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Baskerville MJ, Kovalyova Y, Mejías-Luque R, Gerhard M, Hatzios SK. Isotope tracing reveals bacterial catabolism of host-derived glutathione during Helicobacter pylori infection. PLoS Pathog 2023; 19:e1011526. [PMID: 37494402 PMCID: PMC10406306 DOI: 10.1371/journal.ppat.1011526] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 08/07/2023] [Accepted: 07/01/2023] [Indexed: 07/28/2023] Open
Abstract
Mammalian cells synthesize the antioxidant glutathione (GSH) to shield cellular biomolecules from oxidative damage. Certain bacteria, including the gastric pathogen Helicobacter pylori, can perturb host GSH homeostasis. H. pylori infection significantly decreases GSH levels in host tissues, which has been attributed to the accumulation of reactive oxygen species in infected cells. However, the precise mechanism of H. pylori-induced GSH depletion remains unknown, and tools for studying this process during infection are limited. We developed an isotope-tracing approach to quantitatively monitor host-derived GSH in H. pylori-infected cells by mass spectrometry. Using this method, we determined that H. pylori catabolizes reduced GSH from gastric cells using γ-glutamyl transpeptidase (gGT), an enzyme that hydrolyzes GSH to glutamate and cysteinylglycine (Cys-Gly). gGT is an established virulence factor with immunomodulatory properties that is required for H. pylori colonization in vivo. We found that H. pylori internalizes Cys-Gly in a gGT-dependent manner and that Cys-Gly production during H. pylori infection is coupled to the depletion of intracellular GSH from infected cells. Consistent with bacterial catabolism of host GSH, levels of oxidized GSH did not increase during H. pylori infection, and exogenous antioxidants were unable to restore the GSH content of infected cells. Altogether, our results indicate that H. pylori-induced GSH depletion proceeds via an oxidation-independent mechanism driven by the bacterial enzyme gGT, which fortifies bacterial acquisition of nutrients from the host. Additionally, our work establishes a method for tracking the metabolic fate of host-derived GSH during infection.
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Affiliation(s)
- Maia J. Baskerville
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, United States of America
| | - Yekaterina Kovalyova
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, United States of America
- Department of Chemistry, Yale University, New Haven, Connecticut, United States of America
| | - Raquel Mejías-Luque
- Institute of Medical Microbiology, Immunology and Hygiene, Technical University of Munich, School of Medicine, Munich, Germany
- German Centre for Infection Research, Munich, Germany
| | - Markus Gerhard
- Institute of Medical Microbiology, Immunology and Hygiene, Technical University of Munich, School of Medicine, Munich, Germany
- German Centre for Infection Research, Munich, Germany
| | - Stavroula K. Hatzios
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, United States of America
- Department of Chemistry, Yale University, New Haven, Connecticut, United States of America
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2
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Bandookwala M, Nemani KS, Chatterjee B, Sengupta P. Reactive Metabolites: Generation and Estimation with Electrochemistry Based Analytical Strategy as an Emerging Screening Tool. CURR ANAL CHEM 2020. [DOI: 10.2174/1573411016666200131154202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Analytical scientists have constantly been in search for more efficient and
economical methods for drug simulation studies. Owing to great progress in this field, there are various
techniques available nowadays that mimic drug metabolism in the hepatic microenvironment.
The conventional in vitro and in vivo studies pose inherent methodological drawbacks due to which
alternative analytical approaches are devised for different drug metabolism experiments.
Methods:
Electrochemistry has gained attention due to its benefits over conventional metabolism
studies. Because of the protein binding nature of reactive metabolites, it is difficult to identify them
directly after formation, although the use of trapping agents aids in their successful identification.
Furthermore, various scientific reports confirmed the successful simulation of drug metabolism studies
by electrochemical cells. Electrochemical cells coupled with chromatography and mass spectrometry
made it easy for direct detection of reactive metabolites. In this review, an insight into the application
of electrochemical techniques for metabolism simulation studies has been provided. The sole
use of electrochemical cells, as well as their setups on coupling to liquid chromatography and mass
spectrometry has been discussed. The importance of metabolism prediction in early drug discovery
and development stages along with a brief overview of other conventional methods has also been
highlighted.
Conclusion:
To the best of our knowledge, this is the first article to review the electrochemistry
based strategy for the analysis of reactive metabolites. The outcome of this ‘first of its kind’ review
will significantly help the researchers in the application of electrochemistry based bioanalysis for metabolite
detection.
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Affiliation(s)
- Maria Bandookwala
- National Institute of Pharmaceutical Education and Research (NIPER) - Ahmedabad, Gujarat, India
| | - Kavya Sri Nemani
- National Institute of Pharmaceutical Education and Research (NIPER) - Ahmedabad, Gujarat, India
| | - Bappaditya Chatterjee
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management (SPPSPTM), NMIMS University, Mumbai, India
| | - Pinaki Sengupta
- National Institute of Pharmaceutical Education and Research (NIPER) - Ahmedabad, Gujarat, India
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3
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den Braver MW, Vermeulen NPE, Commandeur JNM. Generic method for the absolute quantification of glutathione S-conjugates: Application to the conjugates of acetaminophen, clozapine and diclofenac. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1046:185-194. [PMID: 28189104 DOI: 10.1016/j.jchromb.2017.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/02/2017] [Accepted: 02/04/2017] [Indexed: 10/20/2022]
Abstract
Modification of cellular macromolecules by reactive drug metabolites is considered to play an important role in the initiation of tissue injury by many drugs. Detection and identification of reactive intermediates is often performed by analyzing the conjugates formed after trapping by glutathione (GSH). Although sensitivity of modern mass spectrometrical methods is extremely high, absolute quantification of GSH-conjugates is critically dependent on the availability of authentic references. Although 1H NMR is currently the method of choice for quantification of metabolites formed biosynthetically, its intrinsically low sensitivity can be a limiting factor in quantification of GSH-conjugates which generally are formed at low levels. In the present study, a simple but sensitive and generic method for absolute quantification of GSH-conjugates is presented. The method is based on quantitative alkaline hydrolysis of GSH-conjugates and subsequent quantification of glutamic acid and glycine by HPLC after precolumn derivatization with o-phthaldialdehyde/N-acetylcysteine (OPA/NAC). Because of the lower stability of the glycine OPA/NAC-derivate, quantification of the glutamic acid OPA/NAC-derivate appeared most suitable for quantification of GSH-conjugates. The novel method was used to quantify the concentrations of GSH-conjugates of diclofenac, clozapine and acetaminophen and quantification was consistent with 1H NMR, but with a more than 100-fold lower detection limit for absolute quantification.
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Affiliation(s)
- Michiel W den Braver
- AIMMS-Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Nico P E Vermeulen
- AIMMS-Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Jan N M Commandeur
- AIMMS-Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
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4
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Zhou Z, Bulgari O, Vailati-Riboni M, Trevisi E, Ballou MA, Cardoso FC, Luchini DN, Loor JJ. Rumen-protected methionine compared with rumen-protected choline improves immunometabolic status in dairy cows during the peripartal period. J Dairy Sci 2016; 99:8956-8969. [PMID: 27592438 DOI: 10.3168/jds.2016-10986] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 07/15/2016] [Indexed: 11/19/2022]
Abstract
The immunometabolic status of peripartal cows is altered due to changes in liver function, inflammation, and oxidative stress. Nutritional management during this physiological state can affect the biological components of immunometabolism. The objectives of this study were to measure concentrations of biomarkers in plasma, liver tissue, and milk, and also polymorphonuclear leukocyte function to assess the immunometabolic status of cows supplemented with rumen-protected methionine (Met) or choline (CHOL). Forty-eight multiparous Holstein cows were used in a randomized complete block design with 2×2 factorial arrangement of Met (Smartamine M, Adisseo NA, Alpharetta, GA) and CHOL (ReaShure, Balchem Inc., New Hampton, NY) level (with or without). Treatments (12 cows each) were control (CON), no Met or CHOL; CON and Met (SMA); CON and CHOL (REA); and CON and Met and CHOL (MIX). From -50 to -21d before expected calving, all cows received the same diet [1.40Mcal of net energy for lactation (NEL)/kg of DM] with no Met or CHOL. From -21d to calving, cows received the same close-up diet (1.52Mcal of NEL/kg of DM) and were assigned randomly to each treatment. From calving to 30d, cows were on the same postpartal diet (1.71Mcal of NEL/kg of DM) and continued to receive the same treatments until 30d. The Met supplementation was adjusted daily at 0.08% DM of diet, and CHOL was supplemented at 60g/cow per day. Liver (-10, 7, 21, and 30d) and blood (-10, 4, 8, 20, and 30d) samples were harvested for biomarker analyses. Neutrophil and monocyte phagocytosis and oxidative burst were assessed at d 1, 4, 14, and 28d. The Met-supplemented cows tended to have greater plasma paraoxonase. Greater plasma albumin and IL-6 as well as a tendency for lower haptoglobin were detected in Met- but not CHOL-supplemented cows. Similarly, cows fed Met compared with CHOL had greater concentrations of total and reduced glutathione (a potent intracellular antioxidant) in liver tissue. Upon a pathogen challenge in vitro, blood polymorphonuclear leukocyte phagocytosis capacity and oxidative burst activity were greater in Met-supplemented cows. Overall, liver and blood biomarker analyses revealed favorable changes in liver function, inflammation status, and immune response in Met-supplemented cows.
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Affiliation(s)
- Z Zhou
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801
| | - O Bulgari
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801; Dipartimento di Medicina Molecolare e Traslazionale, Università degli Studi di Brescia, 25121 Brescia, Italy
| | - M Vailati-Riboni
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801
| | - E Trevisi
- Istituto di Zootecnica Facoltà di Scienze Agrarie, Alimentari e Ambientali, Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy
| | - M A Ballou
- Department of Animal Sciences, Texas Tech University, Lubbock 79409
| | - F C Cardoso
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801
| | | | - J J Loor
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801.
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Grillo MP. Detecting reactive drug metabolites for reducing the potential for drug toxicity. Expert Opin Drug Metab Toxicol 2015; 11:1281-302. [PMID: 26005795 DOI: 10.1517/17425255.2015.1048222] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION A number of withdrawn drugs are known to undergo bioactivation by a range of drug metabolizing enzymes to chemically reactive metabolites that bind covalently to protein and DNA resulting in organ toxicity and carcinogenesis, respectively. An important goal in drug discovery is to identify structural sites of bioactivation within discovery molecules for providing strategic modifications that eliminate or minimize reactive metabolite formation, while maintaining target potency, selectivity and desired pharmacokinetic properties leading to the development of efficacious and nontoxic drugs. AREAS COVERED This review covers experimental techniques currently used to detect reactive drug metabolites and provides recent examples where information from mechanistic in vitro studies was successfully used to redesign candidate drugs leading to blocked or minimized bioactivation. Reviewed techniques include in vitro radiolabeled drug covalent binding to protein and reactive metabolite trapping with reagents such as glutathione, cyanide, semicarbazide and DNA bases. Case studies regarding reactive metabolite detection using a combination of varied techniques, including liquid chromatography-tandem mass spectrometry and NMR analyses and subsequent structural modification are discussed. EXPERT OPINION Information derived from state-of-art mechanistic drug metabolism studies can be used successfully to direct medicinal chemistry towards the synthesis of candidate drugs devoid of bioactivation liabilities, while maintaining desired pharmacology and pharmacokinetic properties.
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Affiliation(s)
- Mark P Grillo
- MyoKardia , 333 Allerton Ave, South San Francisco, CA 94080 , USA
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6
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Dalvie D, Kalgutkar AS, Chen W. Practical approaches to resolving reactive metabolite liabilities in early discovery. Drug Metab Rev 2014; 47:56-70. [DOI: 10.3109/03602532.2014.984813] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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7
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Wen B, Fitch WL. Analytical strategies for the screening and evaluation of chemically reactive drug metabolites. Expert Opin Drug Metab Toxicol 2009; 5:39-55. [PMID: 19236228 DOI: 10.1517/17425250802665706] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Metabolic activation leading to formation of chemically reactive drug metabolites is a long-standing issue for drug development inasmuch as some, but not all, reactive intermediates play a role as mediators of drug-induced toxicities. The risk assessment profile/decision-making guide requires a comprehensive understanding of bioactivation mechanism(s), quantitative magnitude and cellular consequences of this principal and continued safety attrition. OBJECTIVE To evaluate analytical methodologies with improved sensitivity, selectivity and throughput for the analysis of reactive metabolites. CONCLUSIONS Identification and quantification of short-lived electrophilic intermediates through appropriate trapping experiments have become relatively straightforward. Minimizing the bioactivation potential of drug candidates during the discovery/lead optimization phase has been adopted as a default strategy. Together with advances of proteomics, metabolomics and toxicogenomics, an integrated multitier approach possibly provides a deeper insight into mechanistic aspects of drug-induced toxicities, and contributes to bridging the relationships between metabolic activation, drug-protein adduct formation and their toxicological consequences.
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Affiliation(s)
- Bo Wen
- Department of Drug Metabolism and Pharmacokinetics, Roche Palo Alto, Palo Alto, CA 94304, USA.
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8
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Takakusa H, Masumoto H, Makino C, Okazaki O, Sudo K. Quantitative Assessment of Reactive Metabolite Formation using 35S-labeled Glutathione. Drug Metab Pharmacokinet 2009; 24:100-7. [DOI: 10.2133/dmpk.24.100] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Staack RF, Hopfgartner G. New analytical strategies in studying drug metabolism. Anal Bioanal Chem 2007; 388:1365-80. [PMID: 17583803 DOI: 10.1007/s00216-007-1367-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 05/09/2007] [Accepted: 05/11/2007] [Indexed: 01/03/2023]
Abstract
Identification and elucidation of the structures of metabolites play major roles in drug discovery and in the development of pharmaceutical compounds. These studies are also important in toxicology or doping control with either pharmaceuticals or illicit drugs. This review focuses on: new analytical strategies used to identify potential metabolites in biological matrices with and without radiolabeled drugs; use of software for metabolite profiling; interpretation of product spectra; profiling of reactive metabolites; development of new approaches for generation of metabolites; and detection of metabolites with increased sensitivity and simplicity. Most of the new strategies involve mass spectrometry (MS) combined with liquid chromatography (LC).
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Affiliation(s)
- Roland F Staack
- Life Sciences Mass Spectrometry, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 20, Bd d'Yvoy, 1211 Genève 4, Switzerland
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10
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Ma S, Subramanian R. Detecting and characterizing reactive metabolites by liquid chromatography/tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2006; 41:1121-39. [PMID: 16967439 DOI: 10.1002/jms.1098] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Metabolic activation of a drug leading to reactive metabolite(s) that can covalently modify proteins is considered an initial step that may lead to drug-induced organ toxicities. Characterization of reactive metabolites is critical to designing new drug candidates with an improved toxicological profile. High performance liquid chromatography (HPLC) coupled with mass spectrometry (MS) predominates over all analytical tools used for screening and characterization of reactive metabolites. In this review, a brief description of experimental approaches employed for assessing reactive metabolites is followed by a discussion on the reactivity of acyl glucuronides and acyl coenzyme A thioesters. Techniques for high-throughput screening and quantitation of reactive metabolite formation are also described, along with proteomic approaches used to identify protein targets and modification sites by reactive metabolites. Strategies for dealing with reactive metabolites are reviewed. In conclusion, we discuss the challenges and future needs in this field of research.
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Affiliation(s)
- Shuguang Ma
- Pharmacokinetics and Drug Metabolism, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
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Cysyk RL, Parker RJ, Barchi JJ, Steeg PS, Hartman NR, Strong JM. Reaction of geldanamycin and C17-substituted analogues with glutathione: product identifications and pharmacological implications. Chem Res Toxicol 2006; 19:376-81. [PMID: 16544941 DOI: 10.1021/tx050237e] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
17-Dimethylaminoethylamino-17-demethoxygeldanamycin (DMAG) and 17-allylamino-17-demethoxygeldanamycin (17-AAG) are two derivatives of geldanamycin (GA) that are currently undergoing clinical evaluation as anticancer agents. These agents bind to heat shock protein 90 (hsp90), resulting in the destabilization of client proteins and inhibition of tumor growth. In a search for the mechanism of hepatotoxicity, which is a dose-limiting toxicity for these agents, we found that GA and its derivatives, 17-AAG and 17-DMAG, react chemically (i.e., nonenzymatically) with glutathione (GSH). A combination of liquid chromatography/electrospray ionization/mass spectrometry and nuclear magnetic resonance analyses were used to identify the product of this reaction as a GSH adduct in which the thiol group of GSH is substituted in the 19-position of the benzoquinone ring. The reaction proceeds rapidly with GA and 17-DMAG (half-lives of approximately 1.5 and 36 min, respectively) and less rapidly with 17-AAG and its major metabolite, 17-AG (half-lives of approximately 9.8 and 16.7 h). The reaction occurs at pH 7.0, 37 degrees C, and a physiological concentration of GSH, indicating that cellular GSH could play a role in modulating the cellular toxicity of these agents and therefore be a factor in their mechanism of differential toxicity. Moreover, reactions with thiol groups of critical cellular proteins could be important to the mechanism of toxicity with this class of anticancer agents.
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Affiliation(s)
- Richard L Cysyk
- Laboratory of Clinical Pharmacology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993-0002, USA
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Ross MK, Pegram RA. [35S]-labeling of the Salmonella typhimurium glutathione pool to assess glutathione-mediated DNA binding by 1,2-dibromoethane. Chem Biol Interact 2003; 146:39-49. [PMID: 12902151 DOI: 10.1016/s0009-2797(03)00071-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Biotransformation of drugs and environmental chemicals to reactive intermediates is often studied with the use of radiolabeled compounds that are synthesized by expensive and technically difficult procedures. In general, glutathione (GSH) conjugation serves as a detoxification mechanism, and conjugation of reactive intermediates with GSH is often a surrogate marker of reactive species formation. However, several halogenated alkanes can be bioactivated by GSH to yield highly reactive GSH conjugates, some of which are DNA-reactive (e.g. conjugates of 1,2-dibromoethane). The purpose of this study was to metabolically radiolabel the in vivo GSH pool of Salmonella typhimurium with a [35S]-label and to examine the GSH-mediated bioactivation of a model haloalkane, 1,2-dibromoethane, by measuring the binding of [35S]-label to DNA. The strain of Salmonella used in this study had been transformed previously with the gene that codes for rat glutathione transferase theta 1-1 (GSTT1-1), an enzyme that can catalyze formation of genotoxic GSH conjugates. Bacteria were grown to mid-log phase and then incubated with [35S]-L-cysteine in minimal medium (thio-free) until stationary phase of growth was reached. At this stage, the specific activity of Salmonella GSH was estimated to be 7.1 mCi/mmol by derivatization and subsequent HPLC analysis, and GSTT1-1 enzyme activity was still demonstrable in Salmonella cytosol following growth in a minimal medium. The [35S]-labeled bacteria were then exposed to 1,2-dibromoethane (1 mM), and the Salmonella DNA was subsequently purified to quantify [35S]-binding to DNA. The amount of [35S]-label that was covalently bound to DNA in the GSTT1-1-expressing Salmonella strain (33.2 nmol/mg DNA) was sevenfold greater than that of the control strain that does not express GSTT1-1. Neutral thermal hydrolysis of the DNA yielded a single [35S]-labeled adduct with a similar t(R) as S-[2-(N(7)-guanyl)ethyl]GSH, following HPLC analysis of the hydrolysate. This adduct accounted for 95% of the total [35S]-label bound to DNA. Thus, this [35S]-radiolabeling protocol may prove useful for studying the DNA reactivity of GSH conjugates of other halogenated alkanes in a cellular context that maintains GSH at normal physiological levels. This is also, to our knowledge, the first demonstration of de novo incorporation of [35S]-L-cysteine into the bacterial GSH pool.
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Affiliation(s)
- Matthew K Ross
- Curriculum in Toxicology, University of North Carolina, Chapel Hill, NC 27599, USA
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