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Song W, Maris A, Cummings CN, Evangelisti L, Walker NR, Melandri S. The Challenging Conformational Landscape of Cysteamine···H 2O Revealed by the Strong Interplay of Rotational Spectroscopy and Quantum Chemical Calculations. J Phys Chem Lett 2024; 15:10054-10061. [PMID: 39324948 DOI: 10.1021/acs.jpclett.4c02353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2024]
Abstract
A 1:1 molecular complex of cysteamine with water is shown to adopt a cage-like structure where cysteamine accepts a relatively strong hydrogen bond from water while also engaging in two additional weaker interactions (SH···Ow and CH···Ow). Experimental and theoretical approaches confirm this conformer as the global minimum on the potential energy surface. Fitting of key structural parameters to experimentally determined moments of inertia yields consistent and accurate results for rotational and 14N nuclear quadrupole coupling constants which are shown to be challenging to calculate using ab initio methods. Comprehensive analysis of the intermolecular interactions and a thorough comparison with the properties of aminoethanol-water is presented, utilizing independent gradient models based on Hirshfeld partition, quantum theory of atoms-in-molecules, and symmetry-adapted perturbation theory approaches. As expected, the OH group of aminoethanol is a stronger hydrogen bond donor than the SH group in cysteamine, while the CH···Ow interaction is a key determining factor of the conformational landscape in both cysteamine-water and aminoethanol-water complexes. The results show very clearly that the synergy between theoretical calculations and experimental results is not only desirable but mandatory to get the right answers in such complex conformational surfaces. The results are also clear benchmarks for the accuracy of different theoretical methods in assessing the structures and energy order of the conformations.
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Affiliation(s)
- Wentao Song
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126, Bologna, Italy
| | - Assimo Maris
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126, Bologna, Italy
| | - Charlotte N Cummings
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle-upon-Tyne, NE1 7RU, U.K
| | - Luca Evangelisti
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126, Bologna, Italy
| | - Nicholas R Walker
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle-upon-Tyne, NE1 7RU, U.K
| | - Sonia Melandri
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via F. Selmi 2, 40126, Bologna, Italy
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2
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Spathopoulou A, Edenhofer F, Fellner L. Targeting α-Synuclein in Parkinson's Disease by Induced Pluripotent Stem Cell Models. Front Neurol 2022; 12:786835. [PMID: 35145469 PMCID: PMC8821105 DOI: 10.3389/fneur.2021.786835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/24/2021] [Indexed: 11/22/2022] Open
Abstract
Parkinson's disease (PD) is a progressive, neurodegenerative disorder characterized by motor and non-motor symptoms. To date, no specific treatment to halt disease progression is available, only medication to alleviate symptoms can be prescribed. The main pathological hallmark of PD is the development of neuronal inclusions, positive for α-synuclein (α-syn), which are termed Lewy bodies (LBs) or Lewy neurites. However, the cause of the inclusion formation and the loss of neurons remain largely elusive. Various genetic determinants were reported to be involved in PD etiology, including SNCA, DJ-1, PRKN, PINK1, LRRK2, and GBA. Comprehensive insights into pathophysiology of PD critically depend on appropriate models. However, conventional model organisms fall short to faithfully recapitulate some features of this complex disease and as a matter-of-fact access to physiological tissue is limiting. The development of disease models replicating PD that are close to human physiology and dynamic enough to analyze the underlying molecular mechanisms of disease initiation and progression, as well as the generation of new treatment options, is an important and overdue step. Recently, the establishment of induced pluripotent stem cell (iPSC)-derived neural models, particularly from genetic PD-variants, developed into a promising strategy to investigate the molecular mechanisms regarding formation of inclusions and neurodegeneration. As these iPSC-derived neurons can be generated from accessible biopsied samples of PD patients, they carry pathological alterations and enable the possibility to analyze the differences compared to healthy neurons. This review focuses on iPSC models carrying genetic PD-variants of α-syn that will be especially helpful in elucidating the pathophysiological mechanisms of PD. Furthermore, we discuss how iPSC models can be instrumental in identifying cellular targets, potentially leading to the development of new therapeutic treatments. We will outline the enormous potential, but also discuss the limitations of iPSC-based α-syn models.
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3
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Cicchetti F, David L, Siddu A, Denis H. Cysteamine as a novel disease-modifying compound for Parkinson's disease: Over a decade of research supporting a clinical trial. Neurobiol Dis 2019; 130:104530. [DOI: 10.1016/j.nbd.2019.104530] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/04/2019] [Accepted: 07/09/2019] [Indexed: 10/26/2022] Open
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4
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Zhou Z, Jia RX, Zhang G, Wan Y, Zhang Y, Fan Y, Wang Z, Huang P, Wang F. Using cysteine/cystine to overcome oxidative stress in goat oocytes and embryos cultured in vitro. Mol Med Rep 2016; 14:1219-26. [PMID: 27315595 DOI: 10.3892/mmr.2016.5395] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 02/19/2016] [Indexed: 11/06/2022] Open
Abstract
Assisted reproductive techniques expose gametes to excessive concentrations of reactive oxygen species. The present study aimed to evaluate the effects of oxidative stress on apoptosis in goat oocytes and embryonic development. The results demonstrated that the addition of 100 µM hydrogen peroxide (H2O2) into media produces an oxidative environment during oocyte maturation. The number of cumulus cells positive for terminal deoxynucleotidyl transferase UTP nick end labeling, and the activity of caspase 3 in mature oocytes were increased, compared with the control group (P<0.05). In addition, the expression levels of mitochondrial regulators, including peroxisome proliferator‑activated receptor γ coactivator-1 α (PGC-1α) and nuclear respiratory factor‑1 (NRF‑1) were increased in the oxidative oocytes, compared with those in the control group (P<0.05). The ratio of the proapoptotic gene, B cell lymphoma (Bcl-2)-associated X protein (BAX), to the anti‑apoptotic gene, BCL‑2, was higher in the H2O2 group, compared with the control group (P<0.05). To overcome oxidative stress in oocytes and embryos cultured in vitro, 200 µM cysteine and 200 µM cystine were added to the media, thereby increasing the concentration of intracellular glutathione (GSH) and assisting in maintaining the redox state of the cells. In conclusion, cysteine and cystine reduced the oxygen tension caused by H2O2, thereby providing a novel strategy for optimizing in vitro embryonic development systems.
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Affiliation(s)
- Zhengrong Zhou
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
| | - Ruo-Xin Jia
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
| | - Guomin Zhang
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
| | - Yongjie Wan
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
| | - Yanli Zhang
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
| | - Yixuan Fan
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
| | - Ziyu Wang
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
| | - Pan Huang
- Department of Histology and Embryology, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, P.R. China
| | - Feng Wang
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
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5
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Abstract
Pantetheinase is an ubiquitous enzyme which hydrolyses D-pantetheine into cysteamine and pantothenate (vitamin B5) on the dissimilative pathway of CoA. Pantetheinase isoforms are encoded by the Vnn (vanin) genes and Vnn1 is the predominant tissue isoform in mice and humans. In the present article, we review the results showing the regulation of Vnn1 expression during developmental, repair and inflammatory situations and the impact of a Vnn1 deficiency in mouse models of pathologies. We document the involvement of the Vnn1 pantetheinase in situations of increased tissue needs and propose that Vnn1 through recycling of pantothenate and release of cysteamine in tissues participates in the adaptive response of the tissue to stress.
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6
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Hallen A, Jamie JF, Cooper AJL. Imine reductases: a comparison of glutamate dehydrogenase to ketimine reductases in the brain. Neurochem Res 2013; 39:527-41. [PMID: 23314864 DOI: 10.1007/s11064-012-0964-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/12/2012] [Accepted: 12/22/2012] [Indexed: 02/06/2023]
Abstract
A key intermediate in the glutamate dehydrogenase (GDH)-catalyzed reaction is an imine. Mechanistically, therefore, GDH exhibits similarities to the ketimine reductases. In the current review, we briefly discuss (a) the metabolic importance of the GDH reaction in liver and brain, (b) the mechanistic similarities between GDH and the ketimine reductases, (c) the metabolic importance of the brain ketimine reductases, and (d) the neurochemical consequences of defective ketimine reductases. Our review contains many historical references to the early work on amino acid metabolism. This work tends to be overlooked nowadays, but is crucial for a contemporary understanding of the central importance of ketimines in nitrogen and intermediary metabolism. The ketimine reductases are important enzymes linking nitrogen flow among several key amino acids, yet have been little studied. The cerebral importance of the ketimine reductases is an area of biomedical research that deserves far more attention.
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Affiliation(s)
- André Hallen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Balaclava Road, North Ryde, NSW, 2109, Australia,
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7
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Tsikas D, Evans CE, Denton TT, Mitschke A, Gutzki FM, Pinto JT, Khomenko T, Szabo S, Cooper AJL. Stable isotope gas chromatography-tandem mass spectrometry determination of aminoethylcysteine ketimine decarboxylated dimer in biological samples. Anal Biochem 2012; 430:4-15. [PMID: 22858756 DOI: 10.1016/j.ab.2012.07.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 07/20/2012] [Accepted: 07/23/2012] [Indexed: 01/04/2023]
Abstract
Aminoethylcysteine ketimine decarboxylated dimer (AECK-DD; systematic name: 1,2-3,4-5,6-7,8-octahydro-1,8a-diaza-4,6-dithiafluoren-9(8aH)-one) is a previously described metabolite of cysteamine that has been reported to be present in mammalian brain, urine, plasma, and cells in culture and vegetables and to possess potent antioxidative properties. Here, we describe a stable isotope gas chromatography-tandem mass spectrometry (GC-MS/MS) method for specific and sensitive determination of AECK-DD in biological samples. (13)C(2)-labeled AECK-DD was synthesized and used as the internal standard. Derivatization was carried out by N-pentafluorobenzylation with pentafluorobenzyl bromide in acetonitrile. Quantification was performed by selected reaction monitoring of the mass transitions m/z 328 to 268 for AECK-DD and m/z 330 to 270 for [(13)C(2)]AECK-DD in the electron capture negative ion chemical ionization mode. The procedure was systematically validated for human plasma and urine samples. AECK-DD was not detectable in human plasma above approximately 4nM but was present in urine samples of healthy humans at a maximal concentration of 46nM. AECK-DD was detectable in rat brain at very low levels of approximately 8pmol/g wet weight. Higher levels of AECK-DD were detected in mouse brain (∼1nmol/g wet weight). Among nine dietary vegetables evaluated, only shallots were found to contain trace amounts of AECK-DD (∼6.8pmol/g fresh tissue).
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Affiliation(s)
- Dimitrios Tsikas
- Institute of Clinical Pharmacology, Hannover Medical School, Hannover, Germany.
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8
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Gibrat C, Cicchetti F. Potential of cystamine and cysteamine in the treatment of neurodegenerative diseases. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:380-9. [PMID: 21111020 DOI: 10.1016/j.pnpbp.2010.11.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 11/10/2010] [Accepted: 11/17/2010] [Indexed: 01/08/2023]
Abstract
Neurodegenerative disorders are a subset of disabling pathologies characterized, in part, by a progressive and specific loss of certain brain cell populations. Current therapeutic approaches for the treatment of these disorders are mainly designed towards symptom management and do not manifestly block their typified neuronal loss. However, research conducted over the past decade has reflected the increasing interest and need to find disease-modifying molecules. Among the several neuroprotective agents emerging from experimental animal work, cystamine, as well as its reduced form cysteamine, have been identified as potential candidate drugs. Given the significant benefits observed in a Huntington's disease (HD) model, cysteamine has recently leaped to clinical trial. Here, we review the beneficial properties of these compounds as reported in animal studies, their mechanistic underpinnings, and their potential implications for the future treatment of patients suffering from neurodegenerative diseases, and more specifically for HD and Parkinson's disease (PD).
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Affiliation(s)
- C Gibrat
- Centre de Recherche du CHUL (CHUQ), Axe Neurosciences, 2705 Boulevard Laurier, Québec, QC, Canada, G1V 4G2
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9
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Bousquet M, Gibrat C, Ouellet M, Rouillard C, Calon F, Cicchetti F. Cystamine metabolism and brain transport properties: clinical implications for neurodegenerative diseases. J Neurochem 2010; 114:1651-8. [PMID: 20569301 DOI: 10.1111/j.1471-4159.2010.06874.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Cystamine has shown significant neuroprotective properties in preclinical studies of Parkinson's disease (PD) and Huntington's disease (HD). Cysteamine, its FDA-approved reduced form, is scheduled to be tested for clinical efficacy in HD patients. Here, we studied the key cystamine metabolites, namely cysteamine, hypotaurine and taurine, as well as cysteine, in order to identify which one is more distinctively responsible for the neuroprotective action of cystamine. After a single administration of cystamine (10, 50 or 200 mg/kg), naïve mice were perfused with phosphate-buffered saline (PBS) at 1, 3, 12, 24 or 48 h post-injection and brain and plasma samples were analyzed by two distinct HPLC methods. Although plasma levels remained under the detection threshold, significant increases in cysteamine brain levels were detected with the 50 and 200 mg/kg doses in mice perfused 1 and 3 h following cystamine injection. To further assess cysteamine as the candidate molecule for pre-clinical and clinical trials in PD, we evaluated its capacity to cross the blood brain barrier. Using an in situ cerebral perfusion technique, we determined that the brain transport coefficient (Clup) of cysteamine (259 μM) was 0.15 ± 0.02 μL/g/s and was increased up to 0.34 ± 0.07 μL/g/s when co-perfused in the presence of cysteine. Taken together, these results strongly suggest that cysteamine is the neuroactive metabolite of cystamine and may further support its therapeutic use in neurodegenerative diseases, particularly in HD and PD.
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Affiliation(s)
- Mélanie Bousquet
- Centre de Recherche du CHUL (CHUQ), Axe Neurosciences, Québec, Québec, Canada
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10
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Pinto JT, Khomenko T, Szabo S, McLaren GD, Denton TT, Krasnikov BF, Jeitner TM, Cooper AJL. Measurement of sulfur-containing compounds involved in the metabolism and transport of cysteamine and cystamine. Regional differences in cerebral metabolism. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:3434-41. [PMID: 19523884 DOI: 10.1016/j.jchromb.2009.05.041] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 05/15/2009] [Accepted: 05/19/2009] [Indexed: 11/17/2022]
Abstract
An HPLC method with coulometric detection is presented for the quantitation of cysteamine, cystamine, thialysine, glutathione, glutathione disulfide and an oxidized metabolite of thialysine [S-(2-aminoethyl)-L-cysteine ketimine decarboxylated dimer (AECK-DD)]. The advantage of coulometric detection is that derivatization is unnecessary if the analyte is redox sensitive. The method was used to quantitate several sulfur-containing compounds in plasma and brain following gavage feeding of cysteamine to rats. Cysteamine, cystamine, thialysine and AECK-DD were detected in the brains of these animals. Interestingly, cysteamine treatment resulted in greatly elevated levels of cerebral methionine, despite the fact that cysteamine is not a precursor of methionine.
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Affiliation(s)
- John T Pinto
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
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11
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Baek JH, Liu YV, McDonald KR, Wesley JB, Hubbi ME, Byun H, Semenza GL. Spermidine/Spermine-N1-Acetyltransferase 2 Is an Essential Component of the Ubiquitin Ligase Complex That Regulates Hypoxia-inducible Factor 1α. J Biol Chem 2007; 282:23572-80. [PMID: 17558023 DOI: 10.1074/jbc.m703504200] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hypoxia-inducible factor 1 (HIF-1) is a heterodimeric transcription factor that functions as a master regulator of oxygen homeostasis. The HIF-1alpha subunit is subjected to O(2)-dependent prolyl hydroxylation leading to ubiquitination by the von Hippel-Lindau protein (VHL)-Elongin C ubiquitin-ligase complex and degradation by the 26 S proteasome. In this study, we demonstrate that spermidine/spermine-N(1)-acetyltransferase (SSAT) 2 plays an essential role in this process. SSAT2 binds to HIF-1alpha, VHL, and Elongin C and promotes ubiquitination of hydroxylated HIF-1alpha by stabilizing the interaction of VHL and Elongin C. Multivalent interactions by SSAT2 provide a mechanism to ensure efficient complex formation, which is necessary for the extremely rapid ubiquitination and degradation of HIF-1alpha that is observed in oxygenated cells.
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Affiliation(s)
- Jin Hyen Baek
- Vascular Biology Program, Institute for Cell Engineering, Department of Pediatrics, and McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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12
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Lüersen K. Leishmania major thialysine Nepsilon-acetyltransferase: identification of amino acid residues crucial for substrate binding. FEBS Lett 2005; 579:5347-52. [PMID: 16194533 DOI: 10.1016/j.febslet.2005.08.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Revised: 07/28/2005] [Accepted: 08/30/2005] [Indexed: 12/01/2022]
Abstract
Thialysine N(epsilon)-acetyltransferases and spermidine/spermine N-acetyltransferases (SSAT) are closely related members of the GCN5-related N-acetyltransferase superfamily. Accordingly, a putative orthologue from the human protozoan parasite Leishmania major exhibits an almost equal similarity to human SSAT and thialysine N(epsilon)-acetyltransferase. Characterisation of the recombinantly expressed L. major protein indicated that it represents a thialysine N(epsilon)-acetyltransferase, preferring thialysine (S-aminoethyl-l-cysteine) and structurally related amino acids as acceptor molecules. The known thialysine N(epsilon)-acetyltransferases contain five conserved amino acid residues that are replaced in SSAT sequences. Kinetic analyses of the respective recombinant mutant proteins suggest that Ser(82) and Thr(83) of L. major thialysine N(epsilon)-acetyltransferase are key residues for acceptor binding. In addition, the conserved Leu(130) is tentatively involved in specific interaction with the sulphur-containing side chain of thialysine. The presence of these three amino acid residues is suggested to be a means by which thialysine N(epsilon)-acetyltransferases can be distinguished from SSAT sequences.
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Affiliation(s)
- Kai Lüersen
- Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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13
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Coleman CS, Stanley BA, Jones AD, Pegg AE. Spermidine/spermine-N1-acetyltransferase-2 (SSAT2) acetylates thialysine and is not involved in polyamine metabolism. Biochem J 2005; 384:139-48. [PMID: 15283699 PMCID: PMC1134097 DOI: 10.1042/bj20040790] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Spermidine/spermine-N1-acetyltransferase (SSAT1) is a short-lived polyamine catabolic enzyme inducible by polyamines and polyamine analogues. Induction of SSAT1 plays an important role in polyamine homoeostasis, since the N1-acetylated polyamines can be excreted or oxidized by acetylpolyamine oxidase. We have purified a recombinant human acetyltransferase (SSAT2) that shares 45% identity and 61% homology with human SSAT1, but is only distally related to other known members of the GNAT (GCN5-related N-acetyltransferase) family. Like SSAT1, SSAT2 is widely expressed, but did not turn over rapidly, and levels were unaffected by treatments with polyamine analogues. Despite similarity in sequence to SSAT1, polyamines were found to be poor substrates of purified SSAT2, having K(m) values in the low millimolar range and kcat values of <0.01 s(-1). The kcat/K(m) values for spermine and spermidine for SSAT2 were <0.0003% those of SSAT1. Expression of SSAT2 in NIH-3T3 cells was not detrimental to growth, and did not reduce polyamine content or increase acetylpolyamines. These results indicate that SSAT2 is not a polyamine catabolic enzyme, and that polyamines are unlikely to be its natural intracellular substrates. A promising candidate for the physiological substrate of SSAT2 is thialysine [S-(2-aminoethyl)-L-cysteine], which is acetylated predominantly at the epsilon-amino group with K(m) and kcat values of 290 muM and 5.2 s(-1). Thialysine is a naturally occurring modified amino acid that can undergo metabolism to form cyclic ketimine derivatives found in the brain and as urinary metabolites, which can undergo further reaction to form antioxidants. SSAT2 should be renamed 'thialysine N(epsilon)-acetyltransferase', and may regulate this pathway.
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Affiliation(s)
- Catherine S Coleman
- Department of Cellular and Molecular Physiology, The Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, P.O. Box 850, Hershey, PA 17033, USA.
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14
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Abo-Dalo B, Ndjonka D, Pinnen F, Liebau E, Lüersen K. A novel member of the GCN5-related N-acetyltransferase superfamily from Caenorhabditis elegans preferentially catalyses the N-acetylation of thialysine [S-(2-aminoethyl)-L-cysteine]. Biochem J 2005; 384:129-37. [PMID: 15283700 PMCID: PMC1134096 DOI: 10.1042/bj20040789] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The putative diamine N-acetyltransferase D2023.4 has been cloned from the model nematode Caenorhabditis elegans. The 483 bp open reading frame of the cDNA encodes a deduced polypeptide of 18.6 kDa. Accordingly, the recombinantly expressed His6-tagged protein forms an enzymically active homodimer with a molecular mass of approx. 44000 Da. The protein belongs to the GNAT (GCN5-related N-acetyltransferase) superfamily, and its amino acid sequence exhibits considerable similarity to mammalian spermidine/spermine-N1-acetyltransferases. However, neither the polyamines spermidine and spermine nor the diamines putrescine and cadaverine were efficiently acetylated by the protein. The smaller diamines diaminopropane and ethylenediamine, as well as L-lysine, represent better substrates, but, surprisingly, the enzyme most efficiently catalyses the N-acetylation of amino acids analogous with L-lysine. As determined by the k(cat)/K(m) values, the C. elegans N-acetyltransferase prefers thialysine [S-(2-aminoethyl)-L-cysteine], followed by O-(2-aminoethyl)-L-serine and S-(2-aminoethyl)-D,L-homocysteine. Reversed-phase HPLC and mass spectrometric analyses revealed that N-acetylation of L-lysine and L-thialysine occurs exclusively at the amino moiety of the side chain. Remarkably, heterologous expression of C. elegans N-acetyltransferase D2023.4 in Escherichia coli, which does not possess a homologous gene, results in a pronounced resistance against the anti-metabolite thialysine. Furthermore, C. elegans N-acetyltransferase D2023.4 exhibits the highest homology with a number of GNATs found in numerous genomes from bacteria to mammals that have not been biochemically characterized so far, suggesting a novel group of GNAT enzymes closely related to spermidine/spermine-N1-acetyltransferase, but with a distinct substrate specificity. Taken together, we propose to name the enzyme 'thialysine N(epsilon)-acetyltransferase'.
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Affiliation(s)
- Benjamin Abo-Dalo
- *Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359 Hamburg, Germany
| | - Dieudonne Ndjonka
- *Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359 Hamburg, Germany
| | - Francesco Pinnen
- †Dipartimento di Scienze del Farmaco, Universita degli Studi G. D'Annunzio, Via dei Vestini, I-66100 Chieti, Italy
| | - Eva Liebau
- *Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359 Hamburg, Germany
| | - Kai Lüersen
- *Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359 Hamburg, Germany
- To whom correspondence should be addressed (email )
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15
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Cooper AJL. The role of glutamine transaminase K (GTK) in sulfur and alpha-keto acid metabolism in the brain, and in the possible bioactivation of neurotoxicants. Neurochem Int 2004; 44:557-77. [PMID: 15016471 DOI: 10.1016/j.neuint.2003.12.002] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Glutamine transaminase K (GTK), which is a freely reversible glutamine (methionine) aromatic amino acid aminotransferase, is present in most mammalian tissues, including brain. Quantitatively, the most important amine donor in vivo is glutamine. The product of glutamine transamination (i.e., alpha-ketoglutaramate; alphaKGM) is rapidly removed by cyclization and/or conversion to alpha-ketoglutarate. Transamination is therefore "pulled" in the direction of glutamine utilization. Major biological roles of GTK are to maintain low levels of phenylpyruvate and to close the methionine salvage pathway. GTK also catalyzes the transamination of cystathionine, lanthionine, and thialysine to the corresponding alpha-keto acids, which cyclize to ketimines. The cyclic ketimines and several metabolites derived therefrom are found in brain. It is not clear whether these compounds have a biological function or are metabolic dead-ends. However, high-affinity binding of lanthionine ketimine (LK) to brain membranes has been reported. Mammalian tissues possess several enzymes capable of catalyzing transamination of kynurenine in vitro. Two of these kynurenine aminotransferases (KATs), namely KAT I and KAT II, are present in brain and have been extensively studied. KAT I and KAT II are identical to GTK and alpha-aminoadipate aminotransferase, respectively. GTK/KAT I is largely cytosolic in kidney, but mostly mitochondrial in brain. The same gene codes for both forms, but alternative splicing dictates whether a 32-amino acid mitochondrial-targeting sequence is present in the expressed protein. The activity of KAT I is altered by a missense mutation (E61G) in the spontaneously hypertensive rat. The symptoms may be due in part to alteration of kynurenine transamination. However, owing to strong competition from other amino acid substrates, the turnover of kynurenine to kynurenate by GTK/KAT I in nervous tissue must be slow unless kynurenine and GTK are sequestered in a compartment distinct from the major amino acid pools. The possibility is discussed that the spontaneous hypertension in rats carrying the GTK/KAT I mutation may be due in part to disruption of glutamine transamination. GTK is one of several pyridoxal 5'-phosphate (PLP)-containing enzymes that can catalyze non-physiological beta-elimination reactions with cysteine S-conjugates containing a good leaving group attached at the sulfur. These elimination reactions may contribute to the bioactivation of certain electrophiles, resulting in toxicity to kidney, liver, brain, and possibly other organs. On the other hand, the beta-lyase reaction catalyzed by GTK may be useful in the conversion of some cysteine S-conjugate prodrugs to active components in vivo. The roles of GTK in (a) brain nitrogen, sulfur, and aromatic amino acid/kynurenine metabolism, (b) brain alpha-keto acid metabolism, (c) bioactivation of certain electrophiles in brain, (d) prodrug targeting, and (e) maintenance of normal blood pressure deserve further study.
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Affiliation(s)
- Arthur J L Cooper
- Department of Biochemistry, Weill Medical College of Cornell University, Burke Medical Research Institute, 785 Mamaroneck Avenue, White Plains, NY 10605, USA.
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Jester BC, Levengood JD, Roy H, Ibba M, Devine KM. Nonorthologous replacement of lysyl-tRNA synthetase prevents addition of lysine analogues to the genetic code. Proc Natl Acad Sci U S A 2003; 100:14351-6. [PMID: 14623972 PMCID: PMC283595 DOI: 10.1073/pnas.2036253100] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2003] [Indexed: 11/18/2022] Open
Abstract
Insertion of lysine during protein synthesis depends on the enzyme lysyl-tRNA synthetase (LysRS), which exists in two unrelated forms, LysRS1 and LysRS2. LysRS1 has been found in most archaea and some bacteria, and LysRS2 has been found in eukarya, most bacteria, and a few archaea, but the two proteins are almost never found together in a single organism. Comparison of structures of LysRS1 and LysRS2 complexed with lysine suggested significant differences in their potential to bind lysine analogues with backbone replacements. One such naturally occurring compound, the metabolic intermediate S-(2-aminoethyl)-L-cysteine, is a bactericidal agent incorporated during protein synthesis via LysRS2. In vitro tests showed that S-(2-aminoethyl)-L-cysteine is a poor substrate for LysRS1, and that it inhibits LysRS1 200-fold less effectively than it inhibits LysRS2. In vivo inhibition by S-(2-aminoethyl)-L-cysteine was investigated by replacing the endogenous LysRS2 of Bacillus subtilis with LysRS1 from the Lyme disease pathogen Borrelia burgdorferi. B. subtilis strains producing LysRS1 alone were relatively insensitive to growth inhibition by S-(2-aminoethyl)-L-cysteine, whereas a WT strain or merodiploid strains producing both LysRS1 and LysRS2 showed significant growth inhibition under the same conditions. These growth effects arising from differences in amino acid recognition could contribute to the distribution of LysRS1 and LysRS2 in different organisms. More broadly, these data demonstrate how diversity of the aminoacyl-tRNA synthetases prevents infiltration of the genetic code by noncanonical amino acids, thereby providing a natural reservoir of potential antibiotic resistance.
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Affiliation(s)
- Brian C Jester
- Department of Genetics, Smurfit Institute, Trinity College, Dublin 2, Ireland
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Pitari G, Malergue F, Martin F, Philippe JM, Massucci MT, Chabret C, Maras B, Duprè S, Naquet P, Galland F. Pantetheinase activity of membrane-bound Vanin-1: lack of free cysteamine in tissues of Vanin-1 deficient mice. FEBS Lett 2000; 483:149-54. [PMID: 11042271 DOI: 10.1016/s0014-5793(00)02110-4] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pantetheinase (EC 3.5.1.-) is an ubiquitous enzyme which in vitro has been shown to recycle pantothenic acid (vitamin B5) and to produce cysteamine, a potent anti-oxidant. We show that the Vanin-1 gene encodes pantetheinase widely expressed in mouse tissues: (1) a pantetheinase activity is specifically expressed by Vanin-1 transfectants and is immunodepleted by specific antibodies; (2) Vanin-1 is a GPI-anchored pantetheinase, and consequently an ectoenzyme; (3) Vanin-1 null mice are deficient in membrane-bound pantetheinase activity in kidney and liver; (4) in these organs, a major metabolic consequence is the absence of detectable free cysteamine; this demonstrates that membrane-bound pantetheinase is the main source of cysteamine in tissues under physiological conditions. Since the Vanin-1 molecule was previously shown to be involved in the control of thymus reconstitution following sublethal irradiation in vivo, this raises the possibility that Vanin/pantetheinase might be involved in the regulation of some immune functions maybe in the context of the response to oxidative stress.
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Affiliation(s)
- G Pitari
- Dipartmento di Biologia di Base ed Applicata Università di L'Aquila, Italy
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Maras B, Barra D, Duprè S, Pitari G. Is pantetheinase the actual identity of mouse and human vanin-1 proteins? FEBS Lett 1999; 461:149-52. [PMID: 10567687 DOI: 10.1016/s0014-5793(99)01439-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pantetheinase is an amidohydrolase involved in the dissimilative pathway of CoA, allowing the turnover of the pantothenate moiety. We have determined the N-terminal sequence as well as the sequences of a number of tryptic and chymotryptic peptides of the protein isolated from pig kidney. These sequence stretches were used as probes to search in the SwissProt database and significant similarities were found with a GPI-anchored protein (mouse vanin-1, with a suggested role in lymphocyte migration), with two putative proteins encoded by human cDNAs (VNN1 and VNN2) and with human biotinidase. On the basis of sequence similarity, we propose that vanin-1 and VNN1 should be identified as pantetheinase.
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Affiliation(s)
- B Maras
- Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli' and Centro di Biologia Molecolare del Consiglio Nazionale delle Ricerche Università La Sapienza, Piazzale Aldo Moro 5, 00185, Rome, Italy.
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Matarese RM, Macone A, Antonini R, Maggio A, Antonucci A. Identification of aminoethylcysteine ketimine decarboxylated dimer in human plasma. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 732:137-44. [PMID: 10517230 DOI: 10.1016/s0378-4347(99)00272-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aminoethylcysteine ketimine decarboxylated dimer (AECK-DD) is a natural sulfur-containing tricyclic compound detected, until now, in human urine and bovine cerebellum. Recently, the antioxidant properties of this compound, and particularly its protective effect on the in vitro oxidation of low-density lipoproteins, have been demonstrated. In this paper, the identification of AECK-DD in human plasma by means of gas chromatography, high-performance liquid chromatography and gas chromatography-mass spectrometry, performed after a simple and fast purification procedure, is reported.
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Affiliation(s)
- R M Matarese
- Dipartimento di Scienze Biochimiche A. Rossi Fanelli, Università di Roma La Sapienza, Rome, Italy.
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Matarese RM, Macone A, Crescentini G, Duprè S, Cavallini D. Detection of a decarboxylated dimer of aminoethylcysteine ketimine in bovine cerebellum. Neurochem Int 1998; 32:365-8. [PMID: 9596560 DOI: 10.1016/s0197-0186(97)00094-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Aminoethylcysteine ketimine is a sulfur-containing cyclic compound produced by the enzymatic alpha-deamination of the parent aminoethylcysteine that has been detected in bovine brain and cerebellum. Aminoethylcysteine ketimine is known to dimerize spontaneously and easily lose one carboxyl group. This decarboxylated compound, simply named the dimer, has been recently detected in normal human urine. In this article we provide evidence on the occurrence of the dimer in the bovine cerebellum.
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Affiliation(s)
- R M Matarese
- Dipartimento di Scienze Biochimiche A. Rossi Fanelli and Centro di Biologia Molecolare del CNR, Roma, Italy.
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Matarese RM, Macone A, Maggio A, Cavallini D. Aminoethylcysteine ketimine decarboxylated dimer detected in normal human urine by gas-liquid chromatography, selected-ion monitoring and mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 683:269-72. [PMID: 8891925 DOI: 10.1016/0378-4347(96)00105-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Aminoethylcysteine ketimine is a biochemical product known to be converted spontaneously in the decarboxylated dimer. Since the ketimine has been detected in a mammalian brain, it was assumed that also the dimer could be present in the mammalian body and eventually excreted in the urine. Using human urine as the biological source, an extract was prepared which, submitted to gas-liquid chromatography, selected-ion monitoring and mass spectrometry, indicated the presence of the dimer.
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Affiliation(s)
- R M Matarese
- Dipartimento di Scienze Biochimiche A. Rossi Fanelli, University of Roma La Sapienza, Italy
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Pitari G, Maurizi G, Ascenzi P, Ricci G, Duprè S. A kinetic study on pantetheinase inhibition by disulfides. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 226:81-6. [PMID: 7957261 DOI: 10.1111/j.1432-1033.1994.tb20028.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The mammalian enzyme pantetheinase, which hydrolyzes pantetheine to pantothenic acid and cysteamine, is inhibited by many thiol reagents and activated by thiols. Two thiol groups of different reactivity and accessibility are involved in the catalytic process [Ricci, G., Nardini, M., Chiaraluce, R., Duprè, S. & Cavallini, D. (1986) Biochim. Biophys. Acta 870, 82-91]. The inhibition kinetics by some natural and synthetic disulfides [pantethine, cystamine, 5,5'-dithiobis(2-nitrobenzoic acid), 4,4'-dithiodipyridine and oxidized mercaptoethanol] has been studied by two experimental approaches, either by monitoring activity after incubation of the enzyme with the inhibitor or by determining the progress curves in the presence of substrate and inhibitor. Data reported here indicate that pantetheinase reacts irreversibly with various disulfides in a time-dependent manner with the formation of a mixed disulfide apparently preceeded by a conformational change, giving a modified E* form with new kinetic parameters. This modified form may be further competitively inhibited by disulfides interacting with the enzyme at the active site.
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Affiliation(s)
- G Pitari
- Dipartimento di Biologia di base ed applicata, Università de L'Aquila, Italy
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