1
|
Ayuso-Fernández I, Emrich-Mills TZ, Haak J, Golten O, Hall KR, Schwaiger L, Moe TS, Stepnov AA, Ludwig R, Cutsail Iii GE, Sørlie M, Kjendseth Røhr Å, Eijsink VGH. Mutational dissection of a hole hopping route in a lytic polysaccharide monooxygenase (LPMO). Nat Commun 2024; 15:3975. [PMID: 38729930 PMCID: PMC11087555 DOI: 10.1038/s41467-024-48245-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 04/25/2024] [Indexed: 05/12/2024] Open
Abstract
Oxidoreductases have evolved tyrosine/tryptophan pathways that channel highly oxidizing holes away from the active site to avoid damage. Here we dissect such a pathway in a bacterial LPMO, member of a widespread family of C-H bond activating enzymes with outstanding industrial potential. We show that a strictly conserved tryptophan is critical for radical formation and hole transference and that holes traverse the protein to reach a tyrosine-histidine pair in the protein's surface. Real-time monitoring of radical formation reveals a clear correlation between the efficiency of hole transference and enzyme performance under oxidative stress. Residues involved in this pathway vary considerably between natural LPMOs, which could reflect adaptation to different ecological niches. Importantly, we show that enzyme activity is increased in a variant with slower radical transference, providing experimental evidence for a previously postulated trade-off between activity and redox robustness.
Collapse
Affiliation(s)
- Iván Ayuso-Fernández
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway.
| | - Tom Z Emrich-Mills
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Julia Haak
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
- Institute of Inorganic Chemistry, University of Duisburg-Essen, 45141, Essen, Germany
| | - Ole Golten
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Kelsi R Hall
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Lorenz Schwaiger
- Biocatalysis and Biosensing Laboratory, Department of Food Sciences and Technology, Institute of Food Science and Technology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18/2, Vienna, 1190, Austria
| | - Trond S Moe
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Anton A Stepnov
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Roland Ludwig
- Biocatalysis and Biosensing Laboratory, Department of Food Sciences and Technology, Institute of Food Science and Technology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18/2, Vienna, 1190, Austria
| | - George E Cutsail Iii
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
- Institute of Inorganic Chemistry, University of Duisburg-Essen, 45141, Essen, Germany
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Åsmund Kjendseth Røhr
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway.
| |
Collapse
|
2
|
Golten O, Ayuso-Fernández I, Hall KR, Stepnov AA, Sørlie M, Røhr ÅK, Eijsink VGH. Reductants fuel lytic polysaccharide monooxygenase activity in a pH-dependent manner. FEBS Lett 2023; 597:1363-1374. [PMID: 37081294 DOI: 10.1002/1873-3468.14629] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 04/22/2023]
Abstract
Polysaccharide-degrading mono-copper lytic polysaccharide monooxygenases (LPMOs) are efficient peroxygenases that require electron donors (reductants) to remain in the active Cu(I) form and to generate the H2 O2 co-substrate from molecular oxygen. Here, we show how commonly used reductants affect LPMO catalysis in a pH-dependent manner. Between pH 6.0 and 8.0, reactions with ascorbic acid show little pH-dependency, whereas reactions with gallic acid become much faster at increased pH. These dependencies correlate with the reductant ionization state, which affects its ability to react with molecular oxygen and generate H2 O2 . The correlation does not apply to L-cysteine because, as shown by stopped-flow kinetics, increased H2 O2 production at higher pH is counteracted by increased binding of L-cysteine to the copper active site. The findings highlight the importance of the choice of reductant and pH in LPMO reactions.
Collapse
Affiliation(s)
- Ole Golten
- Faculty of Chemistry, Biotechnology and Food Science, NMBU- Norwegian University of Life Sciences, Ås, Norway
| | - Iván Ayuso-Fernández
- Faculty of Chemistry, Biotechnology and Food Science, NMBU- Norwegian University of Life Sciences, Ås, Norway
| | - Kelsi R Hall
- Faculty of Chemistry, Biotechnology and Food Science, NMBU- Norwegian University of Life Sciences, Ås, Norway
| | - Anton A Stepnov
- Faculty of Chemistry, Biotechnology and Food Science, NMBU- Norwegian University of Life Sciences, Ås, Norway
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology and Food Science, NMBU- Norwegian University of Life Sciences, Ås, Norway
| | - Åsmund Kjendseth Røhr
- Faculty of Chemistry, Biotechnology and Food Science, NMBU- Norwegian University of Life Sciences, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU- Norwegian University of Life Sciences, Ås, Norway
| |
Collapse
|
3
|
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: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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.
| |
Collapse
|
4
|
Zhang L, Chen C, Fu J, Lilley B, Berlinicke C, Hansen B, Ding D, Wang G, Wang T, Shou D, Ye Y, Mulligan T, Emmerich K, Saxena MT, Hall KR, Sharrock AV, Brandon C, Park H, Kam TI, Dawson VL, Dawson TM, Shim JS, Hanes J, Ji H, Liu JO, Qian J, Ackerley DF, Rohrer B, Zack DJ, Mumm JS. Large-scale phenotypic drug screen identifies neuroprotectants in zebrafish and mouse models of retinitis pigmentosa. eLife 2021; 10:e57245. [PMID: 34184634 PMCID: PMC8425951 DOI: 10.7554/elife.57245] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/28/2021] [Indexed: 11/25/2022] Open
Abstract
Retinitis pigmentosa (RP) and associated inherited retinal diseases (IRDs) are caused by rod photoreceptor degeneration, necessitating therapeutics promoting rod photoreceptor survival. To address this, we tested compounds for neuroprotective effects in multiple zebrafish and mouse RP models, reasoning drugs effective across species and/or independent of disease mutation may translate better clinically. We first performed a large-scale phenotypic drug screen for compounds promoting rod cell survival in a larval zebrafish model of inducible RP. We tested 2934 compounds, mostly human-approved drugs, across six concentrations, resulting in 113 compounds being identified as hits. Secondary tests of 42 high-priority hits confirmed eleven lead candidates. Leads were then evaluated in a series of mouse RP models in an effort to identify compounds effective across species and RP models, that is, potential pan-disease therapeutics. Nine of 11 leads exhibited neuroprotective effects in mouse primary photoreceptor cultures, and three promoted photoreceptor survival in mouse rd1 retinal explants. Both shared and complementary mechanisms of action were implicated across leads. Shared target tests implicated parp1-dependent cell death in our zebrafish RP model. Complementation tests revealed enhanced and additive/synergistic neuroprotective effects of paired drug combinations in mouse photoreceptor cultures and zebrafish, respectively. These results highlight the value of cross-species/multi-model phenotypic drug discovery and suggest combinatorial drug therapies may provide enhanced therapeutic benefits for RP patients.
Collapse
Affiliation(s)
- Liyun Zhang
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Conan Chen
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Jie Fu
- The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Brendan Lilley
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Cynthia Berlinicke
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Baranda Hansen
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Ding Ding
- Department of Biostatistics, Johns Hopkins UniversityBaltimoreUnited States
| | - Guohua Wang
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Tao Wang
- The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
- School of Chemistry, Xuzhou College of Industrial TechnologyXuzhouChina
- College of Light Industry and Food Engineering, Nanjing Forestry UniversityNanjingChina
| | - Daniel Shou
- The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Ying Ye
- The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Timothy Mulligan
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Kevin Emmerich
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
- Department of Genetic Medicine, Johns Hopkins UniversityBaltimoreUnited States
| | - Meera T Saxena
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Kelsi R Hall
- School of Biological Sciences, Victoria University of WellingtonWellingtonNew Zealand
| | - Abigail V Sharrock
- Department of Biostatistics, Johns Hopkins UniversityBaltimoreUnited States
- School of Biological Sciences, Victoria University of WellingtonWellingtonNew Zealand
| | - Carlene Brandon
- Department of Ophthalmology, Medical University of South CarolinaCharlestonUnited States
| | - Hyejin Park
- Department of Neurology, Johns Hopkins UniversityBaltimoreUnited States
| | - Tae-In Kam
- Department of Neurology, Johns Hopkins UniversityBaltimoreUnited States
- Institute for Cell Engineering, Johns Hopkins UniversityBaltimoreUnited States
| | - Valina L Dawson
- Department of Neurology, Johns Hopkins UniversityBaltimoreUnited States
- Institute for Cell Engineering, Johns Hopkins UniversityBaltimoreUnited States
- Department of Pharmacology and Molecular Sciences, Johns Hopkins UniversityBaltimoreUnited States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins UniversityBaltimoreUnited States
| | - Ted M Dawson
- Department of Neurology, Johns Hopkins UniversityBaltimoreUnited States
- Institute for Cell Engineering, Johns Hopkins UniversityBaltimoreUnited States
- Department of Pharmacology and Molecular Sciences, Johns Hopkins UniversityBaltimoreUnited States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins UniversityBaltimoreUnited States
| | - Joong Sup Shim
- Faculty of Health Sciences, University of Macau, TaipaMacauChina
| | - Justin Hanes
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
- The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - Hongkai Ji
- Department of Biostatistics, Johns Hopkins UniversityBaltimoreUnited States
| | - Jun O Liu
- Department of Pharmacology and Molecular Sciences, Johns Hopkins UniversityBaltimoreUnited States
- Department of Oncology, Johns Hopkins UniversityBaltimoreUnited States
| | - Jiang Qian
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
| | - David F Ackerley
- School of Biological Sciences, Victoria University of WellingtonWellingtonNew Zealand
| | - Baerbel Rohrer
- Department of Ophthalmology, Medical University of South CarolinaCharlestonUnited States
| | - Donald J Zack
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
- The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
- Department of Genetic Medicine, Johns Hopkins UniversityBaltimoreUnited States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins UniversityBaltimoreUnited States
- Department of Molecular Biology and Genetics, Johns Hopkins UniversityBaltimoreUnited States
| | - Jeff S Mumm
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
- The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins UniversityBaltimoreUnited States
- Department of Genetic Medicine, Johns Hopkins UniversityBaltimoreUnited States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins UniversityBaltimoreUnited States
| |
Collapse
|
5
|
McCone JAJ, Somarathne KK, Orme CL, Hewitt RJ, Grant ER, Hall KR, Ackerley DF, La Flamme AC, Harvey JE. Total Synthesis and Bioactivity Studies of Fungal Metabolite (-)-TAN-2483B. Org Lett 2020; 22:9427-9432. [PMID: 33232161 DOI: 10.1021/acs.orglett.0c03303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The first total synthesis of (-)-TAN-2483B, a fungal metabolite possessing a densely functionalized furo[3,4-b]pyran-5-one framework, is achieved in 14 steps from d-mannose. Generation of the 2,6-trans-pyran is by cyclopropane ring expansion followed by α-selective alkynylation. Julia-Kocienski olefination introduces the E-propenyl side chain. Alkyne functionalization and carbonylation stereoselectively establish the bicyclic core of (-)-TAN-2483B. Inhibition of kinases Btk and Bmx, bacterial priority pathogens, and cytokine production in splenocytes indicates promising therapeutic potential.
Collapse
|
6
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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
| |
Collapse
|
7
|
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] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 10/31/2017] [Indexed: 10/18/2022]
|
8
|
Affiliation(s)
- Matteo P. Ferla
- Department of BiochemistryUniversity of OtagoDunedin New Zealand
| | - Jodi L. Brewster
- Department of BiochemistryUniversity of OtagoDunedin New Zealand
| | - Kelsi R. Hall
- Department of BiochemistryUniversity of OtagoDunedin New Zealand
| | - Gary B. Evans
- Ferrier Research InstituteVictoria UniversityLower Hutt New Zealand
| | - Wayne M. Patrick
- Department of BiochemistryUniversity of OtagoDunedin New Zealand
| |
Collapse
|
9
|
Aparicio-Martínez S, Hall KR, Balbuena PB. Theoretical Study on the Properties of Linear and Cyclic Amides in Gas Phase and Water Solution. J Phys Chem A 2006; 110:9183-93. [PMID: 16854032 DOI: 10.1021/jp0611166] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structural and energetic properties of a group of selected amides, of well-known importance for the design of efficient clathrate inhibitors, are calculated with Hartree-Fock and density functional theory, B3LYP, theoretical levels, and a 6-311++g** basis set in the gas phase and a water solution. The conformational behavior of the molecules is studied through the scanning of the torsional potential energy surfaces and by the analysis of the differences in the energetic and structural properties between the isomers. The properties of the amides in water solution are determined within a self-consistent reaction field approach with a polarizable continuum model that allows the calculation of the different contributions to the free energy of solvation. The calculated barriers to rotation are in good agreement with the available experimental data and the comparison of the gas and water results shows the strong effect of the solute polarization. The properties of different amide-water complexes are calculated and compared with available experimental information.
Collapse
Affiliation(s)
- S Aparicio-Martínez
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, USA.
| | | | | |
Collapse
|
10
|
|
11
|
Hall KR, Pinnock M. Food safety: implications for community health. W INDIAN MED J 1986; 35:185-9. [PMID: 3776184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
12
|
Freeman AM, Fleece L, Folks DG, Sokol RS, Hall KR, Pacifico AD, McGiffin DC, Kirklin JK, Zorn GL, Karp RB. Alprazolam treatment of postcoronary bypass anxiety and depression. J Clin Psychopharmacol 1986; 6:39-41. [PMID: 2869060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effectiveness of alprazolam in treating symptoms of anxiety and depression in 60 patients undergoing coronary bypass surgery was assessed in a double-blind, placebo-controlled study. The results indicate that alprazolam treatment for anxiety following coronary bypass surgery, particularly symptoms occurring in the immediate postoperative period, can significantly affect patient outcome. Specifically, only modest but statistically significant improvement was observed in the alprazolam-treated groups at 1-month follow-up; however, alprazolam-treated patients were significantly more likely to experience a very rapid anxiolytic effect by postoperative day 8. The implications of this study are discussed with respect to patient management and models for future studies of anxiety in postoperative patient populations.
Collapse
|
13
|
Freeman AM, Folks DG, Sokol RS, Govier AV, Reves JG, Fleece EL, Hall KR, Zorn GL, Karp RB. Cognitive function after coronary bypass surgery: effect of decreased cerebral blood flow. Am J Psychiatry 1985; 142:110-2. [PMID: 3871310 DOI: 10.1176/ajp.142.1.110] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of regional cerebral blood flow during coronary bypass surgery on performance on the Mini-Mental State Examination was studied in 14 patients. No association between lowered regional cerebral blood flow and cognitive scores was found.
Collapse
|
14
|
Carman JS, Crews EL, Wyatt ES, Dohn HH, Hall KR. Prediction of response to psychotropic medications. Ala J Med Sci 1980; 17:161-5. [PMID: 7416429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
15
|
Navari RM, Gainer JL, Hall KR. Transport in human plasma. Aerosp Med 1971; 42:1123-4. [PMID: 5095512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
16
|
|
17
|
|
18
|
Hall KR. Tool-using behaviour of the Californian sea otter. Med Biol Illus 1965; 15:217. [PMID: 5891597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|