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Caradec T, Plé C, Sicoli G, Petrov R, Pradel E, Sobieski C, Antoine R, Orio M, Herledan A, Willand N, Hartkoorn RC. Small molecule MarR modulators potentiate metronidazole antibiotic activity in aerobic E. coli by inducing activation by the nitroreductase NfsA. J Biol Chem 2024; 300:107431. [PMID: 38825006 PMCID: PMC11259696 DOI: 10.1016/j.jbc.2024.107431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 05/07/2024] [Accepted: 05/22/2024] [Indexed: 06/04/2024] Open
Abstract
Antibiotic-resistant Enterobacterales pose a major threat to healthcare systems worldwide, necessitating the development of novel strategies to fight such hard-to-kill bacteria. One potential approach is to develop molecules that force bacteria to hyper-activate prodrug antibiotics, thus rendering them more effective. In the present work, we aimed to obtain proof-of-concept data to support that small molecules targeting transcriptional regulators can potentiate the antibiotic activity of the prodrug metronidazole (MTZ) against Escherichia coli under aerobic conditions. By screening a chemical library of small molecules, a series of structurally related molecules were identified that had little inherent antibiotic activity but showed substantial activity in combination with ineffective concentrations of MTZ. Transcriptome analyses, functional genetics, thermal shift assays, and electrophoretic mobility shift assays were then used to demonstrate that these MTZ boosters target the transcriptional repressor MarR, resulting in the upregulation of the marRAB operon and its downstream MarA regulon. The associated upregulation of the flavin-containing nitroreductase, NfsA, was then shown to be critical for the booster-mediated potentiation of MTZ antibiotic activity. Transcriptomic studies, biochemical assays, and electron paramagnetic resonance measurements were then used to show that under aerobic conditions, NfsA catalyzed 1-electron reduction of MTZ to the MTZ radical anion which in turn induced lethal DNA damage in E. coli. This work reports the first example of prodrug boosting in Enterobacterales by transcriptional modulators and highlights that MTZ antibiotic activity can be chemically induced under anaerobic growth conditions.
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Affiliation(s)
- Thibault Caradec
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Coline Plé
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Giuseppe Sicoli
- CNRS UMR 8516, Univ. Lille, LASIRE - Laboratory of Advanced Spectroscopy on Interactions, Reactivity and Environment, Villeneuve d'Ascq, France
| | - Ravil Petrov
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Elizabeth Pradel
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Cécilia Sobieski
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Rudy Antoine
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Maylis Orio
- Aix Marseille Univ., CNRS, Centrale Marseille, iSm2, Marseille, France
| | - Adrien Herledan
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, Lille, France
| | - Nicolas Willand
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, Lille, France
| | - Ruben Christiaan Hartkoorn
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, France.
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2
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Sharrock AV, Mumm JS, Williams EM, Čėnas N, Smaill JB, Patterson AV, Ackerley DF, Bagdžiūnas G, Arcus VL. Structural Evaluation of a Nitroreductase Engineered for Improved Activation of the 5-Nitroimidazole PET Probe SN33623. Int J Mol Sci 2024; 25:6593. [PMID: 38928299 PMCID: PMC11203732 DOI: 10.3390/ijms25126593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2024] [Revised: 06/12/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
Bacterial nitroreductase enzymes capable of activating imaging probes and prodrugs are valuable tools for gene-directed enzyme prodrug therapies and targeted cell ablation models. We recently engineered a nitroreductase (E. coli NfsB F70A/F108Y) for the substantially enhanced reduction of the 5-nitroimidazole PET-capable probe, SN33623, which permits the theranostic imaging of vectors labeled with oxygen-insensitive bacterial nitroreductases. This mutant enzyme also shows improved activation of the DNA-alkylation prodrugs CB1954 and metronidazole. To elucidate the mechanism behind these enhancements, we resolved the crystal structure of the mutant enzyme to 1.98 Å and compared it to the wild-type enzyme. Structural analysis revealed an expanded substrate access channel and new hydrogen bonding interactions. Additionally, computational modeling of SN33623, CB1954, and metronidazole binding in the active sites of both the mutant and wild-type enzymes revealed key differences in substrate orientations and interactions, with improvements in activity being mirrored by reduced distances between the N5-H of isoalloxazine and the substrate nitro group oxygen in the mutant models. These findings deepen our understanding of nitroreductase substrate specificity and catalytic mechanisms and have potential implications for developing more effective theranostic imaging strategies in cancer treatment.
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Affiliation(s)
- Abigail V. Sharrock
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand; (A.V.S.)
| | - Jeff S. Mumm
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA;
| | - Elsie M. Williams
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand; (A.V.S.)
| | - Narimantas Čėnas
- Institute of Biochemistry, Life Sciences Center at Vilnius University, Saulėtekio Av. 7, LT-10257 Vilnius, Lithuania;
| | - Jeff B. Smaill
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1142, New Zealand; (J.B.S.); (A.V.P.)
| | - Adam V. Patterson
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Auckland 1142, New Zealand; (J.B.S.); (A.V.P.)
| | - David F. Ackerley
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand; (A.V.S.)
| | - Gintautas Bagdžiūnas
- Institute of Biochemistry, Life Sciences Center at Vilnius University, Saulėtekio Av. 7, LT-10257 Vilnius, Lithuania;
| | - Vickery L. Arcus
- Te Aka Mātuatua School of Science, University of Waikato, Hamilton 3240, New Zealand;
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3
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Russo S, Luján AP, Fraaije MW, Poelarends GJ. Synthesis of Pharmaceutically Relevant Arylamines Enabled by a Nitroreductase from Bacillus tequilensis. Chembiochem 2024; 25:e202300846. [PMID: 38502784 DOI: 10.1002/cbic.202300846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 03/21/2024]
Abstract
Arylamines are essential building blocks for the manufacture of valuable pharmaceuticals, pigments and dyes. However, their current industrial production involves the use of chemocatalytic procedures with a significant environmental impact. As a result, flavin-dependent nitroreductases (NRs) have received increasing attention as sustainable catalysts for more ecofriendly synthesis of arylamines. In this study, we assessed a novel NR from Bacillus tequilensis, named BtNR, for the synthesis of pharmaceutically relevant arylamines, including valuable synthons used in the manufacture of blockbuster drugs such as vismodegib, sonidegib, linezolid and sildenafil. After optimizing the enzymatic reaction conditions, high conversion of nitroaromatics to arylamines (up to 97 %) and good product yields (up to 56 %) were achieved. Our results indicate that BtNR has a broad substrate scope, including bulky nitro benzenes, nitro pyrazoles and nitro pyridines. Hence, BtNR is an interesting biocatalyst for the synthesis of pharmaceutically relevant amine-functionalized aromatics, providing an attractive alternative to traditional chemical synthesis methodologies.
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Affiliation(s)
- Sara Russo
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
- Molecular Enzymology Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Alejandro Prats Luján
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Marco W Fraaije
- Molecular Enzymology Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Gerrit J Poelarends
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
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Valiauga B, Bagdžiūnas G, Sharrock AV, Ackerley DF, Čėnas N. The Catalysis Mechanism of E. coli Nitroreductase A, a Candidate for Gene-Directed Prodrug Therapy: Potentiometric and Substrate Specificity Studies. Int J Mol Sci 2024; 25:4413. [PMID: 38673999 PMCID: PMC11049802 DOI: 10.3390/ijms25084413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/05/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
E. coli nitroreductase A (NfsA) is a candidate for gene-directed prodrug cancer therapy using bioreductively activated nitroaromatic compounds (ArNO2). In this work, we determined the standard redox potential of FMN of NfsA to be -215 ± 5 mV at pH 7.0. FMN semiquinone was not formed during 5-deazaflavin-sensitized NfsA photoreduction. This determines the two-electron character of the reduction of ArNO2 and quinones (Q). In parallel, we characterized the oxidant specificity of NfsA with an emphasis on its structure. Except for negative outliers nitracrine and SN-36506, the reactivity of ArNO2 increases with their electron affinity (single-electron reduction potential, E17) and is unaffected by their lipophilicity and Van der Waals volume up to 386 Å. The reactivity of quinoidal oxidants is not clearly dependent on E17, but 2-hydroxy-1,4-naphthoquinones were identified as positive outliers and a number of compounds with diverse structures as negative outliers. 2-Hydroxy-1,4-naphthoquinones are characterized by the most positive reaction activation entropy and the negative outlier tetramethyl-1,4-benzoquinone by the most negative. Computer modelling data showed that the formation of H bonds with Arg15, Arg133, and Ser40, plays a major role in the binding of oxidants to reduced NfsA, while the role of the π-π interaction of their aromatic structures is less significant. Typically, the calculated hydride-transfer distances during ArNO2 reduction are smallwer than for Q. This explains the lower reactivity of quinones. Another factor that slows down the reduction is the presence of positively charged aliphatic substituents.
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Affiliation(s)
- Benjaminas Valiauga
- Institute of Biochemistry of Life Sciences Center of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania; (B.V.); (G.B.)
| | - Gintautas Bagdžiūnas
- Institute of Biochemistry of Life Sciences Center of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania; (B.V.); (G.B.)
| | - Abigail V. Sharrock
- School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington 6140, New Zealand; (A.V.S.); (D.F.A.)
| | - David F. Ackerley
- School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington 6140, New Zealand; (A.V.S.); (D.F.A.)
| | - Narimantas Čėnas
- Institute of Biochemistry of Life Sciences Center of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania; (B.V.); (G.B.)
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5
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Theys J, Patterson AV, Mowday AM. Clostridium Bacteria: Harnessing Tumour Necrosis for Targeted Gene Delivery. Mol Diagn Ther 2024; 28:141-151. [PMID: 38302842 PMCID: PMC10925577 DOI: 10.1007/s40291-024-00695-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2024] [Indexed: 02/03/2024]
Abstract
Necrosis is a common feature of solid tumours that offers a unique opportunity for targeted cancer therapy as it is absent from normal healthy tissues. Tumour necrosis provides an ideal environment for germination of the anaerobic bacterium Clostridium from endospores, resulting in tumour-specific colonisation. Two main species, Clostridium novyi-NT and Clostridium sporogenes, are at the forefront of this therapy, showing promise in preclinical models. However, anti-tumour activity is modest when used as a single agent, encouraging development of Clostridium as a tumour-selective gene delivery system. Various methods, such as allele-coupled exchange and CRISPR-cas9 technology, can facilitate the genetic modification of Clostridium, allowing chromosomal integration of transgenes to ensure long-term stability of expression. Strains of Clostridium can be engineered to express prodrug-activating enzymes, resulting in the generation of active drug selectively in the tumour microenvironment (a concept termed Clostridium-directed enzyme prodrug therapy). More recently, Clostridium strains have been investigated in the context of cancer immunotherapy, either in combination with immune checkpoint inhibitors or with engineered strains expressing immunomodulatory molecules such as IL-2 and TNF-α. Localised expression of these molecules using tumour-targeting Clostridium strains has the potential to improve delivery and reduce systemic toxicity. In summary, Clostridium species represent a promising platform for cancer therapy, with potential for localised gene delivery and immunomodulation selectively within the tumour microenvironment. The ongoing clinical progress being made with C. novyi-NT, in addition to developments in genetic modification techniques and non-invasive imaging capabilities, are expected to further progress Clostridium as an option for cancer treatment.
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Affiliation(s)
- Jan Theys
- M-Lab, Department of Precision Medicine, GROW - School of Oncology and Reproduction, Maastricht University, 6229 ER, Maastricht, The Netherlands
| | - Adam V Patterson
- Auckland Cancer Society Research Centre, School of Medical Sciences, University of Auckland, Auckland, 1142, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, 1142, New Zealand
| | - Alexandra M Mowday
- Auckland Cancer Society Research Centre, School of Medical Sciences, University of Auckland, Auckland, 1142, New Zealand.
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, 1142, New Zealand.
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6
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Michailidou F. Engineering of Therapeutic and Detoxifying Enzymes. Angew Chem Int Ed Engl 2023; 62:e202308814. [PMID: 37433049 DOI: 10.1002/anie.202308814] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/07/2023] [Accepted: 07/11/2023] [Indexed: 07/13/2023]
Abstract
Therapeutic enzymes present excellent opportunities for the treatment of human disease, modulation of metabolic pathways and system detoxification. However, current use of enzyme therapy in the clinic is limited as naturally occurring enzymes are seldom optimal for such applications and require substantial improvement by protein engineering. Engineering strategies such as design and directed evolution that have been successfully implemented for industrial biocatalysis can significantly advance the field of therapeutic enzymes, leading to biocatalysts with new-to-nature therapeutic activities, high selectivity, and suitability for medical applications. This minireview highlights case studies of how state-of-the-art and emerging methods in protein engineering are explored for the generation of therapeutic enzymes and discusses gaps and future opportunities in the field of enzyme therapy.
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Affiliation(s)
- Freideriki Michailidou
- Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, 8092, Zürich, Switzerland
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7
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Day MA, Jarrom D, Rajah N, Searle PF, Hyde EI, White SA. Oxygen-insensitive nitroreductase E. coli NfsA, but not NfsB, is inhibited by fumarate. Proteins 2023; 91:585-592. [PMID: 36443029 PMCID: PMC10953011 DOI: 10.1002/prot.26451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 11/30/2022]
Abstract
Escherichia coli NfsA and NfsB are founding members of two flavoprotein families that catalyze the oxygen-insensitive reduction of nitroaromatics and quinones by NAD(P)H. This reduction is required for the activity of nitrofuran antibiotics and the enzymes have also been proposed for use with nitroaromatic prodrugs in cancer gene therapy and biocatalysis, but the roles of the proteins in vivo in bacteria are not known. NfsA is NADPH-specific whereas NfsB can also use NADH. The crystal structures of E. coli NfsA and NfsB and several analogs have been determined previously. In our crystal trials, we unexpectedly observed NfsA bound to fumarate. We here present the X-ray structure of the E. coli NfsA-fumarate complex and show that fumarate acts as a weak inhibitor of NfsA but not of NfsB. The structural basis of this differential inhibition is conserved in the two protein families and occurs at fumarate concentrations found in vivo, so impacting the efficacy of these proteins.
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Affiliation(s)
- Martin A. Day
- School of BiosciencesUniversity of BirminghamBirminghamUK
- Institute for Cancer and Genomic SciencesUniversity of BirminghamBirminghamUK
| | - David Jarrom
- School of BiosciencesUniversity of BirminghamBirminghamUK
| | - Navina Rajah
- School of BiosciencesUniversity of BirminghamBirminghamUK
| | - Peter F. Searle
- Institute for Cancer and Genomic SciencesUniversity of BirminghamBirminghamUK
| | - Eva I. Hyde
- School of BiosciencesUniversity of BirminghamBirminghamUK
| | - Scott A. White
- School of BiosciencesUniversity of BirminghamBirminghamUK
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8
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Rich MH, Sharrock AV, Mulligan TS, Matthews F, Brown AS, Lee-Harwood HR, Williams EM, Copp JN, Little RF, Francis JJB, Horvat CN, Stevenson LJ, Owen JG, Saxena MT, Mumm JS, Ackerley DF. A metagenomic library cloning strategy that promotes high-level expression of captured genes to enable efficient functional screening. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.24.534183. [PMID: 36993673 PMCID: PMC10055417 DOI: 10.1101/2023.03.24.534183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Functional screening of environmental DNA (eDNA) libraries is a potentially powerful approach to discover enzymatic "unknown unknowns", but is usually heavily biased toward the tiny subset of genes preferentially transcribed and translated by the screening strain. We have overcome this by preparing an eDNA library via partial digest with restriction enzyme FatI (cuts CATG), causing a substantial proportion of ATG start codons to be precisely aligned with strong plasmid-encoded promoter and ribosome-binding sequences. Whereas we were unable to select nitroreductases from standard metagenome libraries, our FatI strategy yielded 21 nitroreductases spanning eight different enzyme families, each conferring resistance to the nitro-antibiotic niclosamide and sensitivity to the nitro-prodrug metronidazole. We showed expression could be improved by co-expressing rare tRNAs and encoded proteins purified directly using an embedded His6-tag. In a transgenic zebrafish model of metronidazole-mediated targeted cell ablation, our lead MhqN-family nitroreductase proved ~5-fold more effective than the canonical nitroreductase NfsB.
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Affiliation(s)
- Michelle H Rich
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Abigail V Sharrock
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Timothy S Mulligan
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Frazer Matthews
- Department of Genetic Medicine, McKusick-Nathans Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Alistair S Brown
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Hannah R Lee-Harwood
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Elsie M Williams
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Current address: Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Janine N Copp
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Current addresses: Michael Smith Laboratories, University of British Columbia, Vancouver BC V6T 1Z4, Canada; Abcellera Biologics Inc, Vancouver BC V5Y 0A1, Canada
| | - Rory F Little
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Current address: Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, 07745 Jena, Germany
| | - Jenni JB Francis
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Claire N Horvat
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Current address: Teva Pharmaceuticals, Sydney, New South Wales 2113, Australia
| | - Luke J Stevenson
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Jeremy G Owen
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Meera T Saxena
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Jeff S Mumm
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Genetic Medicine, McKusick-Nathans Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - David F Ackerley
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
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9
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Weng C, Yang H, Loh BS, Wong MW, Ang WH. Targeting Pathogenic Formate-Dependent Bacteria with a Bioinspired Metallo-Nitroreductase Complex. J Am Chem Soc 2023; 145:6453-6461. [PMID: 36881731 DOI: 10.1021/jacs.3c00237] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
Nitroreductases (NTRs) constitute an important class of oxidoreductase enzymes that have evolved to metabolize nitro-containing compounds. Their unique characteristics have spurred an array of potential uses in medicinal chemistry, chemical biology, and bioengineering toward harnessing nitro caging groups and constructing NTR variants for niche applications. Inspired by how they carry out enzymatic reduction via a cascade of hydride transfer reactions, we sought to develop a synthetic small-molecule NTR system based on transfer hydrogenation mediated by transition metal complexes harnessing native cofactors. We report the first water-stable Ru-arene complex capable of selectively and fully reducing nitroaromatics into anilines in a biocompatible buffered aqueous environment using formate as the hydride source. We further demonstrated its application to activate nitro-caged sulfanilamide prodrug in formate-abundant bacteria, specifically pathogenic methicillin-resistant Staphylococcus aureus. This proof of concept paves the way for a new targeted antibacterial chemotherapeutic approach leveraging on redox-active metal complexes for prodrug activation via bioinspired nitroreduction.
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Affiliation(s)
- Cheng Weng
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore 117543, Singapore
| | - Hui Yang
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore 117543, Singapore
| | - Boon Shing Loh
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore 117543, Singapore
| | - Ming Wah Wong
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore 117543, Singapore
- NUS Graduate School─Integrative Sciences and Engineering Programme, National University of Singapore, 21 Lower Kent Ridge Road, Singapore 119077, Singapore
| | - Wee Han Ang
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore 117543, Singapore
- NUS Graduate School─Integrative Sciences and Engineering Programme, National University of Singapore, 21 Lower Kent Ridge Road, Singapore 119077, Singapore
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10
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Discovery and characterization of the flavonoids in Cortex Mori Radicis as naturally occurring inhibitors against intestinal nitroreductases. Chem Biol Interact 2022; 368:110222. [PMID: 36244406 DOI: 10.1016/j.cbi.2022.110222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 11/23/2022]
Abstract
Gut bacterial nitroreductases are found to be heavily related with the intestinal toxicity of nitroaromatic compounds in food or medicine, which can be converted into mutagenic and enterotoxic nitroso or N-hydroxyl intermediates. Thus, inhibiting the gut microbe-encoded nitroreductases has become an attractive method to reduce the mutagen metabolites in colon and prevent intestinal diseases. In this study, the inhibitory effects of sixteen constituents in Cortex Mori Radicis on two kinds of gut bacterial nitroreductases (EcNfsA and EcNfsB) were evaluated with nitrofurazone (NFZ) as substrate and NADPH as electron donor. The results clearly demonstrated that four flavonoids including kuwanon G, kuwanon A, sanggenol A and kuwanon C showed dual inhibition on both EcNfsA and EcNfsB mediated NFZ reduction; morusin, morin, and sanggenone C were strong inhibitors towards EcNfsA; kuwanon H and kuwanon E exhibited effective inhibition on EcNfsB. Further inhibition kinetic analysis and molecular docking simulations displayed that all inhibitors above suppressed both EcNfsA and EcNfsB activities in competitive manners, except non-competitive inhibition of morin on EcNfsA and non-competitive inhibition of kuwanon C on EcNfsB, respectively. Taking together, these findings revealed that most flavonoids in Cortex Mori Radicis presented effective inhibition on gut microbial nitroreductases, suggesting that Cortex Mori Radicis might be a promising candidate for ameliorating nitroreductases mediated intestinal mutagenicity.
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11
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Koch NG, Baumann T, Nickling JH, Dziegielewski A, Budisa N. Engineered bacterial host for genetic encoding of physiologically stable protein nitration. Front Mol Biosci 2022; 9:992748. [PMID: 36353730 PMCID: PMC9638147 DOI: 10.3389/fmolb.2022.992748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/16/2022] [Indexed: 11/23/2022] Open
Abstract
Across scales, many biological phenomena, such as protein folding or bioadhesion and cohesion, rely on synergistic effects of different amino acid side chains at multiple positions in the protein sequence. These are often fine-tuned by post-translational modifications that introduce additional chemical properties. Several PTMs can now be genetically encoded and precisely installed at single and multiple sites by genetic code expansion. Protein nitration is a PTM of particular interest because it has been associated with several diseases. However, even when these nitro groups are directly incorporated into proteins, they are often physiologically reduced during or shortly after protein production. We have solved this problem by using an engineered Escherichia coli host strain. Six genes that are associated with nitroreductase activity were removed from the genome in a simple and robust manner. The result is a bacterial expression host that can stably produce proteins and peptides containing nitro groups, especially when these are amenable to modification. To demonstrate the applicability of this strain, we used this host for several applications. One of these was the multisite incorporation of a photocaged 3,4-dihydroxyphenylalanine derivative into Elastin-Like Polypeptides. For this non-canonical amino acid and several other photocaged ncAAs, the nitro group is critical for photocleavability. Accordingly, our approach also enhances the production of biomolecules containing photocaged tyrosine in the form of ortho-nitrobenzyl-tyrosine. We envision our engineered host as an efficient tool for the production of custom designed proteins, peptides or biomaterials for various applications ranging from research in cell biology to large-scale production in biotechnology.
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Affiliation(s)
- Nikolaj G. Koch
- Bioanalytics Group, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
- Biocatalysis Group, Institute of Chemistry, Technische Universität Berlin, Berlin, Germany
| | - Tobias Baumann
- Biocatalysis Group, Institute of Chemistry, Technische Universität Berlin, Berlin, Germany
| | - Jessica H. Nickling
- Biocatalysis Group, Institute of Chemistry, Technische Universität Berlin, Berlin, Germany
| | - Anna Dziegielewski
- Biocatalysis Group, Institute of Chemistry, Technische Universität Berlin, Berlin, Germany
| | - Nediljko Budisa
- Biocatalysis Group, Institute of Chemistry, Technische Universität Berlin, Berlin, Germany
- Chemical Synthetic Biology Group, Department of Chemistry, University of Manitoba, Winnipeg, MB, Canada
- *Correspondence: Nediljko Budisa,
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12
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White SA, Christofferson AJ, Grainger AI, Day MA, Jarrom D, Graziano AE, Searle PF, Hyde EI. The 3D-structure, kinetics and dynamics of the E. coli nitroreductase NfsA with NADP + provide glimpses of its catalytic mechanism. FEBS Lett 2022; 596:2425-2440. [PMID: 35648111 PMCID: PMC9912195 DOI: 10.1002/1873-3468.14413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 05/20/2022] [Accepted: 05/25/2022] [Indexed: 11/12/2022]
Abstract
Nitroreductases activate nitroaromatic antibiotics and cancer prodrugs to cytotoxic hydroxylamines and reduce quinones to quinols. Using steady-state and stopped-flow kinetics, we show that the Escherichia coli nitroreductase NfsA is 20-50 fold more active with NADPH than with NADH and that product release may be rate-limiting. The crystal structure of NfsA with NADP+ shows that a mobile loop forms a phosphate-binding pocket. The nicotinamide ring and nicotinamide ribose are mobile, as confirmed in molecular dynamics (MD) simulations. We present a model of NADPH bound to NfsA. Only one NADP+ is seen bound to the NfsA dimers, and MD simulations show that binding of a second NADP(H) cofactor is unfavourable, suggesting that NfsA and other members of this protein superfamily may have a half-of-sites mechanism.
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Affiliation(s)
| | | | - Alastair I. Grainger
- School of BiosciencesUniversity of BirminghamUK,Present address:
School of Life and Health SciencesAston UniversityBirminghamB4 7ETUK
| | - Martin A. Day
- School of BiosciencesUniversity of BirminghamUK,Institute for Cancer and Genomic SciencesUniversity of BirminghamUK,Present address:
DurhamUK
| | - David Jarrom
- School of BiosciencesUniversity of BirminghamUK,Present address:
Health Technology WalesCardiffCF10 4PLUK
| | - Antonio E. Graziano
- School of BiosciencesUniversity of BirminghamUK,Present address:
Carlsberg Marstons Brewing CompanyNorthamptonNN1 1PZUK
| | - Peter F. Searle
- Institute for Cancer and Genomic SciencesUniversity of BirminghamUK
| | - Eva I. Hyde
- School of BiosciencesUniversity of BirminghamUK
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13
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Inhibition of Escherichia coli nitroreductase by the constituents in Syzygium aromaticum. Chin J Nat Med 2022; 20:506-517. [DOI: 10.1016/s1875-5364(22)60163-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Indexed: 11/23/2022]
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14
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Singleton DC, Mowday AM, Guise CP, Syddall SP, Bai SY, Li D, Ashoorzadeh A, Smaill JB, Wilson WR, Patterson AV. Bioreductive prodrug PR-104 improves the tumour distribution and titre of the nitroreductase-armed oncolytic adenovirus ONYX-411 NTR leading to therapeutic benefit. Cancer Gene Ther 2022; 29:1021-1032. [PMID: 34837065 DOI: 10.1038/s41417-021-00409-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 10/05/2021] [Accepted: 11/09/2021] [Indexed: 11/09/2022]
Abstract
Advances in the field of cancer immunotherapy have stimulated renewed interest in adenoviruses as oncolytic agents. Clinical experience has shown that oncolytic adenoviruses are safe and well tolerated but possess modest single-agent activity. One approach to improve the potency of oncolytic viruses is to utilise their tumour selectivity to deliver genes encoding prodrug-activating enzymes. These enzymes can convert prodrugs into cytotoxic species within the tumour; however, these cytotoxins can interfere with viral replication and limit utility. In this work, we evaluated the activity of a nitroreductase (NTR)-armed oncolytic adenovirus ONYX-411NTR in combination with the clinically tested bioreductive prodrug PR-104. Both NTR-expressing cells in vitro and xenografts containing a minor population of NTR-expressing cells were highly sensitive to PR-104. Pharmacologically relevant prodrug exposures did not interfere with ONYX-411NTR replication in vitro. In vivo, prodrug administration increased virus titre and improved virus distribution within tumour xenografts. Colonisation of tumours with high ONYX-411NTR titre resulted in NTR expression and prodrug activation. The combination of ONYX-411NTR with PR-104 was efficacious against HCT116 xenografts, whilst neither prodrug nor virus were active as single agents. This work highlights the potential for future clinical development of NTR-armed oncolytic viruses in combination with bioreductive prodrugs.
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Affiliation(s)
- Dean C Singleton
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand. .,Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand.
| | - Alexandra M Mowday
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Chris P Guise
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Sophie P Syddall
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Sally Y Bai
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Dan Li
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - Amir Ashoorzadeh
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Jeff B Smaill
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - William R Wilson
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Adam V Patterson
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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15
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Significance of Specific Oxidoreductases in the Design of Hypoxia-Activated Prodrugs and Fluorescent Turn Off–On Probes for Hypoxia Imaging. Cancers (Basel) 2022; 14:cancers14112686. [PMID: 35681666 PMCID: PMC9179281 DOI: 10.3390/cancers14112686] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/08/2022] [Accepted: 05/26/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary Hypoxia-activated prodrugs (HAPs), selectively reduced by specific oxidoreductases under hypoxic conditions, form cytotoxic agents damaging the local cancer cells. On the basis of the reported clinical data concerning several HAPs, one can draw conclusions regarding their preclinical attractiveness and, regrettably, the low efficacy of Phase III clinical trials. Clinical failure may be explained, inter alia, by the lack of screening of patients on the basis of tumor hypoxia and low availability of specific oxidoreductases involved in HAP activation. There is surprisingly little information on the quantification of these enzymes in cells or tissues, compared to the advanced research associated with the use of HAPs. Our knowledge about the expression and activity of these enzymes in various cancer cell lines under hypoxic conditions is inadequate. Only in a few cases were researchers able to demonstrate the differences in the expression or activity of selected oxidoreductases, depending on the oxygen concentration. Additionally, it was cell line dependent. More systematic studies are required. The optical probes, based on turning on the fluorescence emission upon irreversible reduction catalyzed by the overexpressed oxidoreductases, can be helpful in this type of research. Ultimately, such sensors can estimate both the oxidoreductase activity and the degree of oxygenation in one step. To achieve this goal, their response must be correlated with the expression or activity of enzymes potentially involved in turning on their emissions, as determined by biochemical methods. In conclusion, the incorporation of biomarkers to identify hypoxia is a prerequisite for successful HAP therapies. However, it is equally important to assess the level of specific oxidoreductases required for their activation. Abstract Hypoxia is one of the hallmarks of the tumor microenvironment and can be used in the design of targeted therapies. Cellular adaptation to hypoxic stress is regulated by hypoxia-inducible factor 1 (HIF-1). Hypoxia is responsible for the modification of cellular metabolism that can result in the development of more aggressive tumor phenotypes. Reduced oxygen concentration in hypoxic tumor cells leads to an increase in oxidoreductase activity that, in turn, leads to the activation of hypoxia-activated prodrugs (HAPs). The same conditions can convert a non-fluorescent compound into a fluorescent one (fluorescent turn off–on probes), and such probes can be designed to specifically image hypoxic cancer cells. This review focuses on the current knowledge about the expression and activity of oxidoreductases, which are relevant in the activation of HAPs and fluorescent imaging probes. The current clinical status of HAPs, their limitations, and ways to improve their efficacy are briefly discussed. The fluorescence probes triggered by reduction with specific oxidoreductase are briefly presented, with particular emphasis placed on those for which the correlation between the signal and enzyme expression determined with biochemical methods is achievable.
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16
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Musila JM, Rokita SE. Sequence Conservation Does Not Always Signify a Functional Imperative as Observed in the Nitroreductase Superfamily. Biochemistry 2022; 61:703-711. [PMID: 35319879 PMCID: PMC9018611 DOI: 10.1021/acs.biochem.2c00037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Consensus sequences have the potential to help classify the structure and function of proteins and highlight key regions that may contribute to their biological properties. Often, the level of significance will track with the extent of sequence conservation, but this should not be considered universal. Arg and Lys dominate a position adjacent to the N1 and C2 carbonyl of flavin mononucleotide (FMN) bound in the proteins of the nitroreductase superfamily. Although this placement satisfies expectations for stabilizing the reduced form of FMN, the substitution of these residues in three subfamilies promoting distinct reactions demonstrates their importance to catalysis as only modest. Replacing Arg34 with Lys, Gln, or Glu enhances FMN binding to a flavin destructase (BluB) by twofold and diminishes FMN turnover by no more than 25%. Similarly, replacing Lys14 with Arg, Gln, or Glu in a nitroreductase (NfsB) does not perturb the binding of the substrate nitrofurazone. The catalytic efficiency does decrease by 21-fold for the K14Q variant, but no change in the midpoint potential of FMN was observed with any of the variants. Equivalent substitution at Arg38 in iodotyrosine deiodinase (IYD) affects catalysis even more modestly (<10-fold). While the Arg/Lys to Glu substitution inactivates NfsB and IYD, this change also stabilizes one-electron transfer in IYD contrary to predictions based on other classes of flavoproteins. Accordingly, functional correlations developed in certain structural superfamilies may not necessarily translate well to other superfamilies.
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Affiliation(s)
- Jonathan M Musila
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Steven E Rokita
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
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17
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Sharrock AV, Mulligan TS, Hall KR, Williams EM, White DT, Zhang L, Emmerich K, Matthews F, Nimmagadda S, Washington S, Le KD, Meir-Levi D, Cox OL, Saxena MT, Calof AL, Lopez-Burks ME, Lander AD, Ding D, Ji H, Ackerley DF, Mumm JS. NTR 2.0: a rationally engineered prodrug-converting enzyme with substantially enhanced efficacy for targeted cell ablation. Nat Methods 2022; 19:205-215. [PMID: 35132245 PMCID: PMC8851868 DOI: 10.1038/s41592-021-01364-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 11/29/2021] [Indexed: 11/12/2022]
Abstract
Transgenic expression of bacterial nitroreductase (NTR) enzymes sensitizes eukaryotic cells to prodrugs such as metronidazole (MTZ), enabling selective cell-ablation paradigms that have expanded studies of cell function and regeneration in vertebrates. However, first-generation NTRs required confoundingly toxic prodrug treatments to achieve effective cell ablation, and some cell types have proven resistant. Here we used rational engineering and cross-species screening to develop an NTR variant, NTR 2.0, which exhibits ~100-fold improvement in MTZ-mediated cell-specific ablation efficacy, eliminating the need for near-toxic prodrug treatment regimens. NTR 2.0 therefore enables sustained cell-loss paradigms and ablation of previously resistant cell types. These properties permit enhanced interrogations of cell function, extended challenges to the regenerative capacities of discrete stem cell niches, and novel modeling of chronic degenerative diseases. Accordingly, we have created a series of bipartite transgenic reporter/effector resources to facilitate dissemination of NTR 2.0 to the research community.
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Affiliation(s)
- Abigail V Sharrock
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Timothy S Mulligan
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Kelsi R Hall
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Elsie M Williams
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - David T White
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Liyun Zhang
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Kevin Emmerich
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Frazer Matthews
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Saumya Nimmagadda
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Selena Washington
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Katherine D Le
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Danielle Meir-Levi
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Olivia L Cox
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Meera T Saxena
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
- Luminomics, Baltimore, MD, USA
| | - Anne L Calof
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA
- Department of Developmental and Cell Biology, University of California, Irvine, CA, USA
- Center for Complex Biological Systems, University of California, Irvine, CA, USA
| | - Martha E Lopez-Burks
- Department of Developmental and Cell Biology, University of California, Irvine, CA, USA
- Center for Complex Biological Systems, University of California, Irvine, CA, USA
| | - Arthur D Lander
- Department of Developmental and Cell Biology, University of California, Irvine, CA, USA
- Center for Complex Biological Systems, University of California, Irvine, CA, USA
| | - Ding Ding
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Hongkai Ji
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - David F Ackerley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand.
- Centre for Biodiscovery and Maurice Wilkins Centre for Molecular Biodiscovery, Victoria University of Wellington, Wellington, New Zealand.
| | - Jeff S Mumm
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA.
- The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA.
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA.
- Department of Genetic Medicine, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA.
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18
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Use of an optimised enzyme/prodrug combination for Clostridia directed enzyme prodrug therapy induces a significant growth delay in necrotic tumours. Cancer Gene Ther 2022; 29:178-188. [PMID: 33558701 DOI: 10.1038/s41417-021-00296-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 12/20/2020] [Accepted: 01/12/2021] [Indexed: 01/30/2023]
Abstract
Necrosis is a typical histological feature of solid tumours that provides a selective environment for growth of the non-pathogenic anaerobic bacterium Clostridium sporogenes. Modest anti-tumour activity as a single agent encouraged the use of C. sporogenes as a vector to express therapeutic genes selectively in tumour tissue, a concept termed Clostridium Directed Enzyme Prodrug Therapy (CDEPT). Here, we examine the ability of a recently identified Neisseria meningitidis type I nitroreductase (NmeNTR) to metabolise the prodrug PR-104A in an in vivo model of CDEPT. Human HCT116 colon cancer cells stably over-expressing NmeNTR demonstrated significant sensitivity to PR-104A, the imaging agent EF5, and several nitro(hetero)cyclic anti-infective compounds. Chemical induction of necrosis in human H1299 xenografts by the vascular disrupting agent vadimezan promoted colonisation by NmeNTR-expressing C. sporogenes, and efficacy studies demonstrated moderate but significant anti-tumour activity of spores when compared to untreated controls. Inclusion of the pre-prodrug PR-104 into the treatment schedule provided significant additional activity, indicating proof-of-principle. Successful preclinical evaluation of a transferable gene that enables metabolism of both PET imaging agents (for vector visualisation) and prodrugs (for conditional enhancement of efficacy) is an important step towards the prospect of CDEPT entering clinical evaluation.
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19
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Interrogation of the Structure–Activity Relationship of a Lipophilic Nitroaromatic Prodrug Series Designed for Cancer Gene Therapy Applications. Pharmaceuticals (Basel) 2022; 15:ph15020185. [PMID: 35215297 PMCID: PMC8877822 DOI: 10.3390/ph15020185] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/25/2022] [Accepted: 01/27/2022] [Indexed: 11/17/2022] Open
Abstract
PR-104A is a dual hypoxia/nitroreductase gene therapy prodrug by virtue of its ability to undergo either one- or two-electron reduction to its cytotoxic species. It has been evaluated extensively in pre-clinical GDEPT studies, yet off-target human aldo-keto reductase AKR1C3-mediated activation has limited its use. Re-evaluation of this chemical scaffold has previously identified SN29176 as an improved hypoxia-activated prodrug analogue of PR-104A that is free from AKR1C3 activation. However, optimization of the bystander effect of SN29176 is required for use in a GDEPT setting to compensate for the non-uniform distribution of therapeutic gene transfer that is often observed with current gene therapy vectors. A lipophilic series of eight analogues were synthesized from commercially available 3,4-difluorobenzaldehyde. Calculated octanol-water partition coefficients (LogD7.4) spanned > 2 orders of magnitude. 2D anti-proliferative and 3D multicellular layer assays were performed using isogenic HCT116 cells expressing E. coli NfsA nitroreductase (NfsA_Ec) or AKR1C3 to determine enzyme activity and measure bystander effect. A variation in potency for NfsA_Ec was observed, while all prodrugs appeared AKR1C3-resistant by 2D assay. However, 3D assays indicated that increasing prodrug lipophilicity correlated with increased AKR1C3 activation and NfsA_Ec activity, suggesting that metabolite loss from the cell of origin into media during 2D monolayer assays could mask cytotoxicity. Three prodrugs were identified as bono fide AKR1C3-negative candidates whilst maintaining activity with NfsA_Ec. These were converted to their phosphate ester pre-prodrugs before being taken forward into in vivo therapeutic efficacy studies. Ultimately, 2-(5-(bis(2-bromoethyl)amino)-4-(ethylsulfonyl)-N-methyl-2-nitrobenzamido)ethyl dihydrogen phosphate possessed a significant 156% improvement in median survival in mixed NfsA_Ec/WT tumors compared to untreated controls (p = 0.005), whilst still maintaining hypoxia selectivity comparable to PR-104A.
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20
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Liu D, Wanniarachchi TN, Jiang G, Seabra G, Cao S, Bruner SD, Ding Y. Biochemical and structural characterization of Haemophilus influenzae nitroreductase in metabolizing nitroimidazoles. RSC Chem Biol 2022; 3:436-446. [PMID: 35441146 PMCID: PMC8985140 DOI: 10.1039/d1cb00238d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/15/2022] [Indexed: 11/21/2022] Open
Abstract
Nitroheterocycle antibiotics, particularly 5-nitroimidazoles, are frequently used for treating anaerobic infections. The antimicrobial activities of these drugs heavily rely on the in vivo bioactivation, mainly mediated by widely distributed bacterial nitroreductases (NTRs). However, the bioactivation can also lead to severe toxicities and drug resistance. Mechanistic understanding of NTR-mediated 5-nitroimidazole metabolism can potentially aid addressing these issues. Here, we report the metabolism of structurally diverse nitroimidazole drug molecules by a NTR from a human pathogen Haemophilus influenzae (HiNfsB). Our detailed bioinformatic analysis uncovered that HiNfsB represents a group of unexplored oxygen-insensitive NTRs. Biochemical characterization of the recombinant enzyme revealed that HiNfsB effectively metabolizes ten clinically used nitroimidazoles. Furthermore, HiNfsB generated not only canonical nitroreduction metabolites but also stable, novel dimeric products from three nitroimidazoles, whose structures were proposed based on the results of high resolution MS and tandem MS analysis. X-ray structural analysis of the enzyme coupled with site-directed mutagenesis identified four active site residues important to its catalysis and broad substrate scope. Finally, transient expression of HiNfsB sensitized an E. coli mutant strain to 5-nitroimidazoles under anaerobic conditions. Together, these results advance our understanding of the metabolism of nitroimidazole antibiotics mediated by a new NTR group and reinforce the research on the natural antibiotic resistome for addressing the antibiotic resistance crisis. The nitroreductase of Haemophilus influenzae metabolizes clinically used nitroimidazoles, generates dimeric metabolites and anaerobically sensitizes an E. coli mutant to antibiotics. We further uncover its biochemical and structural details.![]()
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Affiliation(s)
- Dake Liu
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida, 32610, USA
| | | | - Guangde Jiang
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida, 32610, USA
| | - Gustavo Seabra
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida, 32610, USA
| | - Shugeng Cao
- Department of Pharmaceutical Sciences, University of Hawai'i at Hilo, Hilo, Hawaii, 96720, USA
| | - Steven D. Bruner
- Department of Chemistry, University of Florida, Gainesville, Florida, 32611, USA
| | - Yousong Ding
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida, 32610, USA
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21
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Hennigan JN, Lynch MD. The past, present, and future of enzyme-based therapies. Drug Discov Today 2022; 27:117-133. [PMID: 34537332 PMCID: PMC8714691 DOI: 10.1016/j.drudis.2021.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/15/2021] [Accepted: 09/10/2021] [Indexed: 01/03/2023]
Abstract
Enzyme-based therapeutics (EBTs) have the potential to tap into an almost unmeasurable amount of enzyme biodiversity and treat myriad conditions. Although EBTs were some of the first biologics used clinically, the rate of development of newer EBTs has lagged behind that of other biologics. Here, we review the history of EBTs, and discuss the state of each class of EBT, their potential clinical advantages, and the unique challenges to their development. Additionally, we discuss key remaining technical barriers that, if addressed, could increase the diversity and rate of the development of EBTs.
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Affiliation(s)
| | - Michael D Lynch
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.
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22
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Yan K, Li J, Wang W, Li Q. Construction of Stable T7 Expression System in Saccharomyces cerevisiae by Improving Nuclear Membrane Permeability with Viroporin HIV-1 Vpu. Appl Biochem Biotechnol 2021; 193:4214-4227. [PMID: 34632548 PMCID: PMC8502630 DOI: 10.1007/s12010-021-03665-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/03/2021] [Indexed: 11/30/2022]
Abstract
T7 expression system (T7 RNA polymerase / T7 promoter), derived from T7 bacteriophage, is one of the most extensively used protein expression systems, which is also an enabling tool in synthetic biology. However, in eukaryote, most of T7 expression system is transient expression system. This is mainly due to the absence of post-transcriptional processing of mRNAs transcribed by T7RNAP in eukaryotic cells, so they cannot effectively pass through nuclear membrane and enter cytoplasm. In this study, Saccharomyces cerevisiae was selected as host to construct stable T7 expression system, in which HIV-1 viroporin (Vpu) was used to improve the permeability of nuclear membrane. Results of NanoLuc® (Nluc) luciferase expression indicated that Vpu could effectively promote the transport of T7 transcripts and increase the amount of protein synthesized. The method of using viroporin to improve permeability of the nuclear membrane provides an effective tool for constructing a stable T7 expression system in eukaryote.
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Affiliation(s)
- Kun Yan
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Jun Li
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Wenya Wang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Qiang Li
- Department of Chemical Engineering, Key Laboratory for Industrial Biocatalysis, Ministry of Education, Tsinghua University, Beijing, 100084, China
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Fosfomycin and nitrofurantoin: classic antibiotics and perspectives. J Antibiot (Tokyo) 2021; 74:547-558. [PMID: 34244614 DOI: 10.1038/s41429-021-00444-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 02/06/2023]
Abstract
Antibiotics are essential molecules for the treatment and prophylaxis of many infectious diseases. However, drugs that combat microbial infections can become a human health threat due to their high and often indiscriminate consumption, considered one of the factors of antimicrobial resistance (AMR) emergence. The AMR crisis, the decrease in new drug development by the pharmaceutical industry, and reduced economic incentives for research have all reduced the options for treating infections, and new strategies are necessary, including the return of some traditional but "forgotten" antibiotics. However, prescriptions for these older drugs including nitrofurantoin and oral fosfomycin, have been based on the results of pioneer studies, and the limited knowledge generated 50-70 years ago may not be enough. To avoid harming patients and further increasing multidrug resistance, systematic evaluation is required, mainly for the drugs prescribed for community-acquired infections, such as urinary tract infections (UTI). Therefore, this review has the objective of reporting the use of two classic drugs from the nitrofuran and phosphonic acid classes for UTI control nowadays. Furthermore, we also explore new approaches used for these antibiotics, including new combination regimes for spectral amplification, and the prospects for reducing bacterial resistance in the fight against bacteria responsible for UTI.
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Čėnas N, Nemeikaitė-Čėnienė A, Kosychova L. Single- and Two-Electron Reduction of Nitroaromatic Compounds by Flavoenzymes: Mechanisms and Implications for Cytotoxicity. Int J Mol Sci 2021; 22:ijms22168534. [PMID: 34445240 PMCID: PMC8395237 DOI: 10.3390/ijms22168534] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 12/14/2022] Open
Abstract
Nitroaromatic compounds (ArNO2) maintain their importance in relation to industrial processes, environmental pollution, and pharmaceutical application. The manifestation of toxicity/therapeutic action of nitroaromatics may involve their single- or two-electron reduction performed by various flavoenzymes and/or their physiological redox partners, metalloproteins. The pivotal and still incompletely resolved questions in this area are the identification and characterization of the specific enzymes that are involved in the bioreduction of ArNO2 and the establishment of their contribution to cytotoxic/therapeutic action of nitroaromatics. This review addresses the following topics: (i) the intrinsic redox properties of ArNO2, in particular, the energetics of their single- and two-electron reduction in aqueous medium; (ii) the mechanisms and structure-activity relationships of reduction in ArNO2 by flavoenzymes of different groups, dehydrogenases-electrontransferases (NADPH:cytochrome P-450 reductase, ferredoxin:NADP(H) oxidoreductase and their analogs), mammalian NAD(P)H:quinone oxidoreductase, bacterial nitroreductases, and disulfide reductases of different origin (glutathione, trypanothione, and thioredoxin reductases, lipoamide dehydrogenase), and (iii) the relationships between the enzymatic reactivity of compounds and their activity in mammalian cells, bacteria, and parasites.
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Affiliation(s)
- Narimantas Čėnas
- Institute of Biochemistry of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania;
- Correspondence: ; Tel.: +370-5-223-4392
| | - Aušra Nemeikaitė-Čėnienė
- State Research Institute Center for Innovative Medicine, Santariškių St. 5, LT-08406 Vilnius, Lithuania;
| | - Lidija Kosychova
- Institute of Biochemistry of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania;
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Sharrock AV, McManaway SP, Rich MH, Mumm JS, Hermans IF, Tercel M, Pruijn FB, Ackerley DF. Engineering the Escherichia coli Nitroreductase NfsA to Create a Flexible Enzyme-Prodrug Activation System. Front Pharmacol 2021; 12:701456. [PMID: 34163368 PMCID: PMC8215503 DOI: 10.3389/fphar.2021.701456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 05/24/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial nitroreductase enzymes that can efficiently convert nitroaromatic prodrugs to a cytotoxic form have numerous applications in targeted cellular ablation. For example, the generation of cytotoxic metabolites that have low bystander potential (i.e., are largely confined to the activating cell) has been exploited for precise ablation of specific cell types in animal and cell-culture models; while enzyme-prodrug combinations that generate high levels of bystander cell killing are useful for anti-cancer strategies such as gene-directed enzyme-prodrug therapy (GDEPT). Despite receiving substantial attention for such applications, the canonical nitroreductase NfsB from Escherichia coli has flaws that limit its utility, in particular a low efficiency of conversion of most prodrugs. Here, we sought to engineer a superior broad-range nitroreductase, E. coli NfsA, for improved activity with three therapeutically-relevant prodrugs: the duocarmycin analogue nitro-CBI-DEI, the dinitrobenzamide aziridine CB1954 and the 5-nitroimidazole metronidazole. The former two prodrugs have applications in GDEPT, while the latter has been employed for targeted ablation experiments and as a precise 'off-switch' in GDEPT models to eliminate nitroreductase-expressing cells. Our lead engineered NfsA (variant 11_78, with the residue substitutions S41Y, L103M, K222E and R225A) generated reduced metabolites of CB1954 and nitro-CBI-DEI that exhibited high bystander efficiencies in both bacterial and 2D HEK-293 cell culture models, while no cell-to-cell transfer was evident for the reduced metronidazole metabolite. We showed that the high bystander efficiency for CB1954 could be attributed to near-exclusive generation of the 2-hydroxylamine reduction product, which has been shown in 3D cell culture to cause significantly greater bystander killing than the 4-hydroxylamine species that is also produced by NfsB. We similarly observed a high bystander effect for nitro-CBI-DEI in HCT-116 tumor spheroids in which only a small proportion of cells were expressing variant 11_78. Collectively, our data identify variant 11_78 as a broadly improved prodrug-activating nitroreductase that offers advantages for both targeted cellular ablation and suicide gene therapy applications.
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Affiliation(s)
- Abigail V. Sharrock
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Sarah P. McManaway
- Auckland Cancer Society Research Centre, The University of Auckland, Auckland, New Zealand
| | - Michelle H. Rich
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Jeff S. Mumm
- The Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States
| | - Ian F. Hermans
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | - Moana Tercel
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
- Auckland Cancer Society Research Centre, The University of Auckland, Auckland, New Zealand
| | - Frederik B. Pruijn
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
- Auckland Cancer Society Research Centre, The University of Auckland, Auckland, New Zealand
| | - David F. Ackerley
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
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Thomas C, Gwenin CD. The Role of Nitroreductases in Resistance to Nitroimidazoles. BIOLOGY 2021; 10:388. [PMID: 34062712 PMCID: PMC8147198 DOI: 10.3390/biology10050388] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/04/2021] [Accepted: 02/10/2021] [Indexed: 01/14/2023]
Abstract
Antimicrobial resistance is a major challenge facing modern medicine, with an estimated 700,000 people dying annually and a global cost in excess of $100 trillion. This has led to an increased need to develop new, effective treatments. This review focuses on nitroimidazoles, which have seen a resurgence in interest due to their broad spectrum of activity against anaerobic Gram-negative and Gram-positive bacteria. The role of nitroreductases is to activate the antimicrobial by reducing the nitro group. A decrease in the activity of nitroreductases is associated with resistance. This review will discuss the resistance mechanisms of different disease organisms, including Mycobacterium tuberculosis, Helicobacter pylori and Staphylococcus aureus, and how these impact the effectiveness of specific nitroimidazoles. Perspectives in the field of nitroimidazole drug development are also summarised.
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Affiliation(s)
- Carol Thomas
- School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK;
| | - Christopher D. Gwenin
- Department of Chemistry, Xi’an Jiaotong-Liverpool University, 111 Ren’ai Road, Suzhou Industrial Park, Suzhou 215123, China
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Ruiz de Garibay G, García de Jalón E, Stigen E, Lund KB, Popa M, Davidson B, Safont MM, Rygh CB, Espedal H, Barrett TM, Haug BE, McCormack E. Repurposing 18F-FMISO as a PET tracer for translational imaging of nitroreductase-based gene directed enzyme prodrug therapy. Am J Cancer Res 2021; 11:6044-6057. [PMID: 33897898 PMCID: PMC8058731 DOI: 10.7150/thno.55092] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/25/2021] [Indexed: 12/25/2022] Open
Abstract
Nitroreductases (NTR) are a family of bacterial enzymes used in gene directed enzyme prodrug therapy (GDEPT) that selectively activate prodrugs containing aromatic nitro groups to exert cytotoxic effects following gene transduction in tumours. The clinical development of NTR-based GDEPT has, in part, been hampered by the lack of translational imaging modalities to assess gene transduction and drug cytotoxicity, non-invasively. This study presents translational preclinical PET imaging to validate and report NTR activity using the clinically approved radiotracer, 18F-FMISO, as substrate for the NTR enzyme. Methods: The efficacy with which 18F-FMISO could be used to report NfsB NTR activity in vivo was investigated using the MDA-MB-231 mammary carcinoma xenograft model. For validation, subcutaneous xenografts of cells constitutively expressing NTR were imaged using 18F-FMISO PET/CT and fluorescence imaging with CytoCy5S, a validated fluorescent NTR substrate. Further, examination of the non-invasive functionality of 18F-FMISO PET/CT in reporting NfsB NTR activity in vivo was assessed in metastatic orthotopic NfsB NTR expressing xenografts and metastasis confirmed by bioluminescence imaging. 18F-FMISO biodistribution was acquired ex vivo by an automatic gamma counter measuring radiotracer retention to confirm in vivo results. To assess the functional imaging of NTR-based GDEPT with 18F-FMISO, PET/CT was performed to assess both gene transduction and cytotoxicity effects of prodrug therapy (CB1954) in subcutaneous models. Results:18F-FMISO retention was detected in NTR+ subcutaneous xenografts, displaying significantly higher PET contrast than NTR- xenografts (p < 0.0001). Substantial 18F-FMISO retention was evident in metastases of orthotopic xenografts (p < 0.05). Accordingly, higher 18F-FMISO biodistribution was prevalent ex vivo in NTR+ xenografts. 18F-FMISO NfsB NTR PET/CT imaging proved useful for monitoring in vivo NTR transduction and the cytotoxic effect of prodrug therapy. Conclusions:18F-FMISO NfsB NTR PET/CT imaging offered significant contrast between NTR+ and NTR- tumours and effective resolution of metastatic progression. Furthermore, 18F-FMISO NfsB NTR PET/CT imaging proved efficient in monitoring the two steps of GDEPT, in vivo NfsB NTR transduction and response to CB1954 prodrug therapy. These results support the repurposing of 18F-FMISO as a readily implementable PET imaging probe to be employed as companion diagnostic test for NTR-based GDEPT systems.
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Vitelli M, Budman H, Pritzker M, Tamer M. Applications of flow cytometry sorting in the pharmaceutical industry: A review. Biotechnol Prog 2021; 37:e3146. [PMID: 33749147 DOI: 10.1002/btpr.3146] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/12/2021] [Accepted: 03/12/2021] [Indexed: 12/17/2022]
Abstract
The article reviews applications of flow cytometry sorting in manufacturing of pharmaceuticals. Flow cytometry sorting is an extremely powerful tool for monitoring, screening and separating single cells based on any property that can be measured by flow cytometry. Different applications of flow cytometry sorting are classified into groups and discussed in separate sections as follows: (a) isolation of cell types, (b) high throughput screening, (c) cell surface display, (d) droplet fluorescent-activated cell sorting (FACS). Future opportunities are identified including: (a) sorting of particular fractions of the cell population based on a property of interest for generating inoculum that will result in improved outcomes of cell cultures and (b) the use of population balance models in combination with FACS to design and optimize cell cultures.
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Affiliation(s)
- Michael Vitelli
- Department of Chemical Engineering, University of Waterloo, Waterloo, Canada
| | - Hector Budman
- Department of Chemical Engineering, University of Waterloo, Waterloo, Canada
| | - Mark Pritzker
- Department of Chemical Engineering, University of Waterloo, Waterloo, Canada
| | - Melih Tamer
- Department of Manufacturing Technology, Sanofi Pasteur, Toronto, Canada
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29
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Hall KR, Robins KJ, Williams EM, Rich MH, Calcott MJ, Copp JN, Little RF, Schwörer R, Evans GB, Patrick WM, Ackerley DF. Intracellular complexities of acquiring a new enzymatic function revealed by mass-randomisation of active-site residues. eLife 2020; 9:59081. [PMID: 33185191 PMCID: PMC7738182 DOI: 10.7554/elife.59081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/12/2020] [Indexed: 11/17/2022] Open
Abstract
Selection for a promiscuous enzyme activity provides substantial opportunity for competition between endogenous and newly-encountered substrates to influence the evolutionary trajectory, an aspect that is often overlooked in laboratory directed evolution studies. We selected the Escherichia coli nitro/quinone reductase NfsA for chloramphenicol detoxification by simultaneously randomising eight active-site residues and interrogating ~250,000,000 reconfigured variants. Analysis of every possible intermediate of the two best chloramphenicol reductases revealed complex epistatic interactions. In both cases, improved chloramphenicol detoxification was only observed after an R225 substitution that largely eliminated activity with endogenous quinones. Error-prone PCR mutagenesis reinforced the importance of R225 substitutions, found in 100% of selected variants. This strong activity trade-off demonstrates that endogenous cellular metabolites hold considerable potential to shape evolutionary outcomes. Unselected prodrug-converting activities were mostly unaffected, emphasising the importance of negative selection to effect enzyme specialisation, and offering an application for the evolved genes as dual-purpose selectable/counter-selectable markers. In the cell, most tasks are performed by big molecules called proteins, which behave like molecular machines. Although proteins are often described as having one job each, this is not always true, and many proteins can perform different roles. Enzymes are a type of protein that facilitate chemical reactions. They are often specialised to one reaction, but they can also accelerate other side-reactions. During evolution, these side-reactions can become more useful and, as a result, the role of the enzyme may change over time. The main role of the enzyme called NfsA in Escherichia coli bacteria is thought to be to convert molecules called quinones into hydroquinones, which can protect the cell from toxic molecules produced in oxidation reactions. As a side-reaction, NfsA has the potential to protect bacteria from an antibiotic called chloramphenicol, but it generally does this with such low efficacy that the effects are negligible. Producing hydroquinones is helpful to the cell in some situations, but if bacteria are regularly exposed to chloramphenicol, NfsA’s role aiding antibiotic resistance could become more important. Over time, the enzyme could evolve to become better at neutralising chloramphenicol. Therefore, NfsA provides an opportunity to study the evolution of proteins and how bacteria adapt to antibiotics. To see how evolution might affect the activity of NfsA, Hall et al. generated 250 million E. coli with either random or targeted changes to the gene that codes for the NfsA enzyme. The resulting variants of NfsA that were most effective against chloramphenicol all had a change that eliminated the enzyme’s ability to convert quinones. This result demonstrates a key trade-off between roles for NfsA, where one must be lost for the other to improve. These results demonstrate the interplay between a protein’s different roles and provide insight into bacterial drug resistance. Additionally, the experiments showed that the bacteria with improved resistance to chloramphenicol also became more sensitive to another antibiotic, metronidazole. These findings could inform the fight against drug-resistant bacterial infections and may also be helpful in guiding the design of proteins with different roles.
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Affiliation(s)
- Kelsi R Hall
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Katherine J Robins
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand
| | - Elsie M Williams
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Michelle H Rich
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand
| | - Mark J Calcott
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - Janine N Copp
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand
| | - Rory F Little
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand
| | - Ralf Schwörer
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand.,Ferrier Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Gary B Evans
- Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand.,Ferrier Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Wayne M Patrick
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
| | - David F Ackerley
- School of Biological Sciences, Victoria University of Wellington, Wellington, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, Wellington, New Zealand
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Ag–Pd Alloy Immobilized on Semi-heterogeneous Support as a Novel Highly Efficient Artificial Nitroreductase: Experimental Design Optimization and Kinetic Study. Catal Letters 2020. [DOI: 10.1007/s10562-020-03418-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Ball P, Halliwell J, Anderson S, Gwenin V, Gwenin C. Evaluation of two xenobiotic reductases from Pseudomonas putida for their suitability for magnetic nanoparticle-directed enzyme prodrug therapy as a novel approach to cancer treatment. Microbiologyopen 2020; 9:e1110. [PMID: 32979040 PMCID: PMC7568253 DOI: 10.1002/mbo3.1110] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/28/2020] [Accepted: 07/30/2020] [Indexed: 02/03/2023] Open
Abstract
Directed enzyme prodrug therapy (DEPT) is a cancer chemotherapy strategy in which bacterial enzymes are delivered to a cancer site before prodrug administration, resulting in prodrug activation at the cancer site and more localized treatment. A major limitation to DEPT is the poor effectiveness of the most studied enzyme for the CB1954 prodrug, NfnB from Escherichia coli, at concentrations suitable for human use. Much research into finding alternative enzymes to NfnB has resulted in the identification of the Xenobiotic reductases, XenA and XenB, which have been shown in the literature to reduce environmentally polluting nitro‐compounds. In this study, they were assessed for their potential use in cancer prodrug therapy strategies. Both proteins were cloned into the pET28a+ expression vector to give the genetically modified proteins XenA‐his and XenB‐his, of which only XenB‐his was active when tested with CB1954. XenB‐his was further modified to include a cysteine‐tag to facilitate direct immobilization on to a gold surface for future magnetic nanoparticle DEPT (MNDEPT) treatments and was named XenB‐cys. When tested using high‐performance liquid chromatography (HPLC), XenB‐his and XenB‐cys both demonstrated a preference for reducing CB1954 at the 4‐nitro position. Furthermore, XenB‐his and XenB‐cys successfully induced cell death in SK‐OV‐3 cells when combined with CB1954. This led to XenB‐cys being identified as a promising candidate for use in future MNDEPT treatments.
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Mechanistic Understanding Enables the Rational Design of Salicylanilide Combination Therapies for Gram-Negative Infections. mBio 2020; 11:mBio.02068-20. [PMID: 32934086 PMCID: PMC7492738 DOI: 10.1128/mbio.02068-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
There is a critical need for more-effective treatments to combat multidrug-resistant Gram-negative infections. Combination therapies are a promising strategy, especially when these enable existing clinical drugs to be repurposed as antibiotics. We examined the mechanisms of action and basis of innate Gram-negative resistance for the anthelmintic drug niclosamide and subsequently exploited this information to demonstrate that niclosamide and analogs kill Gram-negative bacteria when combined with antibiotics that inhibit drug efflux or permeabilize membranes. We confirm the synergistic potential of niclosamide in vitro against a diverse range of recalcitrant Gram-negative clinical isolates and in vivo in a mouse abscess model. We also demonstrate that nitroreductases can confer resistance to niclosamide but show that evolution of these enzymes for enhanced niclosamide resistance confers a collateral sensitivity to other clinical antibiotics. Our results highlight how detailed mechanistic understanding can accelerate the evaluation and implementation of new combination therapies. One avenue to combat multidrug-resistant Gram-negative bacteria is the coadministration of multiple drugs (combination therapy), which can be particularly promising if drugs synergize. The identification of synergistic drug combinations, however, is challenging. Detailed understanding of antibiotic mechanisms can address this issue by facilitating the rational design of improved combination therapies. Here, using diverse biochemical and genetic assays, we examine the molecular mechanisms of niclosamide, a clinically approved salicylanilide compound, and demonstrate its potential for Gram-negative combination therapies. We discovered that Gram-negative bacteria possess two innate resistance mechanisms that reduce their niclosamide susceptibility: a primary mechanism mediated by multidrug efflux pumps and a secondary mechanism of nitroreduction. When efflux was compromised, niclosamide became a potent antibiotic, dissipating the proton motive force (PMF), increasing oxidative stress, and reducing ATP production to cause cell death. These insights guided the identification of diverse compounds that synergized with salicylanilides when coadministered (efflux inhibitors, membrane permeabilizers, and antibiotics that are expelled by PMF-dependent efflux), thus suggesting that salicylanilide compounds may have broad utility in combination therapies. We validate these findings in vivo using a murine abscess model, where we show that niclosamide synergizes with the membrane permeabilizing antibiotic colistin against high-density infections of multidrug-resistant Gram-negative clinical isolates. We further demonstrate that enhanced nitroreductase activity is a potential route to adaptive niclosamide resistance but show that this causes collateral susceptibility to clinical nitro-prodrug antibiotics. Thus, we highlight how mechanistic understanding of mode of action, innate/adaptive resistance, and synergy can rationally guide the discovery, development, and stewardship of novel combination therapies.
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Directed evolution of the B. subtilis nitroreductase YfkO improves activation of the PET-capable probe SN33623 and CB1954 prodrug. Biotechnol Lett 2020; 43:203-211. [PMID: 32851465 DOI: 10.1007/s10529-020-02992-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/13/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVES To use directed evolution to improve YfkO-mediated reduction of the 5-nitroimidazole PET-capable probe SN33623 without impairing conversion of the anti-cancer prodrug CB1954. RESULTS Two iterations of error-prone PCR, purifying selection, and FACS sorting in a DNA damage quantifying GFP reporter strain were used to identify three YfkO variants able to sensitize E. coli host cells to at least 2.4-fold lower concentrations of SN33623 than the native enzyme. Two of these variants were able to be purified in a functional form, and in vitro assays revealed these were twofold and fourfold improved in kcat/KM with SN33623 over wild type YfkO. Serendipitously, the more-active variant was also nearly fourfold improved in kcat/KM versus wild type YfkO in converting CB1954 to a genotoxic drug. CONCLUSIONS The enhanced activation of the PET imaging probe SN33623 and CB1954 prodrug exhibited by the lead evolved variant of YfkO offers prospects for improved enzyme-prodrug therapy.
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Mowday AM, Copp JN, Syddall SP, Dubois LJ, Wang J, Lieuwes NG, Biemans R, Ashoorzadeh A, Abbattista MR, Williams EM, Guise CP, Lambin P, Ackerley DF, Smaill JB, Theys J, Patterson AV. E. coli nitroreductase NfsA is a reporter gene for non-invasive PET imaging in cancer gene therapy applications. Theranostics 2020; 10:10548-10562. [PMID: 32929365 PMCID: PMC7482819 DOI: 10.7150/thno.46826] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/30/2020] [Indexed: 12/13/2022] Open
Abstract
The use of reporter genes to non-invasively image molecular processes inside cells has significant translational potential, particularly in the context of systemically administered gene therapy vectors and adoptively administered cells such as immune or stem cell based therapies. Bacterial nitroreductase enzymes possess ideal properties for reporter gene imaging applications, being of non-human origin and possessing the ability to metabolize a range of clinically relevant nitro(hetero)cyclic substrates. Methods: A library of eleven Escherichia coli nitroreductase candidates were screened for the ability to efficiently metabolize 2-nitroimidazole based positron emission tomography (PET) probes originally developed as radiotracers for hypoxic cell imaging. Several complementary methods were utilized to detect formation of cell-entrapped metabolites, including various in vitro and in vivo models to establish the capacity of the 2-nitroimidazole PET agent EF5 to quantify expression of a nitroreductase candidate. Proof-of-principle PET imaging studies were successfully conducted using 18F-HX4. Results: Recombinant enzyme kinetics, bacterial SOS reporter assays, anti-proliferative assays and flow cytometry approaches collectively identified the major oxygen-insensitive nitroreductase NfsA from E. coli (NfsA_Ec) as the most promising nitroreductase reporter gene. Cells expressing NfsA_Ec were demonstrably labelled with the imaging agent EF5 in a manner that was quantitatively superior to hypoxia, in monolayers (2D), multicellular layers (3D), and in human tumor xenograft models. EF5 retention correlated with NfsA_Ec positive cell density over a range of EF5 concentrations in 3D in vitro models and in xenografts in vivo and was predictive of in vivo anti-tumor activity of the cytotoxic prodrug PR-104. Following PET imaging with 18F-HX4, a significantly higher tumor-to-blood ratio was observed in two xenograft models for NfsA_Ec expressing tumors compared to the parental tumors thereof, providing verification of this reporter gene imaging approach. Conclusion: This study establishes that the bacterial nitroreductase NfsA_Ec can be utilized as an imaging capable reporter gene, with the ability to metabolize and trap 2-nitroimidazole PET imaging agents for non-invasive imaging of gene expression.
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Markel U, Essani KD, Besirlioglu V, Schiffels J, Streit WR, Schwaneberg U. Advances in ultrahigh-throughput screening for directed enzyme evolution. Chem Soc Rev 2020; 49:233-262. [PMID: 31815263 DOI: 10.1039/c8cs00981c] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enzymes are versatile catalysts and their synthetic potential has been recognized for a long time. In order to exploit their full potential, enzymes often need to be re-engineered or optimized for a given application. (Semi-) rational design has emerged as a powerful means to engineer proteins, but requires detailed knowledge about structure function relationships. In turn, directed evolution methodologies, which consist of iterative rounds of diversity generation and screening, can improve an enzyme's properties with virtually no structural knowledge. Current diversity generation methods grant us access to a vast sequence space (libraries of >1012 enzyme variants) that may hide yet unexplored catalytic activities and selectivity. However, the time investment for conventional agar plate or microtiter plate-based screening assays represents a major bottleneck in directed evolution and limits the improvements that are obtainable in reasonable time. Ultrahigh-throughput screening (uHTS) methods dramatically increase the number of screening events per time, which is crucial to speed up biocatalyst design, and to widen our knowledge about sequence function relationships. In this review, we summarize recent advances in uHTS for directed enzyme evolution. We shed light on the importance of compartmentalization to preserve the essential link between genotype and phenotype and discuss how cells and biomimetic compartments can be applied to serve this function. Finally, we discuss how uHTS can inspire novel functional metagenomics approaches to identify natural biocatalysts for novel chemical transformations.
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Affiliation(s)
- Ulrich Markel
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074 Aachen, Germany.
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36
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Protocol for evaluating the abilities of diverse nitroaromatic prodrug metabolites to exit a model Gram negative bacterial vector. MethodsX 2020; 7:100797. [PMID: 32021829 PMCID: PMC6995258 DOI: 10.1016/j.mex.2020.100797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/13/2020] [Indexed: 01/29/2023] Open
Abstract
Bacterial-directed enzyme-prodrug therapy (BDEPT) uses tumour-tropic bacteria armed with a genetically-encoded prodrug-converting enzyme to sensitise tumours to a systemically-administered prodrug. A strong bystander effect (i.e., efficient bacteria-to-tumour transfer of activated prodrug metabolites) is critical to maximise tumour cell killing and avoid bacterial self-sterilisation. To investigate the bystander effect in bacteria we developed a sensitive screen that utilised two Escherichia coli strains grown in co-culture. The first of these was an activator strain that overexpressed the E. coli nitroreductase NfsA, and the second was a nitroreductase null recipient strain bearing an SOS-GFP DNA damage responsive gene construct. In this system, induction of GFP by genotoxic prodrug metabolites can only occur following their transfer from the activator to the recipient cells. This can be monitored both in fluorescence based microtitre plate assays and by flow-cytometry, enabling modelling of the abilities of diverse nitroaromatic prodrug metabolites to exit a Gram negative vector.
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37
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Williams EM, Rich MH, Mowday AM, Ashoorzadeh A, Copp JN, Guise CP, Anderson RF, Flanagan JU, Smaill JB, Patterson AV, Ackerley DF. Engineering Escherichia coli NfsB To Activate a Hypoxia-Resistant Analogue of the PET Probe EF5 To Enable Non-Invasive Imaging during Enzyme Prodrug Therapy. Biochemistry 2019; 58:3700-3710. [PMID: 31403283 DOI: 10.1021/acs.biochem.9b00376] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Gene-directed enzyme prodrug therapy (GDEPT) uses tumor-tropic vectors to deliver prodrug-converting enzymes such as nitroreductases specifically to the tumor environment. The nitroreductase NfsB from Escherichia coli (NfsB_Ec) has been a particular focal point for GDEPT and over the past 25 years has been the subject of several engineering studies seeking to improve catalysis of prodrug substrates. To facilitate clinical development, there is also a need to enable effective non-invasive imaging capabilities. SN33623, a 5-nitroimidazole analogue of 2-nitroimidazole hypoxia probe EF5, has potential for PET imaging exogenously delivered nitroreductases without generating confounding background due to tumor hypoxia. However, we show here that SN33623 is a poor substrate for NfsB_Ec. To address this, we used assay-guided sequence and structure analysis to identify two conserved residues that block SN33623 activation in NfsB_Ec and close homologues. Introduction of the rational substitutions F70A and F108Y into NfsB_Ec conferred high levels of SN33623 activity and enabled specific labeling of E. coli expressing the engineered enzyme. Serendipitously, the F70A and F108Y substitutions also substantially improved activity with the anticancer prodrug CB1954 and the 5-nitroimidazole antibiotic prodrug metronidazole, which is a potential biosafety agent for targeted ablation of nitroreductase-expressing vectors.
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Affiliation(s)
- Elsie M Williams
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
| | - Michelle H Rich
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
| | - Alexandra M Mowday
- Auckland Cancer Society Research Centre, School of Medical Sciences , The University of Auckland , Auckland 1023 , New Zealand
| | - Amir Ashoorzadeh
- Auckland Cancer Society Research Centre, School of Medical Sciences , The University of Auckland , Auckland 1023 , New Zealand
| | - Janine N Copp
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
| | - Christopher P Guise
- Auckland Cancer Society Research Centre, School of Medical Sciences , The University of Auckland , Auckland 1023 , New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery , Auckland 1023 , New Zealand
| | - Robert F Anderson
- Auckland Cancer Society Research Centre, School of Medical Sciences , The University of Auckland , Auckland 1023 , New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery , Auckland 1023 , New Zealand
| | - Jack U Flanagan
- Auckland Cancer Society Research Centre, School of Medical Sciences , The University of Auckland , Auckland 1023 , New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery , Auckland 1023 , New Zealand
| | - Jeff B Smaill
- Auckland Cancer Society Research Centre, School of Medical Sciences , The University of Auckland , Auckland 1023 , New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery , Auckland 1023 , New Zealand
| | - Adam V Patterson
- Auckland Cancer Society Research Centre, School of Medical Sciences , The University of Auckland , Auckland 1023 , New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery , Auckland 1023 , New Zealand
| | - David F Ackerley
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery , Auckland 1023 , New Zealand
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38
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A cofactor consumption screen identifies promising NfsB family nitroreductases for dinitrotoluene remediation. Biotechnol Lett 2019; 41:1155-1162. [DOI: 10.1007/s10529-019-02716-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 08/01/2019] [Indexed: 11/26/2022]
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39
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Güngör T, Önder FC, Tokay E, Gülhan ÜG, Hacıoğlu N, Tok TT, Çelik A, Köçkar F, Ay M. PRODRUGS FOR NITROREDUCTASE BASED CANCER THERAPY- 2: Novel amide/Ntr combinations targeting PC3 cancer cells. Eur J Med Chem 2019; 171:383-400. [DOI: 10.1016/j.ejmech.2019.03.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/26/2019] [Accepted: 03/14/2019] [Indexed: 02/06/2023]
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40
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Zhang L, Guo L, Shan X, Lin X, Gu T, Zhang J, Ge J, Li W, Ge H, Jiang Q, Ning X. An elegant nitroreductase responsive fluorescent probe for selective detection of pathogenic Listeria in vitro and in vivo. Talanta 2019; 198:472-479. [DOI: 10.1016/j.talanta.2019.02.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 12/24/2018] [Accepted: 02/04/2019] [Indexed: 01/24/2023]
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41
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Crofts TS, Sontha P, King AO, Wang B, Biddy BA, Zanolli N, Gaumnitz J, Dantas G. Discovery and Characterization of a Nitroreductase Capable of Conferring Bacterial Resistance to Chloramphenicol. Cell Chem Biol 2019; 26:559-570.e6. [PMID: 30799223 PMCID: PMC6474809 DOI: 10.1016/j.chembiol.2019.01.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/06/2018] [Accepted: 01/14/2019] [Indexed: 12/13/2022]
Abstract
Widespread antibiotic resistance has led to the reappraisal of abandoned antibiotics including chloramphenicol. However, enzyme(s) underlying one form of chloramphenicol resistance, nitroreduction, have eluded identification. Here we demonstrate that expression of the Haemophilus influenzae nitroreductase gene nfsB confers chloramphenicol resistance in Escherichia coli. We characterized the enzymatic product of H. influenzae NfsB acting on chloramphenicol and found it to be amino-chloramphenicol. Kinetic analysis revealed reduction of diverse substrates including the incomplete reduction of 5-nitro antibiotics metronidazole and nitrofurantoin, likely resulting in activation of these antibiotic pro-drugs to their cytotoxic forms. We observed that expression of the H. influenzae nfsB gene in E. coli results in significantly increased susceptibility to metronidazole. Finally, we found that in this strain metronidazole attenuates chloramphenicol resistance synergistically, and in vitro metronidazole weakly inhibits chloramphenicol reduction by NfsB. Our findings reveal the underpinnings of a chloramphenicol resistance mechanism nearly 70 years after its description.
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Affiliation(s)
- Terence S Crofts
- Department of Pathology and Immunology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA; The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA.
| | - Pratyush Sontha
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA
| | - Amber O King
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA
| | - Bin Wang
- Department of Pathology and Immunology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA; The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA
| | - Brent A Biddy
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA
| | - Nicole Zanolli
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA
| | - John Gaumnitz
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA
| | - Gautam Dantas
- Department of Pathology and Immunology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA; The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA; Department of Molecular Microbiology, Washington University in St Louis School of Medicine, Saint Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University in St Louis, Saint Louis, MO 63110, USA.
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42
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Aghahosseini H, Tabatabaei Rezaei SJ, Maleki M, Abdolahnjadian D, Ramazani A, Shahroosvand H. Pt(II)-Based Artificial Nitroreductase: An Efficient and Highly Stable Nanozyme. ChemistrySelect 2019. [DOI: 10.1002/slct.201803776] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Hamideh Aghahosseini
- Department of Chemistry; Faculty of Science; University of Zanjan; P.O. Box 45195-313 Zanjan Iran
| | | | - Mahshid Maleki
- Department of Chemistry; Faculty of Science; University of Zanjan; P.O. Box 45195-313 Zanjan Iran
| | - Davod Abdolahnjadian
- Department of Chemistry; Faculty of Science; University of Zanjan; P.O. Box 45195-313 Zanjan Iran
| | - Ali Ramazani
- Department of Chemistry; Faculty of Science; University of Zanjan; P.O. Box 45195-313 Zanjan Iran
| | - Hashem Shahroosvand
- Department of Chemistry; Faculty of Science; University of Zanjan; P.O. Box 45195-313 Zanjan Iran
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43
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Zhang L, Shan X, Guo L, Zhang J, Ge J, Jiang Q, Ning X. A sensitive and fast responsive fluorescent probe for imaging hypoxic tumors. Analyst 2019; 144:284-289. [DOI: 10.1039/c8an01472h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A BBP possesses a unique fluorescence off–on feature, and can selectively monitor the early tumor formation and treatment response.
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Affiliation(s)
- Lei Zhang
- National Laboratory of Solid State Microstructures
- College of Engineering and Applied Sciences
- Nanjing University
- 210093 Nanjing
- China
| | - Xue Shan
- National Laboratory of Solid State Microstructures
- College of Engineering and Applied Sciences
- Nanjing University
- 210093 Nanjing
- China
| | - Leilei Guo
- State Key Laboratory of National Medicines
- Centre of Advanced Pharmaceuticals and Biomaterials
- China Pharmaceutical University
- Nanjing 210009
- China
| | - Jikang Zhang
- National Laboratory of Solid State Microstructures
- College of Engineering and Applied Sciences
- Nanjing University
- 210093 Nanjing
- China
| | - Junliang Ge
- National Laboratory of Solid State Microstructures
- College of Engineering and Applied Sciences
- Nanjing University
- 210093 Nanjing
- China
| | - Qing Jiang
- The Center of Diagnosis and Treatment for Joint Disease
- Drum Tower Hospital Affiliated to Medical School of Nanjing University
- Nanjing
- China
- Laboratory for Bone and Joint Diseases
| | - Xinghai Ning
- National Laboratory of Solid State Microstructures
- College of Engineering and Applied Sciences
- Nanjing University
- 210093 Nanjing
- China
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44
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Evaluating the abilities of diverse nitroaromatic prodrug metabolites to exit a model Gram negative vector for bacterial-directed enzyme-prodrug therapy. Biochem Pharmacol 2018; 158:192-200. [PMID: 30352235 DOI: 10.1016/j.bcp.2018.10.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/17/2018] [Indexed: 12/12/2022]
Abstract
Gene-directed enzyme-prodrug therapy (GDEPT) employs tumour-tropic vectors including viruses and bacteria to deliver a genetically-encoded prodrug-converting enzyme to the tumour environment, thereby sensitising the tumour to the prodrug. Nitroreductases, able to activate a range of promising nitroaromatic prodrugs to genotoxic metabolites, are of great interest for GDEPT. The bystander effect (cell-to-cell transfer of activated prodrug metabolites) has been quantified for some nitroaromatic prodrugs in mixed multilayer human cell cultures, however while these provide a good model for viral DEPT (VDEPT) they do not inform on the ability of these prodrug metabolites to exit bacterial vectors (relevant to bacterial-DEPT (BDEPT)). To investigate this we grew two Escherichia coli strains in co-culture; an activator strain expressing the nitroreductase E. coli NfsA and a recipient strain containing an SOS-GFP DNA damage responsive gene construct. In this system, induction of GFP by reduced prodrug metabolites can only occur following their transfer from the activator to the recipient cells. We used this to investigate five clinically relevant prodrugs: metronidazole, CB1954, nitro-CBI-DEI, and two dinitrobenzamide mustard prodrug analogues, PR-104A and SN27686. Consistent with the bystander efficiencies previously measured in human cell multilayers, reduced metronidazole exhibited little bacterial cell-to-cell transfer, whereas nitro-CBI-DEI was passed very efficiently from activator to recipient cells post-reduction. However, in contrast with observations in human cell multilayers, the nitrogen mustard prodrug metabolites were not effectively passed between the two bacterial strains, whereas reduced CB1954 was transferred efficiently. Using nitroreductase enzymes that exhibit different biases for the 2- versus 4-nitro substituents of CB1954, we further showed that the 2-nitro reduction products exhibit substantially higher levels of bacterial cell-to-cell transfer than the 4-nitro reduction products, consistent with their relative bystander efficiencies in human cell culture. Overall, our data suggest that prodrugs may differ in their suitability for VDEPT versus BDEPT applications and emphasise the importance of evaluating an enzyme-prodrug partnership in an appropriate context for the intended vector.
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45
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Gruber TD, Krishnamurthy C, Grimm JB, Tadross MR, Wysocki LM, Gartner ZJ, Lavis LD. Cell-Specific Chemical Delivery Using a Selective Nitroreductase-Nitroaryl Pair. ACS Chem Biol 2018; 13:2888-2896. [PMID: 30111097 DOI: 10.1021/acschembio.8b00524] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The utility of small molecules to probe or perturb biological systems is limited by the lack of cell-specificity. "Masking" the activity of small molecules using a general chemical modification and "unmasking" it only within target cells overcomes this limitation. To this end, we have developed a selective enzyme-substrate pair consisting of engineered variants of E. coli nitroreductase (NTR) and a 2-nitro- N-methylimidazolyl (NM) masking group. To discover and optimize this NTR-NM system, we synthesized a series of fluorogenic substrates containing different nitroaromatic masking groups, confirmed their stability in cells, and identified the best substrate for NTR. We then engineered the enzyme for improved activity in mammalian cells, ultimately yielding an enzyme variant (enhanced NTR, or eNTR) that possesses up to 100-fold increased activity over wild-type NTR. These improved NTR enzymes combined with the optimal NM masking group enable rapid, selective unmasking of dyes, indicators, and drugs to genetically defined populations of cells.
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Affiliation(s)
- Todd D Gruber
- Janelia Research Campus , Howard Hughes Medical Institute , Ashburn , Virginia 20147 , United States
| | - Chithra Krishnamurthy
- Janelia Research Campus , Howard Hughes Medical Institute , Ashburn , Virginia 20147 , United States
- Department of Pharmaceutical Chemistry , University of California , San Francisco , California 94158 , United States
| | - Jonathan B Grimm
- Janelia Research Campus , Howard Hughes Medical Institute , Ashburn , Virginia 20147 , United States
| | - Michael R Tadross
- Janelia Research Campus , Howard Hughes Medical Institute , Ashburn , Virginia 20147 , United States
| | - Laura M Wysocki
- Janelia Research Campus , Howard Hughes Medical Institute , Ashburn , Virginia 20147 , United States
| | - Zev J Gartner
- Department of Pharmaceutical Chemistry , University of California , San Francisco , California 94158 , United States
| | - Luke D Lavis
- Janelia Research Campus , Howard Hughes Medical Institute , Ashburn , Virginia 20147 , United States
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46
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Copp JN, Akiva E, Babbitt PC, Tokuriki N. Revealing Unexplored Sequence-Function Space Using Sequence Similarity Networks. Biochemistry 2018; 57:4651-4662. [PMID: 30052428 DOI: 10.1021/acs.biochem.8b00473] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rapidly expanding number of protein sequences found in public databases can improve our understanding of how protein functions evolve. However, our current knowledge of protein function likely represents a small fraction of the diverse repertoire that exists in nature. Integrative computational methods can facilitate the discovery of new protein functions and enzymatic reactions through the observation and investigation of the complex sequence-structure-function relationships within protein superfamilies. Here, we highlight the use of sequence similarity networks (SSNs) to identify previously unexplored sequence and function space. We exemplify this approach using the nitroreductase (NTR) superfamily. We demonstrate that SSN investigations can provide a rapid and effective means to classify groups of proteins, therefore exposing experimentally unexplored sequences that may exhibit novel functionality. Integration of such approaches with systematic experimental characterization will expand our understanding of the functional diversity of enzymes and their associated physiological roles.
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Affiliation(s)
- Janine N Copp
- Michael Smith Laboratories , University of British Columbia , 2185 East Mall , Vancouver , British Columbia V6T 1Z4 , Canada
| | - Eyal Akiva
- Department of Bioengineering and Therapeutic Sciences , University of California , San Francisco , California 94158 , United States.,Quantitative Biosciences Institute , University of California , San Francisco , California 94143 , United States
| | - Patricia C Babbitt
- Department of Bioengineering and Therapeutic Sciences , University of California , San Francisco , California 94158 , United States.,Quantitative Biosciences Institute , University of California , San Francisco , California 94143 , United States
| | - Nobuhiko Tokuriki
- Michael Smith Laboratories , University of British Columbia , 2185 East Mall , Vancouver , British Columbia V6T 1Z4 , Canada
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47
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Miller AF, Park JT, Ferguson KL, Pitsawong W, Bommarius AS. Informing Efforts to Develop Nitroreductase for Amine Production. Molecules 2018; 23:molecules23020211. [PMID: 29364838 PMCID: PMC6017928 DOI: 10.3390/molecules23020211] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 01/03/2018] [Accepted: 01/12/2018] [Indexed: 12/19/2022] Open
Abstract
Nitroreductases (NRs) hold promise for converting nitroaromatics to aromatic amines. Nitroaromatic reduction rate increases with Hammett substituent constant for NRs from two different subgroups, confirming substrate identity as a key determinant of reactivity. Amine yields were low, but compounds yielding amines tend to have a large π system and electron withdrawing substituents. Therefore, we also assessed the prospects of varying the enzyme. Several different subgroups of NRs include members able to produce aromatic amines. Comparison of four NR subgroups shows that they provide contrasting substrate binding cavities with distinct constraints on substrate position relative to the flavin. The unique architecture of the NR dimer produces an enormous contact area which we propose provides the stabilization needed to offset the costs of insertion of the active sites between the monomers. Thus, we propose that the functional diversity included in the NR superfamily stems from the chemical versatility of the flavin cofactor in conjunction with a structure that permits tremendous active site variability. These complementary properties make NRs exceptionally promising enzymes for development for biocatalysis in prodrug activation and conversion of nitroaromatics to valuable aromatic amines. We provide a framework for identifying NRs and substrates with the greatest potential to advance.
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Affiliation(s)
- Anne-Frances Miller
- Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA.
| | - Jonathan T Park
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA.
| | - Kyle L Ferguson
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA.
| | - Warintra Pitsawong
- Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA.
| | - Andreas S Bommarius
- School of Chemical and Biomolecular Engineering, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA.
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48
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Rich MH, Sharrock AV, Hall KR, Ackerley DF, MacKichan JK. Evaluation of NfsA-like nitroreductases from Neisseria meningitidis and Bartonella henselae for enzyme-prodrug therapy, targeted cellular ablation, and dinitrotoluene bioremediation. Biotechnol Lett 2017; 40:359-367. [DOI: 10.1007/s10529-017-2472-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 10/31/2017] [Indexed: 10/18/2022]
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49
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Akiva E, Copp JN, Tokuriki N, Babbitt PC. Evolutionary and molecular foundations of multiple contemporary functions of the nitroreductase superfamily. Proc Natl Acad Sci U S A 2017; 114:E9549-E9558. [PMID: 29078300 PMCID: PMC5692541 DOI: 10.1073/pnas.1706849114] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Insight regarding how diverse enzymatic functions and reactions have evolved from ancestral scaffolds is fundamental to understanding chemical and evolutionary biology, and for the exploitation of enzymes for biotechnology. We undertook an extensive computational analysis using a unique and comprehensive combination of tools that include large-scale phylogenetic reconstruction to determine the sequence, structural, and functional relationships of the functionally diverse flavin mononucleotide-dependent nitroreductase (NTR) superfamily (>24,000 sequences from all domains of life, 54 structures, and >10 enzymatic functions). Our results suggest an evolutionary model in which contemporary subgroups of the superfamily have diverged in a radial manner from a minimal flavin-binding scaffold. We identified the structural design principle for this divergence: Insertions at key positions in the minimal scaffold that, combined with the fixation of key residues, have led to functional specialization. These results will aid future efforts to delineate the emergence of functional diversity in enzyme superfamilies, provide clues for functional inference for superfamily members of unknown function, and facilitate rational redesign of the NTR scaffold.
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Affiliation(s)
- Eyal Akiva
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158
| | - Janine N Copp
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Nobuhiko Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z4;
| | - Patricia C Babbitt
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158;
- California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158
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50
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Lehouritis P, Hogan G, Tangney M. Designer bacteria as intratumoural enzyme biofactories. Adv Drug Deliv Rev 2017; 118:8-23. [PMID: 28916496 DOI: 10.1016/j.addr.2017.09.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 08/18/2017] [Accepted: 09/07/2017] [Indexed: 02/07/2023]
Abstract
Bacterial-directed enzyme prodrug therapy (BDEPT) is an emerging form of treatment for cancer. It is a biphasic variant of gene therapy in which a bacterium, armed with an enzyme that can convert an inert prodrug into a cytotoxic compound, induces tumour cell death following tumour-specific prodrug activation. BDEPT combines the innate ability of bacteria to selectively proliferate in tumours, with the capacity of prodrugs to undergo contained, compartmentalised conversion into active metabolites in vivo. Although BDEPT has undergone clinical testing, it has received limited clinical exposure, and has yet to achieve regulatory approval. In this article, we review BDEPT from the system designer's perspective, and provide detailed commentary on how the designer should strategize its development de novo. We report on contemporary advancements in this field which aim to enhance BDEPT in terms of safety and efficacy. Finally, we discuss clinical and regulatory barriers facing BDEPT, and propose promising approaches through which these hurdles may best be tackled.
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