (R.J.); (R.G.); (H.S.)
| | - Roberto Gramignoli
- Department of Laboratory Medicine, Division of Pathology, Karolinska Institutet, Karolinska University Hospital, S-141 86 Stockholm, Sweden; (A.K.S.); (R.J.); (R.G.); (H.S.)
| | - Adnane Achour
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, & Division of Infectious Diseases, Karolinska University Hospital, SE-171 77 Solna, Sweden;
| | - Hugh Salter
- Department of Laboratory Medicine, Division of Pathology, Karolinska Institutet, Karolinska University Hospital, S-141 86 Stockholm, Sweden; (A.K.S.); (R.J.); (R.G.); (H.S.)
- Moderna, Inc., 200 Technology Square, Cambridge, MA 02139, USA
| | - Mikael Björnstedt
- Department of Laboratory Medicine, Division of Pathology, Karolinska Institutet, Karolinska University Hospital, S-141 86 Stockholm, Sweden; (A.K.S.); (R.J.); (R.G.); (H.S.)
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Pyridoxal 5'-Phosphate-Dependent Enzymes at the Crossroads of Host-Microbe Tryptophan Metabolism. Int J Mol Sci 2020; 21:ijms21165823. [PMID: 32823705 PMCID: PMC7461572 DOI: 10.3390/ijms21165823] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/06/2020] [Accepted: 08/11/2020] [Indexed: 02/07/2023] Open
Abstract
The chemical processes taking place in humans intersects the myriad of metabolic pathways occurring in commensal microorganisms that colonize the body to generate a complex biochemical network that regulates multiple aspects of human life. The role of tryptophan (Trp) metabolism at the intersection between the host and microbes is increasingly being recognized, and multiple pathways of Trp utilization in either direction have been identified with the production of a wide range of bioactive products. It comes that a dysregulation of Trp metabolism in either the host or the microbes may unbalance the production of metabolites with potential pathological consequences. The ability to redirect the Trp flux to restore a homeostatic production of Trp metabolites may represent a valid therapeutic strategy for a variety of pathological conditions, but identifying metabolic checkpoints that could be exploited to manipulate the Trp metabolic network is still an unmet need. In this review, we put forward the hypothesis that pyridoxal 5′-phosphate (PLP)-dependent enzymes, which regulate multiple pathways of Trp metabolism in both the host and in microbes, might represent critical nodes and that modulating the levels of vitamin B6, from which PLP is derived, might represent a metabolic checkpoint to re-orienteer Trp flux for therapeutic purposes.
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A Novel Assay Method to Determine the β-Elimination of Se-Methylselenocysteine to Monomethylselenol by Kynurenine Aminotransferase 1. Antioxidants (Basel) 2020; 9:antiox9020139. [PMID: 32033380 PMCID: PMC7070735 DOI: 10.3390/antiox9020139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 11/16/2022] Open
Abstract
Kynurenine aminotransferase 1 (KYAT1 or CCBL1) plays a major role in Se-methylselenocysteine (MSC) metabolism. It is a bi-functional enzyme that catalyzes transamination and beta-elimination activity with a single substrate. KYAT1 produces methylselenol (CH3SeH) via β-elimination activities with MSC as a substrate. This methylated selenium compound is a major cytotoxic selenium metabolite, causing apoptosis in a wide variety of cancer cells. Methylselenol is volatile and possesses extraordinary nucleophilic properties. We herein describe a simple spectrophotometric assay by combining KYAT1 and thioredoxin reductase (TrxR) to detect CH3SeH in a coupled activity assay. The metabolite methylselenol and its oxidized form from MSC metabolism is utilized as a substrate for TrxR1 and this can be monitored spectroscopically at 340 nm. Our results show the feasibility of monitoring the β-elimination of KYAT1 by our assay and the results were compared to the previously described β-elimination assays measuring pyruvate. By using known inhibitors of KYAT1 and TrxR1, we further validated the respective reaction. Our data provide a simple but accurate method to determine the β-elimination activity of KYAT1, which is of importance for mechanistic studies of a highly interesting selenium compound.
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12
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Maciel LG, Oliveira AA, Romão TP, Leal LLL, Guido RVC, Silva-Filha MHNL, Dos Anjos JV, Soares TA. Discovery of 1,2,4-oxadiazole derivatives as a novel class of noncompetitive inhibitors of 3-hydroxykynurenine transaminase (HKT) from Aedes aegypti. Bioorg Med Chem 2019; 28:115252. [PMID: 31864777 DOI: 10.1016/j.bmc.2019.115252] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 12/14/2022]
Abstract
The mosquito Aedes aegypti is the vector of arboviruses such as Zika, Chikungunya, dengue and yellow fever. These infectious diseases have a major impact on public health. The unavailability of effective vaccines or drugs to prevent or treat most of these diseases makes vector control the main form of prevention. One strategy to promote mosquito population control is the use of synthetic insecticides to inhibit key enzymes in the metabolic pathway of these insects, particularly during larval stages. One of the main targets of the kynurenine detoxification pathway in mosquitoes is the enzyme 3-hydroxykynurenine transaminase (HKT), which catalyzes the conversion of 3-hydroxykynurenine (3-HK) into xanthurenic acid (XA). In this work, we report eleven newly synthesized oxadiazole derivatives and demonstrate that these compounds are potent noncompetitive inhibitors of HKT from Ae. aegypti. The present data provide direct evidence that HKT can be explored as a molecular target for the discovery of novel larvicides against Ae. aegypti. More importantly, it ensures that structural information derived from the HKT 3D-structure can be used to guide the development of more potent inhibitors.
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Affiliation(s)
- Larissa G Maciel
- Department of Fundamental Chemistry - Federal University of Pernambuco, Av. Jornalista Aníbal Fernandes, s/n°Cidade Universitária - Recife, PE 50740-560, Brazil
| | - Andrew A Oliveira
- Sao Carlos Institute of Physics - University of São Paulo, Av. Joao Dagnone, 1100 Jardim Santa Angelina, São Carlos, SP 13563-120, Brazil
| | - Tatiany P Romão
- Institute Aggeu Magalhães (IAM) - FIOCRUZ, Av. Professor Moraes Rego s/n°, Recife, PE 50740-560 Brazil
| | - Laylla L L Leal
- Department of Fundamental Chemistry - Federal University of Pernambuco, Av. Jornalista Aníbal Fernandes, s/n°Cidade Universitária - Recife, PE 50740-560, Brazil
| | - Rafael V C Guido
- Sao Carlos Institute of Physics - University of São Paulo, Av. Joao Dagnone, 1100 Jardim Santa Angelina, São Carlos, SP 13563-120, Brazil
| | | | - Janaína V Dos Anjos
- Department of Fundamental Chemistry - Federal University of Pernambuco, Av. Jornalista Aníbal Fernandes, s/n°Cidade Universitária - Recife, PE 50740-560, Brazil.
| | - Thereza A Soares
- Department of Fundamental Chemistry - Federal University of Pernambuco, Av. Jornalista Aníbal Fernandes, s/n°Cidade Universitária - Recife, PE 50740-560, Brazil.
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13
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Agudelo LZ, Ferreira DMS, Dadvar S, Cervenka I, Ketscher L, Izadi M, Zhengye L, Furrer R, Handschin C, Venckunas T, Brazaitis M, Kamandulis S, Lanner JT, Ruas JL. Skeletal muscle PGC-1α1 reroutes kynurenine metabolism to increase energy efficiency and fatigue-resistance. Nat Commun 2019; 10:2767. [PMID: 31235694 PMCID: PMC6591322 DOI: 10.1038/s41467-019-10712-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/22/2019] [Indexed: 12/02/2022] Open
Abstract
The coactivator PGC-1α1 is activated by exercise training in skeletal muscle and promotes fatigue-resistance. In exercised muscle, PGC-1α1 enhances the expression of kynurenine aminotransferases (Kats), which convert kynurenine into kynurenic acid. This reduces kynurenine-associated neurotoxicity and generates glutamate as a byproduct. Here, we show that PGC-1α1 elevates aspartate and glutamate levels and increases the expression of glycolysis and malate-aspartate shuttle (MAS) genes. These interconnected processes improve energy utilization and transfer fuel-derived electrons to mitochondrial respiration. This PGC-1α1-dependent mechanism allows trained muscle to use kynurenine metabolism to increase the bioenergetic efficiency of glucose oxidation. Kat inhibition with carbidopa impairs aspartate biosynthesis, mitochondrial respiration, and reduces exercise performance and muscle force in mice. Our findings show that PGC-1α1 activates the MAS in skeletal muscle, supported by kynurenine catabolism, as part of the adaptations to endurance exercise. This crosstalk between kynurenine metabolism and the MAS may have important physiological and clinical implications. PGC-1α is activated by exercise and promotes resistance to fatigue in muscles. Here, the authors show that PGC-1α activates the malate-aspartate shuttle, and allows muscle to utilise kynurenine, leading to more efficient glucose oxidation and mitochondrial respiration.
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Affiliation(s)
- Leandro Z Agudelo
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden.,Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Duarte M S Ferreira
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden
| | - Shamim Dadvar
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden
| | - Igor Cervenka
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden
| | - Lars Ketscher
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden
| | - Manizheh Izadi
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden
| | - Liu Zhengye
- Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden
| | - Regula Furrer
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Christoph Handschin
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Tomas Venckunas
- Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, 44221, Kaunas, Lithuania
| | - Marius Brazaitis
- Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, 44221, Kaunas, Lithuania
| | - Sigitas Kamandulis
- Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, 44221, Kaunas, Lithuania
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden
| | - Jorge L Ruas
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, Biomedicum C5, 171 77, Stockholm, Sweden.
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14
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Han Q, Yang C, Lu J, Zhang Y, Li J. Metabolism of Oxalate in Humans: A Potential Role Kynurenine Aminotransferase/Glutamine Transaminase/Cysteine Conjugate Beta-lyase Plays in Hyperoxaluria. Curr Med Chem 2019; 26:4944-4963. [PMID: 30907303 DOI: 10.2174/0929867326666190325095223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/17/2019] [Accepted: 02/22/2019] [Indexed: 11/22/2022]
Abstract
Hyperoxaluria, excessive urinary oxalate excretion, is a significant health problem worldwide. Disrupted oxalate metabolism has been implicated in hyperoxaluria and accordingly, an enzymatic disturbance in oxalate biosynthesis can result in the primary hyperoxaluria. Alanine glyoxylate aminotransferase-1 and glyoxylate reductase, the enzymes involving glyoxylate (precursor for oxalate) metabolism, have been related to primary hyperoxalurias. Some studies suggest that other enzymes such as glycolate oxidase and alanine glyoxylate aminotransferase-2 might be associated with primary hyperoxaluria as well, but evidence of a definitive link is not strong between the clinical cases and gene mutations. There are still some idiopathic hyperoxalurias, which require a further study for the etiologies. Some aminotransferases, particularly kynurenine aminotransferases, can convert glyoxylate to glycine. Based on biochemical and structural characteristics, expression level, subcellular localization of some aminotransferases, a number of them appear able to catalyze the transamination of glyoxylate to glycine more efficiently than alanine glyoxylate aminotransferase-1. The aim of this minireview is to explore other undermining causes of primary hyperoxaluria and stimulate research toward achieving a comprehensive understanding of underlying mechanisms leading to the disease. Herein, we reviewed all aminotransferases in the liver for their functions in glyoxylate metabolism. Particularly, kynurenine aminotransferase-I and III were carefully discussed regarding their biochemical and structural characteristics, cellular localization, and enzyme inhibition. Kynurenine aminotransferase-III is, so far, the most efficient putative mitochondrial enzyme to transaminate glyoxylate to glycine in mammalian livers, might be an interesting enzyme to look over in hyperoxaluria etiology of primary hyperoxaluria and should be carefully investigated for its involvement in oxalate metabolism.
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Affiliation(s)
- Qian Han
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228. China
| | - Cihan Yang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228. China
| | - Jun Lu
- Central South University Xiangya School of Medicine Affiliated Haikou People's Hospital, Haikou, Hainan 570208. China
| | - Yinai Zhang
- Central South University Xiangya School of Medicine Affiliated Haikou People's Hospital, Haikou, Hainan 570208. China
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061. United States
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15
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Rossi F, Miggiano R, Ferraris DM, Rizzi M. The Synthesis of Kynurenic Acid in Mammals: An Updated Kynurenine Aminotransferase Structural KATalogue. Front Mol Biosci 2019; 6:7. [PMID: 30873412 PMCID: PMC6400995 DOI: 10.3389/fmolb.2019.00007] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 02/06/2019] [Indexed: 01/25/2023] Open
Abstract
Kynurenic acid (KYNA) is a bioactive compound that is produced along the kynurenine pathway (KP) during tryptophan degradation. In a few decades, KYNA shifted from being regarded a poorly characterized by-product of the KP to being considered a main player in many aspects of mammalian physiology, including the control of glutamatergic and cholinergic synaptic transmission, and the coordination of immunomodulation. The renewed attention being paid to the study of KYNA homeostasis is justified by the discovery of selective and potent inhibitors of kynurenine aminotransferase II, which is considered the main enzyme responsible for KYNA synthesis in the mammalian brain. Since abnormally high KYNA levels in the central nervous system have been associated with schizophrenia and cognitive impairment, these inhibitors promise the development of novel anti-psychotic and pro-cognitive drugs. Here, we summarize the currently available structural information on human and rodent kynurenine aminotransferases (KATs) as the result of global efforts aimed at describing the full complement of mammalian isozymes. These studies highlight peculiar features of KATs that can be exploited for the development of isozyme-specific inhibitors. Together with the optimization of biochemical assays to measure individual KAT activities in complex samples, this wealth of knowledge will continue to foster the identification and rational design of brain penetrant small molecules to attenuate KYNA synthesis, i.e., molecules capable of lowering KYNA levels without exposing the brain to the harmful withdrawal of KYNA-dependent neuroprotective actions.
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Affiliation(s)
- Franca Rossi
- Biochemistry and Biocrystallography Unit, DSF-Dipartimento di Scienze del Farmaco, University of Piemonte Orientale, Novara, Italy
| | - Riccardo Miggiano
- Biochemistry and Biocrystallography Unit, DSF-Dipartimento di Scienze del Farmaco, University of Piemonte Orientale, Novara, Italy
| | - Davide M Ferraris
- Biochemistry and Biocrystallography Unit, DSF-Dipartimento di Scienze del Farmaco, University of Piemonte Orientale, Novara, Italy
| | - Menico Rizzi
- Biochemistry and Biocrystallography Unit, DSF-Dipartimento di Scienze del Farmaco, University of Piemonte Orientale, Novara, Italy
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16
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Bernardo-García N, Sánchez-Murcia PA, Espaillat A, Martínez-Caballero S, Cava F, Hermoso JA, Gago F. Cold-induced aldimine bond cleavage by Tris in Bacillus subtilis alanine racemase. Org Biomol Chem 2019; 17:4350-4358. [DOI: 10.1039/c9ob00223e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The commonly used Tris buffer acts as a surrogate substrate and deformylates pyridoxal phosphate in a bacterial alanine racemase at subzero temperatures.
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Affiliation(s)
- Noelia Bernardo-García
- Department of Crystallography and Structural Biology
- Institute of Physical Chemistry “Rocasolano”
- CSIC
- 28006 Madrid
- Spain
| | | | - Akbar Espaillat
- Laboratory for Molecular Infection Medicine
- Department of Molecular Biology
- Umeå Centre for Microbial Research
- Umeå University
- 90187 Umeå
| | - Siseth Martínez-Caballero
- Department of Crystallography and Structural Biology
- Institute of Physical Chemistry “Rocasolano”
- CSIC
- 28006 Madrid
- Spain
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine
- Department of Molecular Biology
- Umeå Centre for Microbial Research
- Umeå University
- 90187 Umeå
| | - Juan A. Hermoso
- Department of Crystallography and Structural Biology
- Institute of Physical Chemistry “Rocasolano”
- CSIC
- 28006 Madrid
- Spain
| | - Federico Gago
- Department of Biomedical Sciences
- “Unidad Asociada IQM-CSIC”
- University of Alcalá
- Madrid
- Spain
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17
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Thiyagarajamoorthy DK, Arulanandam CD, Dahms HU, Murugaiah SG, Krishnan M, Rathinam AJ. Marine Bacterial Compounds Evaluated by In Silico Studies as Antipsychotic Drugs Against Schizophrenia. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2018; 20:639-653. [PMID: 30019186 DOI: 10.1007/s10126-018-9835-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 05/24/2018] [Indexed: 06/08/2023]
Abstract
Schizophrenia (SCZ) is one of the brain disorders which affects the thinking and behavioral skills of patients. This disorder comes along with an overproduction of kynurenic acid in the cerebrospinal fluid and the prefrontal cortex of SCZ patients. In this study, marine bacterial compounds were screened for their suitability as antagonists against human kynurenine aminotransferase (hKAT-1) which causes the synthesis of kynurenic acid downstream which ultimately causes the SCZ disorder according to the kynurenic hypothesis of SCZ. The marine actinobacterial compound bonactin shows more promising results than other tested marine compounds such as the histamine H2 blocker famotidine and indole-3-acetic acid (IAC) from docking and in silico toxicological studies carried out here. The obtained results of the Grid-based Ligand Docking with Energetics (Glide) scores of extra-precision (XP) Glide against the target protein hKAT-1 on IAC, famotidine, and bonactin were - 6.581, - 6.500 and - 7.730 kcal/mol where Glide energies were - 29.84, - 28.391, and - 47.565 kcal/mol, respectively. Bonactin is known as an antibacterial and antifungal compound being extracted from a marine Streptomyces sp. Comparing tested compounds against the drug target hKAT-1, bonactin alone showed the best Glide score and Glide energy on the target protein hKAT-1.
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Affiliation(s)
| | - Charli Deepak Arulanandam
- Department of Biomedical Science and Environmental Biology, KMU- Kaohsiung Medical University, Kaohsiung, 80708, Taiwan, Republic Of China
- Department of Medicinal and Applied Chemistry, KMU- Kaohsiung Medical University, Kaohsiung, 80708, Taiwan, Republic Of China
| | - Hans-Uwe Dahms
- Department of Biomedical Science and Environmental Biology, KMU- Kaohsiung Medical University, Kaohsiung, 80708, Taiwan, Republic Of China.
- Research Center for Environmental Medicine, KMU- Kaohsiung Medical University, Kaohsiung, 80708, Taiwan, Republic Of China.
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan, Republic Of China.
| | - Santhosh Gokul Murugaiah
- Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Muthukumar Krishnan
- Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Arthur James Rathinam
- Department of Marine Science, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India.
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18
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Villar-Briones A, Aird SD. Organic and Peptidyl Constituents of Snake Venoms: The Picture Is Vastly More Complex Than We Imagined. Toxins (Basel) 2018; 10:E392. [PMID: 30261630 PMCID: PMC6215107 DOI: 10.3390/toxins10100392] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 09/18/2018] [Accepted: 09/20/2018] [Indexed: 12/24/2022] Open
Abstract
Small metabolites and peptides in 17 snake venoms (Elapidae, Viperinae, and Crotalinae), were quantified using liquid chromatography-mass spectrometry. Each venom contains >900 metabolites and peptides. Many small organic compounds are present at levels that are probably significant in prey envenomation, given that their known pharmacologies are consistent with snake envenomation strategies. Metabolites included purine nucleosides and their bases, neurotransmitters, neuromodulators, guanidino compounds, carboxylic acids, amines, mono- and disaccharides, and amino acids. Peptides of 2⁻15 amino acids are also present in significant quantities, particularly in crotaline and viperine venoms. Some constituents are specific to individual taxa, while others are broadly distributed. Some of the latter appear to support high anabolic activity in the gland, rather than having toxic functions. Overall, the most abundant organic metabolite was citric acid, owing to its predominance in viperine and crotaline venoms, where it chelates divalent cations to prevent venom degradation by venom metalloproteases and damage to glandular tissue by phospholipases. However, in terms of their concentrations in individual venoms, adenosine, adenine, were most abundant, owing to their high titers in Dendroaspis polylepis venom, although hypoxanthine, guanosine, inosine, and guanine all numbered among the 50 most abundant organic constituents. A purine not previously reported in venoms, ethyl adenosine carboxylate, was discovered in D. polylepis venom, where it probably contributes to the profound hypotension caused by this venom. Acetylcholine was present in significant quantities only in this highly excitotoxic venom, while 4-guanidinobutyric acid and 5-guanidino-2-oxopentanoic acid were present in all venoms.
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Affiliation(s)
- Alejandro Villar-Briones
- Division of Research Support, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan.
| | - Steven D Aird
- Division of Faculty Affairs and Ecology and Evolution Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan.
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19
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Sharma R, Razdan K, Bansal Y, Kuhad A. Rollercoaster ride of kynurenines: steering the wheel towards neuroprotection in Alzheimer's disease. Expert Opin Ther Targets 2018; 22:849-867. [PMID: 30223691 DOI: 10.1080/14728222.2018.1524877] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Alzheimer's disease (AD) is associated with cerebral cognitive deficits exhibiting two cardinal hallmarks: accruement of extracellular amyloid plaques and intracellular neurofibrillary tangles composed of hyperphosphorylated tau protein. The currently accessible therapeutic armamentarium merely provides symptomatic relief. Therefore, the cry for prospective neuroprotective strategies seems to be the need of the hour. Areas covered: This review comprehensively establishes correlation between kynurenine pathway (KP) metabolites and AD with major emphasis on its two functionally contrasting neuroactive metabolites i.e. kynurenic acid (KYNA) and quinolinic acid (QUIN) and enlists various clinical studies which hold a potential for future therapeutics in AD. Also, major hypotheses of AD and mechanisms underlying them have been scrutinized with the aim to brush up the readers with basic pathology of AD. Expert opinion: KP is unique in itself as it holds two completely different domains i.e. neurotoxic QUIN and neuroprotective KYNA and disrupted equilibrium between the two has a hand in neurodegeneration. KYNA has long been demonstrated to be neuroprotective but lately being disparaged for cognitive side effects. But we blaze a trail by amalgamating the pharmacological mechanistic studies of KYNA in kinship with α7nAChRs, NMDARs and GABA which lends aid in favour of KA.
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Affiliation(s)
- Radhika Sharma
- a Pharmacology Research Laboratory , University Institute of Pharmaceutical Sciences, UGC-Centre of Advanced Study, Panjab University , Chandigarh , India
| | - Karan Razdan
- b Pharmaceutics division , University Institute of Pharmaceutical Sciences, UGC-Centre of Advanced Study, Panjab University , Chandigarh , India
| | - Yashika Bansal
- a Pharmacology Research Laboratory , University Institute of Pharmaceutical Sciences, UGC-Centre of Advanced Study, Panjab University , Chandigarh , India
| | - Anurag Kuhad
- a Pharmacology Research Laboratory , University Institute of Pharmaceutical Sciences, UGC-Centre of Advanced Study, Panjab University , Chandigarh , India
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20
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Jayawickrama GS, Nematollahi A, Sun G, Church WB. Fragment Screening of Human Kynurenine Aminotransferase-II. SLAS DISCOVERY 2018. [PMID: 29537924 DOI: 10.1177/2472555218764620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Kynurenine aminotransferase-II (KAT-II) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that acts in the tryptophan metabolic pathway by catalyzing the transamination of kynurenine into kynurenic acid (KYNA). It is one of four isoforms in the KAT family, of which it is the primary homologue responsible for KYNA production in the mammalian brain. KAT-II is targeted for inhibition as KYNA is implicated in diseases such as schizophrenia, where it is found in elevated concentrations. Previously, many different approaches have been taken to develop KAT-II inhibitors, and herein fragment-based drug design (FBDD) approaches have been exploited to provide further lead compounds that can be designed into novel inhibitors. Surface plasmon resonance (SPR) was used to screen a fragment library containing 1000 compounds, of which 41 hits were identified. These hits were further evaluated with SPR, and 18 were selected for inhibition studies. From these hits, two fragments, F6037-0164 and F0037-7280, were pursued and determined to have an IC50 of 524.5 (± 25.6) μM and 115.2 (± 4.5) μM, respectively. This strategy shows the viability of using FBDD in gleaning knowledge about KAT-II inhibition and generating leads for the production of KAT-II inhibitors.
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Affiliation(s)
- Gayan S Jayawickrama
- 1 Group in Biomolecular Structure and Informatics, Faculty of Pharmacy, The University of Sydney, Sydney, NSW, Australia
| | - Alireza Nematollahi
- 1 Group in Biomolecular Structure and Informatics, Faculty of Pharmacy, The University of Sydney, Sydney, NSW, Australia
| | - Guanchen Sun
- 1 Group in Biomolecular Structure and Informatics, Faculty of Pharmacy, The University of Sydney, Sydney, NSW, Australia
| | - W Bret Church
- 1 Group in Biomolecular Structure and Informatics, Faculty of Pharmacy, The University of Sydney, Sydney, NSW, Australia
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21
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Kynurenine aminotransferase activity of Aro8/Aro9 engage tryptophan degradation by producing kynurenic acid in Saccharomyces cerevisiae. Sci Rep 2017; 7:12180. [PMID: 28939805 PMCID: PMC5610271 DOI: 10.1038/s41598-017-12392-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 09/07/2017] [Indexed: 12/12/2022] Open
Abstract
Kynurenic acid (KA) is a tryptophan (Trp) metabolite that is synthesised in a branch of kynurenine (KYN) pathway. KYN aminotransferase (KAT) catalyses deamination of KYN, yielding KA. Although KA synthesis is evolutionarily conserved from bacteria to humans, the cellular benefits of synthesising KA are unclear. In this study, we constructed a KAT-null yeast mutant defective in KA synthesis to clarify the cellular function of KA. Amino acid sequence analysis and LC/MS quantification of KA revealed that Aro8 and Aro9 are the major KATs. KA was significantly decreased in the aro8Δ aro9Δ double mutant. We found that aro8Δ aro9Δ cells did not exhibit obvious defects in growth or oxidative stress response when proper amounts of amino acids are supplied in the media. We further found that aro8Δ aro9Δ cells were sensitive to excess Trp. The Trp sensitivity was not rescued by addition of KA, suggesting that Trp sensitivity is not due to the loss of KA. In conclusion, we propose that KAT activity is required for detoxification of Trp by converting it to the less toxic KA.
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22
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Jacobs KR, Castellano-Gonzalez G, Guillemin GJ, Lovejoy DB. Major Developments in the Design of Inhibitors along the Kynurenine Pathway. Curr Med Chem 2017; 24:2471-2495. [PMID: 28464785 PMCID: PMC5748880 DOI: 10.2174/0929867324666170502123114] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/13/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022]
Abstract
Disrupted kynurenine pathway (KP) metabolism has been implicated in the progression of neurodegenerative disease, psychiatric disorders and cancer. Modulation of enzyme activity along this pathway may therefore offer potential new therapeutic strategies for these conditions. Considering their prominent positions in the KP, the enzymes indoleamine 2,3-dioxygenase, kynurenine 3-monooxygenase and kynurenine aminotransferase, appear the most attractive targets. Already, increasing interest in this pathway has led to the identification of a number of potent and selective enzyme inhibitors with promising pre-clinical data and the elucidation of several enzyme crystal structures provides scope to rationalize the molecular mechanisms of inhibitor activity. The field seems poised to yield one or more inhibitors that should find clinical utility.
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Affiliation(s)
- Kelly R Jacobs
- Neuroinflammation Group, Department of Biomedical Research, Faculty of Medicine and Health Sciences, Macquarie University, Sydney. Australia
| | - Gloria Castellano-Gonzalez
- Neuroinflammation Group, Department of Biomedical Research, Faculty of Medicine and Health Sciences, Macquarie University, Sydney. Australia
| | - Gilles J Guillemin
- Department of Biomedical Research, Faculty of Medicine and Health Science, Macquarie University, 2 Technology Place, Sydney. Australia
| | - David B Lovejoy
- Department of Biomedical Research, Faculty of Medicine and Health Science, Macquarie University, 2 Technology Place, Sydney. Australia
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23
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Nadvi NA, Salam NK, Park J, Akladios FN, Kapoor V, Collyer CA, Gorrell MD, Church WB. High resolution crystal structures of human kynurenine aminotransferase-I bound to PLP cofactor, and in complex with aminooxyacetate. Protein Sci 2017; 26:727-736. [PMID: 28097769 DOI: 10.1002/pro.3119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 11/06/2022]
Abstract
In this study, we report two high-resolution structures of the pyridoxal 5' phosphate (PLP)-dependent enzyme kynurenine aminotransferase-I (KAT-I). One is the native structure with the cofactor in the PLP form bound to Lys247 with the highest resolution yet available for KAT-I at 1.28 Å resolution, and the other with the general PLP-dependent aminotransferase inhibitor, aminooxyacetate (AOAA) covalently bound to the cofactor at 1.54 Å. Only small conformational differences are observed in the vicinity of the aldimine (oxime) linkage with which the PLP forms the Schiff base with Lys247 in the 1.28 Å resolution native structure, in comparison to other native PLP-bound structures. We also report the inhibition of KAT-1 by AOAA and aminooxy-phenylpropionic acid (AOPP), with IC50s of 13.1 and 5.7 μM, respectively. The crystal structure of the enzyme in complex with the inhibitor AOAA revealed that the cofactor is the PLP form with the external aldimine linkage. The location of this oxime with the PLP, which forms in place of the native internal aldimine linkage of PLP of the native KAT-I, is away from the position of the native internal aldimine, with the free Lys247 substantially retaining the orientation of the native structure. Tyr101, at the active site, was observed in two conformations in both structures.
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Affiliation(s)
- Naveed A Nadvi
- Group in Biomolecular Structure and Informatics, Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia.,Molecular Hepatology, Centenary Institute and Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Noeris K Salam
- Group in Biomolecular Structure and Informatics, Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
| | - Joohong Park
- Molecular Hepatology, Centenary Institute and Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Fady N Akladios
- Group in Biomolecular Structure and Informatics, Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
| | - Vimal Kapoor
- School of Medicine and Pharmacology, The University of Western Australia, Perth, Western, Australia, Australia
| | - Charles A Collyer
- School of Molecular Bioscience, University of Sydney, Sydney, New South Wales, Australia
| | - Mark D Gorrell
- Molecular Hepatology, Centenary Institute and Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - William Bret Church
- Group in Biomolecular Structure and Informatics, Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
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Guo M, Lu X, Wang Y, Brodelius PE. Comparison of the interaction between lactoferrin and isomeric drugs. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 173:593-607. [PMID: 27776314 DOI: 10.1016/j.saa.2016.10.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/04/2016] [Accepted: 10/17/2016] [Indexed: 06/06/2023]
Abstract
The binding properties of pentacyclic triterpenoid isomeric drugs, i.e. ursolic acid (UA) and oleanolic acid (OA), to bovine lactoferrin (BLF) have been studied by molecule modeling, fluorescence spectroscopy, UV-visible absorbance spectroscopy and infrared spectroscopy (IR). Molecular docking, performed to reveal the possible binding mode or mechanism, suggested that hydrophobic interaction and hydrogen bonding play important roles to stabilize the complex. The results of spectroscopic measurements showed that the two isomeric drugs both strongly quenched the intrinsic fluorescence of BLF through a static quenching procedure although some differences between UA and OA binding strength and non-radiation energy transfer occurred within the molecules. The number of binding sites was 3.44 and 3.10 for UA and OA, respectively, and the efficiency of Förster energy transfer provided a distance of 0.77 and 1.21nm for UA and OA, respectively. The conformation transformation of BLF affected by the drugs conformed to the "all-or-none" pattern. In addition, the changes of the ratios of α-helices, β-sheets and β-turns of BLF during the process of the interaction were obtained. The results of the experiments in combination with the calculations showed that there are two modes of pentacyclic triterpenoid binding to BLF instead of one binding mode only governed by the principle of the lowest bonding energy.
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Affiliation(s)
- Ming Guo
- Department of Chemistry, Zhejiang Agricultural & Forestry University, Lin'an 311300, Zhejiang, China.
| | - Xiaowang Lu
- Department of Chemistry, Zhejiang Agricultural & Forestry University, Lin'an 311300, Zhejiang, China
| | - Yan Wang
- Department of Chemistry, Zhejiang Agricultural & Forestry University, Lin'an 311300, Zhejiang, China
| | - Peter E Brodelius
- Department of Chemistry and Biomedical Sciences, Linnaeus University, 391 82 Kalmar, Sweden.
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25
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Yang C, Zhang L, Han Q, Liao C, Lan J, Ding H, Zhou H, Diao X, Li J. Kynurenine aminotransferase 3/glutamine transaminase L/cysteine conjugate beta-lyase 2 is a major glutamine transaminase in the mouse kidney. Biochem Biophys Rep 2016; 8:234-241. [PMID: 28955961 PMCID: PMC5613967 DOI: 10.1016/j.bbrep.2016.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/19/2016] [Accepted: 09/19/2016] [Indexed: 11/22/2022] Open
Abstract
Background Kynurenine aminotransferase 3 (KAT3) catalyzes the transamination of Kynurenine to kynurenic acid, and is identical to cysteine conjugate beta-lyase 2 (CCBL2) and glutamine transaminase L (GTL). GTL was previously purified from the rat liver and considered as a liver type glutamine transaminase. However, because of the substrate overlap and high sequence similarity of KAT3 and KAT1, it was difficult to assay the specific activity of each KAT and to study the enzyme localization in animals. Methods KAT3 transcript and protein levels as well as enzyme activity in the liver and kidney were analyzed by regular reverse transcription-polymerase chain reaction (RT-PCR), real time RT-PCR, biochemical activity assays combined with a specific inhibition assay, and western blotting using a purified and a highly specific antibody, respectively. Results This study concerns the comparative biochemical characterization and localization of KAT 3 in the mouse. The results showed that KAT3 was present in both liver and kidney of the mouse, but was much more abundant in the kidney than in the liver. The mouse KAT3 is more efficient in transamination of glutamine with indo-3-pyruvate or oxaloacetate as amino group acceptor than the mouse KAT1. Conclusions Mouse KAT3 is a major glutamine transaminase in the kidney although it was named a liver type transaminase. General significance Our data highlights KAT3 as a key enzyme for studying the nephrotoxic mechanism of some xenobiotics and the formation of chemopreventive compounds in the mouse kidney. This suggests tissue localizations of KAT3/GTL/CCBL2 in other animals may be carefully checked. Mouse kynurenine aminotransferase 3 (KAT3) was specifically inhibited by methionine. Mouse KAT3 is more abundant in the kidney than in the liver. Mouse KAT3 is a major glutamine transaminase in the kidney although it was named a liver transaminase.
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Affiliation(s)
- Cihan Yang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228, China
- Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, Hainan 570228, China
| | - Lei Zhang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228, China
- Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, Hainan 570228, China
| | - Qian Han
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228, China
- Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, Hainan 570228, China
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
- Corresponding author at: Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, Hainan 570228, China.
| | - Chenghong Liao
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228, China
- Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, Hainan 570228, China
| | - Jianqiang Lan
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228, China
- Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, Hainan 570228, China
| | - Haizhen Ding
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Hailong Zhou
- Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, Hainan 570228, China
| | - Xiaoping Diao
- Laboratory of Tropical Veterinary Medicine and Vector Biology, College of Agriculture, Hainan University, Haikou, Hainan 570228, China
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
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26
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Ueland PM, McCann A, Midttun Ø, Ulvik A. Inflammation, vitamin B6 and related pathways. Mol Aspects Med 2016; 53:10-27. [PMID: 27593095 DOI: 10.1016/j.mam.2016.08.001] [Citation(s) in RCA: 199] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/27/2016] [Indexed: 12/11/2022]
Abstract
The active form of vitamin B6, pyridoxal 5'-phosphate (PLP), serves as a co-factor in more than 150 enzymatic reactions. Plasma PLP has consistently been shown to be low in inflammatory conditions; there is a parallel reduction in liver PLP, but minor changes in erythrocyte and muscle PLP and in functional vitamin B6 biomarkers. Plasma PLP also predicts the risk of chronic diseases like cardiovascular disease and some cancers, and is inversely associated with numerous inflammatory markers in clinical and population-based studies. Vitamin B6 intake and supplementation improve some immune functions in vitamin B6-deficient humans and experimental animals. A possible mechanism involved is mobilization of vitamin B6 to the sites of inflammation where it may serve as a co-factor in pathways producing metabolites with immunomodulating effects. Relevant vitamin B6-dependent inflammatory pathways include vitamin B6 catabolism, the kynurenine pathway, sphingosine 1-phosphate metabolism, the transsulfuration pathway, and serine and glycine metabolism.
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Affiliation(s)
- Per Magne Ueland
- Department of Clinical Science, University of Bergen, 5021 Bergen, Norway; Laboratory of Clinical Biochemistry, Haukeland University Hospital, 5021 Bergen, Norway.
| | | | | | - Arve Ulvik
- Bevital A/S, Laboratoriebygget, 5021 Bergen, Norway
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27
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Badawy AAB, Dougherty DM. Assessment of the Human Kynurenine Pathway: Comparisons and Clinical Implications of Ethnic and Gender Differences in Plasma Tryptophan, Kynurenine Metabolites, and Enzyme Expressions at Baseline and After Acute Tryptophan Loading and Depletion. Int J Tryptophan Res 2016; 9:31-49. [PMID: 27547036 PMCID: PMC4981220 DOI: 10.4137/ijtr.s38189] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/17/2016] [Accepted: 07/19/2016] [Indexed: 12/24/2022] Open
Abstract
Tryptophan (Trp) metabolism via the kynurenine pathway (KP) was assessed in normal healthy US volunteers at baseline and after acute Trp depletion (ATD) and acute Trp loading (ATL) using amino acid formulations. The hepatic KP accounts for ~90% of overall Trp degradation. Liver Trp 2,3-dioxygenase (TDO) contributes ~70% toward Trp oxidation, with the remainder achieved by subsequent rate-limiting enzymes in the KP. TDO is not influenced by a 1.15 g Trp load, but is maximally activated by a 5.15 g dose. We recommend a 30 mg/kg dose for future ATL studies. ATD activates TDO and enhances the Trp flux down the KP via its leucine component. Higher plasma free [Trp] and lower total [Trp] are observed in women, with no gender differences in kynurenines. Kynurenic acid is lower in female Caucasians, which may explain their lower incidence of schizophrenia. African-American and Hispanic women have a lower TDO and Trp oxidation relative to free Trp than the corresponding men. African-American women have a potentially higher 3-hydroxyanthranilic acid/anthranilic acid ratio, which may protect them against osteoporosis. Future studies of the KP in relation to health and disease should focus on gender and ethnic differences.
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Affiliation(s)
- Abdulla A-B Badawy
- School of Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - Donald M Dougherty
- Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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28
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Kynurenine Aminotransferase Isozyme Inhibitors: A Review. Int J Mol Sci 2016; 17:ijms17060946. [PMID: 27314340 PMCID: PMC4926479 DOI: 10.3390/ijms17060946] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 12/22/2022] Open
Abstract
Kynurenine aminotransferase isozymes (KATs 1–4) are members of the pyridoxal-5’-phosphate (PLP)-dependent enzyme family, which catalyse the permanent conversion of l-kynurenine (l-KYN) to kynurenic acid (KYNA), a known neuroactive agent. As KATs are found in the mammalian brain and have key roles in the kynurenine pathway, involved in different categories of central nervous system (CNS) diseases, the KATs are prominent targets in the quest to treat neurodegenerative and cognitive impairment disorders. Recent studies suggest that inhibiting these enzymes would produce effects beneficial to patients with these conditions, as abnormally high levels of KYNA are observed. KAT-1 and KAT-3 share the highest sequence similarity of the isozymes in this family, and their active site pockets are also similar. Importantly, KAT-2 has the major role of kynurenic acid production (70%) in the human brain, and it is considered therefore that suitable inhibition of this isozyme would be most effective in managing major aspects of CNS diseases. Human KAT-2 inhibitors have been developed, but the most potent of them, chosen for further investigations, did not proceed in clinical studies due to the cross toxicity caused by their irreversible interaction with PLP, the required cofactor of the KAT isozymes, and any other PLP-dependent enzymes. As a consequence of the possibility of extensive undesirable adverse effects, it is also important to pursue KAT inhibitors that reversibly inhibit KATs and to include a strategy that seeks compounds likely to achieve substantial interaction with regions of the active site other than the PLP. The main purpose of this treatise is to review the recent developments with the inhibitors of KAT isozymes. This treatise also includes analyses of their crystallographic structures in complex with this enzyme family, which provides further insight for researchers in this and related studies.
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29
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Pinto JT, Krasnikov BF, Alcutt S, Jones ME, Dorai T, Villar MT, Artigues A, Li J, Cooper AJL. Kynurenine aminotransferase III and glutamine transaminase L are identical enzymes that have cysteine S-conjugate β-lyase activity and can transaminate L-selenomethionine. J Biol Chem 2014; 289:30950-61. [PMID: 25231977 DOI: 10.1074/jbc.m114.591461] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Three of the four kynurenine aminotransferases (KAT I, II, and IV) that synthesize kynurenic acid, a neuromodulator, are identical to glutamine transaminase K (GTK), α-aminoadipate aminotransferase, and mitochondrial aspartate aminotransferase, respectively. GTK/KAT I and aspartate aminotransferase/KAT IV possess cysteine S-conjugate β-lyase activity. The gene for the former enzyme, GTK/KAT I, is listed in mammalian genome data banks as CCBL1 (cysteine conjugate beta-lyase 1). Also listed, despite the fact that no β-lyase activity has been assigned to the encoded protein in the genome data bank, is a CCBL2 (synonym KAT III). We show that human KAT III/CCBL2 possesses cysteine S-conjugate β-lyase activity, as does mouse KAT II. Thus, depending on the nature of the substrate, all four KATs possess cysteine S-conjugate β-lyase activity. These present studies show that KAT III and glutamine transaminase L are identical enzymes. This report also shows that KAT I, II, and III differ in their ability to transaminate methyl-L-selenocysteine (MSC) and L-selenomethionine (SM) to β-methylselenopyruvate (MSP) and α-ketomethylselenobutyrate, respectively. Previous studies have identified these seleno-α-keto acids as potent histone deacetylase inhibitors. Methylselenol (CH3SeH), also purported to have chemopreventive properties, is the γ-elimination product of SM and the β-elimination product of MSC catalyzed by cystathionine γ-lyase (γ-cystathionase). KAT I, II, and III, in part, can catalyze β-elimination reactions with MSC generating CH3SeH. Thus, the anticancer efficacy of MSC and SM will depend, in part, on the endogenous expression of various KAT enzymes and cystathionine γ-lyase present in target tissue coupled with the ability of cells to synthesize in situ either CH3SeH and/or seleno-keto acid metabolites.
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Affiliation(s)
- John T Pinto
- From the Departments of Biochemistry and Molecular Biology and
| | | | - Steven Alcutt
- From the Departments of Biochemistry and Molecular Biology and
| | - Melanie E Jones
- From the Departments of Biochemistry and Molecular Biology and
| | - Thambi Dorai
- Urology, New York Medical College, Valhalla, New York 10595
| | - Maria T Villar
- the Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, and
| | - Antonio Artigues
- the Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, and
| | - Jianyong Li
- the Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061
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30
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Buturak B, Durdagi S, Noskov SY, Ildeniz ATO. Designing of multi-targeted molecules using combination of molecular screening and in silico drug cardiotoxicity prediction approaches. J Mol Graph Model 2014; 50:16-34. [PMID: 24699019 DOI: 10.1016/j.jmgm.2014.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/03/2014] [Accepted: 02/11/2014] [Indexed: 01/25/2023]
Abstract
We have previously investigated and reported a set of phenol- and indole-based derivatives at the binding pockets of carbonic anhydrase isoenzymes using in silico and in vitro analyses. In this study, we extended our analysis to explore multi-targeted molecules from this set of compounds. Thus, 26 ligands are screened at the binding sites of 229 proteins from 5 main enzyme family classes using molecular docking algorithms. Derived docking scores are compared with reported results of ligands at carbonic anhydrase I and II isoenzymes. Results showed potency of multi-targeted drugs of a few compounds from investigated ligand set. These promising ligands are then tested in silico for their cardiotoxicity risks. Results of this work can be used to improve the desired effects of these compounds by molecular engineering studies. In addition these results may lead to further investigation of studied molecules by medicinal chemists to explore different therapeutic aims.
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Affiliation(s)
- Birce Buturak
- Computational Biology and Bioinformatics, Graduate School of Science and Engineering, Kadir Has University, Istanbul, Turkey
| | - Serdar Durdagi
- Department of Biophysics, School of Medicine, Bahcesehir University, Istanbul, Turkey
| | - Sergei Y Noskov
- Institute for Biocomplexity and Informatics, University of Calgary, Calgary, AB, Canada.
| | - A Tugba Ozal Ildeniz
- Computational Biology and Bioinformatics, Graduate School of Science and Engineering, Kadir Has University, Istanbul, Turkey; Department of Bioinformatics and Genetics, Kadir Has University, Istanbul, Turkey.
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31
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Lee M, Sousa MC. Structural basis for substrate specificity in ArnB. A key enzyme in the polymyxin resistance pathway of Gram-negative bacteria. Biochemistry 2014; 53:796-805. [PMID: 24460375 PMCID: PMC3985747 DOI: 10.1021/bi4015677] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
![]()
Cationic Antimicrobial Peptides (CAMPs)
represent a first line
of defense against bacterial colonization. When fighting Gram-negative
bacteria, CAMPs initially interact electrostatically with the negatively
charged phosphate groups in lipid A and are thought to kill bacteria
by disrupting their membrane integrity. However, many human pathogens,
including Salmonella and Pseudomonas, have evolved lipid A modification mechanisms
that result in resistance to CAMPs and related antibiotics such as
Colistin. The addition of 4-amino-4-deoxy-l-Arabinose (Ara4N)
to a phosphate group in lipid A is one such modification, frequently
found in Pseudomonas isolated from
cystic fibrosis patients. The pathway for biosynthesis of Ara4N-lipid
A requires conversion of UDP-Glucuronic acid into UDP-Ara4N and subsequent
transfer of the amino-sugar to lipid A. ArnB is a pyridoxal-phosphate
(PLP) dependent transaminase that catalyzes a crucial step in the
pathway: synthesis of UDP-Ara4N from UDP-4-keto-pentose. Here we present
the 2.3 Å resolution crystal structure of an active site mutant
of ArnB (K188A) in complex with the reaction intermediate aldimine
formed by UDP-Ara4N and PLP. The sugar–nucleotide binding site
is in a cleft between the subunits of the ArnB dimer with the uracil
buried at the interface and the UDP ribose and phosphate groups exposed
to the solvent. The Ara4N moiety is found in the 4C1 conformation and its positioning, stabilized by interactions
with both the protein and cofactor, is compatible with catalysis.
The structure suggests strategies for the development of specific
inhibitors that may prove useful in the treatment of resistant bacteria
such as Pseudomonas found in cystic
fibrosis patients.
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Affiliation(s)
- Myeongseon Lee
- Department of Chemistry and Biochemistry, University of Colorado at Boulder , Boulder, Colorado 80309-0596, United States
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32
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Mani S, Boelsterli UA, Redinbo MR. Understanding and modulating mammalian-microbial communication for improved human health. Annu Rev Pharmacol Toxicol 2013; 3. [PMID: 27942535 PMCID: PMC5145265 DOI: 10.11131/2016/101199] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The molecular basis for the regulation of the intestinal barrier is a very fertile research area. A growing body of knowledge supports the targeting of various components of intestinal barrier function as means to treat a variety of diseases, including the inflammatory bowel diseases. Herein, we will summarize the current state of knowledge of key xenobiotic receptor regulators of barrier function, highlighting recent advances, such that the field and its future are succinctly reviewed. We posit that these receptors confer an additional dimension of host-microbe interaction in the gut, by sensing and responding to metabolites released from the symbiotic microbiota, in innate immunity and also in host drug metabolism. The scientific evidence for involvement of the receptors and its molecular basis for the control of barrier function and innate immunity regulation would serve as a rationale towards development of non-toxic probes and ligands as drugs.
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Affiliation(s)
- Sridhar Mani
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, New York 10461
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33
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XU YU, ZHENG QINGCHUAN, ZHANG HONGXING, SUN CHIACHUNG. HOMOLOGY MODELING AND SUBSTRATE BINDING STUDY OF HUMAN KYNURENINE AMINOTRANSFERASE III. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2012. [DOI: 10.1142/s0219633612500587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Kynurenine aminotransferase III (KAT III) is a novel member of the kynurenine aminotransferase enzyme family. Its active site topology and structure characteristics have not been established. In this study, with extensive computational simulations, including homology modeling and molecular dynamics simulations, a 3D structure model of human KAT III dimer was created and refined. Furthermore, CDOCKER approach was employed to dock two ligands (L-methionine and L-tryptophan) into the active sites of human KAT III dimer and uncover the ligand-binding modes. The complexes were subjected to 5 ns MD simulation, and the results indicate that TYR119 and TRP13 might be the key residues as they have the large contributions to the binding affinity, which is in good agreement with the experimental results. Moreover, another two residues (ASP120 and TYR57) are also found that their strong interactions stabilize the whole system. The structural and biochemical insights obtained from the present study will be helpful for designing the specific inhibitors of human KAT III.
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Affiliation(s)
- YU XU
- State key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, P. R. China
| | - QING-CHUAN ZHENG
- State key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, P. R. China
| | - HONG-XING ZHANG
- State key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, P. R. China
| | - CHIA-CHUNG SUN
- State key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, P. R. China
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Mechanism of cysteine-dependent inactivation of aspartate/glutamate/cysteine sulfinic acid α-decarboxylases. Amino Acids 2012; 44:391-404. [DOI: 10.1007/s00726-012-1342-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 06/05/2012] [Indexed: 02/04/2023]
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35
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Biochemical and structural characterization of mouse mitochondrial aspartate aminotransferase, a newly identified kynurenine aminotransferase-IV. Biosci Rep 2012; 31:323-32. [PMID: 20977429 DOI: 10.1042/bsr20100117] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Mammalian mAspAT (mitochondrial aspartate aminotransferase) is recently reported to have KAT (kynurenine aminotransferase) activity and plays a role in the biosynthesis of KYNA (kynurenic acid) in rat, mouse and human brains. This study concerns the biochemical and structural characterization of mouse mAspAT. In this study, mouse mAspAT cDNA was amplified from mouse brain first stand cDNA and its recombinant protein was expressed in an Escherichia coli expression system. Sixteen oxo acids were tested for the co-substrate specificity of mouse mAspAT and 14 of them were shown to be capable of serving as co-substrates for the enzyme. Structural analysis of mAspAT by macromolecular crystallography revealed that the cofactor-binding residues of mAspAT are similar to those of other KATs. The substrate-binding residues of mAspAT are slightly different from those of other KATs. Our results provide a biochemical and structural basis towards understanding the overall physiological role of mAspAT in vivo and insight into controlling the levels of endogenous KYNA through modulation of the enzyme in the mouse brain.
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Design and synthesis of novel inhibitors of human kynurenine aminotransferase-I. Bioorg Med Chem Lett 2012; 22:1579-81. [DOI: 10.1016/j.bmcl.2011.12.138] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 12/28/2011] [Accepted: 12/29/2011] [Indexed: 11/23/2022]
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He W, Brumos J, Li H, Ji Y, Ke M, Gong X, Zeng Q, Li W, Zhang X, An F, Wen X, Li P, Chu J, Sun X, Yan C, Yan N, Xie DY, Raikhel N, Yang Z, Stepanova AN, Alonso JM, Guo H. A small-molecule screen identifies L-kynurenine as a competitive inhibitor of TAA1/TAR activity in ethylene-directed auxin biosynthesis and root growth in Arabidopsis. THE PLANT CELL 2011; 23:3944-60. [PMID: 22108404 PMCID: PMC3246337 DOI: 10.1105/tpc.111.089029] [Citation(s) in RCA: 265] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 10/08/2011] [Accepted: 10/26/2011] [Indexed: 05/18/2023]
Abstract
The interactions between phytohormones are crucial for plants to adapt to complex environmental changes. One example is the ethylene-regulated local auxin biosynthesis in roots, which partly contributes to ethylene-directed root development and gravitropism. Using a chemical biology approach, we identified a small molecule, l-kynurenine (Kyn), which effectively inhibited ethylene responses in Arabidopsis thaliana root tissues. Kyn application repressed nuclear accumulation of the ETHYLENE INSENSITIVE3 (EIN3) transcription factor. Moreover, Kyn application decreased ethylene-induced auxin biosynthesis in roots, and TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1/TRYPTOPHAN AMINOTRANSFERASE RELATEDs (TAA1/TARs), the key enzymes in the indole-3-pyruvic acid pathway of auxin biosynthesis, were identified as the molecular targets of Kyn. Further biochemical and phenotypic analyses revealed that Kyn, being an alternate substrate, competitively inhibits TAA1/TAR activity, and Kyn treatment mimicked the loss of TAA1/TAR functions. Molecular modeling and sequence alignments suggested that Kyn effectively and selectively binds to the substrate pocket of TAA1/TAR proteins but not those of other families of aminotransferases. To elucidate the destabilizing effect of Kyn on EIN3, we further found that auxin enhanced EIN3 nuclear accumulation in an EIN3 BINDING F-BOX PROTEIN1 (EBF1)/EBF2-dependent manner, suggesting the existence of a positive feedback loop between auxin biosynthesis and ethylene signaling. Thus, our study not only reveals a new level of interactions between ethylene and auxin pathways but also offers an efficient method to explore and exploit TAA1/TAR-dependent auxin biosynthesis.
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Affiliation(s)
- Wenrong He
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Javier Brumos
- Department of Genetics, North Carolina State University, Raleigh, North Carolina 27695
| | - Hongjiang Li
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
- Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, California 92507
| | - Yusi Ji
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Meng Ke
- Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xinqi Gong
- Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qinglong Zeng
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Wenyang Li
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Xinyan Zhang
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Fengying An
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Xing Wen
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Pengpeng Li
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Jinfang Chu
- National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaohong Sun
- National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Cunyu Yan
- National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Nieng Yan
- Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - De-Yu Xie
- Department of Plant Biology, North Carolina State University, Raleigh, North Carolina 27695
| | - Natasha Raikhel
- Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, California 92507
| | - Zhenbiao Yang
- Center for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, California 92507
| | - Anna N. Stepanova
- Department of Genetics, North Carolina State University, Raleigh, North Carolina 27695
| | - Jose M. Alonso
- Department of Genetics, North Carolina State University, Raleigh, North Carolina 27695
| | - Hongwei Guo
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
- Address correspondence to
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Abstract
Alzheimer’s disease (AD) is one of the major causes of dementia. The pathogenesis of the disease is not entirely understood, but the amyloid β peptide (Aβ) and the formation of senile plaques seem to play pivotal roles. Oligomerization of the Aβ is thought to trigger a cascade of events, including oxidative stress, glutamate excitotoxicity and inflammation. The kynurenine (KYN) pathway is the major route for the metabolism of the essential amino acid tryptophan. Some of the metabolites of this pathway, such as 3-hydroxykynurenine and quinolinic acid, are known to have neurotoxic properties, whereas others, such as kynurenic acid, are putative neuroprotectants. Among other routes, the KYN pathway has been shown to be involved in AD pathogenesis, and connections to other known mechanisms have also been demonstrated. Oxidative stress, glutamate excitotoxicity and the neuroinflammation involved in AD pathogenesis have been revealed to be connected to the KYN pathway. Intervention at these key steps may serve as the aim of potential therapy.
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Affiliation(s)
- Zsigmond Tamas Kincses
- Department of Neurology, Albert Szent-Györgyi Clinical Center, University of Szeged, Hungary
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Ferro N, Bredow T, Jacobsen HJ, Reinard T. Route to Novel Auxin: Auxin Chemical Space toward Biological Correlation Carriers. Chem Rev 2010; 110:4690-708. [DOI: 10.1021/cr800229s] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Noel Ferro
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegeler Strasse 12, Bonn, Germany 53115 and Institute for Plant Genetics, Leibniz University of Hannover, Germany
| | - Thomas Bredow
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegeler Strasse 12, Bonn, Germany 53115 and Institute for Plant Genetics, Leibniz University of Hannover, Germany
| | - Hans-Jorg Jacobsen
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegeler Strasse 12, Bonn, Germany 53115 and Institute for Plant Genetics, Leibniz University of Hannover, Germany
| | - Thomas Reinard
- Institute of Physical and Theoretical Chemistry, University of Bonn, Wegeler Strasse 12, Bonn, Germany 53115 and Institute for Plant Genetics, Leibniz University of Hannover, Germany
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Han Q, Cai T, Tagle DA, Li J. Thermal stability, pH dependence and inhibition of four murine kynurenine aminotransferases. BMC BIOCHEMISTRY 2010; 11:19. [PMID: 20482848 PMCID: PMC2890522 DOI: 10.1186/1471-2091-11-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 05/19/2010] [Indexed: 11/10/2022]
Abstract
BACKGROUND Kynurenine aminotransferase (KAT) catalyzes the transamination of kynunrenine to kynurenic acid (KYNA). KYNA is a neuroactive compound and functions as an antagonist of alpha7-nicotinic acetylcholine receptors and is the only known endogenous antagonist of N-methyl-D-aspartate receptors. Four KAT enzymes, KAT I/glutamine transaminase K/cysteine conjugate beta-lyase 1, KAT II/aminoadipate aminotransferase, KAT III/cysteine conjugate beta-lyase 2, and KAT IV/glutamic-oxaloacetic transaminase 2/mitochondrial aspartate aminotransferase, have been reported in mammalian brains. Because of the substrate overlap of the four KAT enzymes, it is difficult to assay the specific activity of each KAT in animal brains. RESULTS This study concerns the functional expression and comparative characterization of KAT I, II, III, and IV from mice. At the applied test conditions, equimolar tryptophan with kynurenine significantly inhibited only mouse KAT I and IV, equimolar methionine inhibited only mouse KAT III and equimolar aspartate inhibited only mouse KAT IV. The activity of mouse KAT II was not significantly inhibited by any proteinogenic amino acids at equimolar concentrations. pH optima, temperature preferences of four KATs were also tested in this study. Midpoint temperatures of the protein melting, half life values at 65 degrees C, and pKa values of mouse KAT I, II, III, and IV were 69.8, 65.9, 64.8 and 66.5 degrees C; 69.7, 27.4, 3.9 and 6.5 min; pH 7.6, 5.7, 8.7 and 6.9, respectively. CONCLUSION The characteristics reported here could be used to develop specific assay methods for each of the four murine KATs. These specific assays could be used to identify which KAT is affected in mouse models for research and to develop small molecule drugs for prevention and treatment of KAT-involved human diseases.
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Affiliation(s)
- Qian Han
- Department of Biochemistry, Virginia Tech, Blacksburg, 24061, USA
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Han Q, Cai T, Tagle DA, Li J. Structure, expression, and function of kynurenine aminotransferases in human and rodent brains. Cell Mol Life Sci 2010; 67:353-68. [PMID: 19826765 PMCID: PMC2867614 DOI: 10.1007/s00018-009-0166-4] [Citation(s) in RCA: 170] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 09/27/2009] [Accepted: 09/29/2009] [Indexed: 01/12/2023]
Abstract
Kynurenine aminotransferases (KATs) catalyze the synthesis of kynurenic acid (KYNA), an endogenous antagonist of N-methyl-D: -aspartate and alpha 7-nicotinic acetylcholine receptors. Abnormal KYNA levels in human brains are implicated in the pathophysiology of schizophrenia, Alzheimer's disease, and other neurological disorders. Four KATs have been reported in mammalian brains, KAT I/glutamine transaminase K/cysteine conjugate beta-lyase 1, KAT II/aminoadipate aminotransferase, KAT III/cysteine conjugate beta-lyase 2, and KAT IV/glutamic-oxaloacetic transaminase 2/mitochondrial aspartate aminotransferase. KAT II has a striking tertiary structure in N-terminal part and forms a new subgroup in fold type I aminotransferases, which has been classified as subgroup Iepsilon. Knowledge regarding KATs is vast and complex; therefore, this review is focused on recent important progress of their gene characterization, physiological and biochemical function, and structural properties. The biochemical differences of four KATs, specific enzyme activity assays, and the structural insights into the mechanism of catalysis and inhibition of these enzymes are discussed.
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Affiliation(s)
- Qian Han
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061 USA
| | - Tao Cai
- OIIB, NIDCR, National Institutes of Health, Bethesda MD, 20892-4322 USA
| | - Danilo A. Tagle
- Neuroscience Center, NINDS, National Institutes of Health, Bethesda, MD 2089-29525 USA
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061 USA
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Quantum mechanics/molecular mechanics (QM/MM) modeling of the irreversible transamination of l-kynurenine to kynurenic acid: The round dance of kynurenine aminotransferase II. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:1802-12. [DOI: 10.1016/j.bbapap.2009.08.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 08/12/2009] [Accepted: 08/18/2009] [Indexed: 11/21/2022]
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