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Das A, Chakrabarty S, Nag D, Paul S, Ganguli A, Chakrabarti G. Heavy water (D 2O) induces autophagy-dependent apoptotic cell death in non-small cell lung cancer A549 cells by generating reactive oxygen species (ROS) upon microtubule disruption. Toxicol In Vitro 2023; 93:105703. [PMID: 37751786 DOI: 10.1016/j.tiv.2023.105703] [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: 05/17/2023] [Revised: 09/13/2023] [Accepted: 09/22/2023] [Indexed: 09/28/2023]
Abstract
OBJECTIVE Deuterium oxide (D2O) or heavy water is known to have diverse biological activities and have a few therapeutic applications due to its limited toxicity to human subjects. In the present study, we investigated the mechanism of D2O-induced cytotoxicity in non-small cell lung cancer A549 cells. RESULTS We found that D2O-treatment resulted in cytotoxicity, cell cycle arrest, and apoptosis in A549 cells in a dose-dependent fashion. In contrast, limited cytotoxicity was observed in lung fibroblasts WI38 cells. Moreover, D2O-treatment resulted in the disruption of the cellular microtubule network, accompanied by the generation of ROS. On further investigation, we observed that the intracellular ROS triggered autophagic responses in D2O-treated cells, leading to apoptosis by inhibiting the oncogenic PI3K/ Akt/ mTOR signaling. D2O-treatment was also found to enhance the efficacy of paclitaxel in A549 cells. SIGNIFICANCE D2O induces autophagy-dependent apoptosis in A549 cells via ROS generation upon microtubule depolymerization and inhibition of PI3K/ Akt/ mTOR signaling. It augments the efficacy of other microtubule-targeting anticancer drug taxol, which indicates the potential therapeutic importance of D2O as an anticancer agent either alone or in combination with other chemotherapeutic drugs.
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Affiliation(s)
- Amlan Das
- Department of Biotechnology and Dr. B.C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, West Bengal 700019, India; Department of Biochemistry, Royal School of Biosciences, The Assam Royal Global University, Assam 781035, India.
| | - Subhendu Chakrabarty
- Department of Biotechnology and Dr. B.C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, West Bengal 700019, India; Department of Microbiology, M.U.C. Women's College, Burdwan, West Bengal 713104, India
| | - Debasish Nag
- Department of Biotechnology and Dr. B.C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, West Bengal 700019, India
| | - Santanu Paul
- Department of Biotechnology and Dr. B.C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, West Bengal 700019, India; Department of Biotechnology, School of Life Sciences, Swami Vivekananda University, Barrackpore, West Bengal 700121, India
| | - Arnab Ganguli
- Department of Microbiology, Techno India University, West Bengal 700091, India
| | - Gopal Chakrabarti
- Department of Biotechnology and Dr. B.C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, West Bengal 700019, India.
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Supra-Optimal Temperature: An Efficient Approach for Overaccumulation of Starch in the Green Alga Parachlorella kessleri. Cells 2021; 10:cells10071806. [PMID: 34359975 PMCID: PMC8306380 DOI: 10.3390/cells10071806] [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: 06/14/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 11/25/2022] Open
Abstract
Green algae are fast-growing microorganisms that are considered promising for the production of starch and neutral lipids, and the chlorococcal green alga Parachlorella kessleri is a favorable model, as it can produce both starch and neutral lipids. P. kessleri commonly divides into more than two daughter cells by a specific mechanism—multiple fission. Here, we used synchronized cultures of the alga to study the effects of supra-optimal temperature. Synchronized cultures were grown at optimal (30 °C) and supra-optimal (40 °C) temperatures and incident light intensities of 110 and 500 μmol photons m−2 s−1. The time course of cell reproduction (DNA replication, cellular division), growth (total RNA, protein, cell dry matter, cell size), and synthesis of energy reserves (net starch, neutral lipid) was studied. At 40 °C, cell reproduction was arrested, but growth and accumulation of energy reserves continued; this led to the production of giant cells enriched in protein, starch, and neutral lipids. Furthermore, we examined whether the increased temperature could alleviate the effects of deuterated water on Parachlorella kessleri growth and division; results show that supra-optimal temperature can be used in algal biotechnology for the production of protein, (deuterated) starch, and neutral lipids.
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Zachleder V, Ivanov IN, Kselíková V, Bialevich V, Vítová M, Ota S, Takeshita T, Kawano S, Bišová K. Characterization of Growth and Cell Cycle Events Affected by Light Intensity in the Green Alga Parachlorella kessleri: A New Model for Cell Cycle Research. Biomolecules 2021; 11:biom11060891. [PMID: 34203860 PMCID: PMC8232753 DOI: 10.3390/biom11060891] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/03/2021] [Accepted: 06/05/2021] [Indexed: 11/16/2022] Open
Abstract
Multiple fission is a cell cycle variation leading to the production of more than two daughter cells. Here, we used synchronized cultures of the chlorococcal green alga Parachlorella kessleri to study its growth and pattern of cell division under varying light intensities. The time courses of DNA replication, nuclear and cellular division, cell size, total RNA, protein content, dry matter and accumulation of starch were observed at incident light intensities of 110, 250 and 500 µmol photons m−2s−1. Furthermore, we studied the effect of deuterated water on Parachlorella kessleri growth and division, to mimic the effect of stress. We describe a novel multiple fission cell cycle pattern characterized by multiple rounds of DNA replication leading to cell polyploidization. Once completed, multiple nuclear divisions were performed with each of them, immediately followed by protoplast fission, terminated by the formation of daughter cells. The multiple fission cell cycle was represented by several consecutive doublings of growth parameters, each leading to the start of a reproductive sequence. The number of growth doublings increased with increasing light intensity and led to division into more daughter cells. This study establishes the baseline for cell cycle research at the molecular level as well as for potential biotechnological applications, particularly directed synthesis of (deuterated) starch and/or neutral lipids as carbon and energy reserves.
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Affiliation(s)
- Vilém Zachleder
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.Z.); (I.N.I.); (V.K.); (V.B.); (M.V.)
| | - Ivan N. Ivanov
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.Z.); (I.N.I.); (V.K.); (V.B.); (M.V.)
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Veronika Kselíková
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.Z.); (I.N.I.); (V.K.); (V.B.); (M.V.)
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Vitali Bialevich
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.Z.); (I.N.I.); (V.K.); (V.B.); (M.V.)
| | - Milada Vítová
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.Z.); (I.N.I.); (V.K.); (V.B.); (M.V.)
| | - Shuhei Ota
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan;
| | - Tsuyoshi Takeshita
- The University of Tokyo Future Center Initiative, Wakashiba 178 4 4, Kashiwa, Chiba 277-0871, Japan; (T.T.); (S.K.)
| | - Shigeyuki Kawano
- The University of Tokyo Future Center Initiative, Wakashiba 178 4 4, Kashiwa, Chiba 277-0871, Japan; (T.T.); (S.K.)
| | - Kateřina Bišová
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.Z.); (I.N.I.); (V.K.); (V.B.); (M.V.)
- Correspondence: ; Tel.: +420-384-340-480
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Kselíková V, Zachleder V, Bišová K. To Divide or Not to Divide? How Deuterium Affects Growth and Division of Chlamydomonas reinhardtii. Biomolecules 2021; 11:861. [PMID: 34207920 PMCID: PMC8226696 DOI: 10.3390/biom11060861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/31/2021] [Accepted: 06/07/2021] [Indexed: 11/16/2022] Open
Abstract
Extensive in vivo replacement of hydrogen by deuterium, a stable isotope of hydrogen, induces a distinct stress response, reduces cell growth and impairs cell division in various organisms. Microalgae, including Chlamydomonas reinhardtii, a well-established model organism in cell cycle studies, are no exception. Chlamydomonas reinhardtii, a green unicellular alga of the Chlorophyceae class, divides by multiple fission, grows autotrophically and can be synchronized by alternating light/dark regimes; this makes it a model of first choice to discriminate the effect of deuterium on growth and/or division. Here, we investigate the effects of high doses of deuterium on cell cycle progression in C. reinhardtii. Synchronous cultures of C. reinhardtii were cultivated in growth medium containing 70 or 90% D2O. We characterize specific deuterium-induced shifts in attainment of commitment points during growth and/or division of C. reinhardtii, contradicting the role of the "sizer" in regulating the cell cycle. Consequently, impaired cell cycle progression in deuterated cultures causes (over)accumulation of starch and lipids, suggesting a promising potential for microalgae to produce deuterated organic compounds.
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Affiliation(s)
- Veronika Kselíková
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.K.); (V.Z.)
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Vilém Zachleder
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.K.); (V.Z.)
| | - Kateřina Bišová
- Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 37981 Třeboň, Czech Republic; (V.K.); (V.Z.)
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Kinetic isotope effects and synthetic strategies for deuterated carbon-11 and fluorine-18 labelled PET radiopharmaceuticals. Nucl Med Biol 2021; 96-97:112-147. [PMID: 33892374 DOI: 10.1016/j.nucmedbio.2021.03.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/19/2021] [Accepted: 03/30/2021] [Indexed: 11/22/2022]
Abstract
The deuterium labelling of pharmaceuticals is a useful strategy for altering pharmacokinetic properties, particularly for improving metabolic resistance. The pharmacological effects of such metabolites are often assumed to be negligible during standard drug discovery and are factored in later at the clinical phases of development, where the risks and benefits of the treatment and side-effects can be wholly assessed. This paradigm does not translate to the discovery of radiopharmaceuticals, however, as the confounding effects of radiometabolites can inevitably show in preliminary positron emission tomography (PET) scans and thus complicate interpretation. Consequently, the formation of radiometabolites is crucial to take into consideration, compared to non-radioactive metabolites, and the application of deuterium labelling is a particularly attractive approach to minimise radiometabolite formation. Herein, we provide a comprehensive overview of the deuterated carbon-11 and fluorine-18 radiopharmaceuticals employed in PET imaging experiments. Specifically, we explore six categories of deuterated radiopharmaceuticals used to investigate the activities of monoamine oxygenase (MAO), choline, translocator protein (TSPO), vesicular monoamine transporter 2 (VMAT2), neurotransmission and the diagnosis of Alzheimer's disease; from which we derive four prominent deuteration strategies giving rise to a kinetic isotope effect (KIE) for reducing the rate of metabolism. Synthetic approaches for over thirty of these deuterated radiopharmaceuticals are discussed from the perspective of deuterium and radioisotope incorporation, alongside an evaluation of the deuterium labelling and radiolabelling efficacies across these independent studies. Clinical and manufacturing implications are also discussed to provide a more comprehensive overview of how deuterated radiopharmaceuticals may be introduced to routine practice.
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Jandova J, Hua AB, Fimbres J, Wondrak GT. Deuterium Oxide (D 2O) Induces Early Stress Response Gene Expression and Impairs Growth and Metastasis of Experimental Malignant Melanoma. Cancers (Basel) 2021; 13:605. [PMID: 33546433 PMCID: PMC7913703 DOI: 10.3390/cancers13040605] [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: 12/29/2020] [Revised: 01/25/2021] [Accepted: 01/29/2021] [Indexed: 11/16/2022] Open
Abstract
There are two stable isotopes of hydrogen, protium (1H) and deuterium (2H; D). Cellular stress response dysregulation in cancer represents both a major pathological driving force and a promising therapeutic target, but the molecular consequences and potential therapeutic impact of deuterium (2H)-stress on cancer cells remain largely unexplored. We have examined the anti-proliferative and apoptogenic effects of deuterium oxide (D2O; 'heavy water') together with stress response gene expression profiling in panels of malignant melanoma (A375V600E, A375NRAS, G361, LOX-IMVI), and pancreatic ductal adenocarcinoma (PANC-1, Capan-2, or MIA PaCa-2) cells with inclusion of human diploid Hs27 skin fibroblasts. Moreover, we have examined the efficacy of D2O-based pharmacological intervention in murine models of human melanoma tumor growth and metastasis. D2O-induction of apoptosis was substantiated by AV-PI flow cytometry, immunodetection of PARP-1, and pro-caspase 3 cleavage, and rescue by pan-caspase inhibition. Differential array analysis revealed early modulation of stress response gene expression in both A375 melanoma and PANC-1 adenocarcinoma cells elicited by D2O (90%; ≤6 h) (upregulated: CDKN1A, DDIT3, EGR1, GADD45A, HMOX1, NFKBIA, or SOD2 (up to 9-fold; p < 0.01)) confirmed by independent RT-qPCR analysis. Immunoblot analysis revealed rapid onset of D2O-induced stress response phospho-protein activation (p-ERK, p-JNK, p-eIF2α, or p-H2AX) or attenuation (p-AKT). Feasibility of D2O-based chemotherapeutic intervention (drinking water (30% w/w)) was demonstrated in a severe combined immunodeficiency (SCID) mouse melanoma metastasis model using luciferase-expressing A375-Luc2 cells. Lung tumor burden (visualized by bioluminescence imaging) was attenuated by D2O, and inhibition of invasiveness was also confirmed in an in vitro Matrigel transwell invasion assay. D2O supplementation also suppressed tumor growth in a murine xenograft model of human melanoma, and median survival was significantly increased without causing adverse effects. These data demonstrate for the first time that systemic D2O administration impairs growth and metastasis of malignant melanoma through the pharmacological induction of deuterium (2H)-stress.
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Affiliation(s)
| | | | | | - Georg T. Wondrak
- Department of Pharmacology and Toxicology, College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, AZ 85724, USA; (J.J.); (A.B.H.); (J.F.)
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Ishikawa Y, Kitagawa H, Sawada T, Seto T, Takahashi K, Yamazaki T. Deuterium oxide protects against myocardial injury induced by ischemia and reperfusion in rats. SCAND CARDIOVASC J 2019; 53:329-336. [PMID: 31455109 DOI: 10.1080/14017431.2019.1657939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Objectives. Although deuterium oxide (D2O) has preservative property on the extracted organ, whether D2O also protects the in situ myocardial injury remains unknown. Using cardiac microdialysis, local administration of D2O through dialysis probe was applied in situ rat heart. We examined the effect of the D2O on the myocardial injury induced ischemia, reperfusion, and chemical hypoxia. Methodology. We measured dialysate myoglobin levels during 30 min of coronary occlusion and reperfusion in the absence and presence of D2O. Furthermore, to confirm the effect of D2O on NaCN induced myocardial injury, we measured the dialysate myoglobin levels with local perfusion of NaCN in the absence and presence of D2O. Results. The dialysate myoglobin levels increased from 177 ± 45 ng/mL at baseline to 3030 ± 1523 ng/mL during 15-30 min of coronary occlusion and further increased to 8588 ± 1684ng/mL at 0-15 min of reperfusion. The dialysate myoglobin levels with 60 min local perfusion of NaCN increased to 1214 ± 279 ng/mL. D2O attenuated myocardial myoglobin release during 15-30 min of coronary occlusion and 0-30 min of reperfusion and 15-60 min of local perfusion of NaCN. Conclusions. D2O might have a beneficial effect of myocardium against ischemia, reperfusion and chemical hypoxia.
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Affiliation(s)
- Yuko Ishikawa
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Hirotoshi Kitagawa
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Tadashi Sawada
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Tomoyoshi Seto
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Kan Takahashi
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Toji Yamazaki
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
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Lv M, Zhang YJ, Zhou F, Ge Y, Zhao MH, Liu Y, Yang KW. Real-time monitoring of D-Ala-D-Ala dipeptidase activity of VanX in living bacteria by isothermal titration calorimetry. Anal Biochem 2019; 578:29-35. [DOI: 10.1016/j.ab.2019.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/17/2019] [Accepted: 05/03/2019] [Indexed: 02/07/2023]
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Deuterium and its impact on living organisms. Folia Microbiol (Praha) 2019; 64:673-681. [DOI: 10.1007/s12223-019-00740-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 07/15/2019] [Indexed: 12/12/2022]
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Zhang YJ, Wang WM, Oelschlaeger P, Chen C, Lei JE, Lv M, Yang KW. Real-Time Monitoring of NDM-1 Activity in Live Bacterial Cells by Isothermal Titration Calorimetry: A New Approach To Measure Inhibition of Antibiotic-Resistant Bacteria. ACS Infect Dis 2018; 4:1671-1678. [PMID: 30383355 DOI: 10.1021/acsinfecdis.8b00147] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The "superbug" infection caused by New Delhi metallo-β-lactamase (NDM-1) has become an emerging threat. Monitoring NDM-1 has proven challenging due to its shuttling between pathogenic bacteria. Here, we report an isothermal titration calorimetry (ITC) method that can monitor activity and inhibition of NDM-1 in live bacterial cells in real time. This method has been exemplified by monitoring of the activity and inhibition of the target enzyme and evaluating the breakdown of antibiotics by pathogenic bacteria expressing β-lactamases. Cell-based studies demonstrate that the NDM-1 expressed in bacterial cells was inhibited by four known inhibitors ethylene diamine tetraacetic acid (EDTA), d-captopril, ebselen and azolylthioacetamide with fifty percent inhibitory concentration (IC50) values of 3.8, 48, 0.55, and 17.5 μM, respectively, which are in good agreement with the data from inhibition kinetics using UV-vis and NMR spectroscopy in vivo. This approach could be applied to screen and evaluate small molecule inhibitors of metallo-β-lactamases (MβLs) in whole cells or to identify drug resistant bacteria.
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Affiliation(s)
- Yue-Juan Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
| | - Wen-Ming Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
| | - Peter Oelschlaeger
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, 309 East Second Street, Pomona, California 91766, United States
| | - Cheng Chen
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
| | - Jin-E Lei
- The First Affiliated Hospital of Xi’an Jiaotong University, 277 West Yanta Road, Xi’an, Shaanxi 710061, P.R. China
| | - Miao Lv
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
| | - Ke-Wu Yang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Chemical Biology Innovation Laboratory, College of Chemistry and Materials Science, Northwest University, 1 Xuefu Avenue, Xi’an, Shaanxi 710127, P. R. China
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Okamoto A, Tokunou Y, Kalathil S, Hashimoto K. Proton Transport in the Outer‐Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron Transport. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201704241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Akihiro Okamoto
- Global Research Center for Environment and Energy based on Nanomaterials Science National Institute for Material Science 1-1 Namiki, Tsukuba Ibaraki 305-0044 Japan
| | - Yoshihide Tokunou
- Department of Applied Chemistry The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Shafeer Kalathil
- Department of Applied Chemistry The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Kazuhito Hashimoto
- Global Research Center for Environment and Energy based on Nanomaterials Science National Institute for Material Science 1-1 Namiki, Tsukuba Ibaraki 305-0044 Japan
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Okamoto A, Tokunou Y, Kalathil S, Hashimoto K. Proton Transport in the Outer-Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron Transport. Angew Chem Int Ed Engl 2017; 56:9082-9086. [PMID: 28608645 PMCID: PMC5575523 DOI: 10.1002/anie.201704241] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Indexed: 01/17/2023]
Abstract
The microbial transfer of electrons to extracellularly located solid compounds, termed extracellular electron transport (EET), is critical for microbial electrode catalysis. Although the components of the EET pathway in the outer membrane (OM) have been identified, the role of electron/cation coupling in EET kinetics is poorly understood. We studied the dynamics of proton transport associated with EET in an OM flavocytochrome complex in Shewanella oneidensis MR‐1. Using a whole‐cell electrochemical assay, a significant kinetic isotope effect (KIE) was observed following the addition of deuterated water (D2O). The removal of a flavin cofactor or key components of the OM flavocytochrome complex significantly increased the KIE in the presence of D2O to values that were significantly larger than those reported for proton channels and ATP synthase, thus indicating that proton transport by OM flavocytochrome complexes limits the rate of EET.
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Affiliation(s)
- Akihiro Okamoto
- Global Research Center for Environment and Energy based on Nanomaterials Science, National Institute for Material Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Yoshihide Tokunou
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Shafeer Kalathil
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Kazuhito Hashimoto
- Global Research Center for Environment and Energy based on Nanomaterials Science, National Institute for Material Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
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Callies O, Hernández Daranas A. Application of isothermal titration calorimetry as a tool to study natural product interactions. Nat Prod Rep 2016; 33:881-904. [DOI: 10.1039/c5np00094g] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The study of molecular interactions of natural products by isothermal titration calorimetry (ITC) is a potent tool to get new insights of the underpinning driving forces.
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Affiliation(s)
- O. Callies
- Institute of Bioorganic Chemistry “Antonio González”
- Center for Biomedical Research of the Canary Islands
- University of La Laguna
- 38206 La Laguna
- Spain
| | - A. Hernández Daranas
- Institute of Bioorganic Chemistry “Antonio González”
- Center for Biomedical Research of the Canary Islands
- University of La Laguna
- 38206 La Laguna
- Spain
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14
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Ong WQ, Citron YR, Schnitzbauer J, Kamiyama D, Huang B. Heavy water: a simple solution to increasing the brightness of fluorescent proteins in super-resolution imaging. Chem Commun (Camb) 2015; 51:13451-3. [PMID: 26226621 PMCID: PMC4544551 DOI: 10.1039/c5cc04575d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Photoactivatable fluorescent proteins (PA-FPs) are widely used in live single-molecule super-resolution imaging but emit substantially fewer photons than organic dyes do. Herein, we show that in heavy water (D2O) instead of H2O, common PA-FPs emit 26-54% more photons, effectively improving the localization precision in super-resolution imaging.
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Affiliation(s)
- Wei Qiang Ong
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA.
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