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Matsui D, Yamada T, Hayashi J, Toyotake Y, Takeda Y, Wakayama M. Biochemical characterization of l-asparagine synthetase from Streptococcus thermophilus and its application in the enzymatic synthesis of β-aspartyl compounds. J Biosci Bioeng 2024:S1389-1723(24)00164-6. [PMID: 38981802 DOI: 10.1016/j.jbiosc.2024.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/30/2024] [Accepted: 06/01/2024] [Indexed: 07/11/2024]
Abstract
β-Aspartyl compounds, such as β-aspartyl hydroxamate (serine racemase inhibitor), β-aspartyl-l-lysine (moisture retention), and β-aspartyl-l-tryptophan (immunomodulator) are physiologically active compounds. There is limited literature on the development of effective methods of production of β-aspartyl compounds. In this study, we describe the biochemical characterization of asparagine synthetase (AS) from Streptococcus thermophilus NBRC 13957 (StAS) and the enzymatic synthesis of β-aspartyl compounds using StAS. Recombinant StAS was expressed in Escherichia coli BL21(DE3) and it displayed activity towards hydroxylamine, methylamine, ethylamine, and ammonia, as acceptors of the β-aspartyl moiety. StAS exhibited higher activity toward hydroxylamine and ethylamine as acceptor substrates compared with the enzymes from Lactobacillus delbrueckii NBRC 13953, Lactobacillus reuteri NBRC 15892, and E. coli. The coupling of the synthesis of β-aspartyl compounds by StAS with an ATP-regeneration system using polyphosphate kinase from Deinococcus proteoliticus NBRC 101906 displayed an approximately 2.5-fold increase in the production of β-aspartylhydroxamate from 1.06 mM to 2.53 mM after a 76-h reaction.
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Affiliation(s)
- Daisuke Matsui
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Taizo Yamada
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Junji Hayashi
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Yosuke Toyotake
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Yoichi Takeda
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Mamoru Wakayama
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
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Luo W, Xu J, Chen H, Zhang H, Yang P, Yu X. Synthesis of L-asparagine Catalyzed by a Novel Asparagine Synthase Coupled With an ATP Regeneration System. Front Bioeng Biotechnol 2021; 9:747404. [PMID: 34631686 PMCID: PMC8495130 DOI: 10.3389/fbioe.2021.747404] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 08/09/2021] [Indexed: 11/23/2022] Open
Abstract
Compared with low-yield extraction from plants and environmentally unfriendly chemical synthesis, biocatalysis by asparagine synthetase (AS) for preparation of L-asparagine (L-Asn) has become a potential synthetic method. However, low enzyme activity of AS and high cost of ATP in this reaction restricts the large-scale preparation of L-Asn by biocatalysis. In this study, gene mining strategy was used to search for novel AS with high enzyme activity by expressing them in Escherichia coli BL21 (DE3) or Bacillus subtilis WB600. The obtained LsaAS-A was determined for its enzymatic properties and used for subsequent preparation of L-Asn. In order to reduce the use of ATP, a class III polyphosphate kinase 2 from Deinococcus ficus (DfiPPK2-Ⅲ) was cloned and expressed in E. coli BL21 (DE3), Rosetta (DE3) or RosettagamiB (DE3) for ATP regeneration. A coupling reaction system including whole cells expressing LsaAS-A and DfiPPK2-Ⅲ was constructed to prepare L-Asn from L-aspartic acid (L-Asp). Batch catalytic experiments showed that sodium hexametaphosphate (>60 mmol L−1) and L-Asp (>100 mmol L−1) could inhibit the synthesis of L-Asn. Under fed-batch mode, L-Asn yield reached 90.15% with twice feeding of sodium hexametaphosphate. A final concentration of 218.26 mmol L−1 L-Asn with a yield of 64.19% was obtained when L-Asp and sodium hexametaphosphate were fed simultaneously.
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Affiliation(s)
- Wei Luo
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Jinglong Xu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Huiying Chen
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, China
| | - Huili Zhang
- College of Life Sciences, University of Shihezi, Shihezi, China
| | - Peilong Yang
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Institute of Feed Research of CAAS, Beijing, China
| | - Xiaobin Yu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
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Ando T, Sugawara Y, Nishio R, Murakami M, Isogai E, Yoneyama H. Cloning and characterization of the glutamate dehydrogenase gene in Streptococcus bovis. Anim Sci J 2016; 88:1027-1033. [PMID: 27878891 DOI: 10.1111/asj.12748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 09/09/2016] [Accepted: 09/28/2016] [Indexed: 11/29/2022]
Abstract
Streptococcus bovis, an etiologic agent of rumen acidosis in cattle, is a rumen bacterium that can grow in a chemically defined medium containing ammonia as a sole source of nitrogen. To understand its ability to assimilate inorganic ammonia, we focused on the function of glutamate dehydrogenase. In order to identify the gene encoding this enzyme, we first amplified an internal region of the gene by using degenerate primers corresponding to hexameric family I and NAD(P)+ binding motifs. Subsequently, inverse PCR was used to identify the whole gene, comprising an open reading frame of 1350 bp that encodes 449 amino acid residues that appear to have the substrate binding site of glutamate dehydrogenase observed in other organisms. Upon introduction of a recombinant plasmid harboring the gene into an Escherichia coli glutamate auxotroph lacking glutamate dehydrogenase and glutamate synthase, the transformants gained the ability to grow on minimal medium without glutamate supplementation. When cell extracts of the transformant were resolved by blue native polyacrylamide gel electrophoresis followed by activity staining, a single protein band appeared that corresponded to the size of S. bovis glutamate dehydrogenase. Based on these results, we concluded that the gene obtained encodes glutamate dehydrogenase in S. bovis.
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Affiliation(s)
- Tasuke Ando
- Laboratory of Animal Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yoko Sugawara
- Laboratory of Animal Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Ryohei Nishio
- Laboratory of Animal Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Miho Murakami
- Laboratory of Animal Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Emiko Isogai
- Laboratory of Animal Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Hiroshi Yoneyama
- Laboratory of Animal Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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Manhas R, Tripathi P, Khan S, Sethu Lakshmi B, Lal SK, Gowri VS, Sharma A, Madhubala R. Identification and functional characterization of a novel bacterial type asparagine synthetase A: a tRNA synthetase paralog from Leishmania donovani. J Biol Chem 2014; 289:12096-12108. [PMID: 24610810 DOI: 10.1074/jbc.m114.554642] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Asparagine is formed by two structurally distinct asparagine synthetases in prokaryotes. One is the ammonia-utilizing asparagine synthetase A (AsnA), and the other is asparagine synthetase B (AsnB) that uses glutamine or ammonia as a nitrogen source. In a previous investigation using sequence-based analysis, we had shown that Leishmania spp. possess asparagine-tRNA synthetase paralog asparagine synthetase A (LdASNA) that is ammonia-dependent. Here, we report the cloning, expression, and kinetic analysis of ASNA from Leishmania donovani. Interestingly, LdASNA was both ammonia- and glutamine-dependent. To study the physiological role of ASNA in Leishmania, gene deletion mutations were attempted via targeted gene replacement. Gene deletion of LdASNA showed a growth delay in mutants. However, chromosomal null mutants of LdASNA could not be obtained as the double transfectant mutants showed aneuploidy. These data suggest that LdASNA is essential for survival of the Leishmania parasite. LdASNA enzyme was recalcitrant toward crystallization so we instead crystallized and solved the atomic structure of its close homolog from Trypanosoma brucei (TbASNA) at 2.2 Å. A very significant conservation in active site residues is observed between TbASNA and Escherichia coli AsnA. It is evident that the absence of an LdASNA homolog from humans and its essentiality for the parasites make LdASNA a novel drug target.
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Affiliation(s)
- Reetika Manhas
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Pankaj Tripathi
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sameena Khan
- Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | | | - Shambhu Krishan Lal
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | | | - Amit Sharma
- Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Rentala Madhubala
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
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Meister A. ACYL PHOSPHATES AS ENZYME-BOUND INTERMEDIATES IN THE BIOSYNTHESIS OF GLUTAMINE, GLUTATHIONE, SUCCINYL COENZYME A, AND CARBAMYL PHOSPHATE*. ACTA ACUST UNITED AC 2012. [DOI: 10.1111/j.2164-0947.1968.tb02563.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Buchanan JM. The amidotransferases. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 39:91-183. [PMID: 4355768 DOI: 10.1002/9780470122846.ch2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Richards NG, Schuster SM. An alternative mechanism for the nitrogen transfer reaction in asparagine synthetase. FEBS Lett 2001; 313:98-102. [PMID: 1358677 DOI: 10.1016/0014-5793(92)81421-h] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In the absence of crystallographic data, the mechanism of nitrogen transfer from glutamine in asparagine synthetase (AS) remains under active investigation. Surprisingly, the glutamine-dependent AS from Escherichia coli (AsnB) appears to lack a conserved histidine residue, necessary for nitrogen transfer if the reaction proceeds by the accepted pathway in other glutamine amidotransferases, but retains the ability to synthesize asparagine. We propose an alternative mechanism for nitrogen transfer in AsnB which obviates the requirement for participation of histidine in this step. Our hypothesis may also be more generally applicable to other glutamine-dependent amidotransferases.
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Affiliation(s)
- N G Richards
- Department of Chemistry, University of Florida, Gainesville 32611
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Richards NG, Schuster SM. Mechanistic issues in asparagine synthetase catalysis. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 1998; 72:145-98. [PMID: 9559053 DOI: 10.1002/9780470123188.ch5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The enzymatic synthesis of asparagine is an ATP-dependent process that utilizes the nitrogen atom derived from either glutamine or ammonia. Despite a long history of kinetic and mechanistic investigation, there is no universally accepted catalytic mechanism for this seemingly straightforward carboxyl group activating enzyme, especially as regards those steps immediately preceding amide bond formation. This chapter considers four issues dealing with the mechanism: (a) the structural organization of the active site(s) partaking in glutamine utilization and aspartate activation; (b) the relationship of asparagine synthetase to other amidotransferases; (c) the way in which ATP is used to activate the beta-carboxyl group; and (d) the detailed mechanism by which nitrogen is transferred.
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Affiliation(s)
- N G Richards
- Department of Chemistry, University of Florida, Gainesville 32611, USA
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Abstract
The lactic dehydrogenase of a strain of Streptococcus bovis specifically requires fructose-1,6-diphosphate for activity. Phosphate or fructose-1-6-diphosphate prevents inactivation of the dehydrogenase, but phosphate and other compounds cannot be substituted for the fructose-1,6-diphosphate required for activity. Lactic dehydrogenases of other species of Streptococcus show a similar requirement for fructose-1,6-diphosphate.
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Boehlein S, Richards N, Schuster S. Glutamine-dependent nitrogen transfer in Escherichia coli asparagine synthetase B. Searching for the catalytic triad. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37307-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Larsen MC, Schuster SM. The topology of the glutamine and ATP binding sites of human asparagine synthetase. Arch Biochem Biophys 1992; 299:15-22. [PMID: 1359839 DOI: 10.1016/0003-9861(92)90238-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Human asparagine synthetase was examined using a combination of chemical modifiers and specific monoclonal antibodies. The studies were designed to determine the topological relation between the nucleotide binding site and the glutamine binding site of the human asparagine synthetase. The purified recombinant enzyme was chemically modified at the glutamine binding site by 6-diazo-5-oxo-L-norleucine (DON), and at the ATP binding site by 8-azidoadenosine 5'-triphosphate (8-N3ATP). The effects of chemical modification with DON included a loss of glutamine-dependent reactions, but no effect on ATP binding as measured during ammonia-dependent asparagine synthesis. Similarly, modification with 8-N3ATP resulted in a loss of ammonia-dependent asparagine synthesis, but no effect on the glutaminase activity. A series of monoclonal antibodies was also examined in relation to their epitopes and the sites modified by the two covalent chemical modifiers. It was found that several antibodies were prevented from binding by specific chemical modification, and that the antibodies could be classified into groups correlating to their relative binding domains. These results are discussed in terms of relative positions of the glutamine and ATP binding sites on asparagine synthetase.
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Affiliation(s)
- M C Larsen
- Department of Chemistry, University of Nebraska-Lincoln 68588-0304
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Saito Y, Nakada Y, Hotta T, Mikami T, Kurisu K, Kiya K, Kawamoto K, Uozumi T. Hypersensitivity of rat glioma sublines with acquired ACNU resistance to L-asparaginase. J Neurosurg 1991; 75:930-4. [PMID: 1682427 DOI: 10.3171/jns.1991.75.6.0930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cell lines resistant to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) show a high degree of collateral sensitivity to L-asparaginase. The mechanism for this phenomenon was investigated by comparing the nutritional requirements and asparagine synthetase activity of the resistant sublines to those of parent cells. Nine ACNU-resistant sublines were isolated from rat glioma 9L cells after incubation with various concentrations of ACNU in Ham's F-12 medium. The 9L cells grew independently of asparagine, developing well in asparagine-deficient Dulbecco's modified Eagle's medium. In contrast, the growth rates of all nine ACNU-resistant sublines decreased under the same conditions and required the addition of 10(-4) M asparagine for maximum growth. Asparagine synthetase activity in the ACNU-resistant cells was much lower than in the 9L cells, suggesting that the requirement for asparagine in the resistant sublines was due to reduced activity of this enzyme. A growth-inhibition assay showed that the ACNU-resistant sublines were more sensitive to L-asparaginase than 9L cells by up to 2 x 10(5)-fold. These results suggest that L-asparaginase therapy has the potential to become a new approach for treating acquired ACNU resistance.
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Affiliation(s)
- Y Saito
- Department of Neurosurgery, Hiroshima University School of Medicine, Japan
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Grafstein D. A role for metabolite enantiomers in the evolution and integration of enzyme driven systems. J Theor Biol 1985; 114:11-20. [PMID: 4010308 DOI: 10.1016/s0022-5193(85)80252-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Blake JS, Salter DN, Smith RH. Incorporation of nitrogen into rumen bacterial fractions of steers given protein- and urea-containing diets. Ammonia assimilation into intracellular bacterial amino acids. Br J Nutr 1983; 50:769-82. [PMID: 6639932 DOI: 10.1079/bjn19830148] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Experiments were carried out in vivo to investigate the pathways of ammonia incorporation into rumen bacteria, bacterial fractions and free amino acids within the bacteria. Steers were alternately given two isoenergetic, isonitrogenous diets containing the nitrogen mainly as either urea or decorticated groundnut meal (DCGM). At the end of each period on a given diet, a solution of 15NH4Cl was infused into the rumen and samples of rumen contents were removed at 2, 10, 20 and 90 min and 5, 10 and 24 h afterwards. Concentrations of ammonia and its 15N enrichment were determined and samples of mixed rumen bacteria were prepared. Bacteria were disrupted ultrasonically and separated into bacterial protein, cell wall and protein-free cell supernatant fractions. Amino acids were separated after hydrolysis and their 15N contents determined. A rumen fluid circulation pump was developed so that representative samples could be taken at very short time intervals after the introduction of the 15N label. Rumen pH changes, rumen fluid dilution rates and patterns of rumen ammonia concentrations were consistent with normal rumen metabolism. Net bacterial synthesis (as calculated from the net outflow of bacteria from the rumen) was significantly (P less than 0.05) greater with the DCGM diet (12.4 g bacterial N/d) than with the urea diet (9.24 g bacterial N/d). With both diets the 15N label rapidly left the rumen ammonia pool and entered the rumen bacteria. Analysis of the bacterial fractions indicated that the label appeared rapidly in the protein-free cell supernatant fraction and more slowly in the bacterial protein and cell wall fractions. With the DCGM diet bacteria apparently utilized intracellular label less efficiently than with the urea diet. The proportion of N in the protein-free cell supernatant was higher with the DCGM diet, suggesting increased levels of intracellular amino acids and peptides, following extracellular protein degradation. Levels of enrichment of the amino acids alanine and glutamate in the protein-free cell supernatant fraction suggested that the enzymes alanine dehydrogenase (EC 1.4.1.1) and glutamate dehydrogenase (EC 1.4.1.2 and 1.4.1.4) may be the major enzymes for assimilating ammonia when concentrations of soluble carbohydrate and rumen ammonia are high in the rumen. The high levels of intracellular alanine are discussed with reference to published work on the excretion of alanine by rumen bacteria.
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Abstract
Neurospora crassa mutants deficient in asparagine synthetase were selected by using the procedure of inositol-less death. Complementation tests among the 100 mutants isolated suggested that their alterations were genetically allelic. Recombination analysis with strain S1007t, an asparagine auxotroph, indicated that the mutations were located near or within the asn gene on linkage group V. In vitro assays with a heterokaryon indicated that the mutation was dominant. Thermal instability of cell extracts from temperature-sensitive strains in an in vitro asparagine synthetase assay determined that the mutations were in the structural gene(s) for asparagine synthetase.
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Hongo S, Sato T. Some molecular properties of asparagine synthetase from rat liver. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 742:484-9. [PMID: 6132621 DOI: 10.1016/0167-4838(83)90265-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Asparagine synthetase purified from rat liver reveals two species (slower migrating band I and faster migrating band II) when subjected to polyacrylamide gel electrophoresis under nondenaturing conditions (S. Hongo and T. Sato (1981) Anal. Biochem. 114, 163-166). We have investigated some molecular properties of these species. Elution of band I from the gel and re-electrophoresis showed that band I yielded band II similar to that of the initial run. Peptide maps by limited proteolysis were very similar and amino acid compositions were also alike in the two species. L-Lysine was identified as the sole NH2-terminal amino acid in both the species. By cross-linking experiments the enzyme was shown to be a dimeric protein. When the purified enzyme was subjected to isoelectric focusing the enzyme activity and protein focused at pH 6.0 in a single peak. These results demonstrate that rat liver asparagine synthetase is composed of two identical subunits. The enzyme, inactivated by storage at -20 degrees C for about 3 months, showed aggregated forms in polyacrylamide gel electrophoresis, and was reactivated markedly by the addition of dithiothreitol.
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Abstract
This review describes the progress which has been made during the last 10 to 15 years in the field of rumen microbiology. It is basically an account of new discoveries in the bacteriology, protozoology, biochemistry, and ecology of the rumen microbial population. As such it covers a wide range of subjects including the isolation and properties of methanogenic bacteria, the role of rumen phycomycete fungi, anaerobic energy conservation, and general metabolic aspects of rumen microorganisms. It also attempts, however, to describe and develop new concepts in rumen microbiology. These consist principally of interactions of the microbemicrobe, microbe-food and microbe-host types, and represent the main areas of recent advance in our understanding of the rumen ecosystem. The development of experimental techniques such as chemostat culture and scanning electron microscopy are shown to have been instrumental in progress in these areas. The paper is concluded with an assessment of our present knowledge of the rumen fermentation, based on the degree of success of experiments with gnotobiotic ruminants inoculated with defined flora and in mathematical modeling of the fermentation. The efficacy of chemical manipulation of the fermentation in ruminant is also discussed in this light.
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Humbert R, Simoni RD. Genetic and biomedical studies demonstrating a second gene coding for asparagine synthetase in Escherichia coli. J Bacteriol 1980; 142:212-20. [PMID: 6102982 PMCID: PMC293932 DOI: 10.1128/jb.142.1.212-220.1980] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Genetic experiments have indicated that asparagine auxotrophs of Escherichias coli K-12 can be made asparagine prototrophs at either of two sites on the chromosome and that wild-type strains require both sites to be mutated to produce asparagine auxotrophy. The former asn locus is now called asnA, and the new gene is designated asnB. The asnB gene is located near gal.AsnA+ asnB and asnA asnB+ strains were constructed, and the asparagine synthetic reaction was characterized in extracts. These studies revealed that the asnA gene codes for the enzyme previously described (H. Cedar and J.H. Schwartz, J. Biol. Chem. 244: 4112-4121, 1969), whereas the asnB gene is involved in the production of an enzyme which differs from the one previously described in its specific activity in extracts, its stability at low and high temperatures, and its apparent ability to use either glutamine or ammonia as amide nitrogen donor. Physiological studies showed that either enzyme alone is sufficient to allow a maximal growth rate under conditions of asparagine limitation.
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Wallace RJ. Effect of ammonia concentration on the composition, hydrolytic activity and nitrogen metabolism of the microbial flora of the rumen. THE JOURNAL OF APPLIED BACTERIOLOGY 1979; 47:443-55. [PMID: 541305 DOI: 10.1111/j.1365-2672.1979.tb01205.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Hongo S, Matsumoto T, Sato T. Purification and properties of asparagine synthetase from rat liver. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 522:258-66. [PMID: 23163 DOI: 10.1016/0005-2744(78)90342-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Asparagine synthetase (L-aspartate:ammonia ligase (AMP-forming, EC 6.3.1.1) activity in rat liver increased when the animals were put on a low casein diet. The enzyme was purified about 280-fold from the supernatant of rat liver homogenate by a procedure comprising ammonium sulfate fractionation. DEAE-Sepharose column chromatography, and Sephadex G-100 gel filtration. The optimal pH of the enzyme was in the range 7.4-7.6 with glutamine as an amide donor. The molecular weight was estimated to be approximately 110,000 by gel filtration. Chloride ion was required for the enzyme activity. The apparent Km values for L-aspartate, L-glutamine, ammonium chloride, ATP, and Cl- were calculated to be 0.76, 4.3, 10, 0.14, and 1.7 mM, respectively. The activity was inhibited by L-asparagine, nucleoside triphosphates except ATP, and sulfhydryl reagents. It has been observed that the properties of asparagine synthetase from rat liver are not so different from those of tumors such as Novikoff hepatoma and RADA 1.
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Erfle JD, Sauer FS, Mahadevan S. Effect of ammonia concentration on activity of enzymes of ammonia assimilation and on synthesis of amino acids by mixed rumen bacteria in continuous culture. J Dairy Sci 1977; 60:1064-72. [PMID: 18495 DOI: 10.3168/jds.s0022-0302(77)83989-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Kleiner D, Kleinschmidt JA. Selective inactivation of nitrogenase in Azotobacter vinelandii batch cultures. J Bacteriol 1976; 128:117-22. [PMID: 977536 PMCID: PMC232833 DOI: 10.1128/jb.128.1.117-122.1976] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
When the exhaustion of sucrose or sulfate or the induction of encystment (by incubation in 0.2% beta-hydroxybutyrate) leads to termination of growth in Azotobacter vinelandii batch cultures, the nitrogenase levels in the organisms decreased rapidly, whereas glutamate synthase and glutamine synthetase levels remained unaltered. Glutamate dehydrogenase activities were low during the whole culture cycle, indicating that ammonia assimilation proceeds via glutamine. Toward depletion of sucrose or during induction of encystment, slight secretion of ammonia with subsequent reabsorption was occasionally observed, whereas massive ammonia excretion occurred when the sulfate became exhausted. The extracellular ammonia levels were paralleled by changes in the glutamine synthetase activity. The inactivation of the nitrogenase is explained as a result of rising oxygen tension, a consequence of a metabolic shift-down (reduced respiration) that occurs in organisms entering the stationary phase.
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17. Asparagine Synthesis. ACTA ACUST UNITED AC 1974. [DOI: 10.1016/s1874-6047(08)60149-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Streeter JG. In vivo and in vitro studies on asparagine biosynthesis in soybean seedlings. Arch Biochem Biophys 1973; 157:613-24. [PMID: 4738382 DOI: 10.1016/0003-9861(73)90681-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Prusiner S, Milner L. A rapid radioactive assay for glutamine synthetase, glutaminase, asparagine synthetase, and asparaginase. Anal Biochem 1970; 37:429-38. [PMID: 4920285 DOI: 10.1016/0003-2697(70)90069-2] [Citation(s) in RCA: 124] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Affiliation(s)
- Sven Erik Rognes
- Botanical Laboratory, University of Oslo, Postbox 1045, Blindern, 3, Oslo, Norway
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Chalupa W, Clark J, Opliger P, Lavker R. Ammonia metabolism in rumen bacteria and mucosa from sheep fed soy protein or urea. J Nutr 1970; 100:161-9. [PMID: 5461136 DOI: 10.1093/jn/100.2.161] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Canellos GP, Haskell CM. Studies of resistance to L-asparaginase in human leukemia. Recent Results Cancer Res 1970; 33:188-93. [PMID: 4949162 DOI: 10.1007/978-3-642-99984-0_23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Prager MD, Bachynsky N. Asparagine synthetase in normal and malignant tissues: correlation with tumor sensitivity to asparaginase. Arch Biochem Biophys 1968; 127:645-54. [PMID: 4880551 DOI: 10.1016/0003-9861(68)90273-7] [Citation(s) in RCA: 78] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Lees EM, Farnden KJ, Elliott WH. Studies on asparagine synthesis and utilization in seedlings. Arch Biochem Biophys 1968; 126:539-46. [PMID: 5672512 DOI: 10.1016/0003-9861(68)90439-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Prager MD, Bachynsky N. Asparagine synthetase in asparaginase resistant and susceptible mouse lymphomas. Biochem Biophys Res Commun 1968; 31:43-7. [PMID: 4869945 DOI: 10.1016/0006-291x(68)90028-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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