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Lemke RAS, Olson SM, Morse K, Karlen SD, Higbee A, Beebe ET, Ralph J, Coon JJ, Fox BG, Donohue TJ. A bacterial biosynthetic pathway for methylated furan fatty acids. J Biol Chem 2020; 295:9786-9801. [PMID: 32434926 PMCID: PMC7380195 DOI: 10.1074/jbc.ra120.013697] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/14/2020] [Indexed: 12/26/2022] Open
Abstract
Fatty acids play many important roles in cells and also in industrial processes. Furan fatty acids (FuFAs) are present in the lipids of some plant, fish, and microbial species and appear to function as second messengers in pathways that protect cells from membrane-damaging agents. We report here the results of chemical, genetic, and synthetic biology experiments to decipher the biosynthesis of the monomethylated FuFA, methyl 9-(3-methyl-5-pentylfuran-2-yl) nonanoate (9M5-FuFA), and its dimethyl counterpart, methyl 9-(3,4-dimethyl-5-pentylfuran-2-yl) nonanoate (9D5-FuFA), in two α-proteobacteria. Each of the steps in FuFA biosynthesis occurs on pre-existing phospholipid fatty acid chains, and we identified pathway intermediates and the gene products that catalyze 9M5-FuFA and 9D5-FuFA synthesis in Rhodobacter sphaeroides 2.4.1 and Rhodopseudomonas palustris CGA009. One previously unknown pathway intermediate was a methylated diunsaturated fatty acid, (10E,12E)-11-methyloctadeca-10,12-dienoic acid (11Me-10t,12t-18:2), produced from (11E)-methyloctadeca-11-enoic acid (11Me-12t-18:1) by a newly identified fatty acid desaturase, UfaD. We also show that molecular oxygen (O2) is the source of the oxygen atom in the furan ring of 9M5-FuFA, and our findings predict that an O2-derived oxygen atom is incorporated into 9M5-FuFA via a protein, UfaO, that uses the 11Me-10t,12t-18:2 fatty acid phospholipid chain as a substrate. We discovered that R. palustris also contains a SAM-dependent methylase, FufM, that produces 9D5-FuFA from 9M5-FuFA. These results uncover the biochemical sequence of intermediates in a bacterial pathway for 9M5-FuFA and 9D5-FuFA biosynthesis and suggest the existence of homologs of the enzymes identified here that could function in FuFA biosynthesis in other organisms.
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Affiliation(s)
- Rachelle A S Lemke
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA.,Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
| | - Stephanie M Olson
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA.,Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
| | - Kaitlin Morse
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
| | - Steven D Karlen
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA.,Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Alan Higbee
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA.,Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin, USA
| | - Emily T Beebe
- Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
| | - John Ralph
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA.,Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Joshua J Coon
- Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA.,Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin, USA.,Department of Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Brian G Fox
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA.,Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Timothy J Donohue
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA .,Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
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Antoniou MN, Nicolas A, Mesnage R, Biserni M, Rao FV, Martin CV. Glyphosate does not substitute for glycine in proteins of actively dividing mammalian cells. BMC Res Notes 2019; 12:494. [PMID: 31395095 PMCID: PMC6686468 DOI: 10.1186/s13104-019-4534-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 08/02/2019] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVES Glyphosate (N-phosphonomethyl glycine) and its commercial herbicide formulations have been shown to exert toxicity via various mechanisms. It has been asserted that glyphosate substitutes for glycine in polypeptide chains leading to protein misfolding and toxicity. However, as no direct evidence exists for glycine to glyphosate substitution in proteins, including in mammalian organisms, we tested this claim by conducting a proteomics analysis of MDA-MB-231 human breast cancer cells grown in the presence of 100 mg/L glyphosate for 6 days. Protein extracts from three treated and three untreated cell cultures were analysed as one TMT-6plex labelled sample, to highlight a specific pattern (+/+/+/-/-/-) of reporter intensities for peptides bearing true glyphosate treatment induced-post translational modifications as well as allowing an investigation of the total proteome. RESULTS Comparative statistical analysis of global proteome changes between glyphosate treated and non-treated samples did not show significant differences. Crucially, filtering of data to focus analysis on peptides potentially bearing glycine for glyphosate replacement revealed that the TMT reporter intensity pattern of all candidates showed conclusively that they are all false discoveries, with none displaying the expected TMT pattern for such a substitution. Thus, the assertion that glyphosate substitutes for glycine in protein polypeptide chains is incorrect.
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Affiliation(s)
- Michael N. Antoniou
- Department of Medical and Molecular Genetics, Faculty of Life Sciences & Medicine, Gene Expression and Therapy Group, King’s College London, Guy’s Hospital, 8th Floor, Tower Wing, Great Maze Pond, London, SE1 9RT UK
| | - Armel Nicolas
- DC Biosciences, James Lindsay Place, Dundee, DD1 5JJ UK
- Present Address: IST Austria Proteomics Service, Lab Building East, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Robin Mesnage
- Department of Medical and Molecular Genetics, Faculty of Life Sciences & Medicine, Gene Expression and Therapy Group, King’s College London, Guy’s Hospital, 8th Floor, Tower Wing, Great Maze Pond, London, SE1 9RT UK
| | - Martina Biserni
- Department of Medical and Molecular Genetics, Faculty of Life Sciences & Medicine, Gene Expression and Therapy Group, King’s College London, Guy’s Hospital, 8th Floor, Tower Wing, Great Maze Pond, London, SE1 9RT UK
| | - Francesco V. Rao
- DC Biosciences, James Lindsay Place, Dundee, DD1 5JJ UK
- Present Address: Platinum Informatics Ltd., Unit 8, The Vision Building, 20 Greenmarket, Dundee, DD1 4QB UK
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Mesnage R, Antoniou MN. Facts and Fallacies in the Debate on Glyphosate Toxicity. Front Public Health 2017; 5:316. [PMID: 29226121 PMCID: PMC5705608 DOI: 10.3389/fpubh.2017.00316] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 11/08/2017] [Indexed: 12/17/2022] Open
Abstract
The safety profile of the herbicide glyphosate and its commercial formulations is controversial. Reviews have been published by individuals who are consultants and employees of companies commercializing glyphosate-based herbicides in support of glyphosate's reapproval by regulatory agencies. These authors conclude that glyphosate is safe at levels below regulatory permissible limits. In contrast, reviews conducted by academic scientists independent of industry report toxic effects below regulatory limits, as well as shortcomings of the current regulatory evaluation of risks associated with glyphosate exposures. Two authors in particular (Samsel and Seneff) have published a series of commentaries proposing that long-term exposure to glyphosate is responsible for many chronic diseases (including cancers, diabetes, neuropathies, obesity, asthma, infections, osteoporosis, infertility, and birth defects). The aim of this review is to examine the evidential basis for these claimed negative health effects and the mechanisms that are alleged to be at their basis. We found that these authors inappropriately employ a deductive reasoning approach based on syllogism. We found that their conclusions are not supported by the available scientific evidence. Thus, the mechanisms and vast range of conditions proposed to result from glyphosate toxicity presented by Samsel and Seneff in their commentaries are at best unsubstantiated theories, speculations, or simply incorrect. This misrepresentation of glyphosate's toxicity misleads the public, the scientific community, and regulators. Although evidence exists that glyphosate-based herbicides are toxic below regulatory set safety limits, the arguments of Samsel and Seneff largely serve to distract rather than to give a rational direction to much needed future research investigating the toxicity of these pesticides, especially at levels of ingestion that are typical for human populations.
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Affiliation(s)
- Robin Mesnage
- Gene Expression and Therapy Group, Faculty of Life Sciences and Medicine, Department of Medical and Molecular Genetics, King's College London, Guy's Hospital, London, United Kingdom
| | - Michael N Antoniou
- Gene Expression and Therapy Group, Faculty of Life Sciences and Medicine, Department of Medical and Molecular Genetics, King's College London, Guy's Hospital, London, United Kingdom
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Arias M, Hoffarth ER, Ishida H, Aramini JM, Vogel HJ. Recombinant expression, antimicrobial activity and mechanism of action of tritrpticin analogs containing fluoro-tryptophan residues. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1858:1012-23. [PMID: 26724205 DOI: 10.1016/j.bbamem.2015.12.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/19/2015] [Accepted: 12/20/2015] [Indexed: 11/16/2022]
Abstract
The increase in antibiotic-resistant bacterial infections has prompted significant academic research into new therapeutic agents targeted against these pathogens. Antimicrobial peptides (AMPs) appear as promising candidates, due their potent antimicrobial activity and their ubiquitous presence in almost all organisms. Tritrpticin is a member of this family of peptides and has been shown to exert a strong antimicrobial activity against several bacterial strains. Tritrpticin's main structural characteristic is the presence of three consecutive Trp residues at the center of the peptide. These residues play an important role in the activity of tritrpticin against Escherichia coli. In this work, a recombinant version of tritrpticin was produced in E. coli using calmodulin as a fusion protein expression tag to overcome the toxicity of the peptide. When used in combination with glyphosate, an inhibitor of the endogenous synthesis of aromatic amino acids, this expression system allowed for the incorporation of fluorinated Trp analogs at very high levels (>90%). The antimicrobial activity of the 4-, 5- and 6-fluoro-Trp-containing tritrpticins against E. coli was as strong as the activity of the native peptide. Similarly, the tritrpticin analogs exhibited comparable abilities to perturb and permeabilize synthetic lipid bilayers as well as the outer and inner membrane of E. coli. Furthermore, the use of 19F NMR spectroscopy established that each individual fluoro-Trp residue interacts differently with SDS micelles, supporting the idea that each Trp in the original tritrpticin plays a different role in the perturbing/permeabilizing activity of the peptide. Moreover, our work demonstrates that the use of fluoro-Trp in solvent perturbation 19F NMR experiments provides detailed site-specific information on the insertion of the Trp residues in biological membrane mimetics. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert.
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Affiliation(s)
- Mauricio Arias
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, T2N 1N4, Canada
| | - Elesha R Hoffarth
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, T2N 1N4, Canada
| | - Hiroaki Ishida
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, T2N 1N4, Canada
| | - James M Aramini
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Hans J Vogel
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, T2N 1N4, Canada.
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Sekar N, Veetil SK, Neerathilingam M. Tender coconut water an economical growth medium for the production of recombinant proteins in Escherichia coli. BMC Biotechnol 2013; 13:70. [PMID: 24004578 PMCID: PMC3847087 DOI: 10.1186/1472-6750-13-70] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 08/19/2013] [Indexed: 11/10/2022] Open
Abstract
Background Escherichia coli is most widely used prokaryotic expression system for the production of recombinant proteins. Several strategies have been employed for expressing recombinant proteins in E.coli. This includes the development of novel host systems, expression vectors and cost effective media. In this study, we exploit tender coconut water (TCW) as a natural and cheaper growth medium for E.coli and Pichia pastoris. Result E.coli and P.pastoris were cultivated in TCW and the growth rate was monitored by measuring optical density at 600 nm (OD600nm), where 1.55 for E.coli and 8.7 for P.pastoris was obtained after 12 and 60 hours, respectively. However, variation in growth rate was observed among TCW when collected from different localities (0.15-2.5 at OD600nm), which is attributed to the varying chemical profile among samples. In this regard, we attempted the supplementation of TCW with different carbon and nitrogen sources to attain consistency in growth rate. Here, supplementation of TCW with 25 mM ammonium sulphate (TCW-S) was noted efficient for the normalization of inconsistency, which further increased the biomass of E.coli by 2 to 10 folds, and 1.5 to 2 fold in P.pastoris. These results indicate that nitrogen source is the major limiting factor for growth. This was supported by total nitrogen and carbon estimation where, nitrogen varies from 20 to 60 mg/100 ml while carbohydrates showed no considerable variation (2.32 to 3.96 g/100 ml). In this study, we also employed TCW as an expression media for recombinant proteins by demonstrating successful expression of maltose binding protein (MBP), MBP-TEV protease fusion and a photo switchable fluorescent protein (mEos2) using TCW and the expression level was found to be equivalent to Luria Broth (LB). Conclusion This study highlights the possible application of TCW-S as a media for cultivation of a variety of microorganisms and recombinant protein expression.
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Affiliation(s)
- Narendrakumar Sekar
- Protein Technology Core, Centre for Cellular and Molecular Platforms, NCBS Campus, GKVK, Bellary Road, Bangalore 560 065, Karnataka, India.
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Tian H, Liu C, Gao XD, Yao WB. Optimization of auto-induction medium for G-CSF production by Escherichia coli using artificial neural networks coupled with genetic algorithm. World J Microbiol Biotechnol 2012; 29:505-13. [PMID: 23132252 DOI: 10.1007/s11274-012-1204-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 10/29/2012] [Indexed: 10/27/2022]
Abstract
Granulocyte colony-stimulating factor (G-CSF) is a cytokine widely used in cancer patients receiving high doses of chemotherapeutic drugs to prevent the chemotherapy-induced suppression of white blood cells. The production of recombinant G-CSF should be increased to meet the increasing market demand. This study aims to model and optimize the carbon source of auto-induction medium to enhance G-CSF production using artificial neural networks coupled with genetic algorithm. In this approach, artificial neural networks served as bioprocess modeling tools, and genetic algorithm (GA) was applied to optimize the established artificial neural network models. Two artificial neural network models were constructed: the back-propagation (BP) network and the radial basis function (RBF) network. The root mean square error, coefficient of determination, and standard error of prediction of the BP model were 0.0375, 0.959, and 8.49 %, respectively, whereas those of the RBF model were 0.0257, 0.980, and 5.82 %, respectively. These values indicated that the RBF model possessed higher fitness and prediction accuracy than the BP model. Under the optimized auto-induction medium, the predicted maximum G-CSF yield by the BP-GA approach was 71.66 %, whereas that by the RBF-GA approach was 75.17 %. These predicted values are in agreement with the experimental results, with 72.4 and 76.014 % for the BP-GA and RBF-GA models, respectively. These results suggest that RBF-GA is superior to BP-GA. The developed approach in this study may be helpful in modeling and optimizing other multivariable, non-linear, and time-variant bioprocesses.
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Affiliation(s)
- H Tian
- State Key Laboratory of Natural Medicines, College of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
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