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Belanger CR, Dostert M, Blimkie TM, Lee AHY, Dhillon BK, Wu BC, Akhoundsadegh N, Rahanjam N, Castillo-Arnemann J, Falsafi R, Pletzer D, Haney CH, Hancock REW. Surviving the host: Microbial metabolic genes required for growth of Pseudomonas aeruginosa in physiologically-relevant conditions. Front Microbiol 2022; 13:1055512. [PMID: 36504765 PMCID: PMC9732424 DOI: 10.3389/fmicb.2022.1055512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/31/2022] [Indexed: 11/27/2022] Open
Abstract
Pseudomonas aeruginosa, like other pathogens, adapts to the limiting nutritional environment of the host by altering patterns of gene expression and utilizing alternative pathways required for survival. Understanding the genes essential for survival in the host gives insight into pathways that this organism requires during infection and has the potential to identify better ways to treat infections. Here, we used a saturated transposon insertion mutant pool of P. aeruginosa strain PAO1 and transposon insertion sequencing (Tn-Seq), to identify genes conditionally important for survival under conditions mimicking the environment of a nosocomial infection. Conditions tested included tissue culture medium with and without human serum, a murine abscess model, and a human skin organoid model. Genes known to be upregulated during infections, as well as those involved in nucleotide metabolism, and cobalamin (vitamin B12) biosynthesis, etc., were required for survival in vivo- and in host mimicking conditions, but not in nutrient rich lab medium, Mueller Hinton broth (MHB). Correspondingly, mutants in genes encoding proteins of nucleotide and cobalamin metabolism pathways were shown to have growth defects under physiologically-relevant media conditions, in vivo, and in vivo-like models, and were downregulated in expression under these conditions, when compared to MHB. This study provides evidence for the relevance of studying P. aeruginosa fitness in physiologically-relevant host mimicking conditions and identified metabolic pathways that represent potential novel targets for alternative therapies.
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Affiliation(s)
- Corrie R. Belanger
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Melanie Dostert
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Travis M. Blimkie
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Amy Huei-Yi Lee
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada,Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Bhavjinder Kaur Dhillon
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Bing Catherine Wu
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Noushin Akhoundsadegh
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Negin Rahanjam
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Javier Castillo-Arnemann
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Reza Falsafi
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Daniel Pletzer
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada,Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Cara H. Haney
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Robert E. W. Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada,*Correspondence: Robert E. W. Hancock,
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2
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Abstract
Diazo groups have broad and tunable reactivity. That and other attributes endow diazo compounds with the potential to be valuable reagents for chemical biologists. The presence of diazo groups in natural products underscores their metabolic stability and anticipates their utility in a biological context. The chemoselectivity of diazo groups, even in the presence of azido groups, presents many opportunities. Already, diazo compounds have served as chemical probes and elicited novel modifications of proteins and nucleic acids. Here, we review advances that have facilitated the chemical synthesis of diazo compounds, and we highlight applications of diazo compounds in the detection and modification of biomolecules.
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Affiliation(s)
- Kalie A. Mix
- Department of Biochemistry, University of Wisconsin–Madison, 433 Babcock Drive, Madison, Wisconsin 53706, United States
| | - Matthew R. Aronoff
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Ronald T. Raines
- Department of Biochemistry, University of Wisconsin–Madison, 433 Babcock Drive, Madison, Wisconsin 53706, United States
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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3
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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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4
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Yao T, Okano G. Simultaneous determination of L-glutamate, acetylcholine and dopamine in rat brain by a flow-injection biosensor system with microdialysis sampling. ANAL SCI 2008; 24:1469-73. [PMID: 18997377 DOI: 10.2116/analsci.24.1469] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A flow-injection biosensor system with an on-line microdialysis sampling system is proposed for the simultaneous detection of neurotransmitters (L-glutamate, acetylcholine and dopamine) released from rat brain cells. The dialysate collected in the sample loop from the microdialysis probe was automatically injected into the flow-injection line with a triple electrode arranged perpendicular to the flow direction. The triple electrode was constructed by hybridizing a poly(1,2-diaminobenzene) film to two enzyme sensing-parts which respond to L-glutamate and acetylcholine, and by coating a Nafion film on a remaining sensing part which responds to dopamine, respectively, without any cross-reactivity. The three sensing parts of the triple electrode responded linearly to the concentrations of L-glutamate and acetylcholine in the range of 0.002-5 mM and to that of dopamine in the range of 0.002-20 mM, respectively, without any interference from oxidizable species present in the dialysate. The proposed flow-injection analytical method could be applied to an in vivo assay of these neurotransmitters released from rat-brain cells by the continuous KCl stimulation.
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Affiliation(s)
- Toshio Yao
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Naka, Sakai, Osaka 599-8531, Japan
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5
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Brown G, Singer A, Proudfoot M, Skarina T, Kim Y, Chang C, Dementieva I, Kuznetsova E, Gonzalez CF, Joachimiak A, Savchenko A, Yakunin AF. Functional and structural characterization of four glutaminases from Escherichia coli and Bacillus subtilis. Biochemistry 2008; 47:5724-35. [PMID: 18459799 DOI: 10.1021/bi800097h] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glutaminases belong to the large superfamily of serine-dependent beta-lactamases and penicillin-binding proteins, and they catalyze the hydrolytic deamidation of L-glutamine to L-glutamate. In this work, we purified and biochemically characterized four predicted glutaminases from Escherichia coli (YbaS and YneH) and Bacillus subtilis (YlaM and YbgJ). The proteins demonstrated strict specificity to L-glutamine and did not hydrolyze D-glutamine or L-asparagine. In each organism, one glutaminase showed higher affinity to glutamine ( E. coli YbaS and B. subtilis YlaM; K m 7.3 and 7.6 mM, respectively) than the second glutaminase ( E. coli YneH and B. subtilis YbgJ; K m 27.6 and 30.6 mM, respectively). The crystal structures of the E. coli YbaS and the B. subtilis YbgJ revealed the presence of a classical beta-lactamase-like fold and conservation of several key catalytic residues of beta-lactamases (Ser74, Lys77, Asn126, Lys268, and Ser269 in YbgJ). Alanine replacement mutagenesis demonstrated that most of the conserved residues located in the putative glutaminase catalytic site are essential for activity. The crystal structure of the YbgJ complex with the glutaminase inhibitor 6-diazo-5-oxo- l-norleucine revealed the presence of a covalent bond between the inhibitor and the hydroxyl oxygen of Ser74, providing evidence that Ser74 is the primary catalytic nucleophile and that the glutaminase reaction proceeds through formation of an enzyme-glutamyl intermediate. Growth experiments with the E. coli glutaminase deletion strains revealed that YneH is involved in the assimilation of l-glutamine as a sole source of carbon and nitrogen and suggested that both glutaminases (YbaS and YneH) also contribute to acid resistance in E. coli.
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Affiliation(s)
- Greg Brown
- Banting and Best Department of Medical Research, Ontario Centre for Structural Proteomics, University of Toronto, Toronto, Ontario M5G 1L6, Canada
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Yano S, Kamemura A, Yoshimune K, Moriguchi M, Yamamoto S, Tachiki T, Wakayama M. Analysis of essential amino acid residues for catalytic activity of glutaminase from Micrococcus luteus K-3. J Biosci Bioeng 2006; 102:362-4. [PMID: 17116585 DOI: 10.1263/jbb.102.362] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Accepted: 08/01/2006] [Indexed: 11/17/2022]
Abstract
Structural-based mutational analysis of salt-tolerant glutaminase from Micrococcus luteus K-3 (Micrococcus glutaminase) revealed that three amino acid residues, S64, K67, and E160, were essential to a catalytic reaction. The result suggested that Micrococcus glutaminase had a possible catalytic mechanism similar to class A beta-lactamase rather than glutaminase-asparaginase from Pseudomonas 7A.
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Affiliation(s)
- Shigekazu Yano
- Department of Bioscience and Bioengineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan
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7
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Chen YT, Chang HY, Lu CL, Peng HL. Evolutionary Analysis of the Two-Component Systems in Pseudomonas aeruginosa PAO1. J Mol Evol 2004; 59:725-37. [PMID: 15599505 DOI: 10.1007/s00239-004-2663-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Accepted: 07/06/2004] [Indexed: 11/28/2022]
Abstract
Gene organization and functional motif analyses of the 123 two-component system (2CS) genes in Pseudomonas aeruginosa PAO1 were carried out. In addition, NJ and ML trees for the sensor kinases and the response regulators were constructed, and the distances measured and comparatively analyzed. It was apparent that more than half of the sensor-regulator gene pairs, especially the 2CSs with OmpR-like regulators, are derivatives of a common ancestor and have most likely co-evolved through gene pair duplication. Several of the 2CS pairs, especially those with NarL-like regulators, however, appeared to be relatively divergent. This is supportive of the recruitment model, in which a sensor gene and regulator gene with different phylogenetic history are assembled to form a 2CS. Correlation of the classification of sensor kinases and response regulators provides further support for these models. Upon comparison of the phylogenetic trees comprised of sensors and regulators, we have identified six congruent clades, which represent the group of the most recently duplicated 2CS gene pairs. Analyses of the congruent 2CS pairs of each of the clades revealed that certain paralogous 2CS pairs may carry a redundant function even after a gene duplication event. Nevertheless, comparative analysis of the putative promoter regions of the paralogs suggested that functional redundancy could be prevented by a differential control. Both codon usage and G+C content of these 2CS genes were found to be comparable with those of the P. aeruginosa genome, suggesting that they are not newly acquired genes.
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Affiliation(s)
- Ying-Tsong Chen
- Department of Biological Science and Technology, National Chiao-Tung University, Hsinchu, Taiwan
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8
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Durá MA, Flores M, Toldrá F. Purification and characterisation of a glutaminase from Debaryomyces spp.. Int J Food Microbiol 2002; 76:117-26. [PMID: 12038568 DOI: 10.1016/s0168-1605(02)00024-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A glutaminase was purified from the cell-free extract of Debaryomyces spp. CECT 11815 by protamine sulphate treatment and several chromatographic procedures including anion exchange chromatography and gel filtration. The purified enzyme consisted of two subunits, with molecular masses of 65 and 50 kDa, respectively. Activity was optimal at 40 degrees C and pH 8.5, and the Km value for L-glutamine was 4.5 mM. The glutaminase exhibited activity against L-gamma-Glu-methyl ester, L-gamma-Glu-hydrazide, and L-albiziin, while L-asparagine, CBZ-L-Gln, CBZ-L-Gln-Gly, glutathione, L-gamma-Glu-pNA and L-gamma-Glu-AMC were not hydrolysed. The enzyme was not affected by PMSF, DTT and EDTA. However, the enzyme was inhibited by sulfhydryl group reagents, DON, L-albizziin, L-asparagine and high concentrations of L-glutamine and ammonium, while L-aspartate did not affect the activity. Phosphate and acetate did not produce any significant effect on the glutaminase activity, but it was slightly stimulated by lactate and borate.
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Affiliation(s)
- M A Durá
- Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Valencia, Spain
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9
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Yao T, Nanjyo Y, Tanaka T, Nishino H. An Electrochemical In Vivo Flow-Injection System for Highly Selective and Sensitive Detection ofL-Glutamate Using Enzyme Reactor Involving Amplification. ELECTROANAL 2001. [DOI: 10.1002/1521-4109(200111)13:16<1361::aid-elan1361>3.0.co;2-d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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10
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Yao T, Nanjyo Y, Nishino H. Micro-flow in vivo analysis of L-glutamate with an on-line enzyme amplifier based on substrate recycling. ANAL SCI 2001; 17:703-8. [PMID: 11707939 DOI: 10.2116/analsci.17.703] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A micro-flow enzyme system with a microdialysis probe is proposed for the amperometric detection of trace amounts of neurotransmitter L-glutamate released from rat brain cells. The L-glutamate oxidase (EC 1.4.3.11)/glutamate dehydrogenase (EC 1.4.1.4) coimmobilized reactor was used to enhance the sensitivity of L-glutamate as an on-line amplifier based on substrate recycling. A poly(1,2-diaminobenzene) film-coated platinum electrode was also used to selectively detect only the hydrogen peroxide generated into a upstream enzyme reactor, without interference from oxidizable species, such as L-ascorbate, the adsorption of low molecular-weight proteins in a dialysate, and NADPH added to the carrier solution to initiate substrate recycling. By the present in vivo system, L-glutamate was selectively assayed with about a 600-fold increase in sensitivity compared with the unamplified responses. The detection limit was 0.08 mumol dm-3. This method was applied to an in vivo assay of L-glutamate in the extracellular space of rat brain; also, monitoring of the L-glutamate level changed after a continuous stimulation of KCl to demonstrate the reliability of the system.
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Affiliation(s)
- T Yao
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
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11
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Palm GJ, Lubkowski J, Derst C, Schleper S, Röhm KH, Wlodawer A. A covalently bound catalytic intermediate in Escherichia coli asparaginase: crystal structure of a Thr-89-Val mutant. FEBS Lett 1996; 390:211-6. [PMID: 8706862 DOI: 10.1016/0014-5793(96)00660-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Escherichia coli asparaginase II catalyzes the hydrolysis of L-asparagine to L-aspartate via a threonine-bound acyl-enzyme intermediate. A nearly inactive mutant in which one of the active site threonines, Thr-89, was replaced by valine was constructed, expressed, and crystallized. Its structure, solved at 2.2 A resolution, shows high overall similarity to the wild-type enzyme, but an aspartyl moiety is covalently bound to Thr-12, resembling a reaction intermediate. Kinetic analysis confirms the deacylation deficiency, which is also explained on a structural basis. The previously identified oxyanion hole is described in more detail.
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Affiliation(s)
- G J Palm
- Macromolecular Structure Laboratory, NCI-Frederick Cancer Research and Development Center, Frederick, MD 21702-1201, USA
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12
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Wakayama M, Nagano Y, Renu N, Kawamura T, Sakai K, Moriguchi M. Molecular cloning and determination of the nucleotide sequence of a gene encoding salt-tolerant glutaminase from Micrococcus luteus K-3. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0922-338x(97)81259-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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13
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Lubkowski J, Wlodawer A, Ammon HL, Copeland TD, Swain AL. Structural characterization of Pseudomonas 7A glutaminase-asparaginase. Biochemistry 1994; 33:10257-65. [PMID: 8068664 DOI: 10.1021/bi00200a005] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The amino acid sequence and a 2-A-resolution crystallographic structure of Pseudomonas 7A glutaminase-asparaginase (PGA) have been determined. PGA, which belongs to the family of tetrameric bacterial amidohydrolases, deamidates glutamine and asparagine. The amino acid sequence of PGA has a high degree of similarity to the sequences of other members of the family. PGA has the same fold as other bacterial amidohydrolases, with the exception of the position of a 20-residue loop that forms part of the active site. In the PGA structure presented here, the active site loop is observed clearly in only one monomer, in an open position, with a conformation different from that observed for other amidohydrolases. In the other three monomers the loop is disordered and cannot be traced. This phenomenon is probably a direct consequence of a very low occupancy of product(s) of the enzymatic reaction bound in the active sites of PGA in these crystals. The active sites are composed of a rigid part and the flexible loop. The rigid part consists of the residues directly involved in the catalytic reaction as well as residues that assist in orienting the substrate. Two residues that are important for activity residue on the flexible loop. We suggest that the flexible loops actively participate in the transport of substrate and product molecules through the amidohydrolase active sites and participate in orienting the substrate molecules properly in relation to the catalytic residues.
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Affiliation(s)
- J Lubkowski
- Macromolecular Structure Laboratory, NCI-Frederick Cancer Research and Development Center, Maryland 21702-1201
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14
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Moriguchi M, Sakai K, Tateyama R, Furuta Y, Wakayama M. Isolation and characterization of salt-tolerant glutaminases from marine Micrococcus luteus K-3. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/0922-338x(94)90143-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Miller M, Rao JK, Wlodawer A, Gribskov MR. A left-handed crossover involved in amidohydrolase catalysis. Crystal structure of Erwinia chrysanthemi L-asparaginase with bound L-aspartate. FEBS Lett 1993; 328:275-9. [PMID: 8348975 DOI: 10.1016/0014-5793(93)80943-o] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The crystal structure of L-asparaginase from Erwinia chrysanthemi in the presence and absence of L-aspartate was determined at 1.8 A resolution. Conserved residues in a left-handed crossover (a rare occurrence in protein structures) link pairs of dimers into the catalytically active tetrameric form of the enzyme. The structure of ErA containing bound aspartic acid shows that this unusual strand connectivity is an essential part of the active site architecture, responsible for releasing the product of the enzymatic hydrolysis. The orientation of the bound aspartate indicates for the first time a threonine residue as a catalytic nucleophile.
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Affiliation(s)
- M Miller
- Macromolecular Structure Laboratory, NCI-FCRDC, Frederick, MD 21702
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16
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Swain AL, Jaskólski M, Housset D, Rao JK, Wlodawer A. Crystal structure of Escherichia coli L-asparaginase, an enzyme used in cancer therapy. Proc Natl Acad Sci U S A 1993; 90:1474-8. [PMID: 8434007 PMCID: PMC45896 DOI: 10.1073/pnas.90.4.1474] [Citation(s) in RCA: 194] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The crystal structure of Escherichia coli asparaginase II (EC 3.5.1.1), a drug (Elspar) used for the treatment of acute lymphoblastic leukemia, has been determined at 2.3 A resolution by using data from a single heavy atom derivative in combination with molecular replacement. The atomic model was refined to an R factor of 0.143. This enzyme, active as a homotetramer with 222 symmetry, belongs to the class of alpha/beta proteins. Each subunit has two domains with unique topological features. On the basis of present structural evidence consistent with previous biochemical studies, we propose locations for the active sites between the N- and C-terminal domains belonging to different subunits and postulate a catalytic role for Thr-89.
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Affiliation(s)
- A L Swain
- Macromolecular Structure Laboratory, National Cancer Institute-Frederick Cancer Research and Development Center, MD 21702-1201
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17
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Harms E, Wehner A, Aung HP, Röhm KH. A catalytic role for threonine-12 of E. coli asparaginase II as established by site-directed mutagenesis. FEBS Lett 1991; 285:55-8. [PMID: 1906013 DOI: 10.1016/0014-5793(91)80723-g] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A threonine-12 to alanine mutant of E. coli asparaginase II (EC 3.5.1.1) has less than 0.01% of the activity of wild-type enzyme. Both tertiary and quaternary structure of the enzyme are essentially unaffected by the mutation; thus the activity loss seems to be the result of a direct impairment of catalytic function. As aspartate is still bound by the mutant enzyme, Thr-12 appears not be involved in substrate binding.
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Affiliation(s)
- E Harms
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907
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18
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Kaartinen V, Williams JC, Tomich J, Yates JR, Hood LE, Mononen I. Glycosaparaginase from human leukocytes. Inactivation and covalent modification with diazo-oxonorvaline. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)67677-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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19
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Stole E, Seddon AP, Wellner D, Meister A. Identification of a highly reactive threonine residue at the active site of gamma-glutamyl transpeptidase. Proc Natl Acad Sci U S A 1990; 87:1706-9. [PMID: 1968636 PMCID: PMC53551 DOI: 10.1073/pnas.87.5.1706] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
gamma-Glutamyl transpeptidase [(5-glutamyl)-peptide:amino-acid 5-glutamyltransferase, EC 2.3.2.2], an enzyme of major importance in glutathione metabolism, was inactivated by treating it with L-(alpha S,5S)-alpha-amino-3-chloro-4,5-dihydro-5-[3-14C]isoxazoleacetic acid. This selective reagent binds stoichiometrically to the enzyme; more than 90% of the label was bound to its light subunit. Enzymatic digestion of the light subunit gave a 14C-labeled peptide that corresponds to amino acid residues 517-527 of the enzyme and two incomplete digestion products that contain this labeled peptide moiety. The radioactivity associated with this peptide was released with threonine-523 during sequencing by the automated gas-phase Edman method. The light subunit contains 14 other threonine residues and a total of 19 serine residues; these were not labeled. Threonine-523 is situated in the enzyme in an environment that greatly increases its reactivity, indicating that other amino acid residues of the enzyme must also participate in the active-site chemistry of the enzyme.
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Affiliation(s)
- E Stole
- Department of Biochemistry, Cornell University Medical College, New York, NY 10021
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Banner C, Hwang JJ, Shapiro RA, Wenthold RJ, Nakatani Y, Lampel KA, Thomas JW, Huie D, Curthoys NP. Isolation of a cDNA for rat brain glutaminase. Brain Res 1988; 427:247-54. [PMID: 3401701 DOI: 10.1016/0169-328x(88)90047-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A single phage was isolated from a lambda gt11 rat brain cDNA library by screening with antibodies prepared against rat renal glutaminase. Partial proteolysis of the fusion protein produced by a lysogen of the isolated phage generated a series of immunoreactive peptides that co-migrated with those derived from the purified brain glutaminase. The cDNA has a single open reading frame which encodes 326 amino acids that are in frame with beta-galactosidase. A 72-kDa protein, corresponding in size to the precursor of mitochondrial glutaminase, was immunoprecipitated from the translation products of rat renal mRNA that selectively hybridized to the cDNA. A probe made from the glutaminase cDNA detected an mRNA about 6 kb in length. This mRNA was present in rat brain and normal kidney RNA, increased 6-fold in acidotic kidney RNA, but was not detectable in liver RNA.
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Affiliation(s)
- C Banner
- Laboratory of Molecular Biology, NINCDS, Bethesda, MD 20892
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21
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Tanaka S, Robinson EA, Appella E, Miller M, Ammon HL, Roberts J, Weber IT, Wlodawer A. Structures of amidohydrolases. Amino acid sequence of a glutaminase-asparaginase from Acinetobacter glutaminasificans and preliminary crystallographic data for an asparaginase from Erwinia chrysanthemi. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68344-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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22
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Ammon HL, Weber IT, Wlodawer A, Harrison RW, Gilliland GL, Murphy KC, Sjölin L, Roberts J. Preliminary crystal structure of Acinetobacter glutaminasificans glutaminase-asparaginase. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)57371-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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23
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24
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25
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Ardawi MS, Newsholme EA. Intracellular localization and properties of phosphate-dependent glutaminase in rat mesenteric lymph nodes. Biochem J 1984; 217:289-96. [PMID: 6696725 PMCID: PMC1153208 DOI: 10.1042/bj2170289] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Phosphate-dependent glutaminase was present at approximately similar activities in lymph nodes from mammals other than rat, and in thymus, spleen, Peyer's patches and bone marrow of the rat. This suggests that glutamine is important in all lymphoid tissues. Phosphate-dependent glutaminase activity was shown to be present primarily in the mitochondria of rat mesenteric lymph nodes, and most of the activity could be released by detergents. The properties of the enzyme in mitochondrial extracts were investigated. The pH optimum was 8.6 and the Km for glutamine was 2.0 mM. The enzyme was activated by phosphate, other phosphorylated compounds including phosphoenolpyruvate, and also leucine: 50% activation occurred at 5, 0.2 and 0.6 mM for phosphate, phosphoenolpyruvate and leucine respectively. The enzyme was inhibited by glutamate, 2-oxoglutarate, citrate and ammonia, and by N-ethylmaleimide and diazo-5-oxo-L-norleucine; 50% inhibition was observed at 0.7 and 0.1 mM for glutamate and 2-oxoglutarate respectively. Some of these properties may be important in the control of the enzyme activity in vivo.
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26
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Steckel J, Roberts J, Philips FS, Chou TC. Kinetic properties and inhibition of Acinetobacter glutaminase-asparaginase. Biochem Pharmacol 1983; 32:971-7. [PMID: 6838661 DOI: 10.1016/0006-2952(83)90613-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Kinetic parameters, substrate specificity and exclusivity of ligands at binding sites of L-glutaminase-L-asparaginase purified from Acinetobacter glutaminasificans were studied in order to gain knowledge about the dual activities of this enzyme and its inhibition by structural analogs. Both L-glutamine and L-asparagine, which showed similar Km (4 approximately 7 X 10(-5) M) and Vmax (molecular activity 1.0 min-1) values, were competitive with each other for the substrate binding site. The products, L-glutamic acid and L-aspartic acid, showed competitive inhibition with respect to either L-glutamine or L-asparagine as substrates. Multiple inhibition of the glutaminase activity by L-glutamic acid and L-aspartic acid indicated that these ligands are mutually exclusive at the product-releasing site. The initial rates of both of the enzyme's activities were competitively inhibited by the following inhibitors (in rates of both of the enzyme's activities were competitively inhibited by the following inhibitors (in decreasing order of activity): 6-diazo-5-oxo-L-norleucine (DON), L-methionine sulfoximine, azaserine, and Acivicin. DON and azaserine inhibited both the asparaginase and glutaminase activities in a time-dependent and irreversible manner. The kinetic data suggest an ordered mechanism with glutamine or asparagine as the first substrate and glutamic acid or aspartic acid, respectively, as the last product. These results also suggest that a single mechanism and a single set of binding sites are responsible for catalyzing both of the enzyme's activities. The data also showed that succinylated enzyme, which has a 10-fold increase of plasma half-life in animals and humans and, thus, has benefit as a cancer chemotherapeutic agent, retained its catalytic activity and maintained Km and Vmax values similar to the native enzyme.
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27
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Shapiro RA, Morehouse RF, Curthoys NP. Inhibition by glutamate of phosphate-dependent glutaminase of rat kidney. Biochem J 1982; 207:561-6. [PMID: 6131666 PMCID: PMC1153898 DOI: 10.1042/bj2070561] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A membrane-associated form of phosphate-dependent glutaminase was derived from sonicated mitochondria and purified essentially free of gamma-glutamyl transpeptidase activity. Increasing concentrations of phosphate cause a sigmoidal activation of the membrane-bound glutaminase. Phosphate also causes a similar effect on the rate of glutaminase inactivation by the two affinity labels, L-2-amino-4-oxo-5-chloropentanoic acid and 6-diazo-5-oxo-L-norleucine, as observed previously for the solubilized and purified enzyme. Therefore the two forms of glutaminase undergo similar phosphate-induced changes in conformation. A sensitive radioactive assay was developed and used to determine the kinetics of glutamate inhibition of the membrane-associated glutaminase. The Km for glutamine decreases from 36 to 4 mM when the phosphate concentration is increased from 5 to 100 mM. Glutamate is a competitive inhibitor with respect to glutamine at both high and low concentrations of phosphate. However, the Ki for glutamate is increased from 5 to 52 mM with increasing phosphate concentration. Therefore glutamine and glutamate interact with the same site on the glutaminase, but the specificity of the site is determined by the available phosphate concentration.
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Paukert JL, Henkin J, Keesey J, DeMoss JA. Anthranilate synthase of Neurospora crassa: reaction and labeling with glutamine analogs. Arch Biochem Biophys 1982; 218:443-9. [PMID: 6218784 DOI: 10.1016/0003-9861(82)90366-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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29
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Abstract
An electrophilic center at saturated carbon generated by the departure of molecular nitrogen shows minimum discrimination between various nucleophiles. The generation of such a center in the active site of a protein is therefore an attractive way of labeling that active site. The chemistry of deamination reactions will be discussed with respect to the practicality of triggering the deamination in the active sites of proteins. Successful applications of this principle using the N-nitrosamide functionality, the alkyl aryl triazene functionality, and the diazo functionality will be described. Reasons why active-site reagents incorporating this type of covert electrophilicity are more specific than those incorporating an overtly electrophilic center (such as -CO-CH2-Halogen) will be advanced. The actual and potential application of deamination precursors to the specific inhibition of physiological activities in living cells will be discussed.
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Tso JY, Hermodson MA, Zalkin H. Glutamine phosphoribosylpyrophosphate amidotransferase from cloned Escherichia coli purF. NH2-terminal amino acid sequence, identification of the glutamine site, and trace metal analysis. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34811-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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Clark VM, Shapiro RA, Curthoys NP. Comparison of the hydrolysis and the covalent binding of 6-diazo-5-oxo-L-[6-14C]norleucine by rat renal phosphate-dependent glutaminase. Arch Biochem Biophys 1982; 213:232-9. [PMID: 6120680 DOI: 10.1016/0003-9861(82)90457-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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32
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Takahashi S, Zukin RS, Steinman HM. gamma-Glutamyl transpeptidase from WI-38 fibroblasts: purification and active site modification studies. Arch Biochem Biophys 1981; 207:87-95. [PMID: 6112969 DOI: 10.1016/0003-9861(81)90012-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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33
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Morehouse RF, Curthoys NP. Properties of rat renal phosphate-dependent glutaminase coupled to Sepharose. Evidence that dimerization is essential for activation. Biochem J 1981; 193:709-16. [PMID: 7305957 PMCID: PMC1162658 DOI: 10.1042/bj1930709] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In the absence of phosphate, purified rat renal phosphate-dependent glutaminase exists as a catalytically inactive protomer. The addition of phosphate results in both dimerization and activation of the glutaminase. Covalent attachment of the dimeric form of the glutaminase to CNBr-activated Sepharose was achieved with 84% retention of activity. At least 70% of the bound glutaminase activity was expressed even in the absence of added phosphate. In addition, 6-diazo-5-oxo-L-norleucine, which interacts only with the catalytically active form of the glutaminase, inactivates the bound dimeric form of glutaminase at the same rate in either the absence or the presence of added phosphate. Therefore retention of dimeric structure is apparently sufficient to maintain glutaminase activity. In contrast, the coupling of the protomeric form of the enzyme to Sepharose resulted in retention of only 3% of the phosphate-induced glutaminase activity. However, up to 48% of this activity could be reconstituted by addition of soluble glutaminase under conditions that promote dimerization. These results indicate that the monomeric form of the glutaminase has minimal inherent activity and that dimerization is an essential step in the phosphate-induced activation of the glutaminase.
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34
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Inactivation of rat renal phosphate-dependent glutaminase with 6-diazo-5-oxo-L-norleucine. Evidence for interaction at the glutamine binding site. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(17)30149-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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35
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Inoue M, Horiuchi S, Morino Y. Inactivation of gamma-glutamyl transpeptidase by phenylmethanesulfonyl fluoride, a specific inactivator of serine enzymes. Biochem Biophys Res Commun 1978; 82:1183-8. [PMID: 29617 DOI: 10.1016/0006-291x(78)90311-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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