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Campero-Basaldua C, González J, García JA, Ramírez E, Hernández H, Aguirre B, Torres-Ramírez N, Márquez D, Sánchez NS, Gómez-Hernández N, Torres-Machorro AL, Riego-Ruiz L, Scazzocchio C, González A. Neo-functionalization in Saccharomyces cerevisiae: a novel Nrg1-Rtg3 chimeric transcriptional modulator is essential to maintain mitochondrial DNA integrity. ROYAL SOCIETY OPEN SCIENCE 2023; 10:231209. [PMID: 37920568 PMCID: PMC10618058 DOI: 10.1098/rsos.231209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 10/11/2023] [Indexed: 11/04/2023]
Abstract
In Saccharomyces cerevisiae, the transcriptional repressor Nrg1 (Negative Regulator of Glucose-repressed genes) and the β-Zip transcription factor Rtg3 (ReTroGrade regulation) mediate glucose repression and signalling from the mitochondria to the nucleus, respectively. Here, we show a novel function of these two proteins, in which alanine promotes the formation of a chimeric Nrg1/Rtg3 regulator that represses the ALT2 gene (encoding an alanine transaminase paralog of unknown function). An NRG1/NRG2 paralogous pair, resulting from a post-wide genome small-scale duplication event, is present in the Saccharomyces genus. Neo-functionalization of only one paralog resulted in the ability of Nrg1 to interact with Rtg3. Both nrg1Δ and rtg3Δ single mutant strains were unable to use ethanol and showed a typical petite (small) phenotype on glucose. Neither of the wild-type genes complemented the petite phenotype, suggesting irreversible mitochondrial DNA damage in these mutants. Neither nrg1Δ nor rtg3Δ mutant strains expressed genes encoded by any of the five polycistronic units transcribed from mitochondrial DNA in S. cerevisiae. This, and the direct measurement of the mitochondrial DNA gene complement, confirmed that irreversible damage of the mitochondrial DNA occurred in both mutant strains, which is consistent with the essential role of the chimeric Nrg1/Rtg3 regulator in mitochondrial DNA maintenance.
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Affiliation(s)
- Carlos Campero-Basaldua
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - James González
- Laboratorio de Biología Molecular y Genómica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de Mexico, México
| | - Janeth Alejandra García
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Edgar Ramírez
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Hugo Hernández
- Departamento de Biología, Facultad de Química, UNAM, México City, Universidad Nacional Autónoma de México, Ciudad de Mexico, México
| | - Beatriz Aguirre
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Nayeli Torres-Ramírez
- Laboratorio de Microscopía Electrónica Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de Mexico, México
| | - Dariel Márquez
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Norma Silvia Sánchez
- Departamento de Genética Molecular, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Nicolás Gómez-Hernández
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, SLP, México
| | - Ana Lilia Torres-Machorro
- Laboratorio de Biología Celular, Departamento de Investigación en Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias ‘Ismael Cosío Villegas', Tlalpan, Mexico
| | - Lina Riego-Ruiz
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, SLP, México
| | - Claudio Scazzocchio
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Alicia González
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
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Cooper AJL, Krasnikov BF, Pinto JT, Kung HF, Li J, Ploessl K. Comparative enzymology of (2S,4R)4-fluoroglutamine and (2S,4R)4-fluoroglutamate. Comp Biochem Physiol B Biochem Mol Biol 2012; 163:108-20. [PMID: 22613816 DOI: 10.1016/j.cbpb.2012.05.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 05/11/2012] [Accepted: 05/14/2012] [Indexed: 11/26/2022]
Abstract
Many cancer cells have a strong requirement for glutamine. As an aid for understanding this phenomenon the (18)F-labeled 2S,4R stereoisomer of 4-fluoroglutamine [(2S,4R)4-FGln] was previously developed for in vivo positron emission tomography (PET). In the present work, comparative enzymological studies of unlabeled (2S,4R)4-FGln and its deamidated product (2S,4R)4-FGlu were conducted as an adjunct to these PET studies. Our findings are as follows: Rat kidney preparations catalyze the deamidation of (2S,4R)4-FGln. (2,4R)4-FGln and (2S,4R)4-FGlu are substrates of various aminotransferases. (2S,4R)4-FGlu is a substrate of glutamate dehydrogenase, but not of sheep brain glutamine synthetase. The compound is, however, a strong inhibitor of this enzyme. Rat liver cytosolic fractions catalyze a γ-elimination reaction with (2S,4R)4-FGlu, generating α-ketoglutarate. Coupling of a deamidase reaction with this γ-elimination reaction provides an explanation for the previous detection of (18)F(-) in tumors exposed to [(18)F](2S,4R)4-FGln. One enzyme contributing to this reaction was identified as alanine aminotransferase, which catalyzes competing γ-elimination and aminotransferase reactions with (2S,4R)4-FGlu. This appears to be the first description of an aminotransferase catalyzing a γ-elimination reaction. The present results demonstrate that (2S,4R)4-FGln and (2S,4R)4-FGlu are useful analogues for comparative studies of various glutamine- and glutamate-utilizing enzymes in normal and cancerous mammalian tissues, and suggest that tumors may metabolize (2S,4R)4-FGln in a generally similar fashion to glutamine. In plants, yeast and bacteria a major route for ammonia assimilation involves the consecutive action of glutamate synthase plus glutamine synthetase (glutamate synthase cycle). It is suggested that (2S,4R)4-FGln and (2S,4R)4-FGlu will be useful probes in studies of ammonia assimilation by the glutamate synthase pathway in these organisms. Finally, glutamine transaminases are conserved in mammals, plants and bacteria, and probably serve to close the methionine salvage pathway, thus linking nitrogen metabolism to sulfur metabolism and one-carbon metabolism. It is suggested that (2S,4R)4-FGln may be useful in studies of the methionine salvage pathway in a variety of organisms.
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Affiliation(s)
- Arthur J L Cooper
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
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3
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García-Campusano F, Anaya VH, Robledo-Arratia L, Quezada H, Hernández H, Riego L, González A. ALT1-encoded alanine aminotransferase plays a central role in the metabolism of alanine in Saccharomyces cerevisiae. Can J Microbiol 2009; 55:368-74. [DOI: 10.1139/w08-150] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the yeast Saccharomyces cerevisiae , the paralogous genes ALT1 and ALT2 have been proposed to encode alanine aminotransferase isozymes. Although in other microorganisms this enzyme constitutes the main pathway for alanine biosynthesis, its role in S. cerevisiae had remained unclear. Results presented in this paper show that under respiratory conditions, Alt1p constitutes the sole pathway for alanine biosynthesis and catabolism, constituting the first example of an alanine aminotransferase that simultaneously carries out both functions. Conversely, under fermentative conditions, it plays a catabolic role and alanine is mainly synthesized through an alternative pathway. It can thus be concluded that ALT1 has functions in alanine biosynthesis and utilization or only alanine utilization under respiratory and fermentative conditions, respectively. ALT2 expression was repressed under all tested conditions, suggesting that Alt2p biosynthesis is strictly controlled and only allowed to express under peculiar physiological conditions.
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Affiliation(s)
- Florencia García-Campusano
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, Mexico City, D.F. 04510, Mexico
- Instituto Nacional de Cardiología, Departamento de Bioquímica, Tlalpan, Mexico City, D.F. 14070, Mexico
- División de Biología Molecular, IPICYT, Camino a la Presa San José No 2055 Lomas, Cuarta Sección 78216, San Luis Potosí, Mexico
| | - Víctor-Hugo Anaya
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, Mexico City, D.F. 04510, Mexico
- Instituto Nacional de Cardiología, Departamento de Bioquímica, Tlalpan, Mexico City, D.F. 14070, Mexico
- División de Biología Molecular, IPICYT, Camino a la Presa San José No 2055 Lomas, Cuarta Sección 78216, San Luis Potosí, Mexico
| | - Luis Robledo-Arratia
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, Mexico City, D.F. 04510, Mexico
- Instituto Nacional de Cardiología, Departamento de Bioquímica, Tlalpan, Mexico City, D.F. 14070, Mexico
- División de Biología Molecular, IPICYT, Camino a la Presa San José No 2055 Lomas, Cuarta Sección 78216, San Luis Potosí, Mexico
| | - Héctor Quezada
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, Mexico City, D.F. 04510, Mexico
- Instituto Nacional de Cardiología, Departamento de Bioquímica, Tlalpan, Mexico City, D.F. 14070, Mexico
- División de Biología Molecular, IPICYT, Camino a la Presa San José No 2055 Lomas, Cuarta Sección 78216, San Luis Potosí, Mexico
| | - Hugo Hernández
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, Mexico City, D.F. 04510, Mexico
- Instituto Nacional de Cardiología, Departamento de Bioquímica, Tlalpan, Mexico City, D.F. 14070, Mexico
- División de Biología Molecular, IPICYT, Camino a la Presa San José No 2055 Lomas, Cuarta Sección 78216, San Luis Potosí, Mexico
| | - Lina Riego
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, Mexico City, D.F. 04510, Mexico
- Instituto Nacional de Cardiología, Departamento de Bioquímica, Tlalpan, Mexico City, D.F. 14070, Mexico
- División de Biología Molecular, IPICYT, Camino a la Presa San José No 2055 Lomas, Cuarta Sección 78216, San Luis Potosí, Mexico
| | - Alicia González
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, Mexico City, D.F. 04510, Mexico
- Instituto Nacional de Cardiología, Departamento de Bioquímica, Tlalpan, Mexico City, D.F. 14070, Mexico
- División de Biología Molecular, IPICYT, Camino a la Presa San José No 2055 Lomas, Cuarta Sección 78216, San Luis Potosí, Mexico
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A novel alternatively spliced transcript of cytosolic alanine aminotransferase gene associated with enhanced gluconeogenesis in liver of Sparus aurata. Int J Biochem Cell Biol 2008; 40:2833-44. [DOI: 10.1016/j.biocel.2008.05.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 05/29/2008] [Accepted: 05/30/2008] [Indexed: 01/15/2023]
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5
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Vedavathi M, Girish KS, Kumar MK. A novel low molecular weight alanine aminotransferase from fasted rat liver. BIOCHEMISTRY (MOSCOW) 2006; 71 Suppl 1:S105-12. [PMID: 16487061 DOI: 10.1134/s0006297906130189] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Alanine is the most effective precursor for gluconeogenesis among amino acids, and the initial reaction is catalyzed by alanine aminotransferase (AlaAT). Although the enzyme activity increases during fasting, this effect has not been studied extensively. The present study describes the purification and characterization of an isoform of AlaAT from rat liver under fasting. The molecular mass of the enzyme is 17.7 kD with an isoelectric point of 4.2; glutamine is the N-terminal residue. The enzyme showed narrow substrate specificity for L-alanine with Km values for alanine of 0.51 mM and for 2-oxoglutarate of 0.12 mM. The enzyme is a glycoprotein. Spectroscopic and inhibition studies showed that pyridoxal phosphate (PLP) and free -SH groups are involved in the enzymatic catalysis. PLP activated the enzyme with a Km of 0.057 mM.
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Affiliation(s)
- M Vedavathi
- Department of Biochemistry, University of Mysore, Manasagangotri, Mysore 570006, India
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6
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Srivastava AS, Oohara I, Suzuki T, Shenouda S, Singh SN, Chauhan DP, Carrier E. Purification and properties of cytosolic alanine aminotransferase from the liver of two freshwater fish, Clarias batrachus and Labeo rohita. Comp Biochem Physiol B Biochem Mol Biol 2004; 137:197-207. [PMID: 14990216 DOI: 10.1016/j.cbpc.2003.11.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2003] [Revised: 11/08/2003] [Accepted: 11/10/2003] [Indexed: 11/19/2022]
Abstract
Cytosolic alanine aminotransferase (c-AAT) was purified up to 203- and 120-fold, from the liver of two freshwater teleosts Clarias batrachus (air-breathing, carnivorous) and Labeo rohita (water-breathing, herbivorous), respectively. The enzyme from both fish showed similar elution profiles on a DEAE-Sephacel ion exchange column. SDS-PAGE of purified enzymes revealed two subunits of 54 and 56 kDa, in both fish. The apparent Km values for l-alanine were 18.5+/-0.48 and 23.55+/-0.60 mM, whereas for 2-oxoglutarate the Km values were observed to be 0.29+/-0.023 and 0.33+/-0.028 mM for the enzyme from C. batrachus and L. rohita, respectively. With l-alanine as substrate, aminooxyacetic acid was found to act as a competitive inhibitor with KI values of 6.4 x 10(-4) and 3.4 x 10(-4) mM with c-AAT of C. batrachus and L. rohita, respectively. However, when 2-oxoglutarate was used as substrate, aminooxyacetic acid showed uncompetitive inhibition with similar KI values for purified c-AAT from both fish. Temperature and pH profiles of the enzyme did not show any marked differences between the two fish examined. These results suggest that liver c-AAT, isolated from these two fish species adapted to different modes of life, remain unaltered structurally. However, at the kinetic level, liver c-AAT from C. batrachus exhibits significantly higher affinity for the substrate l-alanine and decreased affinity for its metabolic inhibitor, in comparison to that of the enzyme purified from L. rohita. Such functional changes seem to be of physiological significance and also provide preliminary evidence for subtle changes in the enzyme as a mark of metabolic adaptation in the fish to different physiological demands.
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Affiliation(s)
- Anand S Srivastava
- School of Medicine, University of California San Diego, La Jolla, CA 92093, USA.
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7
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Matsuzawa T, Kobayashi T, Ogawa H, Kasahara M. Microheterogeneity and intrahepatic localization of human and rat liver cytosolic alanine aminotransferase. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1340:115-22. [PMID: 9217021 DOI: 10.1016/s0167-4838(97)00033-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Native human cytosolic alanine aminotransferase (EC 2.6.1.2) was found to be a homodimer consisting of two 55 kDa subunits. The human enzyme was more cationic and more susceptible to heat inactivation and heavy metal-inhibition than its rat homologue. Isoelectric focussing separated three human isoforms and four rat isoforms of cALT that differed in their isoelectric points. Two subtypes of the enzyme which differed in apparent molecular weight on sodium dodecylsulfate polyacrylamide gel electrophoresis were detected in rat, the liver type and the muscular type. This microheterogeneity was not found for human cytosolic alanine aminotransferase. Immunohistochemical studies revealed that the rat liver enzyme was exclusively localized in periportal hepatocytes, consistent with its role in gluconeogenesis. In human hepatocytes the plasma membrane was intensely stained, implicating an intracellular localization near the plasma membrane.
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Affiliation(s)
- T Matsuzawa
- Department of Biochemistry, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan.
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8
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Ishiguro M, Takio K, Suzuki M, Oyama R, Matsuzawa T, Titani K. Complete amino acid sequence of human liver cytosolic alanine aminotransferase (GPT) determined by a combination of conventional and mass spectral methods. Biochemistry 1991; 30:10451-7. [PMID: 1931970 DOI: 10.1021/bi00107a013] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The complete amino acid sequence of human liver cytosolic alanine aminotransferase (GPT) (EC 2.6.1.2) is presented. Two primary sets of overlapping fragments were obtained by cleavage of the pyridylethylated protein at methionyl and lysyl bonds with cyanogen bromide and Achromobacter protease I, respectively. Isolated peptides were analyzed with a protein sequencer or with a plasma desorption time of flight mass spectrometer and placed in the sequence on the basis of their molecular mass and homology to the sequence of rat GPT. The protein was found to be acetylated at the amino terminus and contained 495 amino acid residues. The Mr of the subunit was calculated to be 54,479, which was in good agreement with a Mr of 55,000 estimated by SDS-PAGE, and also indicated that the active enzyme with a Mr of 114,000 was a homodimer composed of two identical subunits. The amino acid sequence is highly homologous to that of rat GPT (87.9% identity) recently determined [Ishiguro, M., Suzuki, M., Takio, K., Matsuzawa, T., & Titani, K. (1991) Biochemistry 30, 6048-6053]. All of the crucial amino acid residues are conserved in human GPT, which seem to be hydrogen bonding to pyridoxal 5'-phosphate in rat GPT by the sequence homology to other alpha-aminotransferases with known tertiary structures.
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Affiliation(s)
- M Ishiguro
- Division of Biomedical Polymer Science, School of Medicine, Fujita Health University, Aichi, Japan
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9
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Son D, Jo J, Sugiyama T. Purification and characterization of alanine aminotransferase from Panicum miliaceum leaves. Arch Biochem Biophys 1991; 289:262-6. [PMID: 1898070 DOI: 10.1016/0003-9861(91)90470-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Three alanine aminotransferases, two minor (AlaAT-1, AlaAT-3) and one major (AlaAT-2), were detected by native gel electrophoresis of leaf extracts from Panicum miliaceum L. AlaAT-2 was purified to homogeneity and a specific polyclonal antibody was raised against it which did not react with the other two forms of the enzyme. The enzyme, with an apparent molecular size of 102 kDa, appeared to be a dimer of a single 50-kDa polypeptide. The enzyme has a relatively broad pH optima with similar curves for the forward and reverse directions, ranging between 6.5 and 7.5. The Km values of this enzyme were 6.67, 0.15, 5.00, and 0.33 mM for alanine, 2-oxoglutarate, glutamate, and pyruvate, respectively. The activity of AlaAT-2 was found to increase markedly during leaf greening in parallel with the increase of immunochemically titrated protein, and it is suggested to function in the C4 photosynthetic cycle.
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Affiliation(s)
- D Son
- Department of Agricultural Chemistry, School of Agriculture, Nagoya University, Japan
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10
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Ilag LL, Jahn D, Eggertsson G, Söll D. The Escherichia coli hemL gene encodes glutamate 1-semialdehyde aminotransferase. J Bacteriol 1991; 173:3408-13. [PMID: 2045363 PMCID: PMC207952 DOI: 10.1128/jb.173.11.3408-3413.1991] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
delta-Aminolevulinic acid (ALA), the first committed precursor of porphyrin biosynthesis, is formed in Escherichia coli by the C5 pathway in a three-step, tRNA-dependent transformation from glutamate. The first two enzymes of this pathway, glutamyl-tRNA synthetase and Glu-tRNA reductase, are known in E. coli (J. Lapointe and D. Söll, J. Biol. Chem. 247:4966-4974, 1972; D. Jahn, U. Michelsen, and D. Söll, J. Biol. Chem. 266:2542-2548, 1991). Here we present the mapping and cloning of the gene for the third enzyme, glutamate 1-semialdehyde (GSA) aminotransferase, and an initial characterization of the purified enzyme. Ethylmethane sulfonate-induced mutants of E. coli AB354 which required ALA for growth were isolated by selection for respiration-defective strains resistant to the aminoglycoside antibiotic kanamycin. Two mutations were mapped to min 4 at a locus named hemL. Map positions and resulting phenotypes suggest that hemL may be identical with the earlier described porphyrin biosynthesis mutation popC. Complementation of the auxotrophic phenotype by wild-type DNA from the corresponding clone pLC4-43 of the Clarke-Carbon bank (L. Clarke and J. Carbon, Cell 9:91-99, 1976) allowed the isolation of the gene. Physical mapping showed that hemL mapped clockwise next to fhuB. The hemL gene product was overexpressed and purified to apparent homogeneity. The pure protein efficiently converted GSA to ALA. The reaction was stimulated by the addition of pyridoxal 5' -phosphate or pyridoxamine 5' -phosphate and inhibited by gabaculine or aminooxyacetic acid. The molecular mass of the purified GSA aminotransferase under denaturing conditions was 40,000 Da, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme has apparent native molecular mass of approximately 80,000 Da, as determined by rate zonal sedimentation on glycerol gradients and molecular sieving through Superose 12, which indicates a homodimeric alpha2, structure of the protein.
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Affiliation(s)
- L L Ilag
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511
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11
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Gubern G, Imperial S, Busquets M, Cortés A. Heterogeneity of human liver alanine aminotransferase due to sulfhydryl groups oxidation. BIOCHEMICAL MEDICINE AND METABOLIC BIOLOGY 1991; 45:258-62. [PMID: 1883632 DOI: 10.1016/0885-4505(91)90029-k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The cytosolic isoenzyme of human liver alanine aminotransferase exhibited a progressive change in its chromatographic behavior on DEAE-Sepharose when partially purified preparations were stored for up to 8 days at 4 degrees C. This change was characterized by the appearance of an additional chromatographic variant and was avoided by addition of 2-mercaptoethanol. The experimental evidence presented indicates that the progressive oxidation of free sulfhydryl groups of the enzyme is responsible for the charge modifications and heterogeneity observed.
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Affiliation(s)
- G Gubern
- Departament de Bioquimica i Fisiologia, Facultat de Química, Universitat de Barcelona, Spain
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12
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Jahn D, Chen MW, Söll D. Purification and functional characterization of glutamate-1-semialdehyde aminotransferase from Chlamydomonas reinhardtii. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52416-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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13
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Tomisawa H, Ichimoto N, Takanohashi Y, Ichihara S, Fukazawa H, Tateishi M. Purification and characterization of cysteine conjugate transaminases from rat liver. Xenobiotica 1988; 18:1015-28. [PMID: 2852419 DOI: 10.3109/00498258809042224] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
1. Soluble cysteine-conjugate alpha-ketoglutarate transaminase (CAT-I) was purified about 670-fold from rat liver cytosol using s-(p-bromophenyl)-L-cysteine as amino acid substrate. The enzyme preparation of the final step of purification showed a single band in polyacrylamide gel electrophoresis. CAT-I accounted for 64% of the transaminase activity in cytosol. 2. The mol. wt of the enzyme was about 64,000 as determined by gel filtration. Respective Km values for s-(p-bromophenyl)-L-cysteine and alpha-ketoglutaric acid were 1.0 and 1.3 mM in Tris-acetate buffer (pH 7.0). Aminooxyacetic acid, hydroxylamine, and KCN inhibited the enzyme activity. 3. In addition to CAT-I, two isozymes (CAT-IIA and CAT-IIB) were partially purified from rat liver cytosol. In respect of mol. wt, substrate specificity towards cysteine conjugates, and several other properties, CAT-IIA and CAT-IIB were very similar to CAT-I. However, differences were observed for these enzymes in the rate of reverse reaction (formation reaction of cysteine conjugates and alpha-ketoglutaric acid) and substrate specificity towards L-aspartic acid and L-cysteinesulphinic acid.
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Affiliation(s)
- H Tomisawa
- Nippon Roche Research Centre, Kanagawa Prefecture, Japan
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14
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Der Garabedian PA, Vermeersch JJ. Candida L-norleucine,leucine:2-oxoglutarate aminotransferase. Purification and properties. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 167:141-7. [PMID: 3622507 DOI: 10.1111/j.1432-1033.1987.tb13315.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A new enzyme which catalyzes the transamination of L-norleucine (2-aminohexanoic acid) and L-leucine with 2-oxoglutarate was purified to homogeneity from cells of Candida guilliermondii var. membranaefaciens. The relative molecular mass determined by gel filtration was estimated to be close to 100,000. The transaminase behaved as a dimer which consists of two subunits identical in molecular mass (Mr 51,000). The enzyme has a maximum activity in the pH range of 8.0-8.5 and at 55 degrees C. 2-Oxoglutarate, and to a lesser extent pyridoxal 5'-phosphate, were effective protecting agents against increasing temperature. The enzyme exhibits absorption maximum at 330 nm and 410 nm. L-Norleucine, and L-leucine to a lesser extent, are the best amino donors with 2-oxoglutarate as amino acceptor. The Km values for L-norleucine, L-leucine and 2-oxoglutarate determined from the Lineweaver-Burk plot were 1.8 mM, 6.6 mM and 2.0 mM respectively. A ping-pong bi-bi mechanism of inhibition with alternative substrates is found when the enzyme is in the presence of both L-norleucine and L-leucine. The inhibitory effect of various amino acid analogs on the transamination reaction between L-norleucine and 2-oxoglutarate was studied and Ki values were determined.
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Khomutov RM, Hyvönen T, Karvonen E, Kauppinen L, Paalanen T, Paulin L, Eloranta T, Pajula RL, Andersson LC, Pösö H. 1-Aminooxy-3-aminopropane, a new and potent inhibitor of polyamine biosynthesis that inhibits ornithine decarboxylase, adenosylmethionine decarboxylase and spermidine synthase. Biochem Biophys Res Commun 1985; 130:596-602. [PMID: 3861182 DOI: 10.1016/0006-291x(85)90458-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
1-Aminooxy-3-aminopropane was shown to be a potent competitive inhibitor (Ki = 3.2 nM) of homogenous mouse kidney ornithine decarboxylase, a potent irreversible inhibitor (Ki = 50 microM) of homogeneous liver adenosylmethionine decarboxylase and a potent competitive (Ki = 2.3 microM) of homogeneous bovine brain spermidine synthase. It did not inhibit homogeneous bovine brain spermine synthase and it did not serve as a substrate for spermidine synthase. The compound did not inhibit tyrosine aminotransferase, alanine aminotransferase or aspartate aminotransferase, which are pyridoxal phosphate-containing enzymes like ornithine decarboxylase. The inactivation of adenosylmethionine decarboxylase was partially prevented by pyruvate, which is the coenzyme of adenosylmethionine decarboxylase, and by the substrate, adenosylmethionine. 1-Aminooxy-3-aminopropane at 0.5 mM concentration inhibited the growth of HL-60 promyelocytic leukemia cells and this inhibition was prevented by spermidine but not by putrescine.
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16
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Amino Acid and Protein Metabolism. Biochemistry 1985. [DOI: 10.1016/b978-0-08-030811-1.50012-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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17
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Cooper AJ. Glutamate-alanine transaminase. Methods Enzymol 1985; 113:69-71. [PMID: 4088078 DOI: 10.1016/s0076-6879(85)13015-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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18
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Akhtar M, Emery VC, Robinson JA. Chapter 9 Pyridoxal phosphate-dependent enzymic reactions: mechanism and stereochemistry. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/s0167-7306(08)60380-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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19
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Balkow C, Wildner GF. Aspartate aminotransferases ofPanicum miliaceum L. andPanicum antidotale retz. : Inactivation and reconstitution. PLANTA 1982; 154:477-484. [PMID: 24276278 DOI: 10.1007/bf01267817] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/1981] [Accepted: 01/30/1989] [Indexed: 06/02/2023]
Abstract
L-Aspartate: 2-oxoglutarate transaminase was isolated and partially purified from leaves ofPanicum miliaceum (C4, NAD-malic enzyme type) and ofPanicum antidotale (C4, NADP-malic enzyme type). In each preparation two isoenzymes with different kinetic properties could be characterized. The enzyme activity was irreversibly inhibited by 2-aminooxyacetic acid and by 2-amino-4-methoxy-3-butenoic acid. The first inhibitor reacted with pyridoxal 5-phosphate, and its inhibition could be reversed by the exchange of the modified coenzyme. The second inhibitor binds not only to the coenzyme pyridoxal 5-phosphate, but also to the apoprotein. The results of the dissociation and reconstitution experiments were in agreement with the kinetic data, showing that the mode of inactivation was different for 2-aminooxyacetic acid and 2-amino-4-methoxy-3-butenoic acid.
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Affiliation(s)
- C Balkow
- Abteilung Biologie der Ruhr-Universität, Lehrstuhl für Biochemie der Pflanzen, D-4630, Bochum 1, Federal Republic of Germany
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Ruscák M, Orlický J, Zúbor V, Hager H. Alanine aminotransferase in bovine brain: purification and properties. J Neurochem 1982; 39:210-6. [PMID: 7086411 DOI: 10.1111/j.1471-4159.1982.tb04720.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Mitochondrial and cytosolic alanine aminotransferases (EC 2.6.1.2) were partially purified (140- and 180-fold), respectively) from bovine brain cortex by means of (NH4)2SO4 precipitation, gel filtration on Sephadex G-150, and in-exchange chromatography on DEAE A-50 and characterized. The enzymes exhibited identical molecular weights (110,000 +/- 10,000) and pH optima (7.8), but were eluted from CM Sephadex C-50 at different ionic strengths. Isoelectric focusing of the enzymes indicated a pI value of 5.2 for the cytosolic enzyme and 7.2 for the mitochondrial enzyme. The Km values of the mitochondrial enzyme were 5.1 mM, 6.6 mM, 0.7 mM, and 0.4 mM and of the cytosolic isozyme were 30.3 mM, 4.3 mM, 0.7 mM, and 0.5 mM for alanine, glutamate, 2-oxoglutarate, and pyruvate, respectively. The results indicated that two forms of alanine aminotransferase exist in nerve tissue, which suggests that they may play different roles in the cellular metabolism of nerve tissue.
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21
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Astrin KH, Arredondo-Vega FX, Desnick RJ, Smith M. Assignment of the gene for cytosolic alanine aminotransferase (AAT1) to human chromosome 8. Ann Hum Genet 1982; 46:125-33. [PMID: 7114790 DOI: 10.1111/j.1469-1809.1982.tb00703.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The segregation of human cytosolic alanine aminotransferase (AAT1) and the individual human chromosomes has been studied in 27 secondary and tertiary rat hepatoma-human (liver) fibroblast hybrids. The staining solution used to visualize AAT activity on starch gels was specific for AAT since it was visualized only when all components of the stain were present. The locus for human AAT1 has been assigned to chromosome 8.
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22
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Kazarinoff MN. There is an energy cost for catalytic turnover which arises due to enzyme degradation. Arch Biochem Biophys 1981; 208:131-4. [PMID: 7259172 DOI: 10.1016/0003-9861(81)90131-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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23
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Schneider M, Chen P. l-Alanine aminotransferase in Drosophila nigromelanica: isolation, characterization and activity during ontogenesis. ACTA ACUST UNITED AC 1981. [DOI: 10.1016/0020-1790(81)90056-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Pösö H, Pösö AR. Inhibition by aliphatic alcohols of the stimulated activity of ornithine decarboxylase and tyrosine aminotransferase occurring in regenerating rat liver. Biochem Pharmacol 1980; 29:2799-803. [PMID: 6108114 DOI: 10.1016/0006-2952(80)90014-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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25
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Brown AJ, Voelker RA. Genetic and biochemical studies on glutamate-pyruvate transaminase from Drosophila melanogaster. Biochem Genet 1980; 18:303-9. [PMID: 6778473 DOI: 10.1007/bf00484243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We have used electrophoretic variants of glutamate-pyruvate transaminase (GPT, E.C., 2.6.1.2) in Drosophila melanogaster to genetically map the structural gene to position 42.6 on the X chromosome. By pseudodominance tests over several deficiencies we have localized it cytogenetically to the interval 11Fl-2 to 12Al-2. The sedimentation constant (s20,w) of the native enzyme was determined in sucrose density gradients to be 5.9 and the native molecular weight approximately 87,000. The similarity in physical properties to mammalian enzymes suggests that the enzyme may also be dimeric in D. melanogaster.
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26
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Pösö AR, Pösö H. Inhibition of ornithine decarboxylase in regenerating rat liver by acute ethanol treatment. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 606:338-46. [PMID: 7357007 DOI: 10.1016/0005-2787(80)90043-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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27
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Tanase S, Kojima H, Morino Y. Pyridoxal 5'-phosphate binding site of pig heart alanine aminotransferase. Biochemistry 1979; 18:3002-7. [PMID: 465450 DOI: 10.1021/bi00581a015] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
After borohydride reduction, carboxymethylation, and tryptic digestion of the holoenzyme of pig heart alanine aminotransferase, a single icosapeptide containing the N6-(phosphopyridoxyl)lysine residue was isolated by a combination of gel filtration and ion-exchange chromatogrpahy. Its primary structure was determined as Gln-Glu-Leu-Ala-Ser-Phe-His-Ser-Val-Ser-Lsy(Pxy)-Gly-Phe-Met-Gly-Glu-Cys-Gly-Phe-Arg.
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28
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29
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Galau GA, Klein WH, Britten RJ, Davidson EH. Significance of rare m RNA sequences in liver. Arch Biochem Biophys 1977; 179:584-99. [PMID: 851359 DOI: 10.1016/0003-9861(77)90147-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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30
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31
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Dice JF, Goldberg AL. A statistical analysis of the relationship between degradative rates and molecular weights of proteins. Arch Biochem Biophys 1975; 170:213-9. [PMID: 1164028 DOI: 10.1016/0003-9861(75)90112-5] [Citation(s) in RCA: 87] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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32
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Benuck M, Lajtha A. Aminotransferase activity in brain. INTERNATIONAL REVIEW OF NEUROBIOLOGY 1975; 17:85-129. [PMID: 237848 DOI: 10.1016/s0074-7742(08)60208-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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33
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Schousboe A, Wu JY, Roberts E. Subunit structure and kinetic properties of 4-aminobutyrate-2-ketoglutarate transaminase purified from mouse brain. J Neurochem 1974; 23:1189-95. [PMID: 4156051 DOI: 10.1111/j.1471-4159.1974.tb12216.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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34
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Rech J, Crouzet J. Partial purification and initial studies of the tomato L-alanine:2-oxoglutarate aminotransferase. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 350:392-9. [PMID: 4847569 DOI: 10.1016/0005-2744(74)90513-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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35
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Chen SH, Donahue RP, Scott CR. The genetics of glutamic-pyruvic transaminase in mice: inheritance, electrophoretic phenotypes, and postnatal changes. Biochem Genet 1973; 10:23-8. [PMID: 4747555 DOI: 10.1007/bf00485745] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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36
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Litwack G, Rosenfield S. Coenzyme dissociation, a possible determinant of short half-life of inducible enzymes in mammalian liver. Biochem Biophys Res Commun 1973; 52:181-8. [PMID: 4145827 DOI: 10.1016/0006-291x(73)90971-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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37
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Fair DS, Krassner SM. Alanine aminotransferase and aspartate aminotransferase in Leishmania tarentolae. THE JOURNAL OF PROTOZOOLOGY 1971; 18:441-4. [PMID: 5132319 DOI: 10.1111/j.1550-7408.1971.tb03352.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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38
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Abstract
Soluble glutamic-pyruvic transaminase (GPT) has three common phenotypes, each representing the homozygous and heterozygous expression of two alleles, Gpt(1) and Gpt(2) at an autosomal locus. The frequencies of these alleles vary considerably from one population to another.
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39
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41
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Schatz L, Segal HL. Reduction of α-Ketoglutarate by Homogeneous Lactic Dehydrogenase X of Testicular Tissue. J Biol Chem 1969. [DOI: 10.1016/s0021-9258(18)94331-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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42
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Szepesi B, Freedland RA. A possible method for estimating hormone effects on enzyme synthesis. Arch Biochem Biophys 1969; 133:60-9. [PMID: 5810833 DOI: 10.1016/0003-9861(69)90488-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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43
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Segal HL, Abraham GJ, Matsuzawa T. Interaction of rat liver alanine aminotransferase with L-proline. Biochem Biophys Res Commun 1968; 30:63-8. [PMID: 5688916 DOI: 10.1016/0006-291x(68)90713-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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