1
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Ongey EL, Banerjee A. In vitro reconstitution of transition metal transporters. J Biol Chem 2024; 300:107589. [PMID: 39032653 DOI: 10.1016/j.jbc.2024.107589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 06/28/2024] [Accepted: 07/03/2024] [Indexed: 07/23/2024] Open
Abstract
Transition metal ions are critically important across all kingdoms of life. The chemical properties of iron, copper, zinc, manganese, cobalt, and nickel make them very attractive for use as cofactors in metalloenzymes and/or metalloproteins. Their versatile chemistry in aqueous solution enables them to function both as electron donors and acceptors, and thus participate in both reduction and oxidation reactions respectively. Transition metal ions can also function as nonredox multidentate coordination sites that play essential roles in macromolecular structure and function. Malfunction in transition metal transport and homeostasis has been linked to a wide number of human diseases including cancer, diabetes, and neurodegenerative disorders. Transition metal transporters are central players in the physiology of transition metals whereby they move transition metals in and out of cellular compartments. In this review, we provide a comprehensive overview of in vitro reconstitution of the activity of integral membrane transition metal transporters and discuss strategies that have been successfully implemented to overcome the challenges. We also discuss recent advances in our understanding of transition metal transport mechanisms and the techniques that are currently used to decipher the molecular basis of transport activities of these proteins. Deep mechanistic insights into transition metal transport systems will be essential to understand their malfunction in human diseases and target them for potential therapeutic strategies.
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Affiliation(s)
- Elvis L Ongey
- Cell Biology and Neurobiology Branch, National Institutes of Child Health and Human, Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Anirban Banerjee
- Cell Biology and Neurobiology Branch, National Institutes of Child Health and Human, Development, National Institutes of Health, Bethesda, Maryland, USA.
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2
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Górecki K, Hansen JS, Li P, Nayeri N, Lindkvist-Petersson K, Gourdon P. Microfluidic-Derived Detection of Protein-Facilitated Copper Flux Across Lipid Membranes. Anal Chem 2022; 94:11831-11837. [PMID: 35969432 PMCID: PMC9434548 DOI: 10.1021/acs.analchem.2c02081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
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Measurement of protein-facilitated copper flux across
biological
membranes is a considerable challenge. Here, we demonstrate a straightforward
microfluidic-derived approach for visualization and measurement of
membranous Cu flux. Giant unilamellar vesicles, reconstituted with
the membrane protein of interest, are prepared, surface-immobilized,
and assessed using a novel quencher–sensor reporter system
for detection of copper. With the aid of a syringe pump, the external
buffer is exchanged, enabling consistent and precise exchange of solutes,
without causing vesicle rupture or uneven local metal concentrations
brought about by rapid mixing. This approach bypasses common issues
encountered when studying heavy metal-ion flux, thereby providing
a new platform for in vitro studies of metal homeostasis
aspects that are critical for all cells, health, and disease.
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Affiliation(s)
- Kamil Górecki
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund SE-22100, Sweden
| | - Jesper S Hansen
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund SE-22100, Sweden
| | - Ping Li
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund SE-22100, Sweden
| | - Niloofar Nayeri
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund SE-22100, Sweden
| | - Karin Lindkvist-Petersson
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund SE-22100, Sweden
| | - Pontus Gourdon
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund SE-22100, Sweden.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N DK-2200, Denmark
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3
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Placenti MA, Roman EA, González Flecha FL, González-Lebrero RM. Functional characterization of Legionella pneumophila Cu + transport ATPase. The activation by Cu + and ATP. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183822. [PMID: 34826402 DOI: 10.1016/j.bbamem.2021.183822] [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: 08/04/2021] [Revised: 11/08/2021] [Accepted: 11/17/2021] [Indexed: 06/13/2023]
Abstract
Cu+-ATPases are integral membrane proteins belonging to the IB subfamily of the P-type ATPases that couple Cu+ transport to the hydrolysis of ATP. As some structural and functional particularities arise for Cu+-ATPases, several authors suggest that some of the reaction steps of the Albers-Post model postulated for other P-ATPases may be different. In this work we describe a functional characterization of Legionella pneumophila Cu+-ATPase (LpCopA), the first PIB-ATPase whose structure was determined by X-ray crystallography. Cu+-ATPase activity of the enzyme presents a maximum at ∼37 °C and pH 6.6-6.8. Phospholipids enhance LpCopA Cu+-ATPase activity in a non-essential mode where optimal activity is achieved at an asolectin molar fraction of 0.15 and an amphiphile-protein ratio of ~30,000. As described for other P-ATPases, Mg2+ acts as an essential activator. Furthermore, Cu+-ATPase activity dependence on [Cu+] and [ATP] can both be described by a sum of two hyperbolic functions. Based on that, and the [Cu+] and [ATP] dependencies of the best fitting parameters of the hyperbolae pointed above, we propose a minimal reaction scheme for the catalytic mechanism that shares the basic reaction steps of the Albers-Post model for P-type ATPases. The reaction scheme postulated contemplates two different binding affinities for a single ATP (apparent affinities of 0.66 and 550 μM at [Cu+] → ∞) and binding of at least 2 Cu+ with different affinities as well (apparent affinities of 1.4 and 102.5 μM at [ATP] → ∞).
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Affiliation(s)
- M Agueda Placenti
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas, Buenos Aires, Argentina
| | - Ernesto A Roman
- Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas, Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Buenos Aires, Argentina
| | - F Luis González Flecha
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas, Buenos Aires, Argentina.
| | - Rodolfo M González-Lebrero
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas, Buenos Aires, Argentina.
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4
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Zhong T, Jiang N, Li C, Wang G. A highly selective fluorescence and absorption sensor for rapid recognition and detection of Cu 2+ ion in aqueous solution and film. LUMINESCENCE 2021; 37:391-398. [PMID: 34931444 DOI: 10.1002/bio.4180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/29/2021] [Accepted: 11/30/2021] [Indexed: 11/06/2022]
Abstract
A fluorescence and absorption chemosensor (SAAT) based on 5-(hydroxymethyl)-salicylaldehyde (SA) and o-aminothiophenol (AT) was designed and synthesized. SAAT in DMSO-HEPES (20.0 mM, v/v, 1:99, pH=7.0) solution shows a highly selective and sensitive absorption and "on-off" fluorescence response to Cu2+ ions in aqueous solutions over all other competitive metal ions including Na+ , Ag+ , Ba2+ , Ca2+ , Cd2+ , Mg2+ , Zn2+ , Cr3+ , Al3+ , Hg2+ , K+ , Mn2+ , Ni2+ , Sr2+ , Tb3+ and Co2+ . SAAT exhibits ratiometric absorption sensing ability for Cu2+ ions. Importantly, SAAT also can sense Cu2+ ions by fluorescence quenching, the fluorescence intensity of SAAT showed a good linear relationship with Cu2+ concentration, and the detection limit of Cu2+ was 0.34 μM. The results of Job's plot, Benesi-Hildebrand plot, mass spectra, and DFT calculations confirmed that the selective absorption and fluorescence response were attributed to the formation of 1:1 complex between SAAT and Cu2+ . SAAT in test film can identify Cu2+ in water samples by the intuitive fluorescence color change under UV lamp. SAAT has great application value as a selective and sensitive chemosensor to discrimination and detection of Cu2+ ions.
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Affiliation(s)
- Tianyuan Zhong
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Faculty of Chemistry, Northeast Normal University, Changchun, P. R. China
| | - Nan Jiang
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Faculty of Chemistry, Northeast Normal University, Changchun, P. R. China
| | - Chen Li
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Faculty of Chemistry, Northeast Normal University, Changchun, P. R. China
| | - Guang Wang
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Faculty of Chemistry, Northeast Normal University, Changchun, P. R. China
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5
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Salcedo-Sora JE, Robison ATR, Zaengle-Barone J, Franz KJ, Kell DB. Membrane Transporters Involved in the Antimicrobial Activities of Pyrithione in Escherichia coli. Molecules 2021; 26:molecules26195826. [PMID: 34641370 PMCID: PMC8510280 DOI: 10.3390/molecules26195826] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/16/2021] [Accepted: 09/20/2021] [Indexed: 02/06/2023] Open
Abstract
Pyrithione (2-mercaptopyridine-N-oxide) is a metal binding modified pyridine, the antibacterial activity of which was described over 60 years ago. The formulation of zinc-pyrithione is commonly used in the topical treatment of certain dermatological conditions. However, the characterisation of the cellular uptake of pyrithione has not been elucidated, although an unsubstantiated assumption has persisted that pyrithione and/or its metal complexes undergo a passive diffusion through cell membranes. Here, we have profiled specific membrane transporters from an unbiased interrogation of 532 E. coli strains of knockouts of genes encoding membrane proteins from the Keio collection. Two membrane transporters, FepC and MetQ, seemed involved in the uptake of pyrithione and its cognate metal complexes with copper, iron, and zinc. Additionally, the phenotypes displayed by CopA and ZntA knockouts suggested that these two metal effluxers drive the extrusion from the bacterial cell of potentially toxic levels of copper, and perhaps zinc, which hyperaccumulate as a function of pyrithione. The involvement of these distinct membrane transporters contributes to the understanding of the mechanisms of action of pyrithione specifically and highlights, more generally, the important role that membrane transporters play in facilitating the uptake of drugs, including metal-drug compounds.
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Affiliation(s)
- Jesus Enrique Salcedo-Sora
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
- Correspondence: (J.E.S.-S.); (K.J.F.); (D.B.K.)
| | - Amy T. R. Robison
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA; (A.T.R.R.); (J.Z.-B.)
| | - Jacqueline Zaengle-Barone
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA; (A.T.R.R.); (J.Z.-B.)
| | - Katherine J. Franz
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA; (A.T.R.R.); (J.Z.-B.)
- Correspondence: (J.E.S.-S.); (K.J.F.); (D.B.K.)
| | - Douglas B. Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs Lyngby, Denmark
- Correspondence: (J.E.S.-S.); (K.J.F.); (D.B.K.)
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6
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Abeyrathna N, Abeyrathna S, Morgan MT, Fahrni CJ, Meloni G. Transmembrane Cu(I) P-type ATPase pumps are electrogenic uniporters. Dalton Trans 2021; 49:16082-16094. [PMID: 32469032 DOI: 10.1039/d0dt01380c] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cu(i) P-type ATPases are transmembrane primary active ion pumps that catalyze the extrusion of copper ions across cellular membranes. Their activity is critical in controlling copper levels in all kingdoms of life. Biochemical and structural characterization established the structural framework by which Cu-pumps perform their function. However, the details of the overall mechanism of transport (uniporter vs. cotransporter) and electrogenicity still remain elusive. In this work, we developed a platform to reconstitute the model Cu(i)-pump from E. coli (EcCopA) in artificial lipid bilayer small unilamellar vesicles (SUVs) to quantitatively characterize the metal substrate, putative counter-ions and charge translocation. By encapsulating in the liposome lumen fluorescence detector probes (CTAP-3, pyranine and oxonol VI) responsive to diverse stimuli (Cu(i), pH and membrane potential), we correlated substrate, secondary-ion translocation and charge movement events in EcCopA proteoliposomes. This platform centered on multiple fluorescence reporters allowed study of the mechanism and translocation kinetic parameters in real-time for wild-type EcCopA and inactive mutants. The maximal initial Cu(i) transport rate of 165 nmol Cu(i) mg-1 min-1 and KM, Cu(I) = 0.15 ± 0.07 μM was determined with this analysis. We reveal that Cu(i) pumps are primary-active uniporters and electrogenic. The Cu(i) translocation cycle does not require proton counter-transport resulting in electrogenic generation of transmembrane potential upon translocation of one Cu(i) per ATP hydrolysis cycle. Thus, mechanistic differences between Cu(i) pumps and other better characterized P-type ATPases are discussed. The platform opens the venue to study translocation events and mechanisms of transport in other transition metal P-type ATPase pumps.
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Affiliation(s)
- Nisansala Abeyrathna
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX 75080, USA.
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7
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Diederichs T, Tampé R. Single Cell-like Systems Reveal Active Unidirectional and Light-Controlled Transport by Nanomachineries. ACS NANO 2021; 15:6747-6755. [PMID: 33724767 PMCID: PMC8157534 DOI: 10.1021/acsnano.0c10139] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Cellular life depends on transport and communication across membranes, which is emphasized by the fact that membrane proteins are prime drug targets. The cell-like environment of membrane proteins has gained increasing attention based on its important role in function and regulation. As a versatile scaffold for bottom-up synthetic biology and nanoscience, giant liposomes represent minimalistic models of living cells. Nevertheless, the incorporation of fragile multiprotein membrane complexes still remains a major challenge. Here, we report on an approach for the functional reconstitution of membrane assemblies exemplified by human and bacterial ATP-binding cassette (ABC) transporters. We reveal that these nanomachineries transport substrates unidirectionally against a steep concentration gradient. Active substrate transport can be spatiotemporally resolved in single cell-like compartments by light, enabling real-time tracking of substrate export and import in individual liposomes. This approach will help to construct delicate artificial cell-like systems.
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Affiliation(s)
- Tim Diederichs
- Institute of Biochemistry, Biocenter,
Goethe-University Frankfurt, Max-von Laue-Straße 9,
60438 Frankfurt a.M., Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter,
Goethe-University Frankfurt, Max-von Laue-Straße 9,
60438 Frankfurt a.M., Germany
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8
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Herbert FC, Abeyrathna SS, Abeyrathna NS, Wijesundara YH, Brohlin OR, Carraro F, Amenitsch H, Falcaro P, Luzuriaga MA, Durand-Silva A, Diwakara SD, Smaldone RA, Meloni G, Gassensmith JJ. Stabilization of supramolecular membrane protein-lipid bilayer assemblies through immobilization in a crystalline exoskeleton. Nat Commun 2021; 12:2202. [PMID: 33850135 PMCID: PMC8044103 DOI: 10.1038/s41467-021-22285-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/25/2021] [Indexed: 11/09/2022] Open
Abstract
Artificial native-like lipid bilayer systems constructed from phospholipids assembling into unilamellar liposomes allow the reconstitution of detergent-solubilized transmembrane proteins into supramolecular lipid-protein assemblies called proteoliposomes, which mimic cellular membranes. Stabilization of these complexes remains challenging because of their chemical composition, the hydrophobicity and structural instability of membrane proteins, and the lability of interactions between protein, detergent, and lipids within micelles and lipid bilayers. In this work we demonstrate that metastable lipid, protein-detergent, and protein-lipid supramolecular complexes can be successfully generated and immobilized within zeolitic-imidazole framework (ZIF) to enhance their stability against chemical and physical stressors. Upon immobilization in ZIF bio-composites, blank liposomes, and model transmembrane metal transporters in detergent micelles or embedded in proteoliposomes resist elevated temperatures, exposure to chemical denaturants, aging, and mechanical stresses. Extensive morphological and functional characterization of the assemblies upon exfoliation reveal that all these complexes encapsulated within the framework maintain their native morphology, structure, and activity, which is otherwise lost rapidly without immobilization.
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Affiliation(s)
- Fabian C Herbert
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Sameera S Abeyrathna
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Nisansala S Abeyrathna
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Yalini H Wijesundara
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Olivia R Brohlin
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Francesco Carraro
- Institute of Physical and Theoretical Chemistry, Graz University of Technology, Graz, Austria
| | - Heinz Amenitsch
- Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria
| | - Paolo Falcaro
- Institute of Physical and Theoretical Chemistry, Graz University of Technology, Graz, Austria
| | - Michael A Luzuriaga
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Alejandra Durand-Silva
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Shashini D Diwakara
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Ronald A Smaldone
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Gabriele Meloni
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA.
| | - Jeremiah J Gassensmith
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA.
- Department of Bioengineering, The University of Texas at Dallas, Richardson, TX, USA.
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9
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Gracioso LH, Baltazar MPG, Avanzi IR, Karolski B, Oller Nascimento CA, Perpetuo EA. Analysis of copper response inAcinetobactersp. by comparative proteomics. Metallomics 2019; 11:949-958. [DOI: 10.1039/c8mt00365c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Metal contamination exerts environmental pressure on several lifeforms.
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Affiliation(s)
- Louise Hase Gracioso
- Environmental Research and Education Center
- University of São Paulo, CEPEMA-POLI-USP
- Cubatão-SP
- Brazil
- The Interunits Graduate Program in Biotechnology
| | - Marcela Passos Galluzzi Baltazar
- Environmental Research and Education Center
- University of São Paulo, CEPEMA-POLI-USP
- Cubatão-SP
- Brazil
- Chemical Engineering Department
| | - Ingrid Regina Avanzi
- Environmental Research and Education Center
- University of São Paulo, CEPEMA-POLI-USP
- Cubatão-SP
- Brazil
| | - Bruno Karolski
- Environmental Research and Education Center
- University of São Paulo, CEPEMA-POLI-USP
- Cubatão-SP
- Brazil
- Chemical Engineering Department
| | | | - Elen Aquino Perpetuo
- Environmental Research and Education Center
- University of São Paulo, CEPEMA-POLI-USP
- Cubatão-SP
- Brazil
- Department of Marine Sciences
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10
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Logeman BL, Thiele DJ. Reconstitution of a thermophilic Cu + importer in vitro reveals intrinsic high-affinity slow transport driving accumulation of an essential metal ion. J Biol Chem 2018; 293:15497-15512. [PMID: 30131336 PMCID: PMC6177576 DOI: 10.1074/jbc.ra118.004802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/09/2018] [Indexed: 01/01/2023] Open
Abstract
Acquisition of the trace element copper (Cu) is critical to drive essential eukaryotic processes such as oxidative phosphorylation, iron mobilization, peptide hormone biogenesis, and connective tissue maturation. The Ctr1/Ctr3 family of Cu importers, first discovered in fungi and conserved in mammals, are critical for Cu+ movement across the plasma membrane or mobilization from endosomal compartments. Whereas ablation of Ctr1 in mammals is embryonic lethal, and Ctr1 is critical for dietary Cu absorption, cardiac function, and systemic iron distribution, little is known about the intrinsic contribution of Ctr1 for Cu+ permeation through membranes or its mechanism of action. Here, we identify three members of a Cu+ importer family from the thermophilic fungus Chaetomium thermophilum: Ctr3a and Ctr3b, which function on the plasma membrane, and Ctr2, which likely functions in endosomal Cu mobilization. All three proteins drive Cu and isoelectronic silver (Ag) uptake in cells devoid of Cu+ importers. Transport activity depends on signature amino acid motifs that are conserved and essential for all Ctr1/3 transporters. Ctr3a is stable and amenable to purification and was incorporated into liposomes to reconstitute an in vitro Ag+ transport assay characterized by stopped-flow spectroscopy. Ctr3a has intrinsic high-affinity metal ion transport activity that closely reflects values determined in vivo, with slow turnover kinetics. Given structural models for mammalian Ctr1, Ctr3a likely functions as a low-efficiency Cu+ ion channel. The Ctr1/Ctr3 family may be tuned to import essential yet potentially toxic Cu+ ions at a slow rate to meet cellular needs, while minimizing labile intracellular Cu+ pools.
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Affiliation(s)
| | - Dennis J Thiele
- From the Departments of Pharmacology and Cancer Biology,
- Biochemistry, and
- Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina 27710
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11
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Solioz M. Copper Homeostasis in Gram-Positive Bacteria. SPRINGERBRIEFS IN MOLECULAR SCIENCE 2018. [DOI: 10.1007/978-3-319-94439-5_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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12
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Zhao L, Wei J, Zhang F, He C, Zheng S, Duan C. Redox-active copper triangles as an enzymatic molecular flask for light-driven hydrogen production. RSC Adv 2017. [DOI: 10.1039/c7ra09285g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A redox-active Cu-based triangle was developed to encapsulate fluorescein for photocatalytic hydrogen production. Control experiments and inactive ATP as an inhibitor were performed to confirm this enzymatic photocatalytic behaviour.
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Affiliation(s)
- Liang Zhao
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- P. R. China
| | - Jianwei Wei
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- P. R. China
| | - Feili Zhang
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- P. R. China
| | - Cheng He
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- P. R. China
| | - Sijia Zheng
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- P. R. China
| | - Chunying Duan
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- P. R. China
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