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Sánchez-Moguel I, Costa-Silva TA, Pillaca-Pullo OS, Flores-Santos JC, Freire RKB, Carretero G, da Luz Bueno J, Camacho-Córdova DI, Santos JH, Sette LD, Pessoa-Jr A. Antarctic yeasts as a source of L-asparaginase: characterization of a glutaminase-activity free L-asparaginase from psychrotolerant yeast Leucosporidium scottii L115. Process Biochem 2023. [DOI: 10.1016/j.procbio.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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da Silva LS, Doonan LB, Pessoa A, de Oliveira MA, Long PF. Structural and functional diversity of asparaginases: Overview and recommendations for a revised nomenclature. Biotechnol Appl Biochem 2021; 69:503-513. [PMID: 33624365 DOI: 10.1002/bab.2127] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 02/09/2021] [Indexed: 12/19/2022]
Abstract
Asparaginases (ASNases) are a large and structurally diverse group of enzymes ubiquitous amongst archaea, bacteria and eukaryotes, that catalyze hydrolysis of asparagine to aspartate and ammonia. Bacterial ASNases are important biopharmaceuticals for the treatment of acute lymphoblastic leukemia, although some patients experience adverse allergic side effects during treatment with these protein therapeutics. ASNases are currently divided into three families: plant-type ASNases, Rhizobium etli-type ASNases and bacterial-type ASNases. This system is outdated as both bacterial-type and plant-type families also include archaeal, bacterial and eukaryotic enzymes, each with their own distinct characteristics. Herein, phylogenetic studies allied to tertiary structural analyses are described with the aim of proposing a revised and more robust classification system that considers the biochemical diversity of ASNases. Accordingly, based on distinct peptide domains, phylogenetic data, structural analysis and functional characteristics, we recommend that ASNases now be divided into three new distinct classes containing subgroups according to structural and functional aspects. Using this new classification scheme, 25 ASNases were identified as candidates for future new lead discovery.
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Affiliation(s)
- Leonardo Schultz da Silva
- Instituto de Biociências, Universidade Estadual Paulista (UNESP), São Vicente, São Paulo, Brazil.,Institute of Pharmaceutical Science, School of Cancer & Pharmaceutical Sciences, Faculty of Life Sciences & Medicine, King's College London, UK
| | - Liam B Doonan
- Institute of Pharmaceutical Science, School of Cancer & Pharmaceutical Sciences, Faculty of Life Sciences & Medicine, King's College London, UK
| | - Adalberto Pessoa
- Departamento de Tecnologia Tecnologia Bioquímico-Farmacêuticas, Faculdade de Ciencias Farmaceuticas, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | | | - Paul F Long
- Institute of Pharmaceutical Science, School of Cancer & Pharmaceutical Sciences, Faculty of Life Sciences & Medicine, King's College London, UK.,Departamento de Tecnologia Tecnologia Bioquímico-Farmacêuticas, Faculdade de Ciencias Farmaceuticas, Universidade de São Paulo, São Paulo, São Paulo, Brazil
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Expression, purification, and characterization of asparaginase II from Saccharomyces cerevisiae in Escherichia coli. Protein Expr Purif 2019; 159:21-26. [PMID: 30836141 DOI: 10.1016/j.pep.2019.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/17/2018] [Accepted: 02/19/2019] [Indexed: 11/22/2022]
Abstract
l-asparaginase catalyzes the conversion of l-asparagine to l-aspartate and ammonium. This protein is an important therapeutic enzyme used for the treatment of acute lymphoblastic leukemia. In this study, the asparaginase II-encoding gene ASP3 from Saccharomyces cerevisiae was cloned into the expression vector pET28a in-fusion with a 6x histidine tag and was expressed in Escherichia coli BL21 (DE3) cells. The protein was expressed at a high level (225.6 IU/g cells) as an intracellular and soluble molecule and was purified from the supernatant by nickel affinity chromatography. The enzyme showed very low activity against l-glutamine. The denaturing electrophoresis analysis indicated that the recombinant protein had a molecular mass of ∼38 kDa. The native enzyme was a tetramer with a molecular mass of approximately 178 kDa. The enzyme preparation showed antitumor activity against the K562 and Jurkat cell lines comparable or even superior to the E. coli commercial asparaginase.
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Rodrigues D, Pillaca-Pullo O, Torres-Obreque K, Flores-Santos J, Sánchez-Moguel I, Pimenta MV, Basi T, Converti A, Lopes AM, Monteiro G, Fonseca LP, Pessoa AJ. Fed-Batch Production of Saccharomyces cerevisiae L-Asparaginase II by Recombinant Pichia pastoris MUT s Strain. Front Bioeng Biotechnol 2019; 7:16. [PMID: 30800657 PMCID: PMC6375902 DOI: 10.3389/fbioe.2019.00016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 01/22/2019] [Indexed: 01/31/2023] Open
Abstract
L-Asparaginase (ASNase) is used in the treatment of acute lymphoblastic leukemia, being produced and commercialized only from bacterial sources. Alternative Saccharomyces cerevisiae ASNase II coded by the ASP3 gene was biosynthesized by recombinant Pichia pastoris MUT s under the control of the AOX1 promoter, using different cultivation strategies. In particular, we applied multistage fed-batch cultivation divided in four distinct phases to produce ASNase II and determine the fermentation parameters, namely specific growth rate, biomass yield, and enzyme activity. Cultivation of recombinant P. pastoris under favorable conditions in a modified defined medium ensured a dry biomass concentration of 31 gdcw.L-1 during glycerol batch phase, corresponding to a biomass yield of 0.77 gdcw.gglycerol - 1 and a specific growth rate of 0.21 h-1. After 12 h of glycerol feeding under limiting conditions, cell concentration achieved 65 gdcw.L-1 while ethanol concentration was very low. During the phase of methanol induction, biomass concentration achieved 91 gdcw.L-1, periplasmic specific enzyme activity 37.1 U.gdcw - 1 , volumetric enzyme activity 3,315 U.L-1, overall enzyme volumetric productivity 31 U.L-1.h-1, while the specific growth rate fell to 0.039 h-1. Our results showed that the best strategy employed for the ASNase II production was using glycerol fed-batch phase with pseudo exponential feeding plus induction with continuous methanol feeding.
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Affiliation(s)
- David Rodrigues
- Bioengineering Department of Instituto Superior Técnico, Institute of Bioengineering and Biosciences, Universidade de Lisboa, Lisbon, Portugal
| | - Omar Pillaca-Pullo
- Department of Pharmaceutical-Biochemical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Karin Torres-Obreque
- Department of Pharmaceutical-Biochemical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Juan Flores-Santos
- Department of Pharmaceutical-Biochemical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ignacio Sánchez-Moguel
- Department of Pharmaceutical-Biochemical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Marcela V. Pimenta
- Department of Pharmaceutical-Biochemical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Tajindar Basi
- Department of Pharmacy, King's College London, London, United Kingdom
| | - Attilio Converti
- Department of Civil, Chemical and Environmental Engineering, Genova, Italy
| | - André M. Lopes
- Faculty of Pharmaceutical Sciences, University of Campinas, Campinas, Brazil
| | - Gisele Monteiro
- Department of Pharmaceutical-Biochemical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Luís P. Fonseca
- Bioengineering Department of Instituto Superior Técnico, Institute of Bioengineering and Biosciences, Universidade de Lisboa, Lisbon, Portugal
| | - Adalberto Jr. Pessoa
- Department of Pharmaceutical-Biochemical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
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Fujita K, Kunito T, Matsushita J, Nakamura K, Moro H, Yoshida S, Toda H, Otsuka S, Nagaoka K. Nitrogen supply rate regulates microbial resource allocation for synthesis of nitrogen-acquiring enzymes. PLoS One 2018; 13:e0202086. [PMID: 30106996 PMCID: PMC6091965 DOI: 10.1371/journal.pone.0202086] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 07/29/2018] [Indexed: 11/19/2022] Open
Abstract
Although microorganisms will preferentially allocate resources to synthesis of nitrogen (N)-acquiring enzymes when soil N availability is low according to the resource allocation model for extracellular enzyme synthesis, a robust link between microbial N-acquiring enzyme activity and soil N concentration has not been reported. To verify this link, we measured several indices of soil N availability and enzyme activity of four N-acquiring enzymes [N-acetyl-β-glucosaminidase (NAG), protease (PR), urease (UR), and L-asparaginase (LA)] and a carbon (C)-acquiring enzyme [β-D-glucosidase (BG)] in arable and forest soils. Although the ratios of NAG/BG and PR/BG were not significantly related with indices of soil N availability, ratios of LA/BG and UR/BG were strongly and negatively related with potentially mineralizable N estimated by aerobic incubation but not with pools of labile inorganic N and organic N. These results suggest that microorganisms might allocate their resources to LA and UR synthesis in response to N supply rate rather than the size of the easily available N pools. It was also suggested that the underlying mechanism for synthesis was different between these N-acquiring enzymes in soil microorganisms: microbial LA and UR were primarily synthesized to acquire N, whereas NAG and PR syntheses were regulated not only by N availability but also by other factors.
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Affiliation(s)
- Kazuki Fujita
- Department of Environmental Sciences, Faculty of Science, Shinshu University, Matsumoto, Japan
| | - Takashi Kunito
- Department of Environmental Sciences, Faculty of Science, Shinshu University, Matsumoto, Japan
- * E-mail:
| | - Junko Matsushita
- Department of Environmental Sciences, Faculty of Science, Shinshu University, Matsumoto, Japan
| | - Kaori Nakamura
- Department of Environmental Sciences, Faculty of Science, Shinshu University, Matsumoto, Japan
| | - Hitoshi Moro
- Department of Environmental Sciences, Faculty of Science, Shinshu University, Matsumoto, Japan
| | - Seishi Yoshida
- Nagano Prefecture Vegetable and Ornamental Crops Experiment Station, Shiojiri, Japan
| | - Hideshige Toda
- Department of Environmental Sciences, Faculty of Science, Shinshu University, Matsumoto, Japan
| | - Shigeto Otsuka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Kazunari Nagaoka
- Central Region Agricultural Research Center, NARO, Tsukuba, Japan
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Einsfeldt K, Baptista IC, Pereira JCCV, Costa-Amaral IC, da Costa ES, Ribeiro MCM, Land MGP, Alves TLM, Larentis AL, Almeida RV. Recombinant L-Asparaginase from Zymomonas mobilis: A Potential New Antileukemic Agent Produced in Escherichia coli. PLoS One 2016; 11:e0156692. [PMID: 27253887 PMCID: PMC4890785 DOI: 10.1371/journal.pone.0156692] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 05/18/2016] [Indexed: 01/11/2023] Open
Abstract
L-asparaginase is an enzyme used as a chemotherapeutic agent, mainly for treating acute lymphoblastic leukemia. In this study, the gene of L-asparaginase from Zymomonas mobilis was cloned in pET vectors, fused to a histidine tag, and had its codons optimized. The L-asparaginase was expressed extracellularly and intracellularly (cytoplasmically) in Escherichia coli in far larger quantities than obtained from the microorganism of origin, and sufficient for initial cytotoxicity tests on leukemic cells. The in silico analysis of the protein from Z. mobilis indicated the presence of a signal peptide in the sequence, as well as high identity to other sequences of L-asparaginases with antileukemic activity. The protein was expressed in a bioreactor with a complex culture medium, yielding 0.13 IU/mL extracellular L-asparaginase and 3.6 IU/mL intracellular L-asparaginase after 4 h of induction with IPTG. The cytotoxicity results suggest that recombinant L-asparaginase from Z. mobilis expressed extracellularly in E.coli has a cytotoxic and cytostatic effect on leukemic cells.
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Affiliation(s)
- Karen Einsfeldt
- Programa de Engenharia Química, COPPE, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- * E-mail: (ALL); (KE); (RVA)
| | - Isis Cavalcante Baptista
- Programa de Engenharia Química, COPPE, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Clínica Médica, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Juliana Christina Castanheira Vicente Pereira
- Programa de Engenharia Química, COPPE, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Isabele Campos Costa-Amaral
- Programa de Saúde Pública e Meio Ambiente, Escola Nacional de Saúde Pública Sergio Arouca (ENSP), Centro de Estudos da Saúde do Trabalhador e Ecologia Humana (CESTEH), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Rio de Janeiro, Brazil
| | - Elaine Sobral da Costa
- Programa de Pós-Graduação em Clínica Médica, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Maria Cecília Menks Ribeiro
- Programa de Pós-Graduação em Clínica Médica, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Marcelo Gerardin Poirot Land
- Programa de Pós-Graduação em Clínica Médica, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Tito Lívio Moitinho Alves
- Programa de Engenharia Química, COPPE, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Ariane Leites Larentis
- Programa de Saúde Pública e Meio Ambiente, Escola Nacional de Saúde Pública Sergio Arouca (ENSP), Centro de Estudos da Saúde do Trabalhador e Ecologia Humana (CESTEH), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail: (ALL); (KE); (RVA)
| | - Rodrigo Volcan Almeida
- Programa de Pós-Graduação em Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- * E-mail: (ALL); (KE); (RVA)
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7
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Schalk AM, Antansijevic A, Caffrey M, Lavie A. Experimental Data in Support of a Direct Displacement Mechanism for Type I/II L-Asparaginases. J Biol Chem 2016; 291:5088-100. [PMID: 26733195 DOI: 10.1074/jbc.m115.699884] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Indexed: 01/02/2023] Open
Abstract
Bacterial L-asparaginases play an important role in the treatment of certain types of blood cancers. We are exploring the guinea pig L-asparaginase (gpASNase1) as a potential replacement of the immunogenic bacterial enzymes. The exact mechanism used by L-asparaginases to catalyze the hydrolysis of asparagine into aspartic acid and ammonia has been recently put into question. Earlier experimental data suggested that the reaction proceeds via a covalent intermediate using a ping-pong mechanism, whereas recent computational work advocates the direct displacement of the amine by an activated water. To shed light on this controversy, we generated gpASNase1 mutants of conserved active site residues (T19A, T116A, T19A/T116A, K188M, and Y308F) suspected to play a role in hydrolysis. Using x-ray crystallography, we determined the crystal structures of the T19A, T116A, and K188M mutants soaked in asparagine. We also characterized their steady-state kinetic properties and analyzed the conversion of asparagine to aspartate using NMR. Our structures reveal bound asparagine in the active site that has unambiguously not formed a covalent intermediate. Kinetic and NMR assays detect significant residual activity for all of the mutants. Furthermore, no burst of ammonia production was observed that would indicate covalent intermediate formation and the presence of a ping-pong mechanism. Hence, despite using a variety of techniques, we were unable to obtain experimental evidence that would support the formation of a covalent intermediate. Consequently, our observations support a direct displacement rather than a ping-pong mechanism for l-asparaginases.
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Affiliation(s)
- Amanda M Schalk
- From the Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois 60607 and
| | - Aleksandar Antansijevic
- From the Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois 60607 and
| | - Michael Caffrey
- From the Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois 60607 and
| | - Arnon Lavie
- From the Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois 60607 and the Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois 60612
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8
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Ferrara MA, Severino NM, Mansure JJ, Martins AS, Oliveira EM, Siani AC, Pereira N, Torres FA, Bon EP. Asparaginase production by a recombinant Pichia pastoris strain harbouring Saccharomyces cerevisiae ASP3 gene. Enzyme Microb Technol 2006. [DOI: 10.1016/j.enzmictec.2006.03.036] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Kotzia GA, Labrou NE. Cloning, expression and characterisation of Erwinia carotovora l-asparaginase. J Biotechnol 2005; 119:309-23. [PMID: 15951039 DOI: 10.1016/j.jbiotec.2005.04.016] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Revised: 04/08/2005] [Accepted: 04/19/2005] [Indexed: 11/28/2022]
Abstract
Bacterial L-asparaginases (E.C. 3.5.1.1) have been used as therapeutic agents in the treatment of acute childhood lymphoblastic leukaemia. L-asparaginase from Erwinia carotovora NCYC 1526 (ErA) was cloned and expressed in E. coli. The enzyme was purified to homogeneity by a two-step procedure comprising cation-exchange chromatography and affinity chromatography on immobilised L-asparagine. The enzymatic properties of the recombinant enzyme were investigated and the kinetic parameters (K(m), k(cat)) for a number of substrates were determined. Molecular modelling studies were also employed to create a model of ErA, based on the known structure of the Erwinia chrysanthemi enzyme. The molecular model was used to help interpret biochemical data concerning substrate specificity and catalytic mechanism of the enzyme. The kinetic parameters of selected substrates were determined at various pH values, and the pH-dependence profiles of V(max) and V(max)/K(m) were analyzed. The pH-dependence of V(max) shows one transition in the acidic pH range with pK(a)=5.4, and the pH-dependence of V(max)/K(m) exhibits two transitions with pK(a)=5.4 and 8.5. Based on analysis of alternative substrates and molecular modelling studies, it was concluded that the pK(a) at the acidic pH range corresponds to the active site residues Asp115 or Glu82, whereas the pK(a) observed at the alkaline pH range is not due to substrate amino group ionisation, but rather is the result of enzyme ionisation. The effect of temperature and viscosity on the catalytic activity of the enzyme was also investigated and it was concluded that the rate-limiting step of the catalytic reaction is relevant to structural transitions of the protein. Thermodynamic analysis of the activity data showed that the activation energies are dependent on the substrate, and entropy changes appear to be the main determinant contributing to substrate specificity.
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Affiliation(s)
- Georgia A Kotzia
- Laboratory of Enzyme Technology, Department of Agricultural Biotechnology, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
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Tsuji N, Morales TH, Ozols VV, Carmody AB, Chandrashekar R. Identification of an asparagine amidohydrolase from the filarial parasite Dirofilaria immitis. Int J Parasitol 1999; 29:1451-5. [PMID: 10579432 DOI: 10.1016/s0020-7519(99)00087-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The nematode cuticle is a complex extracellular structure which is secreted by an underlying syncytium of hypodermal cells. Recent studies have demonstrated that the cuticle of parasitic nematodes is a dynamic structure with important absorptive, secretory, and enzymatic activities. In addition, the cuticle serves as a protective barrier against the host. A 48-h third stage larval Dirofilaria immitis cDNA library was immunoscreened with sera raised against larval cuticles. One clone, L3MC4 that reacted strongly with the anti-cuticle antisera was sequenced. The composite cDNA sequence comprises 2073 bp coding for a full-length protein of 590 amino acids. GenBank analysis showed that DiAsp had significant similarity to a Caenorhabditis elegans gene-product (54% identity) and to other asparaginases at the amino acid level. Escherichia coli-expressed recombinant DiAsp (rDiAsp) catalysed the hydrolysis of asparagine to aspartate and ammonia. Antibodies raised against D. immitis larval cuticles reacted with rDiAsp in immunoblots. This is the first report of identification of a cDNA clone encoding an asparaginase enzyme from a parasitic nematode.
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Affiliation(s)
- N Tsuji
- Heska Corporation, Fort Collins, Colorado 80525, USA
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11
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Ramakrishnan MS, Joseph R. Characterization of an extracellular asparaginase ofRhodosporidium toruloidesCBS14 exhibiting unique physicochemical properties. Can J Microbiol 1996. [DOI: 10.1139/m96-047] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An asparaginase specific for L-asparagine was purified from Rhodosporidium toruloides CBS14 to apparent homogeneity. The enzyme was associated with L-glutaminase activity (Km, 1.43 × 10−3 M for L-asparagine and 6.45 × 10−3 M for L-glutamine). The enzyme was found to be a homodimer with a subunit molecular mass of 87 kDa. Chemical modification of tryptophan residues significantly reduced both L-asparaginase and L-glutaminase activities of the enzyme, which was prevented by the presence of either of the substrates L-asparagine or L-glutamine. The pH and temperature optima for both activities were 6.35 and 37 °C. The enzyme was serologically identical with the asparaginases of some of the other Rhodotorula and Rhodosporidium yeasts but was distinct from the asparaginase of Saccharomyces cerevisiae.Key words: asparaginase, glutaminase, Rhodosporidium toruloides.
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13
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Kim KW, Roon RJ. Asparaginase II of Saccharomyces cerevisiae: positive selection of two mutations that prevent enzyme synthesis. J Bacteriol 1984; 157:958-61. [PMID: 6365897 PMCID: PMC215357 DOI: 10.1128/jb.157.3.958-961.1984] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A positive selection method, D-aspartic acid beta-hydroxamate resistance, was used to isolate Saccharomyces cerevisiae strains lacking the ability to synthesize asparaginase II. Of 100 such mutant strains, 93 exhibited mutations which were allelic with asp3, a previously characterized mutation. The other seven strains carried a new mutation, asp6. The asp6 mutation segregated 2:2 in asp6 X wild-type crosses and assorted from the asp3 mutation in asp6 X asp3 crosses. All seven asp6 mutant isolates reverted at a relatively high frequency, whereas the asp3 mutant isolates did not revert under the same conditions. Various independent asp3 isolates were mated to give heteroallelic diploids, which when sporulated and spread on D-asparagine medium yielded no recombinant strains.
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14
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Pahuja SL, Reid TW. Thin-layer chromatographic determination of L-asparaginase in the presence of human serum. JOURNAL OF CHROMATOGRAPHY 1983; 273:431-5. [PMID: 6345564 DOI: 10.1016/s0378-4347(00)80966-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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15
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Roon RJ, Murdoch M, Kunze B, Dunlop PC. Derepression of asparaginase II during exponential growth of Saccharomyces cerevisiae on ammonium ion. Arch Biochem Biophys 1982; 219:101-9. [PMID: 6758700 DOI: 10.1016/0003-9861(82)90138-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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16
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Kang L, Keeler ML, Dunlop PC, Roon RJ. Nitrogen catabolite repression in a glutamate auxotroph of Saccharomyces cerevisiae. J Bacteriol 1982; 151:29-35. [PMID: 6123500 PMCID: PMC220181 DOI: 10.1128/jb.151.1.29-35.1982] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The biosynthesis of asparaginase II in Saccharomyces cerevisiae is subject to nitrogen catabolite repression. In the present study we examined the physiological effects of glutamate auxotrophy on cellular metabolism and on the nitrogen catabolite repression of asparaginase II. Glutamate auxotrophic cells, incubated without a glutamate supplement, had a diminished internal pool of alpha-ketoglutarate and a concomitant inability to equilibrate ammonium ion with alpha-amino nitrogen. In the glutamate auxotroph, asparaginase II biosynthesis exhibited a decreased sensitivity to nitrogen catabolite repression by ammonium ion but normal sensitivity to nitrogen catabolite repression by all amino acids tested.
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17
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Dunlop PC, Meyer GM, Roon RJ. Nitrogen catabolite repression of asparaginase II in Saccharomyces cerevisiae. J Bacteriol 1980; 143:422-6. [PMID: 6995441 PMCID: PMC294261 DOI: 10.1128/jb.143.1.422-426.1980] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The biosynthesis of asparaginase II in Saccharomyces cerevisiae is subject to strong catabolite repression by a variety of nitrogen compounds. In the present study, asparaginase II synthesis was examined in a wild-type yeast strain and in strains carrying gdhA, gdhCR, or gdhCS mutations. The following effects were observed: (i) In the wild-type strain, the biosynthesis of asparaginase II was strongly repressed when either 10 mM ammonium sulfate or various amino acids (10 mM) served as the source of nitrogen. (ii) In a yeast strain carrying the gdhA mutation, asparaginase II was synthesized at fully derepressed levels when 10 mM ammonium sulfate was the source of nitrogen. When amino acids (10 mM) served as the nitrogen source, asparaginase II synthesis was strongly repressed. (iii) In a strain carrying the gdhCR mutation, the synthesis of asparaginase II was partially (30 to 40%) derepressed when either 10 mM ammonium sulfate or amino acids were present in the medium. (iv) In a yeast strain containing both gdhA and gdhCR mutations, asparaginase II synthesis was fully derepressed when 10 mM ammonium sulfate was the nitrogen source and partially derepressed when 10 mM amino acids were present. (v) Yeast strains carrying the gdhCS mutation were indistinguishable from the wild-type strain with respect to asparaginase II synthesis.
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