1
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Wang M, Xiong Q, Wang M, Lewis NHC, Ying D, Yan G, Hoenig E, Han Y, Lee OS, Peng G, Zhou H, Schatz GC, Liu C. Lanthanide transport in angstrom-scale MoS 2-based two-dimensional channels. SCIENCE ADVANCES 2024; 10:eadh1330. [PMID: 38489373 PMCID: PMC10942105 DOI: 10.1126/sciadv.adh1330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/09/2024] [Indexed: 03/17/2024]
Abstract
Rare earth elements (REEs), critical to modern industry, are difficult to separate and purify, given their similar physicochemical properties originating from the lanthanide contraction. Here, we systematically study the transport of lanthanide ions (Ln3+) in artificially confined angstrom-scale two-dimensional channels using MoS2-based building blocks in an aqueous environment. The results show that the uptake and permeability of Ln3+ assume a well-defined volcano shape peaked at Sm3+. This transport behavior is rooted from the tradeoff between the barrier for dehydration and the strength of interactions of lanthanide ions in the confinement channels, reminiscent of the Sabatier principle. Molecular dynamics simulations reveal that Sm3+, with moderate hydration free energy and intermediate affinity for channel interaction, exhibit the smallest dehydration degree, consequently resulting in the highest permeability. Our work not only highlights the distinct mass transport properties under extreme confinement but also demonstrates the potential of dialing confinement dimension and chemistry for greener REEs separation.
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Affiliation(s)
- Mingzhan Wang
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Qinsi Xiong
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Maoyu Wang
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Nicholas H. C. Lewis
- Department of Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, University of Chicago, Chicago, IL 60637, USA
| | - Dongchen Ying
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Gangbin Yan
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Eli Hoenig
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Yu Han
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - One-Sun Lee
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Guiming Peng
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Hua Zhou
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - George C. Schatz
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Chong Liu
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
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2
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Larrinaga WB, Cotruvo JA, Worrell BT, Eaton SS, Eaton GR. Electron Paramagnetic Resonance, Electronic Ground State, and Electron Spin Relaxation of Seven Lanthanide Ions Bound to Lanmodulin and the Bioinspired Chelator, 3,4,3-LI(1,2-HOPO). Chemistry 2023; 29:e202303215. [PMID: 37802965 DOI: 10.1002/chem.202303215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/08/2023]
Abstract
The electron paramagnetic resonance (EPR) spectra of lanthanide(III) ions besides Gd3+ , bound to small-molecule and protein chelators, are uncharacterized. Here, the EPR properties of 7 lanthanide(III) ions bound to the natural lanthanide-binding protein, lanmodulin (LanM), and the synthetic small-molecule chelator, 3,4,3-LI(1,2-HOPO) ("HOPO"), were systematically investigated. Echo-detected pulsed EPR spectra reveal intense signals from ions for which the normal continuous-wave first-derivative spectra are negligibly different from zero. Spectra of Kramers lanthanide ions Ce3+ , Nd3+ , Sm3+ , Er3+ , and Yb3+ , and non-Kramers Tb3+ and Tm3+ , bound to LanM are more similar to the ions in dilute aqueous:ethanol solution than to those coordinated with HOPO. Lanmodulins from two bacteria, with distinct metal-binding sites, had similar spectra for Tb3+ but different spectra for Nd3+ . Spin echo dephasing rates (1/Tm ) are faster for lanthanides than for most transition metals and limited detection of echoes to temperatures below ~6 to 12 K. Dephasing rates were environment dependent and decreased in the order water:ethanol>LanM>HOPO, which is attributed to decreasing librational motion. These results demonstrate that the EPR spectra and relaxation times of lanthanide(III) ions are sensitive to coordination environment, motivating wider application of these methods for characterization of both small-molecule and biomolecule interactions with lanthanides.
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Affiliation(s)
- Wyatt B Larrinaga
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States
| | - Joseph A Cotruvo
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States
| | - Brady T Worrell
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, 80208, United States
| | - Sandra S Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, 80208, United States
| | - Gareth R Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, 80208, United States
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3
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Deblonde GJP, Morrison K, Mattocks JA, Cotruvo JA, Zavarin M, Kersting AB. Impact of a Biological Chelator, Lanmodulin, on Minor Actinide Aqueous Speciation and Transport in the Environment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20830-20843. [PMID: 37897703 DOI: 10.1021/acs.est.3c06033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/30/2023]
Abstract
Minor actinides are major contributors to the long-term radiotoxicity of nuclear fuels and other radioactive wastes. In this context, understanding their interactions with natural chelators and minerals is key to evaluating their transport behavior in the environment. The lanmodulin family of metalloproteins is produced by ubiquitous bacteria and Methylorubrum extorquens lanmodulin (LanM) was recently identified as one of nature's most selective chelators for trivalent f-elements. Herein, we investigated the behavior of neptunium, americium, and curium in the presence of LanM, carbonate ions, and common minerals (calcite, montmorillonite, quartz, and kaolinite). We show that LanM's aqueous complexes with Am(III) and Cm(III) remain stable in carbonate-bicarbonate solutions. Furthermore, the sorption of Am(III) to these minerals is strongly impacted by LanM, while Np(V) sorption is not. With calcite, even a submicromolar concentration of LanM leads to a significant reduction in the Am(III) distribution coefficient (Kd, from >104 to ∼102 mL/g at pH 8.5), rendering it even more mobile than Np(V). Thus, LanM-type chelators can potentially increase the mobility of trivalent actinides and lanthanide fission products under environmentally relevant conditions. Monitoring biological chelators, including metalloproteins, and their biogenerators should therefore be considered during the evaluation of radioactive waste repository sites and the risk assessment of contaminated sites.
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Affiliation(s)
- Gauthier J-P Deblonde
- Physical and Life Sciences Directorate, Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Keith Morrison
- Physical and Life Sciences Directorate, Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Joseph A Mattocks
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Joseph A Cotruvo
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mavrik Zavarin
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Annie B Kersting
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
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4
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Martin KE, Mattocks JA, Śmiłowicz D, Aluicio-Sarduy E, Whetter JN, Engle JW, Cotruvo JA, Boros E. Radiolabeling and in vivo evaluation of lanmodulin with biomedically relevant lanthanide isotopes. RSC Chem Biol 2023; 4:414-421. [PMID: 37292057 PMCID: PMC10246553 DOI: 10.1039/d3cb00020f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/04/2023] [Indexed: 06/10/2023] Open
Abstract
Short-lived, radioactive lanthanides comprise an emerging class of radioisotopes attractive for biomedical imaging and therapy applications. To deliver such isotopes to target tissues, they must be appended to entities that target antigens overexpressed on the target cell's surface. However, the thermally sensitive nature of biomolecule-derived targeting vectors requires the incorporation of these isotopes without the use of denaturing temperatures or extreme pH conditions; chelating systems that can capture large radioisotopes under mild conditions are therefore highly desirable. Herein, we demonstrate the successful radiolabeling of the lanthanide-binding protein, lanmodulin (LanM), with medicinally relevant radioisotopes: 177Lu, 132/135La and 89Zr. Radiolabeling of the endogenous metal-binding sites of LanM, as well exogenous labeling of a protein-appended chelator, was successfully conducted at 25 °C and pH 7 with radiochemical yields ranging from 20-82%. The corresponding radiolabeled constructs possess good formulation stability in pH 7 MOPS buffer over 24 hours (>98%) in the presence of 2 equivalents of natLa carrier. In vivo experiments with [177Lu]-LanM, [132/135La]-LanM, and a prostate cancer targeting-vector linked conjugate, [132/135La]-LanM-PSMA, reveal that endogenously labeled constructs produce bone uptake in vivo. Exogenous, chelator-tag mediated radiolabeling to produce [89Zr]-DFO-LanM enables further study of the protein's in vivo behavior, demonstrating low bone and liver uptake, and renal clearance of the protein itself. While these results indicate that additional stabilization of LanM is required, this study establishes precedence for the radiochemical labeling of LanM with medically relevant lanthanide radioisotopes.
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Affiliation(s)
- Kirsten E Martin
- Department of Chemistry, Stony Brook University, Stony Brook New York 11794 USA
| | - Joseph A Mattocks
- Department of Chemistry, The Pennsylvania State University, University Park Pennsylvania 16802 USA
| | - Dariusz Śmiłowicz
- Department of Chemistry, Stony Brook University, Stony Brook New York 11794 USA
| | - Eduardo Aluicio-Sarduy
- Department of Medical Physics, University of Wisconsin Madison Wisconsin 53705 USA
- Department of Radiology, University of Wisconsin Madison Wisconsin 53705 USA
| | - Jennifer N Whetter
- Department of Chemistry, Stony Brook University, Stony Brook New York 11794 USA
| | - Jonathan W Engle
- Department of Medical Physics, University of Wisconsin Madison Wisconsin 53705 USA
- Department of Radiology, University of Wisconsin Madison Wisconsin 53705 USA
| | - Joseph A Cotruvo
- Department of Chemistry, The Pennsylvania State University, University Park Pennsylvania 16802 USA
| | - Eszter Boros
- Department of Chemistry, Stony Brook University, Stony Brook New York 11794 USA
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5
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Mattocks JA, Jung JJ, Lin CY, Dong Z, Yennawar NH, Featherston ER, Kang-Yun CS, Hamilton TA, Park DM, Boal AK, Cotruvo JA. Enhanced rare-earth separation with a metal-sensitive lanmodulin dimer. Nature 2023; 618:87-93. [PMID: 37259003 PMCID: PMC10232371 DOI: 10.1038/s41586-023-05945-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/13/2023] [Indexed: 06/02/2023]
Abstract
Technologically critical rare-earth elements are notoriously difficult to separate, owing to their subtle differences in ionic radius and coordination number1-3. The natural lanthanide-binding protein lanmodulin (LanM)4,5 is a sustainable alternative to conventional solvent-extraction-based separation6. Here we characterize a new LanM, from Hansschlegelia quercus (Hans-LanM), with an oligomeric state sensitive to rare-earth ionic radius, the lanthanum(III)-induced dimer being >100-fold tighter than the dysprosium(III)-induced dimer. X-ray crystal structures illustrate how picometre-scale differences in radius between lanthanum(III) and dysprosium(III) are propagated to Hans-LanM's quaternary structure through a carboxylate shift that rearranges a second-sphere hydrogen-bonding network. Comparison to the prototypal LanM from Methylorubrum extorquens reveals distinct metal coordination strategies, rationalizing Hans-LanM's greater selectivity within the rare-earth elements. Finally, structure-guided mutagenesis of a key residue at the Hans-LanM dimer interface modulates dimerization in solution and enables single-stage, column-based separation of a neodymium(III)/dysprosium(III) mixture to >98% individual element purities. This work showcases the natural diversity of selective lanthanide recognition motifs, and it reveals rare-earth-sensitive dimerization as a biological principle by which to tune the performance of biomolecule-based separation processes.
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Affiliation(s)
- Joseph A Mattocks
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Jonathan J Jung
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Chi-Yun Lin
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Ziye Dong
- Critical Materials Institute, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Neela H Yennawar
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Emily R Featherston
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Christina S Kang-Yun
- Critical Materials Institute, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Timothy A Hamilton
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Dan M Park
- Critical Materials Institute, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
| | - Amie K Boal
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA.
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA.
| | - Joseph A Cotruvo
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA.
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6
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Prejanò M, Toscano M, Marino T. Periodicity of the Affinity of Lanmodulin for Trivalent Lanthanides and Actinides: Structural and Electronic Insights from Quantum Chemical Calculations. Inorg Chem 2023; 62:7461-7470. [PMID: 37128767 DOI: 10.1021/acs.inorgchem.3c00754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Lanmodulin (LanM) is the first identified macrochelator that has naturally evolved to sequester ions of rare earth elements (REEs) such as Y and all lanthanides, reversibly. This natural protein showed a 106 times better affinity for lanthanide cations than for Ca, which is a naturally abundant and biologically relevant element. Recent experiments have shown that its metal ion binding activity can be further extended to some actinides, like Np, Pu, and Am. For this reason, it was thought that LanM could be adopted for the separation of REE ions and actinides, thus increasing the interest in its potential use for industry-oriented applications. In this work, a systematic study of the affinity of LanM for lanthanides and actinides has been carried out, taking into account all trivalent ions belonging to the 4f (from La to Lu) and 5f (from Ac to Lr) series, starting from their chemistry in solution. On the basis of a recently published nuclear magnetic resonance structure, a model of the LanM-binding site was built and a detailed structural and electronic description of initial aquo- and LanM-metal ion complexes was provided. The obtained binding energies are in agreement with the available experimental data. A possible reason that could explain the origin of the affinity of LanM for these metal ions is also discussed.
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Affiliation(s)
- Mario Prejanò
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Via P. Bucci, 87036 Rende, Italy
| | - Marirosa Toscano
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Via P. Bucci, 87036 Rende, Italy
| | - Tiziana Marino
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Via P. Bucci, 87036 Rende, Italy
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7
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Hemmann JL, Keller P, Hemmerle L, Vonderach T, Ochsner AM, Bortfeld-Miller M, Günther D, Vorholt JA. Lanpepsy is a novel lanthanide-binding protein involved in the lanthanide response of the obligate methylotroph Methylobacillus flagellatus. J Biol Chem 2023; 299:102940. [PMID: 36702252 PMCID: PMC9988556 DOI: 10.1016/j.jbc.2023.102940] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/24/2023] Open
Abstract
Lanthanides were recently discovered as metals required in the active site of certain methanol dehydrogenases. Since then, the characterization of the lanthanome, that is, proteins involved in sensing, uptake, and utilization of lanthanides, has become an active field of research. Initial exploration of the response to lanthanides in methylotrophs has revealed that the lanthanome is not conserved and that multiple mechanisms for lanthanide utilization must exist. Here, we investigated the lanthanome in the obligate model methylotroph Methylobacillus flagellatus. We used a proteomic approach to analyze differentially regulated proteins in the presence of lanthanum. While multiple known proteins showed induction upon growth in the presence of lanthanum (Xox proteins, TonB-dependent receptor), we also identified several novel proteins not previously associated with lanthanide utilization. Among these was Mfla_0908, a periplasmic 19 kDa protein without functional annotation. The protein comprises two characteristic PepSY domains, which is why we termed the protein lanpepsy (LanP). Based on bioinformatic analysis, we speculated that LanP could be involved in lanthanide binding. Using dye competition assays, quantification of protein-bound lanthanides by inductively coupled plasma mass spectrometry, as well as isothermal titration calorimetry, we demonstrated the presence of multiple lanthanide binding sites that showed selectivity over the chemically similar calcium ion. LanP thus represents the first member of the PepSY family that binds lanthanides. Although the physiological role of LanP is still unclear, its identification is of interest for applications toward the sustainable purification and separation of rare-earth elements.
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Affiliation(s)
- Jethro L Hemmann
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland.
| | - Philipp Keller
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Lucas Hemmerle
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Thomas Vonderach
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Andrea M Ochsner
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | | | - Detlef Günther
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Julia A Vorholt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland.
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8
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Daumann LJ, Pol A, Op den Camp HJM, Martinez-Gomez NC. A perspective on the role of lanthanides in biology: Discovery, open questions and possible applications. Adv Microb Physiol 2022; 81:1-24. [PMID: 36167440 DOI: 10.1016/bs.ampbs.2022.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Because of their use in high technologies like computers, smartphones and renewable energy applications, lanthanides (belonging to the group of rare earth elements) are essential for our daily lives. A range of applications in medicine and biochemical research made use of their photo-physical properties. The discovery of a biological role for lanthanides has boosted research in this new field. Several methanotrophs and methylotrophs are strictly dependent on the presence of lanthanides in the growth medium while others show a regulatory response. After the first demonstration of a lanthanide in the active site of the XoxF-type pyrroloquinoline quinone methanol dehydrogenases, follow-up studies showed the same for other pyrroloquinoline quinone-containing enzymes. In addition, research focused on the effect of lanthanides on regulation of gene expression and uptake mechanism into bacterial cells. This review briefly describes the discovery of the role of lanthanides in biology and focuses on open questions in biological lanthanide research and possible application of lanthanide-containing bacteria and enzymes in recovery of these special elements.
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Affiliation(s)
- Lena J Daumann
- Department of Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Arjan Pol
- Department of Microbiology, RIBES, Radboud University, Nijmegen, The Netherlands
| | - Huub J M Op den Camp
- Department of Microbiology, RIBES, Radboud University, Nijmegen, The Netherlands.
| | - N Cecilia Martinez-Gomez
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States
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9
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Mandal P, Kretzschmar J, Drobot B. Not just a background: pH buffers do interact with lanthanide ions-a Europium(III) case study. J Biol Inorg Chem 2022; 27:249-260. [PMID: 35150337 PMCID: PMC8907096 DOI: 10.1007/s00775-022-01930-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/14/2022] [Indexed: 12/23/2022]
Abstract
The interaction between Eu(III) ion and different pH buffers, popular in biology and biochemistry, viz. HEPES, PIPES, MES, MOPS, and TRIS, has been studied by solution nuclear magnetic resonance spectroscopy (NMR) and time-resolved laser-induced fluorescence spectroscopy (TRLFS) techniques. The Good’s buffers reveal non-negligible interaction with Eu(III) as determined from their complex stability constants, where the sites of interaction are the morpholine and piperazine nitrogen atoms, respectively. In contrast, TRIS buffer shows practically no affinity towards Eu(III). Therefore, when investigating lanthanides, TRIS buffer should be preferred over Good’s buffers.
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Affiliation(s)
- Poulami Mandal
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Jerome Kretzschmar
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Björn Drobot
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328, Dresden, Germany.
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10
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Improved Recovery and Selectivity of Lanthanide-Ion-Binding Cyclic Peptide Hosts by Changing the Position of Acidic Amino Acids. MINERALS 2022. [DOI: 10.3390/min12020148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The development of an effective host molecule to separate lanthanide (Ln) ions and a method for predicting its guest recognition/self-assembly behavior based on primary chemical structures are highly sought after in both academia and industry. Herein, we report the improvement of one-pot Ln ion recovery and a performance prediction method for four new cyclic peptide hosts that differ in the position of acidic amino acids. These cyclic peptide hosts could recognize Ln3+ directly through a 1:1 complexation–precipitation process and exhibited high Lu3+ selectivity in spite of similar ion size and electronegativity when the positions of the acidic amino acids were changed. This unpredictable selectivity was explained by considering the dipole moment, lowest unoccupied molecular orbital, and cohesion energy. In addition, a semi-empirical function using these parameters was proposed for screening the sequence and estimating the isolated yields without long-time molecular dynamics calculations. The insights obtained from this study can be employed for the development of high-performance peptides for the selective recovery of Ln and other metal ions, as well as for the construction of diverse supramolecular recognition systems.
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11
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Mattocks JA, Cotruvo JA, Deblonde GJP. Engineering lanmodulin's selectivity for actinides over lanthanides by controlling solvent coordination and second-sphere interactions. Chem Sci 2022; 13:6054-6066. [PMID: 35685815 PMCID: PMC9132084 DOI: 10.1039/d2sc01261h] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 04/25/2022] [Indexed: 11/21/2022] Open
Abstract
Developing chelators that combine high affinity and selectivity for lanthanides and/or actinides is paramount for numerous industries, including rare earths mining, nuclear waste management, and cancer medicine. In particular, achieving selectivity between actinides and lanthanides is notoriously difficult. The protein lanmodulin (LanM) is one of Nature's most selective chelators for trivalent actinides and lanthanides. However, mechanistic understanding of LanM's affinity and selectivity for f-elements remains limited. In order to decipher, and possibly improve, the features of LanM's metal-binding sites that contribute to this actinide/lanthanide selectivity, we characterized five LanM variants, substituting the aspartate residue at the 9th position of each metal-binding site with asparagine, histidine, alanine, methionine, and selenomethionine. Spectroscopic measurements with lanthanides (Nd3+ and Eu3+) and actinides (243Am3+ and 248Cm3+) reveal that, contrary to the behavior of small chelator complexes, metal-coordinated water molecules enhance LanM's affinity for f-elements and pH-stability of its complexes. Furthermore, the results show that the native aspartate does not coordinate the metal directly but rather hydrogen bonds to coordinated solvent. By tuning this first-sphere/second-sphere interaction, the asparagine variant nearly doubles LanM's selectivity for actinides versus lanthanides. This study not only clarifies the essential role of coordinated solvent for LanM's physiological function and separation applications, but it also demonstrates that LanM's preference for actinides over lanthanides can be further improved. More broadly, it demonstrates how biomolecular scaffolds possess an expanded repertoire of tunable interactions compared to most small-molecule ligands – providing an avenue for high-performance LanM-based actinide/lanthanide separation methods and bio-engineered chelators optimized for specific medical isotopes. Nature’s most potent protein for f-elements, lanmodulin, relies on subtle first-sphere/second-sphere interactions to bind metal ions. Dissecting lanmodulin’s binding mechanism yielded variants with enhanced actinide/lanthanide selectivity.![]()
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Affiliation(s)
- Joseph A. Mattocks
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Joseph A. Cotruvo
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Gauthier J.-P. Deblonde
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
- Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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12
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Gutenthaler SM, Tsushima S, Steudtner R, Gailer M, Hoffmann-Röder A, Drobot B, Daumann LJ. Lanmodulin peptides – unravelling the binding of the EF-Hand loop sequences stripped from the structural corset. Inorg Chem Front 2022; 9:4009-4021. [PMID: 36091973 PMCID: PMC9362731 DOI: 10.1039/d2qi00933a] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 05/23/2022] [Indexed: 12/25/2022]
Abstract
Lanmodulin (LanM), a naturally lanthanide (Ln)-binding protein with a remarkable selectivity for Lns over Ca(ii) and affinities in the picomolar range, is an attractive target to address challenges in Ln separation. Why LanM has such a high selectivity is currently not entirely understood; both specific amino acid sequences of the EF-Hand loops and cooperativity effects have been suggested. Here, we removed the effect of cooperativity and synthesised all four 12-amino acid EF-Hand loop peptides, and investigated their affinity for two Lns (Eu(iii) and Tb(iii)), the actinide Cm(iii) and Ca(ii). Using isothermal titration calorimetry and time-resolved laser fluorescence spectroscopy (TRLFS) combined with parallel factor analysis, we show that the four short peptides behave very similarly, having affinities in the micromolar range for Eu(iii) and Tb(iii). Ca(ii) was shown not to bind to the peptides, which was verified with circular dichroism spectroscopy. This technique also revealed an increase in structural organisation upon Eu(iii) addition, which was supported by molecular dynamics simulations. Lastly, we put Eu(iii) and Cm(iii) in direct competition using TRLFS. Remarkably, a slightly higher affinity for Cm(iii) was found. Our results demonstrate that the picomolar affinities in LanM are largely an effect of pre-structuring and therefore a reduction of flexibility in combination with cooperative effects, and that all EF-Hand loops possess similar affinities when detached from the protein backbone, albeit still retaining the high selectivity for lanthanides and actinides over calcium. Taking a closer look at Lanmodulin’s remarkable selectivity for lanthanides (Ln) over Ca(ii) and high Ln/actinide affinities on the amino acid level by investigating the four binding-loops as peptides with Ca(ii), Eu(iii), Tb(iii) and Cm(iii).![]()
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Affiliation(s)
- Sophie M. Gutenthaler
- Department of Chemistry Ludwig-Maximilians-University Munich Butenandtstraße 5-13, 81377 München, Germany
| | - Satoru Tsushima
- Institute of Resource Ecology Helmholtz-Zentrum Dresden-Rossendorf e.V. Bautzner Landstraße 400, 01328 Dresden, Germany
- International Research Frontiers Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Meguro 152-8550, Tokyo, Japan
| | - Robin Steudtner
- Institute of Resource Ecology Helmholtz-Zentrum Dresden-Rossendorf e.V. Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Manuel Gailer
- Department of Chemistry Ludwig-Maximilians-University Munich Butenandtstraße 5-13, 81377 München, Germany
| | - Anja Hoffmann-Röder
- Department of Chemistry Ludwig-Maximilians-University Munich Butenandtstraße 5-13, 81377 München, Germany
| | - Björn Drobot
- Institute of Resource Ecology Helmholtz-Zentrum Dresden-Rossendorf e.V. Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Lena J. Daumann
- Department of Chemistry Ludwig-Maximilians-University Munich Butenandtstraße 5-13, 81377 München, Germany
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