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Sigmund F, Berezin O, Beliakova S, Magerl B, Drawitsch M, Piovesan A, Gonçalves F, Bodea SV, Winkler S, Bousraou Z, Grosshauser M, Samara E, Pujol-Martí J, Schädler S, So C, Irsen S, Walch A, Kofler F, Piraud M, Kornfeld J, Briggman K, Westmeyer GG. Genetically encoded barcodes for correlative volume electron microscopy. Nat Biotechnol 2023; 41:1734-1745. [PMID: 37069313 PMCID: PMC10713455 DOI: 10.1038/s41587-023-01713-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 02/14/2023] [Indexed: 04/19/2023]
Abstract
While genetically encoded reporters are common for fluorescence microscopy, equivalent multiplexable gene reporters for electron microscopy (EM) are still scarce. Here, by installing a variable number of fixation-stable metal-interacting moieties in the lumen of encapsulin nanocompartments of different sizes, we developed a suite of spherically symmetric and concentric barcodes (EMcapsulins) that are readable by standard EM techniques. Six classes of EMcapsulins could be automatically segmented and differentiated. The coding capacity was further increased by arranging several EMcapsulins into distinct patterns via a set of rigid spacers of variable length. Fluorescent EMcapsulins were expressed to monitor subcellular structures in light and EM. Neuronal expression in Drosophila and mouse brains enabled the automatic identification of genetically defined cells in EM. EMcapsulins are compatible with transmission EM, scanning EM and focused ion beam scanning EM. The expandable palette of genetically controlled EM-readable barcodes can augment anatomical EM images with multiplexed gene expression maps.
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Affiliation(s)
- Felix Sigmund
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Oleksandr Berezin
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Sofia Beliakova
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Bernhard Magerl
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Martin Drawitsch
- Research Group, Circuits of Birdsong, Max Planck Institute for Biological Intelligence, Martinsried, Germany
| | - Alberto Piovesan
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Filipa Gonçalves
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Silviu-Vasile Bodea
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Stefanie Winkler
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Zoe Bousraou
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Martin Grosshauser
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany
| | - Eleni Samara
- Department Circuits-Computation-Models, Max Planck Institute for Biological Intelligence, Martinsried, Germany
| | - Jesús Pujol-Martí
- Department Circuits-Computation-Models, Max Planck Institute for Biological Intelligence, Martinsried, Germany
| | | | - Chun So
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Goettingen, Germany
| | - Stephan Irsen
- Max Planck Institute for Neurobiology of Behavior-caesar (MPINB), Bonn, Germany
| | - Axel Walch
- Research Unit Analytical Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Marie Piraud
- Helmholtz AI, Helmholtz Munich, Neuherberg, Germany
| | - Joergen Kornfeld
- Research Group, Circuits of Birdsong, Max Planck Institute for Biological Intelligence, Martinsried, Germany
| | - Kevin Briggman
- Max Planck Institute for Neurobiology of Behavior-caesar (MPINB), Bonn, Germany
| | - Gil Gregor Westmeyer
- Munich Institute of Biomedical Engineering, Department of Bioscience, TUM School of Natural Sciences and TUM School of Medicine, Technical University of Munich, Munich, Germany.
- Institute for Synthetic Biomedicine, Helmholtz Munich, Neuherberg, Germany.
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Cao M, Peng Q, Wang Y, Luo G, Feng L, Zhao S, Yuan Y, Wang N. High-efficiency uranium extraction from seawater by low-cost natural protein hydrogel. Int J Biol Macromol 2023; 242:124792. [PMID: 37169051 DOI: 10.1016/j.ijbiomac.2023.124792] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/26/2023] [Accepted: 05/05/2023] [Indexed: 05/13/2023]
Abstract
Utilization of uranium resource in seawater are highly possible to meet the growth demands for the sustainable development of nuclear energy industry. Bio-adsorbents exhibit high performance in terms of adsorption selectivity, equilibrium speed, and environmental friendliness, while the high fabrication cost hinders their practical application. In this study, a low-cost soy protein isolate (SPI) is used to fabricate adsorbent named SPI hydrogel for uranium extraction. This is the first report on applying bio-adsorbents derived from low-cost natural proteins for uranium extraction. The SPI hydrogel showed high uranium adsorption capacity of 53.94 mg g-1 in simulated nuclear wastewater and 5.29 mg g-1 is achieved in natural seawater, which is higher than all currently available adsorbents based on non-modified natural biomolecules. The amino and oxygen-containing groups are identified as the functional groups for uranyl binding by providing four oxygen and two nitrogen atoms to form equatorial coordination with uranyl, which guarantees the high binding selectivity and affinity to uranyl ions. The low cost for accessing the raw material together with the environmental friendliness, high salt tolerance, high uranium adsorption ability, and high selectivity to uranium, make SPI hydrogel a promising adsorbent for uranium extraction from seawater and nuclear wastewater.
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Affiliation(s)
- Meng Cao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Qin Peng
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou 571158, China.
| | - Yue Wang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Guangsheng Luo
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Lijuan Feng
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Shilei Zhao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Yihui Yuan
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China.
| | - Ning Wang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China.
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Wang R, Zhu Z, Cheng W, Chang C, Song X, Huang F. Cadmium accumulation and isotope fractionation in typical protozoa Tetrahymena: A new perspective on remediation of Cd pollution in wastewater. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131517. [PMID: 37146330 DOI: 10.1016/j.jhazmat.2023.131517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/17/2023] [Accepted: 04/25/2023] [Indexed: 05/07/2023]
Abstract
Cadmium (Cd) pollution threatens water safety and human health, which has raised serious public concern. Tetrahymena is a model protozoan, possessing the potential to remediate Cd contaminated water given the rapid expression of thiols. However, the mechanism of Cd accumulation in Tetrahymena has not been well understood, which hinders its application in environmental remediation. This study elucidated the pathway of Cd accumulation in Tetrahymena using Cd isotope fractionation. Our results showed that Tetrahymena preferentially absorb light Cd isotopes, with Δ114/110CdTetrahymena-solution = -0.20 ± 0.02‰ ∼ - 0.29 ± 0.02‰, which implies that the intracellular Cd is probably in the form of Cd-S. The fractionation generated by Cd complexation with thiols is constant (Δ114/110CdTetrahymena-remaining solution ∼ -0.28 ± 0.02‰), which is not affected by the concentrations of Cd in intracellular and culture medium, nor by the physiological changes in cells. Furthermore, the detoxification process of Tetrahymena results in an increase in cellular Cd accumulation from 11.7% to 23.3% with the elevated Cd concentrations in batch Cd stress culture experiments. This study highlights the promising application of Cd isotope fractionation in Tetrahymena for the remediation of heavy metal pollution in water.
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Affiliation(s)
- Ruirui Wang
- CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhiqiang Zhu
- Hefei National Research Center for Physical Sciences at the Microscale, MOE Key Laboratory of Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Wenhan Cheng
- CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; College of Resources and Environment, Anhui Agriculture University, Hefei, Anhui 230036, China
| | - Chuanyu Chang
- CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaoyuan Song
- Hefei National Research Center for Physical Sciences at the Microscale, MOE Key Laboratory of Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Fang Huang
- CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China; CAS Center for Excellence in Comparative Planetology, University of Science and Technology of China, Hefei, Anhui 230026, China.
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4
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Byrnes I, Rossbach LM, Brede DA, Grolimund D, Ferreira Sanchez D, Nuyts G, Čuba V, Reinoso-Maset E, Salbu B, Janssens K, Oughton D, Scheibener S, Teien HC, Lind OC. Synchrotron-Based X-ray Fluorescence Imaging Elucidates Uranium Toxicokinetics in Daphnia magna. ACS NANO 2023; 17:5296-5305. [PMID: 36921214 PMCID: PMC10062025 DOI: 10.1021/acsnano.2c06111] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 03/13/2023] [Indexed: 06/17/2023]
Abstract
A combination of synchrotron-based elemental analysis and acute toxicity tests was used to investigate the biodistribution and adverse effects in Daphnia magna exposed to uranium nanoparticle (UNP, 3-5 nm) suspensions or to uranium reference (Uref) solutions. Speciation analysis revealed similar size distributions between exposures, and toxicity tests showed comparable acute effects (UNP LC50: 402 μg L-1 [336-484], Uref LC50: 268 μg L-1 [229-315]). However, the uranium body burden was 3- to 5-fold greater in UNP-exposed daphnids, and analysis of survival as a function of body burden revealed a ∼5-fold higher specific toxicity from the Uref exposure. High-resolution X-ray fluorescence elemental maps of intact, whole daphnids from sublethal, acute exposures of both treatments revealed high uranium accumulation onto the gills (epipodites) as well as within the hepatic ceca and the intestinal lumen. Uranium uptake into the hemolymph circulatory system was inferred from signals observed in organs such as the heart and the maxillary gland. The substantial uptake in the maxillary gland and the associated nephridium suggests that these organs play a role in uranium removal from the hemolymph and subsequent excretion. Uranium was also observed associated with the embryos and the remnants of the chorion, suggesting uptake in the offspring. The identification of target organs and tissues is of major importance to the understanding of uranium and UNP toxicity and exposure characterization that should ultimately contribute to reducing uncertainties in related environmental impact and risk assessments.
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Affiliation(s)
- Ian Byrnes
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
| | - Lisa Magdalena Rossbach
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
| | - Dag Anders Brede
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
| | - Daniel Grolimund
- Swiss
Light Source, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
| | | | - Gert Nuyts
- AXIS
Group, NANOlab Center of Excellence, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Václav Čuba
- Faculty
of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Brehova 7, 166 36 Prague 1, Czech Republic
| | - Estela Reinoso-Maset
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
| | - Brit Salbu
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
| | - Koen Janssens
- AXIS
Group, NANOlab Center of Excellence, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Deborah Oughton
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
| | - Shane Scheibener
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
| | - Hans-Christian Teien
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
| | - Ole Christian Lind
- Centre
for Environmental Radioactivity (CERAD), Faculty of Environmental
Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
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5
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Vallet A, Martin-Laffon J, Favier A, Revel B, Bonnot T, Vidaud C, Armengaud J, Gaillard JC, Delangle P, Devime F, Figuet S, Serre NBC, Erba EB, Brutscher B, Ravanel S, Bourguignon J, Alban C. The plasma membrane-associated cation-binding protein PCaP1 of Arabidopsis thaliana is a uranyl-binding protein. JOURNAL OF HAZARDOUS MATERIALS 2023; 446:130668. [PMID: 36608581 DOI: 10.1016/j.jhazmat.2022.130668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/14/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Uranium (U) is a naturally-occurring radionuclide that is toxic to living organisms. Given that proteins are primary targets of U(VI), their identification is an essential step towards understanding the mechanisms of radionuclide toxicity, and possibly detoxification. Here, we implemented a chromatographic strategy including immobilized metal affinity chromatography to trap protein targets of uranyl in Arabidopsis thaliana. This procedure allowed the identification of 38 uranyl-binding proteins (UraBPs) from root and shoot extracts. Among them, UraBP25, previously identified as plasma membrane-associated cation-binding protein 1 (PCaP1), was further characterized as a protein interacting in vitro with U(VI) and other metals using spectroscopic and structural approaches, and in planta through analyses of the fate of U(VI) in Arabidopsis lines with altered PCaP1 gene expression. Our results showed that recombinant PCaP1 binds U(VI) in vitro with affinity in the nM range, as well as Cu(II) and Fe(III) in high proportions, and that Ca(II) competes with U(VI) for binding. U(VI) induces PCaP1 oligomerization through binding at the monomer interface, at both the N-terminal structured domain and the C-terminal flexible region. Finally, U(VI) translocation in Arabidopsis shoots was affected in pcap1 null-mutant, suggesting a role for this protein in ion trafficking in planta.
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Affiliation(s)
- Alicia Vallet
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, IBS, 38000 Grenoble, France
| | | | - Adrien Favier
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, IBS, 38000 Grenoble, France
| | - Benoît Revel
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, 38000 Grenoble, France
| | - Titouan Bonnot
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, 38000 Grenoble, France
| | - Claude Vidaud
- BIAM, CEA, CNRS, Univ. Aix-Marseille, 13108 Saint-Paul-lez-Durance, France
| | - Jean Armengaud
- Département Médicaments et Technologies pour la Santé (DMTS), Université Paris-Saclay, CEA, INRAE, SPI, F-F-30200 Bagnols-sur-Cèze, France
| | - Jean-Charles Gaillard
- Département Médicaments et Technologies pour la Santé (DMTS), Université Paris-Saclay, CEA, INRAE, SPI, F-F-30200 Bagnols-sur-Cèze, France
| | - Pascale Delangle
- Univ. Grenoble Alpes, CEA, CNRS, GRE-INP, IRIG, SyMMES, 38000 Grenoble, France
| | - Fabienne Devime
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, 38000 Grenoble, France
| | - Sylvie Figuet
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, 38000 Grenoble, France
| | - Nelson B C Serre
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, 38000 Grenoble, France
| | | | | | - Stéphane Ravanel
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, 38000 Grenoble, France
| | | | - Claude Alban
- Univ. Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, 38000 Grenoble, France.
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Melenbacher A, Heinlein L, Hartwig A, Stillman MJ. 63Cu(I) binding to human kidney 68Zn7-βα MT1A: determination of Cu(I)-thiolate cluster domain specificity from ESI-MS and room temperature phosphorescence spectroscopy. Metallomics 2023; 15:mfac101. [PMID: 36583699 PMCID: PMC9846682 DOI: 10.1093/mtomcs/mfac101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 12/29/2022] [Indexed: 12/31/2022]
Abstract
Mammalian metallothioneins (MTs) are important proteins in Zn(II) and Cu(I) homeostasis with the Zn(II) and Cu(I) binding to the 20 cysteines in metal-thiolate clusters. Previous electrospray ionization (ESI) mass spectrometric (MS) analyses of Cu(I) binding to Zn7-MT were complicated by significant overlap of the natural abundance isotopic patterns for Zn(II) and Cu(I) leading to impossibly ambiguous stoichiometries. In this paper, isotopically pure 63Cu(I) and 68Zn(II) allowed determination of the specific stoichiometries in the 68 Zn,63Cu-βα MT1A species formed following the stepwise addition of 63Cu(I) to 68Zn7-βα MT1A. These species were characterized by ESI-MS and room temperature emission spectroscopy. The key species that form and their emission band centres are Zn5Cu5-βα MT1A (λ = 684 nm), Zn4Cu6-βα MT1A (λ = 750 nm), Zn3Cu9-βα MT1A (λ = 750 nm), Zn2Cu10-βα MT1A (λ = 750 nm), and Zn1Cu14-βα MT1A (λ = 634 nm). The specific domain stoichiometry of each species was determined by assessing the species forming following 63Cu(I) addition to the 68Zn3-β MT1A and 68Zn4-α MT1A domain fragments. The domain fragment emission suggests that Zn5Cu5-βα MT1A contains a Zn1Cu5-β cluster and the Zn4Cu6-βα MT1A, Zn3Cu9-βα MT1A, and Zn2Cu10-βα MT1A each contain a Cu6-β cluster. The species forming with >10 mol. eq. of 63Cu(I) in βα-MT1A exhibit emission from the Cu6-β cluster and an α domain cluster. This high emission intensity is seen at the end of the titrations of 68Zn7-βα MT1A and the 68Zn4-α MT1A domain fragment suggesting that the initial presence of the Zn(II) results in clustered Cu(I) binding in the α domain.
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Affiliation(s)
- Adyn Melenbacher
- Department of Chemistry, The University of Western Ontario, 1151 Richmond St., London, Ontario, ON N6A 5B7, Canada
| | - Lina Heinlein
- Department of Chemistry, The University of Western Ontario, 1151 Richmond St., London, Ontario, ON N6A 5B7, Canada
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Karlsruhe, Baden-Württemberg, 76131, Germany
| | - Andrea Hartwig
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Karlsruhe, Baden-Württemberg, 76131, Germany
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, 1151 Richmond St., London, Ontario, ON N6A 5B7, Canada
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Chakdar H, Thapa S, Srivastava A, Shukla P. Genomic and proteomic insights into the heavy metal bioremediation by cyanobacteria. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127609. [PMID: 34772552 DOI: 10.1016/j.jhazmat.2021.127609] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/16/2021] [Accepted: 10/24/2021] [Indexed: 06/13/2023]
Abstract
Heavy metals (HMs) pose a global ecological threat due to their toxic effects on aquatic and terrestrial life. Effective remediation of HMs from the environment can help to restore soil's fertility and ecological vigor, one of the key Sustainable Development Goals (SDG) set by the United Nations. The cyanobacteria have emerged as a potential option for bioremediation of HMs due to their unique adaptations and robust metabolic machineries. Generally, cyanobacteria deploy multifarious mechanisms such as biosorption, bioaccumulation, activation of metal transporters, biotransformation and induction of detoxifying enzymes to sequester and minimize the toxic effects of heavy metals. Therefore, understanding the physiological responses and regulation of adaptation mechanisms at molecular level is necessary to unravel the candidate genes and proteins which can be manipulated to improve the bioremediation efficiency of cyanobacteria. Chaperons, cellular metabolites (extracellular polymers, biosurfactants), transcriptional regulators, metal transporters, phytochelatins and metallothioneins are some of the potential targets for strain engineering. In the present review, we have discussed the potential of cyanobacteria for HM bioremediation and provided a deeper insight into their genomic and proteomic regulation of various tolerance mechanisms. These approaches might pave new possibilities of implementing genetic engineering strategies for improving bioremediation efficiency with a future perspective.
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Affiliation(s)
- Hillol Chakdar
- Microbial Technology Unit II, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau 275103, Uttar Pradesh, India
| | - Shobit Thapa
- Microbial Technology Unit II, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau 275103, Uttar Pradesh, India
| | - Amit Srivastava
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, ID 47907-2048, United States
| | - Pratyoosh Shukla
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India; Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana, India.
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Misra CS, Sounderajan S, Apte SK. Metal removal by metallothionein and an acid phosphatase PhoN, surface-displayed on the cells of the extremophile, Deinococcus radiodurans. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126477. [PMID: 34323731 DOI: 10.1016/j.jhazmat.2021.126477] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/31/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
The utility of surface layer proteins (Hpi and SlpA) of the radiation resistant bacterium, Deinococcus radiodurans, was investigated for surface display and bioremediation of cadmium and uranium. The smtA gene, from Synechococcus elongatus (encoding the metal binding metallothionein protein), was cloned and over-expressed in D. radiodurans, either as such or as a chimeric gene fused with hpi ORF (Hpi-SmtA), or fused to the nucleotide sequence encoding the SLH domain of the SlpA protein (SLH-SmtA). The expressed fusion proteins localized to the deinococcal cell surface, while the SmtA protein localized to the cytoplasm. Recombinant cells surface-displaying the SLH-SmtA or Hpi-SmtA fusion proteins respectively removed 1.5-3 times more cadmium than those expressing only cytosolic SmtA. The deinococcal Hpi protein layer per se also contributed to U binding, by conferring substantial negative charge to deinococcal cell surface. The ORF of an acid phosphatase, PhoN was fused with the hpi or SLH domain DNA sequence and purified. Isolated Hpi-PhoN and SLH-PhoN, immobilized on deinococcal peptidoglycan showed efficient uranium precipitation (446 and 160 mg U/g biomass used respectively). The study demonstrates effective exploitation of the deinococcal S layer protein components for (a) cell surface-based sequestration of cadmium, and (b) cell-free preparations for uranium remediation.
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Affiliation(s)
- Chitra Seetharam Misra
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400094, India.
| | - Suvarna Sounderajan
- Analytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400094, India
| | - Shree Kumar Apte
- School of Biosciences, UM-DAE-Centre for Excellence in Basic Sciences, Vidyanagari, Kalina, Mumbai 400098, India.
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9
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Chatterjee S, Kumari S, Rath S, Priyadarshanee M, Das S. Diversity, structure and regulation of microbial metallothionein: metal resistance and possible applications in sequestration of toxic metals. Metallomics 2020; 12:1637-1655. [PMID: 32996528 DOI: 10.1039/d0mt00140f] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Metallothioneins (MTs) are a group of cysteine-rich, universal, low molecular weight proteins distributed widely in almost all major taxonomic groups ranging from tiny microbes to highly organized vertebrates. The primary function of this protein is storage, transportation and binding of metals, which enable microorganisms to detoxify heavy metals. In the microbial world, these peptides were first identified in a cyanobacterium Synechococcus as the SmtA protein which exhibits high affinity towards rising level of zinc and cadmium to preserve metal homeostasis in a cell. In yeast, MTs aid in reserving copper and confer protection against copper toxicity by chelating excess copper ions in a cell. Two MTs, CUP1 and Crs5, originating from Saccharomyces cerevisiae predominantly bind to copper though are capable of binding with zinc and cadmium ions. MT superfamily 7 is found in ciliated protozoa which show high affinity towards copper and cadmium. Several tools and techniques, such as western blot, capillary electrophoresis, inductively coupled plasma, atomic emission spectroscopy and high performance liquid chromatography, have been extensively utilized for the detection and quantification of microbial MTs which are utilized for the efficient remediation and sequestration of heavy metals from a contaminated environment.
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Affiliation(s)
- Shreosi Chatterjee
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela 769 008, Odisha, India.
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10
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Bhopatkar AA, Uversky VN, Rangachari V. Disorder and cysteines in proteins: A design for orchestration of conformational see-saw and modulatory functions. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 174:331-373. [PMID: 32828470 DOI: 10.1016/bs.pmbts.2020.06.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Being responsible for more than 90% of cellular functions, protein molecules are workhorses in all the life forms. In order to cater for such a high demand, proteins have evolved to adopt diverse structures that allow them to perform myriad of functions. Beginning with the genetically directed amino acid sequence, the classical understanding of protein function involves adoption of hierarchically complex yet ordered structures. However, advances made over the last two decades have revealed that inasmuch as 50% of eukaryotic proteome exists as partially or fully disordered structures. Significance of such intrinsically disordered proteins (IDPs) is further realized from their ability to exhibit multifunctionality, a feature attributable to their conformational plasticity. Among the coded amino acids, cysteines are considered to be "order-promoting" due to their ability to form inter- or intramolecular disulfide bonds, which confer robust thermal stability to the protein structure in oxidizing conditions. The co-existence of order-promoting cysteines with disorder-promoting sequences seems counter-intuitive yet many proteins have evolved to contain such sequences. In this chapter, we review some of the known cysteine-containing protein domains categorized based on the number of cysteines they possess. We show that many protein domains contain disordered sequences interspersed with cysteines. We show that a positive correlation exists between the degree of cysteines and disorder within the sequences that flank them. Furthermore, based on the computational platform, IUPred2A, we show that cysteine-rich sequences display significant disorder in the reduced but not the oxidized form, increasing the potential for such sequences to function in a redox-sensitive manner. Overall, this chapter provides insights into an exquisite evolutionary design wherein disordered sequences with interspersed cysteines enable potential modulatory protein functions under stress and environmental conditions, which thus far remained largely inconspicuous.
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Affiliation(s)
- Anukool A Bhopatkar
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, United States
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States; Laboratory of New Methods in Biology, Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, Russia
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, United States; Center of Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, MS, United States.
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11
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Lin YW. Uranyl Binding to Proteins and Structural-Functional Impacts. Biomolecules 2020; 10:biom10030457. [PMID: 32187982 PMCID: PMC7175365 DOI: 10.3390/biom10030457] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 03/08/2020] [Accepted: 03/13/2020] [Indexed: 01/29/2023] Open
Abstract
The widespread use of uranium for civilian purposes causes a worldwide concern of its threat to human health due to the long-lived radioactivity of uranium and the high toxicity of uranyl ion (UO22+). Although uranyl–protein/DNA interactions have been known for decades, fewer advances are made in understanding their structural-functional impacts. Instead of focusing only on the structural information, this article aims to review the recent advances in understanding the binding of uranyl to proteins in either potential, native, or artificial metal-binding sites, and the structural-functional impacts of uranyl–protein interactions, such as inducing conformational changes and disrupting protein-protein/DNA/ligand interactions. Photo-induced protein/DNA cleavages, as well as other impacts, are also highlighted. These advances shed light on the structure-function relationship of proteins, especially for metalloproteins, as impacted by uranyl–protein interactions. It is desired to seek approaches for biological remediation of uranyl ions, and ultimately make a full use of the double-edged sword of uranium.
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Affiliation(s)
- Ying-Wu Lin
- School of Chemistry and Chemical Engineering, University of South China, Hengyang 421001, China; ; Tel.: +86-734-8578079
- Laboratory of Protein Structure and Function, University of South China, Hengyang 421001, China
- Hunan Key Laboratory for the Design and Application of Actinide Complexes, University of South China, Hengyang 421001, China
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12
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Melenbacher A, Korkola NC, Stillman MJ. The pathways and domain specificity of Cu(i) binding to human metallothionein 1A. Metallomics 2020; 12:1951-1964. [DOI: 10.1039/d0mt00215a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We describe the sequential formation of 3 key Cu(i)–thiolate clusters in human metallothionein 1A using a combination of ESI-MS and phosphorescence lifetime methods.
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Affiliation(s)
- Adyn Melenbacher
- Department of Chemistry
- The University of Western Ontario
- London
- Canada
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13
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Götzke L, Schaper G, März J, Kaden P, Huittinen N, Stumpf T, Kammerlander KK, Brunner E, Hahn P, Mehnert A, Kersting B, Henle T, Lindoy LF, Zanoni G, Weigand JJ. Coordination chemistry of f-block metal ions with ligands bearing bio-relevant functional groups. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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14
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Wong DL, Stillman MJ. Metallothionein: An Aggressive Scavenger-The Metabolism of Rhodium(II) Tetraacetate (Rh 2(CH 3CO 2) 4). ACS OMEGA 2018; 3:16314-16327. [PMID: 31458267 PMCID: PMC6643557 DOI: 10.1021/acsomega.8b02161] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/13/2018] [Indexed: 06/10/2023]
Abstract
Anthropogenic sources of xenobiotic metals with no physiological benefit are increasingly prevalent in the environment. The platinum group metals (Pd, Pt, Rh, Ru, Os, and Ir) are found in marine and plant species near urban sources, and are known to bioaccumulate, introducing these metals into the human food chain. Many of these metals are also being used in innovative cancer therapy, which leads to a direct source of exposure for humans. This paper aims to further our understanding of nontraditional metal metabolism via metallothionein, a protein involved in physiologically important metal homeostasis. The aggressive reaction of metallothionein and dirhodium(II) tetraacetate, a common synthetic catalyst known for its cytotoxicity, was studied in detail in vitro. Optical spectroscopic and equilibrium and time-dependent mass spectral data were used to define binding constants for this robust reaction, and molecular dynamics calculations were conducted to explain the observed results.
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Affiliation(s)
- Daisy L. Wong
- Department of Chemistry, The
University of Western Ontario, 1151 Richmond Street, N6A 5B7 London, Ontario, Canada
| | - Martin J. Stillman
- Department of Chemistry, The
University of Western Ontario, 1151 Richmond Street, N6A 5B7 London, Ontario, Canada
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15
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Scheller JS, Irvine GW, Stillman MJ. Unravelling the mechanistic details of metal binding to mammalian metallothioneins from stoichiometric, kinetic, and binding affinity data. Dalton Trans 2018; 47:3613-3637. [PMID: 29431781 DOI: 10.1039/c7dt03319b] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Metallothioneins (MTs) are small, cysteine-rich proteins, found throughout Nature. Their ability to bind a number of different metals with a range of stoichiometric ratios means that this protein family is critically important for essential metal (Zn2+ and Cu+) homeostasis, metal storage, metal donation to nascent metalloenzymes as well as heavy metal detoxification. With its 20 cysteines, metallothionein is also considered to protect cells against oxidative stress. MT has been studied by a large number of researchers over the last 6 decades using a variety of spectroscopic techniques. The lack of distinguishing chromophores for the multitude of binding sites has made the evaluation of stoichiometric properties for different metals challenging. Initially, only 113Cd-NMR spectroscopy could provide strong evidence for the proposed cluster formation of Cd-MT. The extraordinary development of electrospray ionization mass spectrometry (ESI-MS), where all coexisting species in solution are observed, revolutionized MT research. Prior to the use of ESI-MS data, a range of "magic numbers" representing metal-to-MT molar ratios were reported from optical spectroscopic studies. The availability of ESI mass spectral data led to (i) the confirmation of cluster formation, (ii) a conceptual understanding of the cooperativity involved in multiple metal binding events, (iii) the presence of domain specificity between regions of the protein and (iv) mechanistic details involving both binding affinities and rate constants. The kinetic experiments identified the presence of multiple individual binding sites, each with a unique rate constant and an analogous binding affinity. The almost linear trend in rate constants as a function of bound As3+ provided a unique insight that became a critical step in the complete understanding of the mechanistic details of the metalation of MT. To fully define the biological function of this sulfur-rich protein it is necessary to determine kinetic rate constants and binding affinities for the essential metals. Recently, Zn2+ competition experiments between both of the isolated fragments (α and β) and the full-length protein (βα-MT 1a) as well as Zn2+ competition between βα-MT 1a and carbonic anhydrase were reported. From these data, the trend in binding affinities and the values of the Kf of the 7 bimolecular reactions involved in metalation were determined. From the analysis of ESI-MS data for Cu+ binding to βα-MT 1a at different pH-values, a trend in the 20 binding affinities for the complete metalation mechanism was reported. This review details a personal view of the historical development of the determination of stoichiometry for metal binding, the structure of the binding sites, the rates of the metalation reactions and the underlying binding affinities for each metalation step. We have attempted to summarize the experimental developments that led to the publication in May 2017 of the experimental determination of the 20 binding constants for the 20 sequential bimolecular reactions for Cu+ binding to the 20 Cys of apoMT as a function of pH that show the appearance and disappearance of clusters. We report both published data and in a series of tables an assembly of stoichiometries, and equilibrium constants for Zn2+ and Cu+ for many different metallothioneins.
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Affiliation(s)
- Judith S Scheller
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
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16
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Isolated domains of recombinant human apo-metallothionein 1A are folded at neutral pH: a denaturant and heat-induced unfolding study using ESI-MS. Biosci Rep 2018; 38:BSR20180592. [PMID: 29858425 PMCID: PMC6050192 DOI: 10.1042/bsr20180592] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 12/25/2022] Open
Abstract
Metallothioneins (MTs) are characterized by their high metal loading capacity, small molecular weight, and abundant cysteine residues. It has long been thought that metal-free, or apo-MT peptides were unstructured and only adopted as a distinct conformation upon forming the metal clusters, described as metal-induced folding. More recent studies have suggested that the presence of a globular, yet loosely defined structure actually exists that can be disrupted or unfolded. Residue modification and ion-mobility ESI (IM-ESI)-MS have been used to examine this unusual unfolding process. The structure of apo-MT plays a critical role as the starting point in the flexible metalation pathways that can accommodate numerous soft metals. ESI-MS measurements of the product species formed following the cysteine alkylation of the isolated domain fragments of recombinant human apo-MT 1A with n-ethylmaleimide (NEM) were used in the present study to monitor the denaturant- and heat-induced unfolding at physiological pH. The results indicate that these apo-MT fragments adopt distinct structures at neutral pH that react co-operatively with NEM when folded and non-cooperatively when heated or exposed to high concentrations of the denaturant guanidinium chloride (GdmCl). From these studies, we can conclude that at neutral pH, the domain fragments are folded into globular structures where some of the free cysteine residues are buried within the core and are stabilized by hydrogen bonds. Metalation therefore, must take place from the folded conformation.
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17
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T V D, Chandwadkar P, Acharya C. NmtA, a novel metallothionein of Anabaena sp. strain PCC 7120 imparts protection against cadmium stress but not oxidative stress. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 199:152-161. [PMID: 29626757 DOI: 10.1016/j.aquatox.2018.03.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/12/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
Metallothioneins (MTs) are low molecular weight, sulfhydryl-containing, cysteine-rich, metal-binding proteins. Eukaryotes have multiple metallothionein genes; however, there is dearth of reports on prokaryotic metallothioneins. Bacterial MTs with SmtA from Synechococcus PCC 7942 as prototype have been studied in the context of cadmium detoxification. In this study, a smtA related ORF, namely nmtA, was identified in the heterocystous, nitrogen-fixing cyanobacterium, Anabaena PCC 7120. A recombinant N-terminal histidine-tagged Anabaena NmtA protein was overexpressed in Escherichia coli and purified. The protein was identified by peptide mass fingerprinting using MALDI-TOF Mass Spectrometry as putative metallothionein of Anabaena PCC 7120 with a calculated mass of ∼6.1 kDa. While the native metallated NmtA exhibited resistance against proteolysis, metal free apo-NmtA resulting from acid and dithiothreitol (DTT) treatment could be digested by proteinase K revealing a metal dependent proteolytic protection of NmtA. Expression of nmtA in Anabaena PCC 7120 was induced evidently by cadmium, zinc and copper but not by uranium or hydrogen peroxide. Recombinant Anabaena PCC 7120 overexpressing NmtA protein revealed superior cadmium tolerance but showed limited influence against oxidative stress tolerance as compared with the strain carrying vector alone. In contrast, a mutant of Synechococcus PCC 7942 deficient in MT locus was found to be highly susceptible to H2O2 indicating a likely involvement of cyanobacterial MT in protection against oxidative damage. Overall, the study improved our understanding of metal tolerance mechanisms in Anabaena PCC 7120 by demonstrating a key role of NmtA in cadmium tolerance.
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Affiliation(s)
- Divya T V
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - Pallavi Chandwadkar
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - Celin Acharya
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India.
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18
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Imam HT, Blindauer CA. Differential reactivity of closely related zinc(II)-binding metallothioneins from the plant Arabidopsis thaliana. J Biol Inorg Chem 2018; 23:137-154. [PMID: 29218630 PMCID: PMC5756572 DOI: 10.1007/s00775-017-1516-6] [Citation(s) in RCA: 4] [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: 10/02/2017] [Accepted: 11/12/2017] [Indexed: 12/04/2022]
Abstract
The dynamics of metal binding to and transfer from metalloproteins involved in metal homeostasis are important for understanding cellular distribution of metal ions. The dicotyledonous plant Arabidopsis thaliana has two type 4 seed-specific metallothionein homologues, MT4a and MT4b, with likely roles in zinc(II) homeostasis. These two metallothioneins are 84% identical, with full conservation of all metal-binding cysteine and histidine residues. Yet, differences in their spatial and temporal expression patterns suggested divergence in their biological roles. To investigate whether biological functions are reflected in molecular properties, we compare aspects of zinc(II)-binding dynamics of full-length MT4a and MT4b, namely the pH dependence of zinc(II) binding and protein folding, and zinc(II) transfer to the chelator EDTA. UV-Vis and NMR spectroscopies as well as native electrospray ionisation mass spectrometry consistently showed that transfer from Zn6MT4a is considerably faster than from Zn6MT4b, with pseudo-first-order rate constants for the fastest observed step of k obs = 2.8 × 10-4 s-1 (MT4b) and k obs = 7.5 × 10-4 s-1 (MT4a) (5 µM protein, 500 µM EDTA, 25 mM Tris buffer, pH 7.33, 298 K). 2D heteronuclear NMR experiments allowed locating the most labile zinc(II) ions in domain II for both proteins. 3D homology models suggest that reactivity of this domain is governed by the local environment around the mononuclear Cys2His2 site that is unique to type 4 MTs. Non-conservative amino acid substitutions in this region affect local electrostatics as well as whole-domain dynamics, with both effects rendering zinc(II) ions bound to MT4a more reactive in metal transfer reactions. Therefore, domain II of MT4a is well suited to rapidly release its bound zinc(II) ions, in broad agreement with a previously suggested role of MT4a in zinc(II) transport and delivery to other proteins.
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Affiliation(s)
- Hasan T Imam
- Department of Chemistry, The University of Warwick, Coventry, CV4 7AL, UK
- School of Chemistry, University of St. Andrews, St. Andrews, KY16 9ST, UK
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19
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Irvine GW, Heinlein L, Renaud JB, Sumarah MW, Stillman MJ. Formation of oxidative and non-oxidative dimers in metallothioneins: Implications for charge-state analysis for structural determination. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:2118-2124. [PMID: 28987027 DOI: 10.1002/rcm.8006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/19/2017] [Accepted: 09/24/2017] [Indexed: 05/10/2023]
Abstract
RATIONALE Metallothioneins (MTs) are a class of dynamic proteins that have been investigated extensively using mass spectrometric methods due to their amenability to ionization. Here we detect the formation of oxidative and non-oxidative MT dimers using high-resolution mass spectrometry (HRMS) which has previously been overlooked with lower-resolution techniques. METHODS Recombinant human MT1a and its isolated domain fragments were analyzed by high-resolution Thermo Q-Exactive and Bruker time-of-flight (TOF) mass spectrometers. Covalent Cys modification was performed using N-ethylmalemide to probe the effect of Cys oxidation on dimer formation. RESULTS Dimerization was detected in the analysis of select charge states of Zn7 MT and apo-βMT. Specifically, high resolution (140 k) revealed the +6 dimer peaks overlapping with the +3 charge state, but not with the other charge states (+4, +5, +6). The proteins with covalently modified Cys did not show dimer formation in any of their charge states. Apo-α and apo-βαMT also did not form dimers under the conditions tested. CONCLUSIONS Dimerization of MT was detected for zinc metalated and certain apo-MT forms with HRMS, which was not seen with lower-resolution techniques. These dimers appear overlapped only with certain charge states, confounding their analysis for structural characterization of MTs. The Zn-MT dimers appeared to be non-oxidative; however, the formation of dimers in the apo-protein is likely dependent on Cys oxidation.
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Affiliation(s)
- Gordon W Irvine
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Lina Heinlein
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
- Department of Food Chemistry and Toxicology, University of Karlsruhe, Profach 6980, D-76128, Karlsruhe, Germany
| | - Justin B Renaud
- London Research and Development Center, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
| | - Mark W Sumarah
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
- London Research and Development Center, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
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20
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Irvine GW, Stillman MJ. Residue Modification and Mass Spectrometry for the Investigation of Structural and Metalation Properties of Metallothionein and Cysteine-Rich Proteins. Int J Mol Sci 2017; 18:ijms18050913. [PMID: 28445428 PMCID: PMC5454826 DOI: 10.3390/ijms18050913] [Citation(s) in RCA: 9] [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: 03/24/2017] [Revised: 04/18/2017] [Accepted: 04/20/2017] [Indexed: 12/23/2022] Open
Abstract
Structural information regarding metallothioneins (MTs) has been hard to come by due to its highly dynamic nature in the absence of metal-thiolate cluster formation and crystallization difficulties. Thus, typical spectroscopic methods for structural determination are limited in their usefulness when applied to MTs. Mass spectrometric methods have revolutionized our understanding of protein dynamics, structure, and folding. Recently, advances have been made in residue modification mass spectrometry in order to probe the hard-to-characterize structure of apo- and partially metalated MTs. By using different cysteine specific alkylation reagents, time dependent electrospray ionization mass spectrometry (ESI-MS), and step-wise “snapshot” ESI-MS, we are beginning to understand the dynamics of the conformers of apo-MT and related species. In this review we highlight recent papers that use these and similar techniques for structure elucidation and attempt to explain in a concise manner the data interpretations of these complex methods. We expect increasing resolution in our picture of the structural conformations of metal-free MTs as these techniques are more widely adopted and combined with other promising tools for structural elucidation.
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Affiliation(s)
- Gordon W Irvine
- Department of Chemistry, The University of Western Ontario, London, ON N6A 3K7, Canada.
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, London, ON N6A 3K7, Canada.
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Brundo MV, Pecoraro R, Marino F, Salvaggio A, Tibullo D, Saccone S, Bramanti V, Buccheri MA, Impellizzeri G, Scuderi V, Zimbone M, Privitera V. Toxicity Evaluation of New Engineered Nanomaterials in Zebrafish. Front Physiol 2016; 7:130. [PMID: 27148069 PMCID: PMC4829578 DOI: 10.3389/fphys.2016.00130] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 03/24/2016] [Indexed: 11/24/2022] Open
Abstract
The effect of the nanoparticles on the marine organisms, depends on their size, chemical composition, surface structure, solubility and shape. In order to take advantage from their activity, preserving the surrounding environment from a possible pollution, we are trying to trap the nanoparticles into new nanomaterials. The nanomaterials tested were synthesized proposing a ground-breaking approach by an upside-down vision of the Au/TiO2 nano-system to avoid the release of nanoparticles. The system was synthesized by wrapping Au nanoparticles with a thin layer of TiO2. The non-toxicity of the nano-system was established by testing the effect of the material on zebrafish larvae. Danio rerio o zebrafish was considered an excellent model for the environmental biomonitoring of aquatic environments and the Zebrafish Embryo Toxicity Test (ZFET) is considered an alternative method of animal test. For this reason zebrafish larvae were exposed to different concentrations of nanoparticles of TiO2 and Au and new nanomaterials. As biomarkers of exposure, we evaluated the expression of metallothioneins by immunohistochemistry analysis and western blotting analysis also. The results obtained by toxicity test showed that neither mortality as well as sublethal effects were induced by the different nanomaterials and nanoparticles tested. Only zebrafish larvae exposed to free Au nanoparticles showed a different response to anti-MT antibody. In fact, the immunolocalization analysis highlighted an increase of the metallothioneins synthesis.
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Affiliation(s)
- Maria V. Brundo
- Department of Biological, Geological and Environmental Science, University of CataniaCatania, Italy
| | - Roberta Pecoraro
- Department of Biological, Geological and Environmental Science, University of CataniaCatania, Italy
| | - Fabio Marino
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Polo Universitario dell'AnnunziataMessina, Italy
| | | | - Daniele Tibullo
- Department of Biological, Geological and Environmental Science, University of CataniaCatania, Italy
| | - Salvatore Saccone
- Department of Biological, Geological and Environmental Science, University of CataniaCatania, Italy
| | - Vincenzo Bramanti
- Department of Biomedical and Biotechnology Sciences, University of CataniaCatania, Italy
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22
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Wu QY, Wang CZ, Lan JH, Chai ZF, Shi WQ. Theoretical insight into the binding affinity enhancement of serine with the uranyl ion through phosphorylation. RSC Adv 2016. [DOI: 10.1039/c6ra14906e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Various type complexes of uranyl ion with serine and phosphoserine were investigated which showed phosphorylation induced binding affinity enhancement of serine with the uranyl ion.
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Affiliation(s)
- Qun-Yan Wu
- Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing
- China
| | - Cong-Zhi Wang
- Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing
- China
| | - Jian-Hui Lan
- Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing
- China
| | - Zhi-Fang Chai
- Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing
- China
| | - Wei-Qun Shi
- Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety
- Institute of High Energy Physics
- Chinese Academy of Sciences
- Beijing
- China
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