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Li Q, Zhao Q, Guo J, Li X, Song J. Transcriptomic Analysis of Diethylstilbestrol in Daphnia Magna: Energy Metabolism and Growth Inhibition. TOXICS 2023; 11:197. [PMID: 36851071 PMCID: PMC9962875 DOI: 10.3390/toxics11020197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/01/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
With the widespread use of diethylstilbestrol (DES), it has become a common contaminant in the aquatic environment. It is toxic to a wide range of aquatic organisms, disrupting the water flea growth and further interfering with several ecosystem services. Nevertheless, the molecular mechanism of DES in water fleas is still unexplicit. In this study, the 21-day chronic test showed that a negative effect of growth and reproduction can be observed with DES exposure. Subsequently applied transcriptomic analysis illustrated the molecular mechanism in mode freshwater invertebrate Daphnia magna (D. magna) exposed to 2, 200, and 1000 μg·L-1 of DES for 9 days. Meanwhile, exposure to DES at 200 and 1000 μg·L-1 significantly restrains the growth (body length) and reproduction (first spawning time) of D. magna. Identified differentially expressed genes (DEGs) are majorly enriched relative to energy metabolism, lipid metabolism, the digestive system, transport and catabolism pathways which were remarkably changed. These repressed and up-regulated pathways, in relation to energy synthesis and metabolism, may be the reasons for the reduced body length and delayed first spawning time. Taken together, this study revealed that DES is a threat to D. magna in the aquatic environment and clarifies the molecular mechanism of the toxicity.
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Affiliation(s)
- Qi Li
- Correspondence: ; Tel.: +86-135-7200-0931
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Park MG, Han AR, Kim SY, Kim TY, Kim HM, Lee CJ. High-yield synthesis and purification of recombinant human GABA transaminase for high-throughput screening assays. J Enzyme Inhib Med Chem 2021; 36:2016-2024. [PMID: 34514924 PMCID: PMC8439235 DOI: 10.1080/14756366.2021.1975697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 11/17/2022] Open
Abstract
Many studies have focussed on modulating the activity of γ-aminobutyric acid transaminase (GABA-T), a GABA-catabolizing enzyme, for treating neurological diseases, such as epilepsy and drug addiction. Nevertheless, human GABA-T synthesis and purification have not been established. Thus, biochemical and drug design studies on GABA-T have been performed by using porcine GABA-T mostly and even bacterial GABA-T. Here we report an optimised protocol for overexpression of 6xHis-tagged human GABA-T in human cells followed by a two-step protein purification. Then, we established an optimised human GABA-T (0.5 U/mg) activity assay. Finally, we compared the difference between human and bacterial GABA-T in sensitivity to two irreversible GABA-T inhibitors, gabaculine and vigabatrin. Human GABA-T in homodimeric form showed 70-fold higher sensitivity to vigabatrin than bacterial GABA-T in multimeric form, indicating the importance of using human GABA-T. In summary, our newly developed protocol can be an important first step in developing more effective human GABA-T modulators.
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Affiliation(s)
- Mingu Gordon Park
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, South Korea
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Ah-reum Han
- Center for Biomolecular and Cellular Structure, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Su Yeon Kim
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Tai Young Kim
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Ho Min Kim
- Center for Biomolecular and Cellular Structure, Institute for Basic Science (IBS), Daejeon, South Korea
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - C. Justin Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, South Korea
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
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Li N, Zhou J, Wang H, Mu C, Wang C. The iTRAQ-based quantitative proteomics reveals metabolic changes in Scylla paramamosain under different light intensities during indoor overwintering. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 207:111384. [PMID: 33011457 DOI: 10.1016/j.ecoenv.2020.111384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
Light intensity is one of the ecological factors that appreciably affects the metabolism of Scylla paramamosain during overwintering. This study adopted the isobaric tag for relative and absolute quantitation (iTRAQ) method to investigate metabolic changes of S. paramamosain under three illumination levels (0, 1.43 and 40.31 μmol m-2·s-1) for four months during indoor overwintering. The iTRAQ identified 3282 proteins, among which 267 exhibited significant differential expression (122 upregulated and 145 downregulated) in the low light group, and 299 with significant differential expression (252 upregulated and 47 downregulated) in the high light group. Analysis of these results showed that there were different metabolic regulatory patterns under different light intensities. Low light is more conducive to the survival of S. paramamosain, which needs to produce and consume relatively less energy to sustain physiological activities. Thus, the essential proteins associated with physiological activities were significantly upregulated, while those related to energy production were significantly downregulated. In contrast, high light exerts a certain stress on the survival of S. paramamosain and required more energy to cope with this stress, which forced a significant upregulation of proteins related to stress response and energy production. The findings of this study highlighted the metabolic regulatory mechanisms of S. paramamosain under different light intensities.
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Affiliation(s)
- Na Li
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Junming Zhou
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Huan Wang
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Changkao Mu
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Chunlin Wang
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
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Silverman RB. Design and Mechanism of GABA Aminotransferase Inactivators. Treatments for Epilepsies and Addictions. Chem Rev 2018; 118:4037-4070. [PMID: 29569907 DOI: 10.1021/acs.chemrev.8b00009] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
When the brain concentration of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) diminishes below a threshold level, the excess neuronal excitation can lead to convulsions. This imbalance in neurotransmission can be corrected by inhibition of the enzyme γ-aminobutyric acid aminotransferase (GABA-AT), which catalyzes the conversion of GABA to the excitatory neurotransmitter l-glutamic acid. It also has been found that raising GABA levels can antagonize the rapid elevation and release of dopamine in the nucleus accumbens, which is responsible for the reward response in addiction. Therefore, the design of new inhibitors of GABA-AT, which increases brain GABA levels, is an important approach to new treatments for epilepsy and addiction. This review summarizes findings over the last 40 or so years of mechanism-based inactivators (unreactive compounds that require the target enzyme to catalyze their conversion to the inactivating species, which inactivate the enzyme prior to their release) of GABA-AT with emphasis on their catalytic mechanisms of inactivation, presented according to organic chemical mechanism, with minimal pharmacology, except where important for activity in epilepsy and addiction. Patents, abstracts, and conference proceedings are not covered in this review. The inactivation mechanisms described here can be applied to the inactivations of a wide variety of unrelated enzymes.
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Affiliation(s)
- Richard B Silverman
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Center for Developmental Therapeutics , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208-3113 , United States
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Molecular characterization and tissue expression of carboxypeptidase H (CPH) gene in flounder (Paralichthys olivaceus). BIOTECHNOL BIOPROC E 2011. [DOI: 10.1007/s12257-010-0278-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lee JH, Son MY, Yoon MY, Choi JD, Kim YT. Isolation and characterization of ornithine decarboxylase gene from flounder (Paralichthys olivaceus). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2004; 6:453-462. [PMID: 15791490 DOI: 10.1007/s10126-004-4100-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2003] [Accepted: 12/28/2003] [Indexed: 05/24/2023]
Abstract
Ornithine decarboxylase (ODC) is a homodimeric enzyme dependent on pyridoxal 5'-phosphate. We identified a complementary DNA clone corresponding to ODC from the brain of adult flounder (Paralichthys olivaceus). The flounder ODC cDNA consisted of 2939 bp encoding 272 amino acid residues. The flounder ODC showed 80.3% sequence identity to zebrafish and 70.8% to rat at the amino acid level. Comparison of the structure and nucleotide sequence of the ODC genes revealed that the gene is highly conserved in the flounder, zebrafish, and rat. The presence of ODC mRNA species in brain, kidney, liver, and embryo was confirmed using the reverse transcriptase polymerase chain reaction. The recombinant protein of flounder ODC containing a short histidine tag at the carboxyl terminus was overexpressed in Escherichia coli BL21 (DE3) codon plus using an inducible T7 expression system, and was purified by Ni-NTA affinity chromatography.
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Affiliation(s)
- Jae Hyung Lee
- Department of Microbiology, Pukyong National University, Busan 608-737, Korea.
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Van Cauwenberghe OR, Makhmoudova A, McLean MD, Clark SM, Shelp BJ. Plant pyruvate-dependent gamma-aminobutyrate transaminase: identification of anArabidopsiscDNA and its expression inEscherichia coli. ACTA ACUST UNITED AC 2002. [DOI: 10.1139/b02-087] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Both pyruvate- and 2-oxoglutarate-dependent gamma-aminobutyrate transaminase (GABA-T) activities are present in crude tobacco (Nicotiana tabacum L.) leaf extracts. In this study, GABA:pyruvate-T activity was partially purified using mitochondrial isolation and protein solubilization in 3-[3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, and a combination of chromatographic and electrophoretic procedures. A partial amino acid sequence of the putative 55-kDa GABA-T subunit enabled identification of a predicted Arabidopsis thaliana (L.) Heynh. GABA:pyruvate-T expressed sequence tag and subsequent amplification of a 1515 bp open reading frame encoding a 504-amino acid polypeptide. Computer analysis using web-based tools revealed the presence of a putative mitochondrial signal sequence and a pyridoxal-5-phosphate binding domain in the polypeptide. Functional expression of the GABA-T cDNA in Escherichia coli revealed that the recombinant protein uses pyruvate but not 2-oxoglutarate. The Arabidopsis GABA:pyruvate-T cDNA could form the basis for identification of multiple GABA-T isoforms and generation of GABA-T mutants for determining the fate of GABA nitrogen and elucidating the physiological function of GABA in plants.Key words: amino acceptor, gamma-aminobutyrate, gamma-aminobutyrate transaminase, protein purification, heterologous expression, recombinant protein.
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Jeon SG, Bahn JH, Jang JS, Park J, Kwon OS, Cho SW, Choi SY. Human brain GABA transaminase tissue distribution and molecular expression. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:5601-7. [PMID: 10951220 DOI: 10.1046/j.1432-1327.2000.01626.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human brain gamma-aminobutyrate transaminase is differentially expressed in a tissue-specific manner. mRNA master dot-blot analysis for 50 different human tissues, including different brain regions and fetal tissues, provided a complete map of the tissue distribution. Genomic Southern analysis revealed that the gamma-aminobutyrate transaminase gene is a single copy, at least 15 kb in size. In addition, human brain gamma-aminobutyrate transaminase cDNA was expressed in Escherichia coli using a pGEX expression vector system. Catalytically active gamma-aminobutyrate transaminase was expressed in large quantities and the purified recombinant enzyme had kinetic parameters that were indistinguishable from those isolated from other mammalian brains. The human enzyme was inactivated by a well-known antiepileptic drug vigabatrin. Values of Ki and kinact were 1 mM and 0.35 min-1, respectively. Results from inactivation kinetics suggested that human gamma-aminobutyrate transaminase is more sensitive to the vigabatrin drug than the enzyme isolated from bovine brain.
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Affiliation(s)
- S G Jeon
- Department of Genetic Engineering, Hallym University, Chunchon, Korea
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Medina-Kauwe LK, Tobin AJ, De Meirleir L, Jaeken J, Jakobs C, Nyhan WL, Gibson KM. 4-Aminobutyrate aminotransferase (GABA-transaminase) deficiency. J Inherit Metab Dis 1999; 22:414-27. [PMID: 10407778 DOI: 10.1023/a:1005500122231] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
4-Aminobutyrate aminotransferase (GABA-transaminase, GABA-T, EC 2.6.1.19) deficiency (McKusick 137150), an inborn error of GABA degradation, has until now been documented in only a single Flemish child. Compared to the other defects of GABA degradation, succinic semialdehyde dehydrogenase (SSADH, EC 1.2.1.24) deficiency with > 150 patients (McKusick 271980) and pyridoxine-dependent seizures with > 100 patients ('putative' glutamic acid decarboxylase (GAD, EC 4.1.1.15) deficiency; McKusick 266100), GABA-T deficiency is very rare. We present a summary of the clinical, biochemical, enzymatic and molecular findings on the index proband, and a recently identified second patient, with GABA-T deficiency. The phenotype in both included psychomotor retardation, hypotonia, hyperreflexia, lethargy, refractory seizures and electroencephalographic abnormalities. In an effort to elucidate the molecular basis of GABA-T deficiency, we isolated and characterized a 1.5 kb cDNA encoding human GABA-T, in addition to a 41 kb genomic clone which encompassed the GABA-T coding region. Standard methods of cloning and sequencing revealed an A-to-G transition at nucleotide 754 of the coding region in lymphoblast cDNAs derived from the index proband. This mutation resulted in substitution of an invariant arginine at amino acid 220 by lysine. Expression of the mutant in E. coli, followed by isolation and enzymatic characterization of the recombinant protein, revealed an enzyme whose Vmax was reduced to 25% of wild-type activity. The patient and father were heterozygous for this allele; the second allele in the patient remains unidentified. Genomic Southern analysis revealed that the second proband most likely harbours a deletion in the 3' region of the GABA-T gene.
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Affiliation(s)
- L K Medina-Kauwe
- Institute for Genetic Medicine, University of California, Los Angeles, USA
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