1
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Osterberg MK, Smith AK, Campbell C, Deredge DJ, Stemmler TL, Giedroc DP. Coupling of zinc and GTP binding drives G-domain folding in Acinetobacter baumannii ZigA. Biophys J 2024; 123:979-991. [PMID: 38459695 PMCID: PMC11052692 DOI: 10.1016/j.bpj.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/22/2024] [Accepted: 03/05/2024] [Indexed: 03/10/2024] Open
Abstract
COG0523 proteins, also known as nucleotide-dependent metallochaperones, are a poorly understood class of small P-loop G3E GTPases. Multiple family members play critical roles in bacterial pathogen survival during an infection as part of the adaptive response to host-mediated "nutritional immunity." Our understanding of the structure, dynamics, and molecular-level function of COG0523 proteins, apart from the eukaryotic homolog, Zng1, remains in its infancy. Here, we use X-ray absorption spectroscopy to establish that Acinetobacter baumannii (Ab) ZigA coordinates ZnII using all three cysteines derived from the invariant CXCC motif to form an S3(N/O) coordination complex, a feature inconsistent with the ZnII-bound crystal structure of a distantly related COG0523 protein of unknown function from Escherichia coli, EcYjiA. The binding of ZnII and guanine nucleotides is thermodynamically linked in AbZigA, and this linkage is more favorable for the substrate GTP relative to the product GDP. Part of this coupling originates with nucleotide-induced stabilization of the G-domain tertiary structure as revealed by global thermodynamics measurements and hydrogen-deuterium exchange mass spectrometry (HDX-MS). HDX-MS also reveals that the HDX behavior of the G2 (switch 1) loop is highly sensitive to nucleotide status and becomes more exchange labile in the GDP (product)-bound state. Significant long-range perturbation of local stability in both the G-domain and the C-terminal domain define a candidate binding pocket for a client protein that appears sensitive to nucleotide status (GDP versus GTP). We place these new insights into the structure, dynamics, and energetics of intermolecular metal transfer into the context of a model for AbZigA metallochaperone function.
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Affiliation(s)
| | - Ally K Smith
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland
| | - Courtney Campbell
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan
| | - Daniel J Deredge
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana.
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2
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Kim M, Le MT, Fan L, Campbell C, Sen S, Capdevila DA, Stemmler TL, Giedroc DP. Characterization of the Zinc Uptake Repressor (Zur) from Acinetobacter baumannii. Biochemistry 2024; 63:660-670. [PMID: 38385972 PMCID: PMC11019503 DOI: 10.1021/acs.biochem.3c00679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Bacterial cells tightly regulate the intracellular concentrations of essential transition metal ions by deploying a panel of metal-regulated transcriptional repressors and activators that bind to operator-promoter regions upstream of regulated genes. Like other zinc uptake regulator (Zur) proteins, Acinetobacter baumannii Zur represses transcription of its regulon when ZnII is replete and binds more weakly to DNA when ZnII is limiting. Previous studies established that Zur proteins are homodimeric and harbor at least two metal sites per protomer or four per dimer. CdII X-ray absorption spectroscopy (XAS) of the Cd2Zn2 AbZur metalloderivative with CdII bound to the allosteric sites reveals a S(N/O)3 first coordination shell. Site-directed mutagenesis suggests that H89 and C100 from the N-terminal DNA binding domain and H107 and E122 from the C-terminal dimerization domain comprise the regulatory metal site. KZn for this allosteric site is 6.0 (±2.2) × 1012 M-1 with a functional "division of labor" among the four metal ligands. N-terminal domain ligands H89 and C100 contribute far more to KZn than H107 and E122, while C100S AbZur uniquely fails to bind to DNA tightly as measured by an in vitro transcription assay. The heterotropic allosteric coupling free energy, ΔGc, is negative, consistent with a higher KZn for the AbZur-DNA complex and defining a bioavailable ZnII set-point of ≈6 × 10-14 M. Small-angle X-ray scattering (SAXS) experiments reveal that only the wild-type Zn homodimer undergoes allosteric switching, while the C100S AbZur fails to switch. These data collectively suggest that switching to a high affinity DNA-binding conformation involves a rotation/translation of one protomer relative to the other in a way that is dependent on the integrity of C100. We place these findings in the context of other Zur proteins and Fur family repressors more broadly.
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Affiliation(s)
- Minyong Kim
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - My Tra Le
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Lixin Fan
- Basic Science Program, Frederick National Laboratory for Cancer Research, SAXS Core Facility of the National Cancer Institute, Frederick, Maryland 21702, United States
| | - Courtney Campbell
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201-2417, United States
| | - Sambuddha Sen
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Daiana A Capdevila
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), C1405 BWE Buenos Aires, Argentina
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201-2417, United States
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, United States
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3
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Prasad P, Hunt LA, Pall AE, Ranasinghe M, Williams AE, Stemmler TL, Demeler B, Hammer NI, Chakraborty S. Photocatalytic Hydrogen Evolution by a De Novo Designed Metalloprotein that Undergoes Ni-Mediated Oligomerization Shift. Chemistry 2023; 29:e202202902. [PMID: 36440875 PMCID: PMC10308963 DOI: 10.1002/chem.202202902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 11/29/2022]
Abstract
De novo metalloprotein design involves the construction of proteins guided by specific repeat patterns of polar and apolar residues, which, upon self-assembly, provide a suitable environment to bind metals and produce artificial metalloenzymes. While a wide range of functionalities have been realized in de novo designed metalloproteins, the functional repertoire of such constructs towards alternative energy-relevant catalysis is currently limited. Here we show the application of de novo approach to design a functional H2 evolving protein. The design involved the assembly of an amphiphilic peptide featuring cysteines at tandem a/d sites of each helix. Intriguingly, upon NiII addition, the oligomers shift from a major trimeric assembly to a mix of dimers and trimers. The metalloprotein produced H2 photocatalytically with a bell-shape pH dependence, having a maximum activity at pH 5.5. Transient absorption spectroscopy is used to determine the timescales of electron transfer as a function of pH. Selective outer sphere mutations are made to probe how the local environment tunes activity. A preferential enhancement of activity is observed via steric modulation above the NiII site, towards the N-termini, compared to below the NiII site towards the C-termini.
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Affiliation(s)
- Pallavi Prasad
- Department of Chemistry and Biochemistry, The University of Mississippi, University, MS, 38677 (USA)
| | - Leigh Anna Hunt
- Department of Chemistry and Biochemistry, The University of Mississippi, University, MS, 38677 (USA)
| | - Ashley E. Pall
- Department of Pharmaceutical Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI, 48201-2417 (USA)
| | - Maduni Ranasinghe
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401,University Dr W, Lethbridge, AB T1K 6T5 (CA)
| | - Ashley E. Williams
- Department of Chemistry and Biochemistry, The University of Mississippi, University, MS, 38677 (USA)
| | - Timothy L. Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI, 48201-2417 (USA)
| | - Borries Demeler
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401,University Dr W, Lethbridge, AB T1K 6T5 (CA)
| | - Nathan I. Hammer
- Department of Chemistry and Biochemistry, The University of Mississippi, University, MS, 38677 (USA)
| | - Saumen Chakraborty
- Department of Chemistry and Biochemistry, The University of Mississippi, University, MS, 38677 (USA)
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4
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Stoltzfus AT, Campbell CJ, Worth MM, Hom K, Stemmler TL, Michel SLJ. Pb(II) coordination to the nonclassical zinc finger tristetraprolin: retained function with an altered fold. J Biol Inorg Chem 2023; 28:85-100. [PMID: 36478265 DOI: 10.1007/s00775-022-01980-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/26/2022] [Indexed: 12/13/2022]
Abstract
Tristetraprolin (TTP) is a nonclassical CCCH zinc finger (ZF) that plays a crucial role in regulating inflammation. TTP regulates cytokine mRNAs by specific binding of its two conserved ZF domains (CysX8CysX5CysX3His) to adenylate-uridylate-rich sequences (AREs) at the 3'-untranslated region, leading to degradation of the RNA. Dysregulation of TTP in animal models has demonstrated several cytokine-related syndromes, including chronic inflammation and autoimmune disorders. Exposure to Pb(II), a prevalent environmental toxin, is known to contribute to similar pathologies, in part by disruption of and/or competition with cysteine-rich metalloproteins. TTP's role during stress as a ubiquitous translational regulator of cell signaling (and dysfunction), which may underpin various phenotypes of Pb(II) toxicity, highlights the importance of understanding the interaction between TTP and Pb(II). The impact of Pb(II) binding on TTP's fold and RNA-binding function was analyzed via UV-Vis spectroscopy, circular dichroism, X-ray absorption spectroscopy, nuclear magnetic resonance spectroscopy, and fluorescence anisotropy. A construct containing the two ZF domains of TTP (TTP-2D) bound to Pb(II) with nanomolar affinity and exhibited a different geometry and fold in comparison to Zn2-TTP-2D. Despite the altered secondary structure, Pb(II)-substituted TTP-2D bound a canonical ARE sequence more selectively than Zn2-TTP-2D. Taken together, these data suggest that Pb(II) may interfere with proper TTP regulation and hinder the cell's ability to respond to inflammation.
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Affiliation(s)
- Andrew T Stoltzfus
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, 21201, USA
| | - Courtney J Campbell
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA
| | - Madison M Worth
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, 21201, USA
| | - Kellie Hom
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, 21201, USA
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA
| | - Sarah L J Michel
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, 21201, USA.
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5
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Rodrigues AV, Batelu S, Hinton TV, Rotondo J, Thompson L, Brunzelle JS, Stemmler TL. Drosophila melanogaster frataxin: protein crystal and predicted solution structure with identification of the iron-binding regions. Acta Crystallogr D Struct Biol 2023; 79:22-30. [PMID: 36601804 PMCID: PMC9815096 DOI: 10.1107/s2059798322011639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 12/03/2022] [Indexed: 12/24/2022] Open
Abstract
Friedreich's ataxia (FRDA) is a hereditary cardiodegenerative and neurodegenerative disease that affects 1 in 50 000 Americans. FRDA arises from either a cellular inability to produce sufficient quantities or the production of a nonfunctional form of the protein frataxin, a key molecule associated with mitochondrial iron-sulfur cluster biosynthesis. Within the mitochondrial iron-sulfur cluster (ISC) assembly pathway, frataxin serves as an allosteric regulator for cysteine desulfurase, the enzyme that provides sulfur for [2Fe-2S] cluster assembly. Frataxin is a known iron-binding protein and is also linked to the delivery of ferrous ions to the scaffold protein, the ISC molecule responsible for the direct assembly of [2Fe-2S] clusters. The goal of this report is to provide structural details of the Drosophila melanogaster frataxin ortholog (Dfh), using both X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy, in order to provide the foundational insight needed to understand the structure-function correlation of the protein. Additionally, NMR iron(II) titrations were used to provide metal contacts on the protein to better understand how it binds iron and aids its delivery to the ISC scaffold protein. Here, the structural and functional similarities of Dfh to its orthologs are also outlined. Structural data show that bacterial, yeast, human and Drosophila frataxins are structurally similar, apart from a structured C-terminus in Dfh that is likely to aid in protein stability. The iron-binding location on helix 1 and strand 1 of Dfh is also conserved across orthologs.
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Affiliation(s)
- Andria V Rodrigues
- Department of Biochemistry and Molecular Biology, Wayne State University, Detroit, Michigan, USA
| | - Sharon Batelu
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA
| | - Tiara V Hinton
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA
| | - John Rotondo
- Department of Biochemistry and Molecular Biology, Wayne State University, Detroit, Michigan, USA
| | - Lindsey Thompson
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA
| | - Joseph S Brunzelle
- Northwestern Synchrotron Research Centers, Life Science Collaborative Access Team, Northwestern University, Evanston, Illinois, USA
| | - Timothy L Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University, Detroit, Michigan, USA
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6
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Hinton TV, Batelu S, Gleason N, Stemmler TL. Molecular characteristics of proteins within the mitochondrial Fe-S cluster assembly complex. Micron 2021; 153:103181. [PMID: 34823116 DOI: 10.1016/j.micron.2021.103181] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 11/29/2022]
Abstract
Iron-Sulfur (Fe-S) clusters are essential for life, as they are widely utilized in nearly every biochemical pathway. When bound to proteins, Fe-S clusters assist in catalysis, signal recognition, and energy transfer events, as well as additional cellular pathways including cellular respiration and DNA repair and replication. In Eukaryotes, Fe-S clusters are produced through coordinated activity by mitochondrial Iron-Sulfur Cluster (ISC) assembly pathway proteins through direct assembly, or through the production of the activated sulfur substrate used by the Cytosolic Iron-Sulfur Cluster Assembly (CIA) pathway. In the mitochondria, Fe-S cluster assembly is accomplished through the coordinated activity of the ISC pathway protein complex composed of a cysteine desulfurase, a scaffold protein, the accessory ISD11 protein, the acyl carrier protein, frataxin, and a ferredoxin; downstream events that accomplish Fe-S cluster transfer and delivery are driven by additional chaperone/delivery proteins that interact with the ISC assembly complex. Deficiency in human production or activity of Fe-S cluster containing proteins is often detrimental to cell and organism viability. Here we summarize what is known about the structure and functional activities of the proteins involved in the early steps of assembling [2Fe-2S] clusters before they are transferred to proteins devoted to their delivery. Our goal is to provide a comprehensive overview of how the ISC assembly apparatus proteins interact to make the Fe-S cluster which can be delivered to proteins downstream to the assembly event.
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Affiliation(s)
- Tiara V Hinton
- Department of Pharmaceutical Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, USA.
| | - Sharon Batelu
- Department of Pharmaceutical Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, USA.
| | - Noah Gleason
- Department of Pharmaceutical Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, USA.
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, USA.
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7
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Campbell CJ, Pall AE, Naik AR, Thompson LN, Stemmler TL. Molecular Details of the Frataxin-Scaffold Interaction during Mitochondrial Fe-S Cluster Assembly. Int J Mol Sci 2021; 22:6006. [PMID: 34199378 PMCID: PMC8199681 DOI: 10.3390/ijms22116006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 12/23/2022] Open
Abstract
Iron-sulfur clusters are essential to almost every life form and utilized for their unique structural and redox-targeted activities within cells during many cellular pathways. Although there are three different Fe-S cluster assembly pathways in prokaryotes (the NIF, SUF and ISC pathways) and two in eukaryotes (CIA and ISC pathways), the iron-sulfur cluster (ISC) pathway serves as the central mechanism for providing 2Fe-2S clusters, directly and indirectly, throughout the entire cell in eukaryotes. Proteins central to the eukaryotic ISC cluster assembly complex include the cysteine desulfurase, a cysteine desulfurase accessory protein, the acyl carrier protein, the scaffold protein and frataxin (in humans, NFS1, ISD11, ACP, ISCU and FXN, respectively). Recent molecular details of this complex (labeled NIAUF from the first letter from each ISC protein outlined earlier), which exists as a dimeric pentamer, have provided real structural insight into how these partner proteins arrange themselves around the cysteine desulfurase, the core dimer of the (NIAUF)2 complex. In this review, we focus on both frataxin and the scaffold within the human, fly and yeast model systems to provide a better understanding of the biophysical characteristics of each protein alone and within the FXN/ISCU complex as it exists within the larger NIAUF construct. These details support a complex dynamic interaction between the FXN and ISCU proteins when both are part of the NIAUF complex and this provides additional insight into the coordinated mechanism of Fe-S cluster assembly.
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Affiliation(s)
| | | | | | | | - Timothy L. Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA; (C.J.C.); (A.E.P.); (A.R.N.); (L.N.T.)
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8
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Brandis JEP, Kihn KC, Taraban MB, Schnorr J, Confer AM, Batelu S, Sun D, Rodriguez JD, Jiang W, Goldberg DP, Langguth P, Stemmler TL, Yu YB, Kane MA, Polli JE, Michel SLJ. Evaluation of the Physicochemical Properties of the Iron Nanoparticle Drug Products: Brand and Generic Sodium Ferric Gluconate. Mol Pharm 2021; 18:1544-1557. [PMID: 33621099 DOI: 10.1021/acs.molpharmaceut.0c00922] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Complex iron nanoparticle-based drugs are one of the oldest and most frequently administered classes of nanomedicines. In the US, there are seven FDA-approved iron nanoparticle reference drug products, of which one also has an approved generic drug product (i.e., sodium ferric gluconate (SFG)). These products are indicated for the treatment of iron deficiency anemia and are administered intravenously. On the molecular level, iron nanomedicines are colloids composed of an iron oxide core with a carbohydrate coating. This formulation makes nanomedicines more complex than conventional small molecule drugs. As such, these products are often referred to as nonbiological complex drugs (e.g., by the nonbiological complex drugs (NBCD) working group) or complex drug products (e.g., by the FDA). Herein, we report a comprehensive study of the physiochemical properties of the iron nanoparticle product SFG. SFG is the single drug for which both an innovator (Ferrlecit) and generic product are available in the US, allowing for comparative studies to be performed. Measurements focused on the iron core of SFG included optical spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), X-ray powder diffraction (XRPD), 57Fe Mössbauer spectroscopy, and X-ray absorbance spectroscopy (XAS). The analysis revealed similar ferric-iron-oxide structures. Measurements focused on the carbohydrate shell comprised of the gluconate ligands included forced acid degradation, dynamic light scattering (DLS), analytical ultracentrifugation (AUC), and gel permeation chromatography (GPC). Such analysis revealed differences in composition for the innovator versus the generic SFG. These studies have the potential to contribute to future quality assessment of iron complex products and will inform on a pharmacokinetic study of two therapeutically equivalent iron gluconate products.
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Affiliation(s)
- Joel E P Brandis
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Kyle C Kihn
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Marc B Taraban
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Julia Schnorr
- Department of Pharmaceutical Technology and Biopharmaceutics, Johannes Gutenberg University Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | - Alex M Confer
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Sharon Batelu
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | - Dajun Sun
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Jason D Rodriguez
- Division of Pharmaceutical Analysis, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, St. Louis, MO 20903, United States
| | - Wenlei Jiang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Peter Langguth
- Department of Pharmaceutical Technology and Biopharmaceutics, Johannes Gutenberg University Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | - Yihua Bruce Yu
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Maureen A Kane
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - James E Polli
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Sarah L J Michel
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
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9
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Pritts JD, Hursey MS, Michalek JL, Batelu S, Stemmler TL, Michel SLJ. Unraveling the RNA Binding Properties of the Iron-Sulfur Zinc Finger Protein CPSF30. Biochemistry 2020; 59:970-982. [PMID: 32027124 DOI: 10.1021/acs.biochem.9b01065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cleavage and polyadenylation specificity factor 30 (CPSF30) is a "zinc finger" protein that plays a crucial role in the transition of pre-mRNA to RNA. CPSF30 contains five conserved CCCH domains and a CCHC "zinc knuckle" domain. CPSF30 activity is critical for pre-mRNA processing. A truncated form of the protein, in which only the CCCH domains are present, has been shown to specifically bind AU-rich pre-mRNA targets; however, the RNA binding and recognition properties of full-length CPSF30 are not known. Herein, we report the isolation and biochemical characterization of full-length CPSF30. We report that CPSF30 contains one 2Fe-2S cluster in addition to five zinc ions, as measured by inductively coupled plasma mass spectrometry, ultraviolet-visible spectroscopy, and X-ray absorption spectroscopy. Utilizing fluorescence anisotropy RNA binding assays, we show that full-length CPSF30 has high binding affinity for two types of pre-mRNA targets, AAUAAA and polyU, both of which are conserved sequence motifs present in the majority of pre-mRNAs. Binding to the AAUAAA motif requires that the five CCCH domains of CPSF30 be present, whereas binding to polyU sequences requires the entire, full-length CPSF30. These findings implicate the CCHC "zinc knuckle" present in the full-length protein as being critical for mediating polyU binding. We also report that truncated forms of the protein, containing either just two CCCH domains (ZF2 and ZF3) or the CCHC "zinc knuckle" domain, do not exhibit any RNA binding, indicating that CPSF30/RNA binding requires several ZF (and/or Fe-S cluster) domains working in concert to mediate RNA recognition.
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Affiliation(s)
- Jordan D Pritts
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, United States
| | - Matthew S Hursey
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, United States
| | - Jamie L Michalek
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, United States
| | - Sharon Batelu
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | - Sarah L J Michel
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, United States
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10
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Ok K, Li W, Neu HM, Batelu S, Stemmler TL, Kane MA, Michel SLJ. Frontispiece: Role of Gold in Inflammation and Tristetraprolin Activity. Chemistry 2020. [DOI: 10.1002/chem.202080763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kiwon Ok
- Department of Pharmaceutical SciencesUniversity of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
| | - Wenjing Li
- Department of Pharmaceutical SciencesUniversity of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
| | - Heather M. Neu
- Department of Pharmaceutical SciencesUniversity of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
| | - Sharon Batelu
- Department of Pharmaceutical SciencesWayne State University 259 Mack Avenue Detroit MI 48201 USA
| | - Timothy L. Stemmler
- Department of Pharmaceutical SciencesWayne State University 259 Mack Avenue Detroit MI 48201 USA
| | - Maureen A. Kane
- Department of Pharmaceutical SciencesUniversity of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
| | - Sarah L. J. Michel
- Department of Pharmaceutical SciencesUniversity of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
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11
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Koebke KJ, Batelu S, Kandegedara A, Smith SR, Stemmler TL. Refinement of protein Fe(II) binding characteristics utilizing a competition assay exploiting small molecule ferrous chelators. J Inorg Biochem 2020; 203:110882. [PMID: 31683123 DOI: 10.1016/j.jinorgbio.2019.110882] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 12/20/2022]
Abstract
Iron is the most prevalent metal in biology. Its chemical and redox versatility allows it to direct activity of many Fe binding proteins. While iron's biological applications are diverse, challenges inherent in having Fe(II) present at high abundance means cells must ensure delivery to the correct recipient, while also ensuring its chemistry is regulated. Having a detailed understanding of the biophysical characteristics of a protein's iron binding characteristics allows us to understand general cellular metal homeostasis events. Unfortunately, most spectroscopic techniques available to measure metal binding affinity require protein be in a homogeneous state. Homogeneity creates an artificial environment when measuring metal binding since within cells numerous additional metal binding biomolecules compete with the target. Here we investigate commercially available Fe(II) chelators with spectral markers coupled to metal binding and release. Our goal was to determine their utility as competitors while measuring aspects of metal binding by apoproteins during a metal binding competition assay. Adding chelators during apoprotein metal binding mimics heterogeneous metal binding environments present in vivo, and provides a more realistic metal binding affinity measurement. Ferrous chelators explored within this report include: Rhod-5N, Magfura-2, Fura-4F, Fura-2, and TPA (Tris-(2-byridyl-methyl)amine; each forms a 1:1 complex with Fe(II) and combined cover a binding range of 5 orders of magnitude (micromolar to nanomolar Kd). These chelators were used to calibrate binding affinities for yeast and fly frataxin (Yfh1 and Dfh, respectively), involved in mitochondrial FeS cluster bioassembly.
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Affiliation(s)
- Karl J Koebke
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Sharon Batelu
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Ashoka Kandegedara
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Sheila R Smith
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI 48101, USA
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA.
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12
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Ok K, Li W, Neu HM, Batelu S, Stemmler TL, Kane MA, Michel SLJ. Role of Gold in Inflammation and Tristetraprolin Activity. Chemistry 2020; 26:1535-1547. [DOI: 10.1002/chem.201904837] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Kiwon Ok
- Department of Pharmaceutical Sciences University of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
| | - Wenjing Li
- Department of Pharmaceutical Sciences University of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
| | - Heather M. Neu
- Department of Pharmaceutical Sciences University of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
| | - Sharon Batelu
- Department of Pharmaceutical Sciences Wayne State University 259 Mack Avenue Detroit MI 48201 USA
| | - Timothy L. Stemmler
- Department of Pharmaceutical Sciences Wayne State University 259 Mack Avenue Detroit MI 48201 USA
| | - Maureen A. Kane
- Department of Pharmaceutical Sciences University of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
| | - Sarah L. J. Michel
- Department of Pharmaceutical Sciences University of Maryland School of Pharmacy 20 Penn St. Baltimore MD 21201 USA
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13
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Rawat S, Kondapalli KC, Rodrigues AV, Stemmler TL. Backbone resonance assignments and secondary structure of the apo-Drosophila melanogaster frataxin homolog (Dfh). Biomol NMR Assign 2019; 13:377-381. [PMID: 31440902 PMCID: PMC6800216 DOI: 10.1007/s12104-019-09910-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
Friedreich's ataxia, the most prevalent hereditary ataxia, is caused by a patient's inability to produce a viable form of the protein frataxin. Frataxin plays an essential role in cellular iron regulation and has been shown to participate in the assembly of iron-sulfur (Fe-S) clusters under a variety of roles, including modulating persulfide production and directing Fe(II) delivery to the assembly scaffold protein. While the activity and structure of multiple eukaryotic frataxin orthologs have been characterized, the fly ortholog has numerous advantages over other orthologs with regards to protein stability, its activity towards Fe-S cluster assembly and its stability for forming stable proteins partner assemblies. Given the obvious advantages for studying the Drosophila melanogaster frataxin homolog (Dfh) over its orthologs, we have undertaken a structural characterization of apo-Dfh as the first step towards solving the solution structure of the protein alone and in complex with protein partners within the Fe-S cluster assembly pathway.
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Affiliation(s)
- Swati Rawat
- Department of Biochemistry and Molecular Biology, Wayne State University, Detroit, MI, 48201, USA
| | - Kalyan C Kondapalli
- Department of Natural Sciences, University of Michigan - Dearborn, Dearborn, MI, 48128, USA
| | - Andria V Rodrigues
- Department of Biochemistry and Molecular Biology, Wayne State University, Detroit, MI, 48201, USA
| | - Timothy L Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University, Detroit, MI, 48201, USA.
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA.
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14
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Lewis BE, Mason Z, Rodrigues AV, Nuth M, Dizin E, Cowan JA, Stemmler TL. Unique roles of iron and zinc binding to the yeast Fe-S cluster scaffold assembly protein "Isu1". Metallomics 2019; 11:1820-1835. [PMID: 31532427 DOI: 10.1039/c9mt00172g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Mitochondrial Fe-S cluster biosynthesis is accomplished within yeast utilizing the biophysical attributes of the "Isu1" scaffold assembly protein. As a member of a highly homologous protein family, Isu1 has sequence conservation between orthologs and a conserved ability to assemble [2Fe-2S] clusters. Regardless of species, scaffold orthologs have been shown to exist in both "disordered" and "structured" conformations, a structural architecture that is directly related to conformations utilized during Fe-S cluster assembly. During assembly, the scaffold helps direct the delivery and utilization of Fe(ii) and persulfide substrates to produce [2Fe-2S] clusters, however Zn(ii) binding alters the activity of the scaffold while at the same time stabilizes the protein in its structured state. Additional studies confirm Zn binds to the scaffold's Cys rich active site, and has an impact on the protein's ability to make Fe-S clusters. Understanding the interplay between Fe(ii) and Zn(ii) binding to Isu1 in vitro may help clarify metal loading events that occur during Fe-S cluster assembly in vivo. Here we determine the metal : protein stoichiometry for Isu1 Zn and Fe binding to be 1 : 1 and 2 : 1, respectively. As expected, while Zn binding shifts the Isu1 to its structured state, folding is not influenced by Fe(ii) binding. X-ray absorption spectroscopy (XAS) confirms Zn(ii) binds to the scaffold's cysteine rich active site but Fe(ii) binds at a location distinct from the active site. XAS results show Isu1 binding initially of either Fe(ii) or Zn(ii) does not significantly perturb the metal site structure of alternate metal. XAS confirmed that four scaffold orthologs bind iron as high-spin Fe(ii) at a site composed of ca. 6 oxygen and nitrogen nearest neighbor ligands. Finally, in our report Zn binding dramatically reduces the Fe-S cluster assembly activity of Isu1 even in the presence of frataxin. Given the Fe-binding activity we report for Isu1 and its orthologs here, a possible mechanism involving Fe(ii) transport to the scaffold's active site during cluster assembly has been considered.
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Affiliation(s)
- Brianne E Lewis
- Department of Pharmaceutical Science, Wayne State University, Detroit, MI 48201, USA.
| | - Zachary Mason
- Department of Pharmaceutical Science, Wayne State University, Detroit, MI 48201, USA.
| | - Andria V Rodrigues
- Department of Pharmaceutical Science, Wayne State University, Detroit, MI 48201, USA.
| | - Manunya Nuth
- Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Eric Dizin
- Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
| | - J A Cowan
- Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Timothy L Stemmler
- Department of Pharmaceutical Science, Wayne State University, Detroit, MI 48201, USA.
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15
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Tsednee M, Castruita M, Salomé PA, Sharma A, Lewis BE, Schmollinger SR, Strenkert D, Holbrook K, Otegui MS, Khatua K, Das S, Datta A, Chen S, Ramon C, Ralle M, Weber PK, Stemmler TL, Pett-Ridge J, Hoffman BM, Merchant SS. Manganese co-localizes with calcium and phosphorus in Chlamydomonas acidocalcisomes and is mobilized in manganese-deficient conditions. J Biol Chem 2019; 294:17626-17641. [PMID: 31527081 DOI: 10.1074/jbc.ra119.009130] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/09/2019] [Indexed: 12/27/2022] Open
Abstract
Exposing cells to excess metal concentrations well beyond the cellular quota is a powerful tool for understanding the molecular mechanisms of metal homeostasis. Such improved understanding may enable bioengineering of organisms with improved nutrition and bioremediation capacity. We report here that Chlamydomonas reinhardtii can accumulate manganese (Mn) in proportion to extracellular supply, up to 30-fold greater than its typical quota and with remarkable tolerance. As visualized by X-ray fluorescence microscopy and nanoscale secondary ion MS (nanoSIMS), Mn largely co-localizes with phosphorus (P) and calcium (Ca), consistent with the Mn-accumulating site being an acidic vacuole, known as the acidocalcisome. Vacuolar Mn stores are accessible reserves that can be mobilized in Mn-deficient conditions to support algal growth. We noted that Mn accumulation depends on cellular polyphosphate (polyP) content, indicated by 1) a consistent failure of C. reinhardtii vtc1 mutant strains, which are deficient in polyphosphate synthesis, to accumulate Mn and 2) a drastic reduction of the Mn storage capacity in P-deficient cells. Rather surprisingly, X-ray absorption spectroscopy, EPR, and electron nuclear double resonance revealed that only little Mn2+ is stably complexed with polyP, indicating that polyP is not the final Mn ligand. We propose that polyPs are a critical component of Mn accumulation in Chlamydomonas by driving Mn relocation from the cytosol to acidocalcisomes. Within these structures, polyP may, in turn, escort vacuolar Mn to a number of storage ligands, including phosphate and phytate, and other, yet unidentified, compounds.
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Affiliation(s)
| | - Madeli Castruita
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095
| | - Patrice A Salomé
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095.,Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095
| | - Ajay Sharma
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Brianne E Lewis
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201
| | - Stefan R Schmollinger
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095.,Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095
| | - Daniela Strenkert
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095.,Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095
| | - Kristen Holbrook
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095
| | - Marisa S Otegui
- Departments of Botany and Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Kaustav Khatua
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Sayani Das
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Ankona Datta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Si Chen
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439
| | - Christina Ramon
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550
| | - Martina Ralle
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239
| | - Peter K Weber
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550
| | - Brian M Hoffman
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095 .,Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095
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16
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Truong PT, Broering EP, Dzul SP, Chakraborty I, Stemmler TL, Harrop TC. Simultaneous nitrosylation and N-nitrosation of a Ni-thiolate model complex of Ni-containing SOD. Chem Sci 2018; 9:8567-8574. [PMID: 30568781 PMCID: PMC6253683 DOI: 10.1039/c8sc03321h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/17/2018] [Indexed: 11/21/2022] Open
Abstract
Nitric oxide (NO) is used as a substrate analogue/spectroscopic probe of metal sites that bind and activate oxygen and its derivatives. To assess the interaction of superoxide with the Ni center in Ni-containing superoxide dismutase (NiSOD), we studied the reaction of NO+ and NO with the model complex, Et4N[Ni(nmp)(SPh-o-NH2-p-CF3)] (1; nmp2- = dianion of N-(2-mercaptoethyl)picolinamide; -SPh-o-NH2-p-CF3 = 2-amino-4-(trifluoromethyl)benzenethiolate) and its oxidized analogue 1ox , respectively. The ultimate products of these reactions are the disulfide of -SPh-o-NH2-p-CF3 and the S,S-bridged tetrameric complex [Ni4(nmp)4], a result of S-based redox activity. However, introduction of NO to 1 affords the green dimeric {NiNO}10 complex (Et4N)2[{Ni(κ2-SPh-o-NNO-p-CF3)(NO)}2] (2) via NO-induced loss of nmp2- as the disulfide and N-nitrosation of the aromatic thiolate. Complex 2 was characterized by X-ray crystallography and several spectroscopies. These measurements are in-line with other tetrahedral complexes in the {NiNO}10 classification. In contrast to the established stability of this metal-nitrosyl class, the Ni-NO bond of 2 is labile and release of NO from this unit was quantified by trapping the NO with a CoII-porphyrin (70-80% yield). In the process, the Ni ends up coordinated by two o-nitrosaminobenzenethiolato ligands to result in the structurally characterized trans-(Et4N)2[Ni(SPh-o-NNO-p-CF3)2] (3), likely by a disproportionation mechanism. The isolation and characterization of 2 and 3 suggest that: (i) the strongly donating thiolates dominate the electronic structure of Ni-nitrosyls that result in less covalent Ni-NO bonds, and (ii) superoxide undergoes disproportionation via an outer-sphere mechanism in NiSOD as complexes in the {NiNO}9/8 state have yet to be isolated.
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Affiliation(s)
- Phan T Truong
- Department of Chemistry , Center for Metalloenzyme Studies , The University of Georgia , Athens , Georgia 30602 , USA .
| | - Ellen P Broering
- Department of Chemistry , Center for Metalloenzyme Studies , The University of Georgia , Athens , Georgia 30602 , USA .
| | - Stephen P Dzul
- Departments of Pharmaceutical Sciences, Biochemistry, and Molecular Biology , Wayne State University , Detroit , Michigan 48201 , USA
| | - Indranil Chakraborty
- Department of Chemistry and Biochemistry , Florida International University , Miami , Florida 33199 , USA
| | - Timothy L Stemmler
- Departments of Pharmaceutical Sciences, Biochemistry, and Molecular Biology , Wayne State University , Detroit , Michigan 48201 , USA
| | - Todd C Harrop
- Department of Chemistry , Center for Metalloenzyme Studies , The University of Georgia , Athens , Georgia 30602 , USA .
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17
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Abstract
Ions greatly influence protein structure-function and are critical to health and disease. A 10, 000-fold higher calcium in the sarcoplasmic reticulum (SR) of muscle suggests elevated calcium levels near active calcium channels at the SR membrane and the impact of localized high calcium on the structure-function of the motor protein myosin. In the current study, combined quantum dot (QD)-based nanothermometry and circular dichroism (CD) spectroscopy enabled detection of previously unknown enthalpy changes and associated structural remodeling of myosin, impacting its function following exposure to elevated calcium. Cadmium telluride QDs adhere to myosin, function as thermal sensors, and reveal that exposure of myosin to calcium is exothermic, resulting in lowering of enthalpy, a decrease in alpha helical content measured using CD spectroscopy, and the consequent increase in motor efficiency. Isolated muscle fibers subjected to elevated levels of calcium further demonstrate fiber lengthening and decreased motility of actin filaments on myosin-functionalized substrates. Our results, in addition to providing new insights into our understanding of muscle structure-function, establish a novel approach to understand the enthalpy of protein-ion interactions and the accompanying structural changes that may occur within the protein molecule.
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Affiliation(s)
- Eric R. Kuhn
- Department of Physiology, School of Medicine, Wayne State University, Detroit, Michigan 48201, United States
| | - Akshata R. Naik
- Department of Physiology, School of Medicine, Wayne State University, Detroit, Michigan 48201, United States
| | - Brianne E. Lewis
- Department of Pharmaceutical Science, College of Pharmacy, Wayne State University, Detroit, Michigan 48201, United States
| | - Keith M. Kokotovich
- Department of Physiology, School of Medicine, Wayne State University, Detroit, Michigan 48201, United States
| | - Meishan Li
- Department of Physiology and Pharmacology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Timothy L. Stemmler
- Department of Pharmaceutical Science, College of Pharmacy, Wayne State University, Detroit, Michigan 48201, United States
| | - Lars Larsson
- Department of Physiology and Pharmacology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Bhanu P. Jena
- Department of Physiology, School of Medicine, Wayne State University, Detroit, Michigan 48201, United States
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18
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Fisher OS, Kenney GE, Ross MO, Ro SY, Lemma BE, Batelu S, Thomas PM, Sosnowski VC, DeHart CJ, Kelleher NL, Stemmler TL, Hoffman BM, Rosenzweig AC. Characterization of a long overlooked copper protein from methane- and ammonia-oxidizing bacteria. Nat Commun 2018; 9:4276. [PMID: 30323281 PMCID: PMC6189053 DOI: 10.1038/s41467-018-06681-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 09/20/2018] [Indexed: 12/24/2022] Open
Abstract
Methane-oxidizing microbes catalyze the oxidation of the greenhouse gas methane using the copper-dependent enzyme particulate methane monooxygenase (pMMO). Isolated pMMO exhibits lower activity than whole cells, however, suggesting that additional components may be required. A pMMO homolog, ammonia monooxygenase (AMO), converts ammonia to hydroxylamine in ammonia-oxidizing bacteria (AOB) which produce another potent greenhouse gas, nitrous oxide. Here we show that PmoD, a protein encoded within many pmo operons that is homologous to the AmoD proteins encoded within AOB amo operons, forms a copper center that exhibits the features of a well-defined CuA site using a previously unobserved ligand set derived from a cupredoxin homodimer. PmoD is critical for copper-dependent growth on methane, and genetic analyses strongly support a role directly related to pMMO and AMO. These findings identify a copper-binding protein that may represent a missing link in the function of enzymes critical to the global carbon and nitrogen cycles. Methane- and ammonia-oxidizing bacteria use the integral membrane, copper-dependent enzymes particulate methane monooxygenase (pMMO) and ammonia monooxygenase (AMO) to oxidize methane and ammonia. Here the authors structurally characterize the copper-binding protein PmoD, which contains an unusual CuA site and their genetic analyses strongly support a pMMO and AMO related function of PmoD.
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Affiliation(s)
- Oriana S Fisher
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Grace E Kenney
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Matthew O Ross
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Soo Y Ro
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Betelehem E Lemma
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Sharon Batelu
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, 48201, MI, USA
| | - Paul M Thomas
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Victoria C Sosnowski
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Caroline J DeHart
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Neil L Kelleher
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, 48201, MI, USA
| | - Brian M Hoffman
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA
| | - Amy C Rosenzweig
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, 60208, IL, USA.
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19
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Ro SY, Ross MO, Deng YW, Batelu S, Lawton TJ, Hurley JD, Stemmler TL, Hoffman BM, Rosenzweig AC. From micelles to bicelles: Effect of the membrane on particulate methane monooxygenase activity. J Biol Chem 2018; 293:10457-10465. [PMID: 29739854 DOI: 10.1074/jbc.ra118.003348] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 05/06/2018] [Indexed: 11/06/2022] Open
Abstract
Particulate methane monooxygenase (pMMO) is a copper-dependent integral membrane metalloenzyme that converts methane to methanol in methanotrophic bacteria. Studies of isolated pMMO have been hindered by loss of enzymatic activity upon its removal from the native membrane. To characterize pMMO in a membrane-like environment, we reconstituted pMMOs from Methylococcus (Mcc.) capsulatus (Bath) and Methylomicrobium (Mm.) alcaliphilum 20Z into bicelles. Reconstitution into bicelles recovers methane oxidation activity lost upon detergent solubilization and purification without substantial alterations to copper content or copper electronic structure, as observed by electron paramagnetic resonance (EPR) spectroscopy. These findings suggest that loss of pMMO activity upon isolation is due to removal from the membranes rather than caused by loss of the catalytic copper ions. A 2.7 Å resolution crystal structure of pMMO from Mm. alcaliphilum 20Z reveals a mononuclear copper center in the PmoB subunit and indicates that the transmembrane PmoC subunit may be conformationally flexible. Finally, results from extended X-ray absorption fine structure (EXAFS) analysis of pMMO from Mm. alcaliphilum 20Z were consistent with the observed monocopper center in the PmoB subunit. These results underscore the importance of studying membrane proteins in a membrane-like environment and provide valuable insight into pMMO function.
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Affiliation(s)
- Soo Y Ro
- From the Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208 and
| | - Matthew O Ross
- From the Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208 and
| | - Yue Wen Deng
- From the Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208 and
| | - Sharon Batelu
- the Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201
| | - Thomas J Lawton
- From the Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208 and
| | - Joseph D Hurley
- From the Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208 and
| | - Timothy L Stemmler
- the Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201
| | - Brian M Hoffman
- From the Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208 and
| | - Amy C Rosenzweig
- From the Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208 and
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20
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Dzul SP, Rocha AG, Rawat S, Kandegedara A, Kusowski A, Pain J, Murari A, Pain D, Dancis A, Stemmler TL. In vitro characterization of a novel Isu homologue from Drosophila melanogaster for de novo FeS-cluster formation. Metallomics 2017; 9:48-60. [PMID: 27738674 DOI: 10.1039/c6mt00163g] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
FeS-clusters are utilized by numerous proteins within several biological pathways that are essential for life. In eukaryotes, the primary FeS-cluster production pathway is the mitochondrial iron-sulfur cluster (ISC) pathway. In Saccharomyces cerevisiae, de novo FeS-cluster formation is accomplished through coordinated assembly with the substrates iron and sulfur by the scaffold assembly protein "Isu1". Sulfur for cluster assembly is provided by cysteine desulfurase "Nfs1", a protein that works in union with its accessory protein "Isd11". Frataxin "Yfh1" helps direct cluster assembly by serving as a modulator of Nfs1 activity, by assisting in the delivery of sulfur and Fe(ii) to Isu1, or more likely through a combination of these and other possible roles. In vitro studies on the yeast ISC machinery have been limited, however, due to the inherent instability of recombinant Isu1. Isu1 is a molecule prone to degradation and aggregation. To circumvent Isu1 instability, we have replaced yeast Isu1 with the fly ortholog to stabilize our in vitro ISC assembly system and assist us in elucidating molecular details of the yeast ISC pathway. Our laboratory previously observed that recombinant frataxin from Drosophila melanogaster has remarkable stability compared to the yeast ortholog. Here we provide the first characterization of D. melanogaster Isu1 (fIscU) and demonstrate its ability to function within the yeast ISC machinery both in vivo and in vitro. Recombinant fIscU has physical properties similar to that of yeast Isu1. It functions as a stable dimer with similar Fe(ii) affinity and ability to form two 2Fe-2S clusters as the yeast dimer. The fIscU and yeast ISC proteins are compatible in vitro; addition of Yfh1 to Nfs1-Isd11 increases the rate of FeS-cluster formation on fIscU to a similar extent observed with Isu1. Finally, fIscU expressed in mitochondria of a yeast strain lacking Isu1 (and its paralog Isu2) is able to completely reverse the deletion phenotypes. These results demonstrate fIscU can functionally replace yeast Isu1 and it can serve as a powerful tool for exploring molecular details within the yeast ISC pathway.
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Affiliation(s)
- Stephen P Dzul
- Departments of Pharmaceutical Science, and Biochemistry and Molecular Biology, Wayne State University, Detroit, MI 48201, USA
| | - Agostinho G Rocha
- Department of Medicine, Division of Hematology-Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Swati Rawat
- Departments of Pharmaceutical Science, and Biochemistry and Molecular Biology, Wayne State University, Detroit, MI 48201, USA
| | - Ashoka Kandegedara
- Departments of Pharmaceutical Science, and Biochemistry and Molecular Biology, Wayne State University, Detroit, MI 48201, USA
| | - April Kusowski
- Departments of Pharmaceutical Science, and Biochemistry and Molecular Biology, Wayne State University, Detroit, MI 48201, USA
| | - Jayashree Pain
- Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103, USA
| | - Anjaneyulu Murari
- Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103, USA
| | - Debkumar Pain
- Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103, USA
| | - Andrew Dancis
- Department of Medicine, Division of Hematology-Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Timothy L Stemmler
- Departments of Pharmaceutical Science, and Biochemistry and Molecular Biology, Wayne State University, Detroit, MI 48201, USA
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21
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Pawitwar SS, Nadar VS, Kandegedara A, Stemmler TL, Rosen BP, Yoshinaga M. Biochemical Characterization of ArsI: A Novel C-As Lyase for Degradation of Environmental Organoarsenicals. Environ Sci Technol 2017; 51:11115-11125. [PMID: 28936873 PMCID: PMC5870903 DOI: 10.1021/acs.est.7b03180] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Organoarsenicals such as the methylarsenical methylarsenate (MAs(V)) and aromatic arsenicals including roxarsone (4-hydroxy-3-nitrobenzenearsenate or Rox(V)) have been extensively used as an herbicide and growth enhancers in animal husbandry, respectively. They undergo environmental degradation to more toxic inorganic arsenite (As(III)) that contaminates crops and drinking water. We previously identified a bacterial gene (arsI) responsible for aerobic demethylation of methylarsenite (MAs(III)). The gene product, ArsI, is an Fe(II)-dependent extradiol dioxygenase that cleaves the carbon-arsenic (C-As) bond in MAs(III) and in trivalent aromatic arsenicals. The objective of this study was to elucidate the ArsI mechanism. Using isothermal titration calorimetry, we determined the dissociation constants and ligand-to-protein stoichiometry of ArsI for Fe(II), MAs(III), and aromatic phenylarsenite. Using a combination of methods including chemical modification, site-directed mutagenesis, and fluorescent spectroscopy, we demonstrated that amino acid residues predicted to participate in Fe(II)-binding (His5-His62-Glu115) and substrate binding (Cys96-Cys97) are involved in catalysis. Finally, the products of Rox(III) degradation were identified as As(III) and 2-nitrohydroquinone, demonstrating that ArsI is a dioxygenase that incorporates one oxygen atom from dioxygen into the carbon and the other to the arsenic to catalyze cleavage of the C-As bond. These results augment our understanding of the mechanism of this novel C-As lyase.
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Affiliation(s)
- Shashank S. Pawitwar
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Venkadesh S. Nadar
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Ashoka Kandegedara
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | - Timothy L. Stemmler
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | - Barry P. Rosen
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Masafumi Yoshinaga
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
- Corresponding Author: Phone: 305-348-1489; fax: 305-348-0651; ; http://orcid.org/0000-0002-7243-1761
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22
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Truong PT, Gale EM, Dzul SP, Stemmler TL, Harrop TC. Steric Enforcement about One Thiolate Donor Leads to New Oxidation Chemistry in a NiSOD Model Complex. Inorg Chem 2017; 56:7761-7780. [PMID: 28459242 DOI: 10.1021/acs.inorgchem.7b00485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ni-containing superoxide dismutase (NiSOD) represents an unusual member of the SOD family due to the presence of oxygen-sensitive Ni-SCys bonds at its active site. Reported in this account is the synthesis and properties of the NiII complex of the N3S2 ligand [N3S2Me2]3- ([N3S2Me2]3- = deprotonated form of 2-((2-mercapto-2-methylpropyl)(pyridin-2-ylmethyl)amino)-N-(2-mercaptoethyl)acetamide), namely Na[Ni(N3S2Me2)] (2), as a NiSOD model that features sterically robust gem-(CH3)2 groups on the thiolate α-C positioned trans to the carboxamide. The crystal structure of 2, coupled with spectroscopic measurements from 1H NMR, X-ray absorption, IR, UV-vis, and mass spectrometry (MS), reveal a planar NiII (S = 0) ion coordinated by only the N2S2 basal donors of the N3S2 ligand. While the structure and spectroscopic properties of 2 resemble those of NiSODred and other models, the asymmetric S ligands open up new reaction paths upon chemical oxidation. One unusual oxidation product is the planar NiII-N3S complex [Ni(Lox)] (5; Lox = 2-(5,5-dimethyl-2-(pyridin-2-yl)thiazolidin-3-yl)-N-(2-mercaptoethyl)acetamide), where two-electron oxidation takes place at the substituted thiolate and py-CH2 carbon to generate a thiazolidine heterocycle. Electrochemical measurements of 2 reveal irreversible events wholly consistent with thiolate redox, which were identified by comparison to the ZnII complex Na[Zn(N3S2Me2)] (3). Although no reaction is observed between 2 and azide, reaction of 2 with superoxide produces multiple products on the basis of UV-vis and MS data, one of which is 5. Density functional theory (DFT) computations suggest that the HOMO in 2 is π* with primary contributions from Ni-dπ/S-pπ orbitals. These contributions can be modulated and biased toward Ni when electron-withdrawing groups are placed on the thiolate α-C. Analysis of the oxidized five-coordinate species 2ox* by DFT reveal a singly occupied spin-up (α) MO that is largely thiolate based, which supports the proposed NiIII-thiolate/NiII-thiyl radical intermediates that ultimately yield 5 and other products.
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Affiliation(s)
- Phan T Truong
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar Street, Athens, Georgia 30602, United States
| | - Eric M Gale
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar Street, Athens, Georgia 30602, United States
| | - Stephen P Dzul
- Departments of Pharmaceutical Sciences, Biochemistry and Molecular Biology, Wayne State University , Detroit, Michigan 48201, United States
| | - Timothy L Stemmler
- Departments of Pharmaceutical Sciences, Biochemistry and Molecular Biology, Wayne State University , Detroit, Michigan 48201, United States
| | - Todd C Harrop
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar Street, Athens, Georgia 30602, United States
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23
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Steiner RA, Dzul SP, Stemmler TL, Harrop TC. Synthesis and Speciation-Dependent Properties of a Multimetallic Model Complex of NiSOD That Exhibits Unique Hydrogen-Bonding. Inorg Chem 2017; 56:2849-2862. [PMID: 28212040 DOI: 10.1021/acs.inorgchem.6b02997] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The complex Na3[{NiII(nmp)}3S3BTAalk)] (1) (nmp2- = deprotonated form of N-(2-mercaptoethyl)picolinamide; H3S3BTAalk = N1,N3,N5-tris(2-mercaptoethyl)benzene-1,3,5-tricarboxamide, where H = dissociable protons), supported by the thiolate-benzenetricarboxamide scaffold (S3BTAalk), has been synthesized as a trimetallic model of nickel-containing superoxide dismutase (NiSOD). X-ray absorption spectroscopy (XAS) and 1H NMR measurements on 1 indicate that the NiII centers are square-planar with N2S2 coordination, and Ni-N and Ni-S distances of 1.95 and 2.16 Å, respectively. Additional evidence from IR indicates the presence of H-bonds in 1 from the approximately -200 cm-1 shift in νNH from free ligand. The presence of H-bonds allows for speciation that is temperature-, concentration-, and solvent-dependent. In unbuffered water and at low temperature, a dimeric complex (1A; λ = 410 nm) that aggregates through intermolecular NH···O═C bonds of BTA units is observed. Dissolution of 1 in pH 7.4 buffer or in unbuffered water at temperatures above 50 °C results in monomeric complex (1M; λ = 367 nm) linked through intramolecular NH···S bonds. DFT computations indicate a low energy barrier between 1A and 1M with nearly identical frontier MOs and Ni-ligand metrics. Notably, 1A and 1M exhibit remarkable stability in protic solvents such as MeOH and H2O, in stark contrast to monometallic [NiII(nmp)(SR)]- complexes. The reactivity of 1 with excess O2, H2O2, and O2•- is species-dependent. IR and UV-vis reveal that 1A in MeOH reacts with excess O2 to yield an S-bound sulfinate, but does not react with O2•-. In contrast, 1M is stable to O2 in pH 7.4 buffer, but reacts with O2•- to yield a putative [NiII(nmp)(O2)]- complex from release of the BTA-thiolate based on EPR.
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Affiliation(s)
- Ramsey A Steiner
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar St, Athens, Georgia 30602, United States
| | - Stephen P Dzul
- Departments of Pharmaceutical Sciences, and Biochemistry and Molecular Biology, Wayne State University , Detroit, Michigan 48201, United States
| | - Timothy L Stemmler
- Departments of Pharmaceutical Sciences, and Biochemistry and Molecular Biology, Wayne State University , Detroit, Michigan 48201, United States
| | - Todd C Harrop
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar St, Athens, Georgia 30602, United States
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24
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Ruetz M, Kumutima J, Lewis BE, Filipovic MR, Lehnert N, Stemmler TL, Banerjee R. A distal ligand mutes the interaction of hydrogen sulfide with human neuroglobin. J Biol Chem 2017; 292:6512-6528. [PMID: 28246171 DOI: 10.1074/jbc.m116.770370] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 02/16/2017] [Indexed: 11/06/2022] Open
Abstract
Hydrogen sulfide is a critical signaling molecule, but high concentrations cause cellular toxicity. A four-enzyme pathway in the mitochondrion detoxifies H2S by converting it to thiosulfate and sulfate. Recent studies have shown that globins like hemoglobin and myoglobin can also oxidize H2S to thiosulfate and hydropolysulfides. Neuroglobin, a globin enriched in the brain, was reported to bind H2S tightly and was postulated to play a role in modulating neuronal sensitivity to H2S in conditions such as stroke. However, the H2S reactivity of the coordinately saturated heme in neuroglobin is expected a priori to be substantially lower than that of the 5-coordinate hemes present in myoglobin and hemoglobin. To resolve this discrepancy, we explored the role of the distal histidine residue in muting the reactivity of human neuroglobin toward H2S. Ferric neuroglobin is slowly reduced by H2S and catalyzes its inefficient oxidative conversion to thiosulfate. Mutation of the distal His64 residue to alanine promotes rapid binding of H2S and its efficient conversion to oxidized products. X-ray absorption, EPR, and resonance Raman spectroscopy highlight the chemically different reaction options influenced by the distal histidine ligand. This study provides mechanistic insights into how the distal heme ligand in neuroglobin caps its reactivity toward H2S and identifies by cryo-mass spectrometry a range of sulfide oxidation products with 2-6 catenated sulfur atoms with or without oxygen insertion, which accumulate in the absence of the His64 ligand.
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Affiliation(s)
| | - Jacques Kumutima
- the Departments of Chemistry and Biophysics, University of Michigan, Ann Arbor, Michigan 48109
| | - Brianne E Lewis
- the Department of Pharmaceutical Science, Wayne State University, Detroit, Michigan 48201-2417
| | - Milos R Filipovic
- the University of Bordeaux, IBGC, UMR 5090, F33077 Bordeaux, France, and.,CNRS, Institute of Biochemistry and Cellular Genetics, UMR 5095, F33077 Bordeaux, France
| | - Nicolai Lehnert
- the Departments of Chemistry and Biophysics, University of Michigan, Ann Arbor, Michigan 48109
| | - Timothy L Stemmler
- the Department of Pharmaceutical Science, Wayne State University, Detroit, Michigan 48201-2417
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25
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Mahapatra G, Varughese A, Ji Q, Lee I, Liu J, Vaishnav A, Sinkler C, Kapralov AA, Moraes CT, Sanderson TH, Stemmler TL, Grossman LI, Kagan VE, Brunzelle JS, Salomon AR, Edwards BFP, Hüttemann M. Phosphorylation of Cytochrome c Threonine 28 Regulates Electron Transport Chain Activity in Kidney: IMPLICATIONS FOR AMP KINASE. J Biol Chem 2016; 292:64-79. [PMID: 27758862 DOI: 10.1074/jbc.m116.744664] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/20/2016] [Indexed: 11/06/2022] Open
Abstract
Mammalian cytochrome c (Cytc) plays a key role in cellular life and death decisions, functioning as an electron carrier in the electron transport chain and as a trigger of apoptosis when released from the mitochondria. However, its regulation is not well understood. We show that the major fraction of Cytc isolated from kidneys is phosphorylated on Thr28, leading to a partial inhibition of respiration in the reaction with cytochrome c oxidase. To further study the effect of Cytc phosphorylation in vitro, we generated T28E phosphomimetic Cytc, revealing superior behavior regarding protein stability and its ability to degrade reactive oxygen species compared with wild-type unphosphorylated Cytc Introduction of T28E phosphomimetic Cytc into Cytc knock-out cells shows that intact cell respiration, mitochondrial membrane potential (ΔΨm), and ROS levels are reduced compared with wild type. As we show by high resolution crystallography of wild-type and T28E Cytc in combination with molecular dynamics simulations, Thr28 is located at a central position near the heme crevice, the most flexible epitope of the protein apart from the N and C termini. Finally, in silico prediction and our experimental data suggest that AMP kinase, which phosphorylates Cytc on Thr28 in vitro and colocalizes with Cytc to the mitochondrial intermembrane space in the kidney, is the most likely candidate to phosphorylate Thr28 in vivo We conclude that Cytc phosphorylation is mediated in a tissue-specific manner and leads to regulation of electron transport chain flux via "controlled respiration," preventing ΔΨm hyperpolarization, a known cause of ROS and trigger of apoptosis.
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Affiliation(s)
- Gargi Mahapatra
- From the Center for Molecular Medicine and Genetics and.,the Departments of Biochemistry and Molecular Biology
| | - Ashwathy Varughese
- From the Center for Molecular Medicine and Genetics and.,the Departments of Biochemistry and Molecular Biology
| | | | - Icksoo Lee
- From the Center for Molecular Medicine and Genetics and.,the College of Medicine, Dankook University, Cheonan-si, Chungcheongnam-do 31116, Republic of Korea
| | - Jenney Liu
- From the Center for Molecular Medicine and Genetics and
| | | | | | - Alexandr A Kapralov
- the Center for Free Radical and Antioxidant Health and the Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15219
| | - Carlos T Moraes
- the Department of Neurology, University of Miami School of Medicine, Miami, Florida 33136, and
| | | | - Timothy L Stemmler
- Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201
| | | | - Valerian E Kagan
- the Center for Free Radical and Antioxidant Health and the Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15219
| | - Joseph S Brunzelle
- the Life Sciences Collaborative Access Team, Northwestern University, Center for Synchrotron Research, Argonne, Illinois 60439
| | - Arthur R Salomon
- the MCB Department, Brown University, Providence, Rhode Island 02912
| | | | - Maik Hüttemann
- From the Center for Molecular Medicine and Genetics and .,the Departments of Biochemistry and Molecular Biology
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26
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Walter MR, Dzul SP, Rodrigues AV, Stemmler TL, Telser J, Conradie J, Ghosh A, Harrop TC. Synthesis of CoII–NO– Complexes and Their Reactivity as a Source of Nitroxyl. J Am Chem Soc 2016; 138:12459-71. [DOI: 10.1021/jacs.6b05896] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Melody R. Walter
- Department
of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
| | - Stephen P. Dzul
- Departments
of Pharmaceutical Sciences, Biochemistry, and Molecular Biology, Wayne State University, Detroit, Michigan 48201, United States
| | - Andria V. Rodrigues
- Departments
of Pharmaceutical Sciences, Biochemistry, and Molecular Biology, Wayne State University, Detroit, Michigan 48201, United States
| | - Timothy L. Stemmler
- Departments
of Pharmaceutical Sciences, Biochemistry, and Molecular Biology, Wayne State University, Detroit, Michigan 48201, United States
| | - Joshua Telser
- Department
of Biological, Chemical, and Physical Sciences, Roosevelt University, 430 South Michigan Avenue, Chicago, Illinois 60605, United States
| | - Jeanet Conradie
- Department
of Chemistry, University of the Free State, 9300 Bloemfontein, Republic of South Africa
| | - Abhik Ghosh
- Department
of Chemistry and Center for Theoretical and
Computational Chemistry, University of Tromsø, N-9037 Tromsø, Norway
| | - Todd C. Harrop
- Department
of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
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27
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Bostelaar T, Vitvitsky V, Kumutima J, Lewis BE, Yadav PK, Brunold TC, Filipovic M, Lehnert N, Stemmler TL, Banerjee R. Hydrogen Sulfide Oxidation by Myoglobin. J Am Chem Soc 2016; 138:8476-88. [PMID: 27310035 PMCID: PMC5464954 DOI: 10.1021/jacs.6b03456] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Enzymes in the sulfur network generate the signaling molecule, hydrogen sulfide (H2S), from the amino acids cysteine and homocysteine. Since it is toxic at elevated concentrations, cells are equipped to clear H2S. A canonical sulfide oxidation pathway operates in mitochondria, converting H2S to thiosulfate and sulfate. We have recently discovered the ability of ferric hemoglobin to oxidize sulfide to thiosulfate and iron-bound hydropolysulfides. In this study, we report that myoglobin exhibits a similar capacity for sulfide oxidation. We have trapped and characterized iron-bound sulfur intermediates using cryo-mass spectrometry and X-ray absorption spectroscopy. Further support for the postulated intermediates in the chemically challenging conversion of H2S to thiosulfate and iron-bound catenated sulfur products is provided by EPR and resonance Raman spectroscopy in addition to density functional theory computational results. We speculate that the unusual sensitivity of skeletal muscle cytochrome c oxidase to sulfide poisoning in ethylmalonic encephalopathy, resulting from the deficiency in a mitochondrial sulfide oxidation enzyme, might be due to the concentration of H2S by myoglobin in this tissue.
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Affiliation(s)
- Trever Bostelaar
- Department of Biological Chemistry, University of Michigan,
Ann Arbor, Michigan 48109, United States
| | - Victor Vitvitsky
- Department of Biological Chemistry, University of Michigan,
Ann Arbor, Michigan 48109, United States
| | - Jacques Kumutima
- Department of Chemistry and Department of Biophysics,
University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Brianne E. Lewis
- Department of Pharmaceutical Science, Wayne State
University, Detroit, Michigan 48201-2417, United States
| | - Pramod K. Yadav
- Department of Biological Chemistry, University of Michigan,
Ann Arbor, Michigan 48109, United States
| | - Thomas C. Brunold
- Department of Chemistry, University of Wisconsin, Madison,
Wisconsin 53706, United States
| | - Milos Filipovic
- University of Bordeaux, IBGC, and CNRS, IBGC, UMR 5095,
F-33077 Bordeaux, France
| | - Nicolai Lehnert
- Department of Chemistry and Department of Biophysics,
University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Timothy L. Stemmler
- Department of Pharmaceutical Science, Wayne State
University, Detroit, Michigan 48201-2417, United States
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan,
Ann Arbor, Michigan 48109, United States
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28
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Patel SJ, Lewis BE, Long JE, Nambi S, Sassetti CM, Stemmler TL, Argüello JM. Fine-tuning of Substrate Affinity Leads to Alternative Roles of Mycobacterium tuberculosis Fe2+-ATPases. J Biol Chem 2016; 291:11529-39. [PMID: 27022029 DOI: 10.1074/jbc.m116.718239] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Indexed: 11/06/2022] Open
Abstract
Little is known about iron efflux transporters within bacterial systems. Recently, the participation of Bacillus subtilis PfeT, a P1B4-ATPase, in cytoplasmic Fe(2+) efflux has been proposed. We report here the distinct roles of mycobacterial P1B4-ATPases in the homeostasis of Co(2+) and Fe(2+) Mutation of Mycobacterium smegmatis ctpJ affects the homeostasis of both ions. Alternatively, an M. tuberculosis ctpJ mutant is more sensitive to Co(2+) than Fe(2+), whereas mutation of the homologous M. tuberculosis ctpD leads to Fe(2+) sensitivity but no alterations in Co(2+) homeostasis. In vitro, the three enzymes are activated by both Fe(2+) and Co(2+) and bind 1 eq of either ion at their transport site. However, equilibrium binding affinities and activity kinetics show that M. tuberculosis CtpD has higher affinity for Fe(2+) and twice the Fe(2+)-stimulated activity than the CtpJs. These parameters are paralleled by a lower activation and affinity for Co(2+) Analysis of Fe(2+) and Co(2+) binding to CtpD by x-ray absorption spectroscopy shows that both ions are five- to six-coordinate, constrained within oxygen/nitrogen environments with similar geometries. Mutagenesis studies suggest the involvement of invariant Ser, His, and Glu residues in metal coordination. Interestingly, replacement of the conserved Cys at the metal binding pocket leads to a large reduction in Fe(2+) but not Co(2+) binding affinity. We propose that CtpJ ATPases participate in the control of steady state Fe(2+) levels. CtpD, required for M. tuberculosis virulence, is a high affinity Fe(2+) transporter involved in the rapid response to iron dyshomeostasis generated upon redox stress.
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Affiliation(s)
- Sarju J Patel
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
| | - Brianne E Lewis
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201
| | - Jarukit E Long
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, and
| | - Subhalaxmi Nambi
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, and
| | - Christopher M Sassetti
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, and Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201
| | - José M Argüello
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609,
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29
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Barupala DP, Dzul SP, Riggs-Gelasco PJ, Stemmler TL. Synthesis, delivery and regulation of eukaryotic heme and Fe-S cluster cofactors. Arch Biochem Biophys 2016; 592:60-75. [PMID: 26785297 PMCID: PMC4784227 DOI: 10.1016/j.abb.2016.01.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 01/13/2016] [Accepted: 01/14/2016] [Indexed: 11/25/2022]
Abstract
In humans, the bulk of iron in the body (over 75%) is directed towards heme- or Fe-S cluster cofactor synthesis, and the complex, highly regulated pathways in place to accomplish biosynthesis have evolved to safely assemble and load these cofactors into apoprotein partners. In eukaryotes, heme biosynthesis is both initiated and finalized within the mitochondria, while cellular Fe-S cluster assembly is controlled by correlated pathways both within the mitochondria and within the cytosol. Iron plays a vital role in a wide array of metabolic processes and defects in iron cofactor assembly leads to human diseases. This review describes progress towards our molecular-level understanding of cellular heme and Fe-S cluster biosynthesis, focusing on the regulation and mechanistic details that are essential for understanding human disorders related to the breakdown in these essential pathways.
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Affiliation(s)
- Dulmini P Barupala
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Stephen P Dzul
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | | | - Timothy L Stemmler
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA.
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30
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Bafaro EM, Antala S, Nguyen TV, Dzul SP, Doyon B, Stemmler TL, Dempski RE. The large intracellular loop of hZIP4 is an intrinsically disordered zinc binding domain. Metallomics 2015; 7:1319-30. [PMID: 25882556 PMCID: PMC4558264 DOI: 10.1039/c5mt00066a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The human (h) ZIP4 transporter is a plasma membrane protein which functions to increase the cytosolic concentration of zinc. hZIP4 transports zinc into intestinal cells and therefore has a central role in the absorption of dietary zinc. hZIP4 has eight transmembrane domains and encodes a large intracellular loop between transmembrane domains III and IV, M3M4. Previously, it has been postulated that this domain regulates hZIP4 levels in the plasma membrane in a zinc-dependent manner. The objective of this research was to examine the zinc binding properties of the large intracellular loop of hZIP4. Therefore, we have recombinantly expressed and purified M3M4 and showed that this domain binds two zinc ions. Using a combination of site-directed mutagenesis, metal binding affinity assays, and X-ray absorption spectroscopy, we demonstrated that the two Zn(2+) ions bind sequentially, with the first Zn(2+) binding to a CysHis3 site with a nanomolar binding affinity, and the second Zn(2+) binding to a His4 site with a weaker affinity. Circular dichroism spectroscopy revealed that the M3M4 domain is intrinsically disordered, with only a small structural change induced upon Zn(2+) coordination. Our data supports a model in which the intracellular M3M4 domain senses high cytosolic Zn(2+) concentrations and regulates the plasma membrane levels of the hZIP4 transporter in response to Zn(2+) binding.
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Affiliation(s)
- Elizabeth M Bafaro
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA.
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31
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Smith AT, Barupala D, Stemmler TL, Rosenzweig AC. A new metal binding domain involved in cadmium, cobalt and zinc transport. Nat Chem Biol 2015; 11:678-84. [PMID: 26192600 PMCID: PMC4543396 DOI: 10.1038/nchembio.1863] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/28/2015] [Indexed: 11/26/2022]
Abstract
The P1B-ATPases, which couple cation transport across membranes to ATP hydrolysis, are central to metal homeostasis in all organisms. An important feature of P1B-ATPases is the presence of soluble metal binding domains that regulate transport activity. Only one type of MBD has been characterized extensively, but bioinformatics analyses indicate that a diversity of MBDs may exist in nature. Here we report the biochemical, structural, and functional characterization of a new MBD from the Cupriavidus metallidurans P1B-4-ATPase CzcP (CzcP MBD). The CzcP MBD binds two Cd2+, Co2+, or Zn2+ ions in distinct and unique sites, and adopts an unexpected fold consisting of two fused ferredoxin-like domains. Both in vitro and in vivo activity assays using full length CzcP, truncated CzcP, and several variants indicate a regulatory role for the MBD and distinct functions for the two metal binding sites. Taken together, these findings elucidate a previously unknown MBD and suggest new regulatory mechanisms for metal transport by P1B-ATPases.
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Affiliation(s)
- Aaron T Smith
- 1] Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA. [2] Department of Chemistry, Northwestern University, Evanston, Illinois, USA
| | - Dulmini Barupala
- Department of Pharmaceutical Sciences and Cardiovascular Research Institute, Wayne State University, School of Medicine, Detroit, Michigan, USA
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences and Cardiovascular Research Institute, Wayne State University, School of Medicine, Detroit, Michigan, USA
| | - Amy C Rosenzweig
- 1] Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA. [2] Department of Chemistry, Northwestern University, Evanston, Illinois, USA
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Plegaria JS, Dzul SP, Zuiderweg ERP, Stemmler TL, Pecoraro VL. Apoprotein Structure and Metal Binding Characterization of a de Novo Designed Peptide, α3DIV, that Sequesters Toxic Heavy Metals. Biochemistry 2015; 54:2858-73. [PMID: 25790102 DOI: 10.1021/acs.biochem.5b00064] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
De novo protein design is a biologically relevant approach that provides a novel process in elucidating protein folding and modeling the metal centers of metalloproteins in a completely unrelated or simplified fold. An integral step in de novo protein design is the establishment of a well-folded scaffold with one conformation, which is a fundamental characteristic of many native proteins. Here, we report the NMR solution structure of apo α3DIV at pH 7.0, a de novo designed three-helix bundle peptide containing a triscysteine motif (Cys18, Cys28, and Cys67) that binds toxic heavy metals. The structure comprises 1067 NOE restraints derived from multinuclear multidimensional NOESY, as well as 138 dihedral angles (ψ, φ, and χ1). The backbone and heavy atoms of the 20 lowest energy structures have a root mean square deviation from the mean structure of 0.79 (0.16) Å and 1.31 (0.15) Å, respectively. When compared to the parent structure α3D, the substitution of Leu residues to Cys enhanced the α-helical content of α3DIV while maintaining the same overall topology and fold. In addition, solution studies on the metalated species illustrated metal-induced stability. An increase in the melting temperatures was observed for Hg(II), Pb(II), or Cd(II) bound α3DIV by 18-24 °C compared to its apo counterpart. Further, the extended X-ray absorption fine structure analysis on Hg(II)-α3DIV produced an average Hg(II)-S bond length at 2.36 Å, indicating a trigonal T-shaped coordination environment. Overall, the structure of apo α3DIV reveals an asymmetric distorted triscysteine metal binding site, which offers a model for native metalloregulatory proteins with thiol-rich ligands that function in regulating toxic heavy metals, such as ArsR, CadC, MerR, and PbrR.
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Affiliation(s)
| | - Stephen P Dzul
- #Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | | | - Timothy L Stemmler
- #Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, United States
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Rodrigues AV, Kandegedara A, Rotondo JA, Dancis A, Stemmler TL. Iron loading site on the Fe-S cluster assembly scaffold protein is distinct from the active site. Biometals 2015; 28:567-76. [PMID: 25782577 DOI: 10.1007/s10534-015-9846-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/05/2015] [Indexed: 11/30/2022]
Abstract
Iron-sulfur (Fe-S) cluster containing proteins are utilized in almost every biochemical pathway. The unique redox and coordination chemistry associated with the cofactor allows these proteins to participate in a diverse set of reactions, including electron transfer, enzyme catalysis, DNA synthesis and signaling within several pathways. Due to the high reactivity of the metal, it is not surprising that biological Fe-S cluster assembly is tightly regulated within cells. In yeast, the major assembly pathway for Fe-S clusters is the mitochondrial ISC pathway. Yeast Fe-S cluster assembly is accomplished using the scaffold protein (Isu1) as the molecular foundation, with assistance from the cysteine desulfurase (Nfs1) to provide sulfur, the accessory protein (Isd11) to regulate Nfs1 activity, the yeast frataxin homologue (Yfh1) to regulate Nfs1 activity and participate in Isu1 Fe loading possibly as a chaperone, and the ferredoxin (Yah1) to provide reducing equivalents for assembly. In this report, we utilize calorimetric and spectroscopic methods to provide molecular insight into how wt-Isu1 from S. cerevisiae becomes loaded with iron. Isothermal titration calorimetry and an iron competition binding assay were developed to characterize the energetics of protein Fe(II) binding. Differential scanning calorimetry was used to identify thermodynamic characteristics of the protein in the apo state or under iron loaded conditions. Finally, X-ray absorption spectroscopy was used to characterize the electronic and structural properties of Fe(II) bound to Isu1. Current data are compared to our previous characterization of the D37A Isu1 mutant, and these suggest that when Isu1 binds Fe(II) in a manner not perturbed by the D37A substitution, and that metal binding occurs at a site distinct from the cysteine rich active site in the protein.
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Affiliation(s)
- Andria V Rodrigues
- Departments of Biochemistry and Molecular Biology, Wayne State University, Detroit, MI, USA
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Hong-Hermesdorf A, Miethke M, Gallaher SD, Kropat J, Dodani SC, Chan J, Barupala D, Domaille DW, Shirasaki DI, Loo JA, Weber PK, Pett-Ridge J, Stemmler TL, Chang CJ, Merchant SS. Subcellular metal imaging identifies dynamic sites of Cu accumulation in Chlamydomonas. Nat Chem Biol 2014; 10:1034-42. [PMID: 25344811 PMCID: PMC4232477 DOI: 10.1038/nchembio.1662] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 09/05/2014] [Indexed: 12/03/2022]
Abstract
We identified a Cu accumulating structure with a dynamic role in intracellular Cu homeostasis. During Zn limitation, Chlamydomonas reinhardtii hyperaccumulated Cu, dependent on the nutritional Cu sensor CRR1, but was functionally Cu-deficient. Visualization of intracellular Cu revealed major Cu accumulation sites coincident with electron-dense structures that stained positive for low pH and polyphosphate, suggesting that they are lysosome-related organelles. NanoSIMS showed colocalization of Ca and Cu, and X-ray absorption spectroscopy (XAS) was consistent with Cu+ accumulation in an ordered structure. Zn resupply restored Cu homeostasis concomitant with reduced abundance of these structures. Cu isotope labeling demonstrated that sequestered Cu+ became bio-available for the synthesis of plastocyanin, and transcriptome profiling indicated that mobilized Cu became visible to CRR1. Cu trafficking to intracellular accumulation sites may be a strategy for preventing protein mis-metallation during Zn deficiency and enabling efficient cuproprotein (re)-metallation upon Zn resupply.
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Affiliation(s)
- Anne Hong-Hermesdorf
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA
| | - Marcus Miethke
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA
| | - Sean D Gallaher
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA
| | - Janette Kropat
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA
| | - Sheel C Dodani
- 1] Department of Chemistry, University of California-Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, California, USA
| | - Jefferson Chan
- 1] Department of Chemistry, University of California-Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, California, USA
| | - Dulmini Barupala
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA
| | - Dylan W Domaille
- 1] Department of Chemistry, University of California-Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, California, USA
| | - Dyna I Shirasaki
- Department of Biological Chemistry, University of California-Los Angeles, Los Angeles, California, USA
| | - Joseph A Loo
- 1] Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA. [2] Department of Biological Chemistry, University of California-Los Angeles, Los Angeles, California, USA. [3] Institute for Genomics and Proteomics, University of California-Los Angeles, Los Angeles, USA
| | - Peter K Weber
- Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, USA
| | - Jennifer Pett-Ridge
- Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, USA
| | - Timothy L Stemmler
- Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan, USA
| | - Christopher J Chang
- 1] Department of Chemistry, University of California-Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California-Berkeley, Berkeley, California, USA
| | - Sabeeha S Merchant
- 1] Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA. [2] Institute for Genomics and Proteomics, University of California-Los Angeles, Los Angeles, USA
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Abstract
Research on the one-electron reduced analogue of NO, namely nitroxyl (HNO/NO(-)), has revealed distinguishing properties regarding its utility as a therapeutic. However, the fleeting nature of HNO requires the design of donor molecules. Metal nitrosyl (MNO) complexes could serve as potential HNO donors. The synthesis, spectroscopic/structural characterization, and HNO donor properties of a {CoNO}(8) complex in a pyrrole/imine ligand frame are reported. The {CoNO}(8) complex [Co(LN4(PhCl))(NO)] (1) does not react with established HNO targets such as Fe(III) hemes or Ph3P. However, in the presence of stoichiometric H(+) 1 behaves as an HNO donor. Complex 1 readily reacts with [Fe(TPP)Cl] or Ph3P to afford the {FeNO}(7) porphyrin or Ph3P═O/Ph3P═NH, respectively. In the absence of an HNO target, the {Co(NO)2}(10) dinitrosyl (3) is the end product. Complex 1 also reacts with O2 to yield the corresponding Co(III)-η(1)-ONO2 (2) nitrato analogue. This report is the first to suggest an HNO donor role for {CoNO}(8) with biotargets such as Fe(III)-porphyrins.
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Affiliation(s)
- Melody A Rhine
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , Athens, Georgia 30602, United States
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Sirajuddin S, Barupala D, Helling S, Marcus K, Stemmler TL, Rosenzweig AC. Effects of zinc on particulate methane monooxygenase activity and structure. J Biol Chem 2014; 289:21782-94. [PMID: 24942740 PMCID: PMC4118136 DOI: 10.1074/jbc.m114.581363] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 06/11/2014] [Indexed: 11/06/2022] Open
Abstract
Particulate methane monooxygenase (pMMO) is a membrane-bound metalloenzyme that oxidizes methane to methanol in methanotrophic bacteria. Zinc is a known inhibitor of pMMO, but the details of zinc binding and the mechanism of inhibition are not understood. Metal binding and activity assays on membrane-bound pMMO from Methylococcus capsulatus (Bath) reveal that zinc inhibits pMMO at two sites that are distinct from the copper active site. The 2.6 Å resolution crystal structure of Methylocystis species strain Rockwell pMMO reveals two previously undetected bound lipids, and metal soaking experiments identify likely locations for the two zinc inhibition sites. The first is the crystallographic zinc site in the pmoC subunit, and zinc binding here leads to the ordering of 10 previously unobserved residues. A second zinc site is present on the cytoplasmic side of the pmoC subunit. Parallels between these results and zinc inhibition studies of several respiratory complexes suggest that zinc might inhibit proton transfer in pMMO.
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Affiliation(s)
- Sarah Sirajuddin
- From the Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Dulmini Barupala
- the Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, and
| | - Stefan Helling
- the Medical Proteome Center, Department of Functional Proteomics, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Katrin Marcus
- the Medical Proteome Center, Department of Functional Proteomics, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Timothy L Stemmler
- the Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, and
| | - Amy C Rosenzweig
- From the Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208,
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Pandey A, Gordon DM, Pain J, Stemmler TL, Dancis A, Pain D. Frataxin directly stimulates mitochondrial cysteine desulfurase by exposing substrate-binding sites, and a mutant Fe-S cluster scaffold protein with frataxin-bypassing ability acts similarly. J Biol Chem 2013; 288:36773-86. [PMID: 24217246 PMCID: PMC3873537 DOI: 10.1074/jbc.m113.525857] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 11/09/2013] [Indexed: 01/17/2023] Open
Abstract
For iron-sulfur (Fe-S) cluster synthesis in mitochondria, the sulfur is derived from the amino acid cysteine by the cysteine desulfurase activity of Nfs1. The enzyme binds the substrate cysteine in the pyridoxal phosphate-containing site, and a persulfide is formed on the active site cysteine in a manner depending on the accessory protein Isd11. The persulfide is then transferred to the scaffold Isu, where it combines with iron to form the Fe-S cluster intermediate. Frataxin is implicated in the process, although it is unclear where and how, and deficiency causes Friedreich ataxia. Using purified proteins and isolated mitochondria, we show here that the yeast frataxin homolog (Yfh1) directly and specifically stimulates cysteine binding to Nfs1 by exposing substrate-binding sites. This novel function of frataxin does not require iron, Isu1, or Isd11. Once bound to Nfs1, the substrate cysteine is the source of the Nfs1 persulfide, but this step is independent of frataxin and strictly dependent on Isd11. Recently, a point mutation in Isu1 was found to bypass many frataxin functions. The data presented here show that the Isu1 suppressor mimics the frataxin effects on Nfs1, explaining the bypassing activity. We propose a regulatory mechanism for the Nfs1 persulfide-forming activity. Specifically, at least two separate conformational changes must occur in the enzyme for optimum activity as follows: one is mediated by frataxin interaction that exposes the "buried" substrate-binding sites, and the other is mediated by Isd11 interaction that brings the bound substrate cysteine and the active site cysteine in proximity for persulfide formation.
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Affiliation(s)
- Alok Pandey
- From the Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey 07101
| | - Donna M. Gordon
- From the Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey 07101
| | - Jayashree Pain
- From the Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey 07101
| | - Timothy L. Stemmler
- the Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201, and
| | - Andrew Dancis
- the Department of Medicine, Division of Hematology-Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Debkumar Pain
- From the Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey 07101
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38
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Zielazinski EL, González-Guerrero M, Subramanian P, Stemmler TL, Argüello JM, Rosenzweig AC. Sinorhizobium meliloti Nia is a P(1B-5)-ATPase expressed in the nodule during plant symbiosis and is involved in Ni and Fe transport. Metallomics 2013; 5:1614-1623. [PMID: 24056637 DOI: 10.1039/c3mt00195d] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The P1B-ATPases are a ubiquitous family of metal transporters. These transporters are classified into subfamilies on the basis of substrate specificity, which is conferred by conserved amino acids in the last three transmembrane domains. Five subfamilies have been identified to date, and representative members of four (P1B-1 to P1B-4) have been studied. The fifth family (P1B-5), of which some members contain a C-terminal hemerythrin (Hr) domain, is less well characterized. The S. meliloti Sma1163 gene encodes for a P1B-5-ATPase, denoted Nia (Nickel-iron ATPase), that is induced by exogenous Fe(2+) and Ni(2+). The nia mutant accumulates nickel and iron, suggesting a possible role in detoxification of these two elements under free-living conditions, as well as in symbiosis, when the highest expression levels are measured. This function is supported by an inhibitory effect of Fe(2+) and Ni(2+) on the pNPPase activity, and by the ability of Nia to bind Fe(2+) in the transmembrane domain. Optical and X-ray absorption spectroscopic studies of the isolated Hr domain confirm the presence of a dinuclear iron center and suggest that this domain might function as an iron sensor.
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Affiliation(s)
- Eliza L Zielazinski
- Departments of Molecular Biosciences and of Chemistry. Northwestern University, Evanston, Illinois, USA.
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, Madrid, Spain
| | - Poorna Subramanian
- Department of Biochemistry and Molecular Biology and the Cardiovascular Research Institute, Wayne State University, School of Medicine, Detroit, Michigan, USA
| | - Timothy L Stemmler
- Department of Biochemistry and Molecular Biology and the Cardiovascular Research Institute, Wayne State University, School of Medicine, Detroit, Michigan, USA
| | - José M Argüello
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA.
| | - Amy C Rosenzweig
- Departments of Molecular Biosciences and of Chemistry. Northwestern University, Evanston, Illinois, USA.
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Leidgens S, Bullough KZ, Shi H, Li F, Shakoury-Elizeh M, Yabe T, Subramanian P, Hsu E, Natarajan N, Nandal A, Stemmler TL, Philpott CC. Each member of the poly-r(C)-binding protein 1 (PCBP) family exhibits iron chaperone activity toward ferritin. J Biol Chem 2013; 288:17791-802. [PMID: 23640898 DOI: 10.1074/jbc.m113.460253] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The mechanisms through which iron-dependent enzymes receive their metal cofactors are largely unknown. Poly r(C)-binding protein 1 (PCBP1) is an iron chaperone for ferritin; both PCBP1 and its paralog PCBP2 are required for iron delivery to the prolyl hydroxylase that regulates HIF1. Here we show that PCBP2 is also an iron chaperone for ferritin. Co-expression of PCBP2 and human ferritins in yeast activated the iron deficiency response and increased iron deposition into ferritin. Depletion of PCBP2 in Huh7 cells diminished iron incorporation into ferritin. Both PCBP1 and PCBP2 were co-immunoprecipitated with ferritin in HEK293 cells, and expression of both PCBPs was required for ferritin complex formation in cells. PCBP1 and -2 exhibited high affinity binding to ferritin in vitro. Mammalian genomes encode 4 PCBPs, including the minimally expressed PCBPs 3 and 4. Expression of PCBP3 and -4 in yeast activated the iron deficiency response, but only PCBP3 exhibited strong interactions with ferritin. Expression of PCBP1 and ferritin in an iron-sensitive, ccc1 yeast strain intensified the toxic effects of iron, whereas expression of PCBP4 protected the cells from iron toxicity. Thus, PCBP1 and -2 form a complex for iron delivery to ferritin, and all PCBPs may share iron chaperone activity.
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Affiliation(s)
- Sebastien Leidgens
- From the Liver Diseases Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-1800, USA
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40
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Gopalasubramaniam SK, Kondapalli KC, Millán-Pacheco C, Pastor N, Stemmler TL, Moran JF, Arredondo-Peter R. Soybean dihydrolipoamide dehydrogenase (ferric leghemoglobin reductase 2) interacts with and reduces ferric rice non-symbiotic hemoglobin 1. Scijet 2013; 2:33. [PMID: 25431759 PMCID: PMC4243682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ferrous oxygenated hemoglobins (Hb2+O2) autoxidize to ferric Hb3+, but Hb3+ is reduced to Hb2+ by enzymatic and non-enzymatic mechanisms. We characterized the interaction between the soybean ferric leghemoglobin reductase 2 (FLbR2) and ferric rice non-symbiotic Hb1 (Hb13+). Spectroscopic analysis showed that FLbR2 reduces Hb13+. Analysis by tryptophan fluorescence quenching showed that FLbR2 interacts with Hb13+, however the use of ITC and IEF techniques revealed that this interaction is weak. In silico modeling showed that predicted FLbR2 and native Hb13+ interact at the FAD-binding domain of FLbR2 and the CD-loop and helix F of Hb13+.
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Affiliation(s)
- Sabarinathan K. Gopalasubramaniam
- Lab. de Biofísica y Biología Molecular, Universidad Autónoma del Estado de Morelos, Ave. Universidad 1001 Col. Chamilpa, 62210 Cuernavaca, Morelos, México
| | - Kalyan C. Kondapalli
- Dept. of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA
| | - César Millán-Pacheco
- Fac. de Ciencias, Universidad Autónoma del Estado de Morelos, Ave. Universidad 1001, Col. Chamilpa, 62210 Cuernavaca, Morelos, México
| | - Nina Pastor
- Fac. de Ciencias, Universidad Autónoma del Estado de Morelos, Ave. Universidad 1001, Col. Chamilpa, 62210 Cuernavaca, Morelos, México
| | - Timothy L. Stemmler
- Dept. of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA
| | - Jose F. Moran
- Depto. de Ciencias del Medio Natural/Dept. of Environmental Sciences, Public University of Navarre, Spain
| | - Raúl Arredondo-Peter
- Lab. de Biofísica y Biología Molecular, Universidad Autónoma del Estado de Morelos, Ave. Universidad 1001 Col. Chamilpa, 62210 Cuernavaca, Morelos, México
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Abstract
The P(1B)-type ATPases are a ubiquitous family of P-type ATPases involved in the transport of transition metal ions. Divided into subclasses based on sequence characteristics and substrate specificity, these integral membrane transporters play key roles in metal homeostasis, metal tolerance, and the biosynthesis of metalloproteins. The P(1B-4)-ATPases have the simplest architecture of the five P(1B)-ATPase families and have been suggested to play a role in Co(2+) transport. A P(1B-4)-ATPase from Sulfitobacter sp. NAS-14.1, designated sCoaT, has been cloned, expressed, and purified. Activity assays indicate that sCoaT is specific for Co(2+). A single Co(2+) binding site is present, and optical, electron paramagnetic resonance, and X-ray absorption spectroscopic data are consistent with tetrahedral coordination by oxygen and nitrogen ligands, including a histidine and likely a water. Surprisingly, there is no evidence for coordination by sulfur. Mutation of a conserved cysteine residue, Cys 327, in the signature transmembrane Ser-Pro-Cys metal binding motif does not abolish the ATP hydrolysis activity or affect the spectroscopic analysis, establishing that this residue is not involved in the initial Co(2+) binding by sCoaT. In contrast, replacements of conserved transmembrane residues Ser 325, His 657, Glu 658, and Thr 661 with alanine abolish ATP hydrolysis activity and Co(2+) binding, indicating that these residues are necessary for Co(2+) transport. These data represent the first in vitro characterization of a P(1B-4)-ATPase and its Co(2+) binding site.
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Affiliation(s)
- Eliza L Zielazinski
- Departments of Molecular Biosciences and Chemistry, Northwestern University, Evanston, Illinois 60208, USA
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42
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Kowert BA, Stemmler ABJ, Stemmler TL, Gentemann SJ, Watson MB, Goodwill VS. Molecular motion of the bis(maleonitriledithiolato)nickel trianion in solution. J Phys Chem B 2012; 116:7687-94. [PMID: 22731510 DOI: 10.1021/jp302598z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electron spin resonance (ESR) has been used to study the reorientational motion of the bis(maleonitriledithiolato)nickel trianion, [Ni(mnt)(2)](3-), in diethylene glycol dimethyl ether (diglyme). [Ni(mnt)(2)](3-) has one unpaired electron and was prepared by reducing the dianion, [Ni(mnt)(2)](2-), with potassium metal. The trianion and dianion are members of the redox series [Ni(mnt)(2)](n-) with n = 0, 1, 2, and 3. The monoanion, [Ni(mnt)(2)](-), also has S = 1/2 and its rotational diffusion in diglyme was the subject of previous ESR studies. This made possible the comparison of the reorientational data for two different oxidation states of the same planar complex in the same solvent. Differences were found; isotropic rotational diffusion produced agreement between the trianion's experimental and calculated spectra, whereas the monoanion's simulations required axially symmetric reorientation with diffusion about the long in-plane axis three times faster than that about the two perpendicular axes. At a given temperature, the monoanion's reorientation rates about the long in-plane axis and two perpendicular axes were faster than the trianion's isotropic rate by factors of ∼27 and ∼9, respectively. These differences suggest that [Ni(mnt)(2)](-) and [Ni(mnt)(2)](3-) have different shapes and sizes in solution; the monoanion is approximately a prolate ellipsoid, whereas the trianion is larger and more spherical. [Ni(mnt)(2)](3-) appears to be ion-paired, whereas in accord with results from other techniques, [Ni(mnt)(2)](-) is not.
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Affiliation(s)
- Bruce A Kowert
- Department of Chemistry, St. Louis University, 3501 Laclede Ave., St. Louis, Missouri 63103, USA.
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Smith SM, Rawat S, Telser J, Hoffman BM, Stemmler TL, Rosenzweig AC. Crystal structure and characterization of particulate methane monooxygenase from Methylocystis species strain M. Biochemistry 2011; 50:10231-40. [PMID: 22013879 PMCID: PMC3364217 DOI: 10.1021/bi200801z] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Particulate methane monooxygenase (pMMO) is an integral membrane metalloenzyme that oxidizes methane to methanol in methanotrophic bacteria. Previous biochemical and structural studies of pMMO have focused on preparations from Methylococcus capsulatus (Bath) and Methylosinus trichosporium OB3b. A pMMO from a third organism, Methylocystis species strain M, has been isolated and characterized. Both membrane-bound and solubilized Methylocystis sp. strain M pMMO contain ~2 copper ions per 100 kDa protomer and exhibit copper-dependent propylene epoxidation activity. Spectroscopic data indicate that Methylocystis sp. strain M pMMO contains a mixture of Cu(I) and Cu(II), of which the latter exhibits two distinct type 2 Cu(II) electron paramagnetic resonance (EPR) signals. Extended X-ray absorption fine structure (EXAFS) data are best fit with a mixture of Cu-O/N and Cu-Cu ligand environments with a Cu-Cu interaction at 2.52-2.64 Å. The crystal structure of Methylocystis sp. strain M pMMO was determined to 2.68 Å resolution and is the best quality pMMO structure obtained to date. It provides a revised model for the pmoA and pmoC subunits and has led to an improved model of M. capsulatus (Bath) pMMO. In these new structures, the intramembrane zinc/copper binding site has a different coordination environment from that in previous models.
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Affiliation(s)
- Stephen M. Smith
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Swati Rawat
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, Michigan 48201, United States
| | - Joshua Telser
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Brian M. Hoffman
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Timothy L. Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, Michigan 48201, United States
| | - Amy C. Rosenzweig
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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Nandal A, Ruiz JC, Subramanian P, Ghimire-Rijal S, Sinnamon RA, Stemmler TL, Bruick RK, Philpott CC. Activation of the HIF prolyl hydroxylase by the iron chaperones PCBP1 and PCBP2. Cell Metab 2011; 14:647-57. [PMID: 22055506 PMCID: PMC3361910 DOI: 10.1016/j.cmet.2011.08.015] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Revised: 05/20/2011] [Accepted: 08/31/2011] [Indexed: 01/23/2023]
Abstract
Mammalian cells express dozens of iron-containing proteins, yet little is known about the mechanism of metal ligand incorporation. Human poly (rC) binding protein 1 (PCBP1) is an iron chaperone that binds iron and delivers it to ferritin, a cytosolic iron storage protein. We have identified the iron-dependent prolyl hydroxylases (PHDs) and asparaginyl hydroxylase (FIH1) that modify hypoxia-inducible factor α (HIFα) as targets of PCBP1. Depletion of PCBP1 or PCBP2 in cells led to loss of PHD activity, manifested by reduced prolyl hydroxylation of HIF1α, impaired degradation of HIF1α through the VHL/proteasome pathway, and accumulation of active HIF1 transcription factor. PHD activity was restored in vitro by addition of excess Fe(II), or purified Fe-PCBP1, and PCBP1 bound to PHD2 and FIH1 in vivo. These data indicated that PCBP1 was required for iron incorporation into PHD and suggest a broad role for PCBP1 and 2 in delivering iron to cytosolic nonheme iron enzymes.
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Affiliation(s)
- Anjali Nandal
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julio C. Ruiz
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Poorna Subramanian
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Sudipa Ghimire-Rijal
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Ruth Ann Sinnamon
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Timothy L. Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Richard K. Bruick
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Caroline C. Philpott
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Correspondence:
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45
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Ye J, He Y, Skalicky J, Rosen BP, Stemmler TL. Resonance assignments and secondary structure prediction of the As(III) metallochaperone ArsD in solution. Biomol NMR Assign 2011; 5:109-112. [PMID: 21063813 PMCID: PMC3364515 DOI: 10.1007/s12104-010-9279-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 10/21/2010] [Indexed: 05/30/2023]
Abstract
ArsD is a metallochaperone that delivers As(III) to the ArsA ATPase, the catalytic subunit of the ArsAB pump encoded by the arsRDABC operon of Escherichia coli plasmid R773. Conserved ArsD cysteine residues (Cys(12), Cys(13) and Cys(18)) construct the As(III) binding site of the protein, however a global structural understanding of this arsenic binding remains unclear. We have obtained NMR assignments for ArsD as a starting point for probing structural changes on the protein that occur in response to metalloid binding and upon formation of a complex with ArsA. The predicted solution structure of ArsD is in agreement with recently published crystallographic structural results.
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Affiliation(s)
- Jun Ye
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Abstract
Iron-sulfur clusters are multifaceted iron-containing cofactors coordinated and utilized by numerous proteins in nearly all biological systems. Fe-S-cluster-containing proteins help direct pathways essential for cell viability and participate in biological applications ranging from nucleotide biosynthesis and stability, protein translation, enzyme catalysis, and mitochondrial metabolism. Fe-S-containing proteins function by utilizing the unique electronic and chemical properties inherent in the Fe containing cofactor. Fe-S clusters are constructed of inorganic iron and sulfide arranged in a distinct caged structural makeup ranging from [Fe(2) -S(2) ], [Fe(3) -S(4) ], [Fe(4) -S(4) ], up to [Fe(8) -S(8) ] clusters. In eukaryotes, cluster activity is controlled in part at the assembly level and the major pathway for cluster production exists within the mitochondria. Recent insight into the pathway of mitochondrial cluster assembly has come from new in vivo and in vitro reports that provided direct insight into how all protein partners within the assembly pathway interact. However, we are only just beginning to understand the role of each protein within this complex pageant that is mitochondrial Fe-S cluster assembly. In this report we present results, using the yeast model for mitochondrial assembly, to describe the molecular details of how important proteins in the pathway coordinate for cluster assembly.
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Affiliation(s)
- Swati Rawat
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, 540 E. Canfield Ave. Detroit, MI 48201 (USA), Fax: (+01)313-577-5712
| | - Timothy L. Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, 540 E. Canfield Ave. Detroit, MI 48201 (USA), Fax: (+01)313-577-5712
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Cook JD, Kondapalli KC, Rawat S, Childs WC, Murugesan Y, Dancis A, Stemmler TL. Molecular details of the yeast frataxin-Isu1 interaction during mitochondrial Fe-S cluster assembly. Biochemistry 2010; 49:8756-65. [PMID: 20815377 PMCID: PMC3005940 DOI: 10.1021/bi1008613] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Frataxin, a conserved nuclear-encoded mitochondrial protein, plays a direct role in iron-sulfur cluster biosynthesis within the ISC assembly pathway. Humans with frataxin deficiency have Friedreich's ataxia, a neurodegenerative disorder characterized by mitochondrial iron overload and disruption in Fe-S cluster synthesis. Biochemical and genetic studies have shown frataxin interacts with the iron-sulfur cluster assembly scaffold protein (in yeast, there are two, Isu1 and Isu2), indicating frataxin plays a direct role in cluster assembly, possibly by serving as an iron chaperone in the assembly pathway. Here we provide molecular details of how yeast frataxin (Yfh1) interacts with Isu1 as a structural module to improve our understanding of the multiprotein complex assembly that completes Fe-S cluster assembly; this complex also includes the cysteine desulfurase (Nfs1 in yeast) and the accessory protein (Isd11), together in the mitochondria. Thermodynamic binding parameters for protein partner and iron binding were measured for the yeast orthologs using isothermal titration calorimetry. Nuclear magnetic resonance spectroscopy was used to provide the molecular details to understand how Yfh1 interacts with Isu1. X-ray absorption studies were used to electronically and structurally characterize how iron is transferred to Isu1 and then incorporated into an Fe-S cluster. These results were combined with previously published data to generate a structural model for how the Fe-S cluster protein assembly complex can come together to accomplish Fe-S cluster assembly.
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Affiliation(s)
- Jeremy D. Cook
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, MI, 48201 USA
| | - Kalyan C. Kondapalli
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, MI, 48201 USA
| | - Swati Rawat
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, MI, 48201 USA
| | - William C. Childs
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, MI, 48201 USA
| | - Yogapriya Murugesan
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, MI, 48201 USA
| | - Andrew Dancis
- Department of Medicine, Division of Hematology-Oncology, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Timothy L. Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, MI, 48201 USA
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Abstract
Friedreich ataxia is an inherited neurodegenerative disease caused by frataxin deficiency. Frataxin is a conserved mitochondrial protein that plays a role in FeS cluster assembly in mitochondria. FeS clusters are modular cofactors that perform essential functions throughout the cell. They are synthesized by a multistep and multisubunit mitochondrial machinery that includes the scaffold protein Isu for assembling a protein-bound FeS cluster intermediate. Frataxin interacts with Isu, iron, and the cysteine desulfurase Nfs1, which supplies sulfide, thus placing it at the center of mitochondrial FeS cluster biosynthesis.
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Affiliation(s)
- Timothy L Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan 48201, France
| | - Emmanuel Lesuisse
- Laboratoire Mitochondrie, Metaux et Stress Oxydant, Institut Jacques Monod, CNRS-Universite Paris Diderot, 75205 Paris, France
| | - Debkumar Pain
- Department of Pharmacology and Physiology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07101
| | - Andrew Dancis
- Department of Medicine, Division of Hematology-Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
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Traverso ME, Subramanian P, Davydov R, Hoffman BM, Stemmler TL, Rosenzweig AC. Identification of a hemerythrin-like domain in a P1B-type transport ATPase. Biochemistry 2010; 49:7060-8. [PMID: 20672819 PMCID: PMC2935145 DOI: 10.1021/bi100866b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The P(1B)-type ATPases couple the energy of ATP hydrolysis to metal ion translocation across cell membranes. Important for prokaryotic metal resistance and essential metal distribution in eukaryotes, P(1B)-ATPases are divided into subclasses on the basis of their metal substrate specificities. Sequence analysis of putative P(1B-5)-ATPases, for which the substrate has not been identified, led to the discovery of a C-terminal soluble domain homologous to hemerythrin (Hr) proteins and domains. The Hr domain from the Acidothermus cellulolyticus P(1B-5)-ATPase was cloned, expressed, and purified (P(1B-5)-Hr). P(1B-5)-Hr binds two iron ions per monomer and adopts a predominantly helical fold. Optical absorption features of the iron-loaded and azide-treated protein are consistent with features observed for other Hr proteins. Autoxidation to the met form is very rapid, as reported for other prokaryotic Hr domains. The presence of a diiron center was confirmed by electron paramagnetic resonance (EPR) and X-ray absorption spectroscopic (XAS) data. The occurrence of a Hr-like domain in a P-type ATPase is unprecedented and suggests new regulatory mechanisms as well as an expanded function for Hr proteins in biology.
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Affiliation(s)
- Matthew E. Traverso
- Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston IL 60208
- Department of Chemistry, Northwestern University, Evanston IL 60208
| | - Poorna Subramanian
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit MI 48202
| | - Roman Davydov
- Department of Chemistry, Northwestern University, Evanston IL 60208
| | - Brian M. Hoffman
- Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston IL 60208
- Department of Chemistry, Northwestern University, Evanston IL 60208
| | - Timothy L. Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit MI 48202
| | - Amy C. Rosenzweig
- Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston IL 60208
- Department of Chemistry, Northwestern University, Evanston IL 60208
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50
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Abstract
Approximately 11% smaller t-/v-SNARE ring complexes are generated using 50 nm cholesterol-associated vesicles as opposed to vesicles containing L-alpha-lysophosphatidylcholine (LPC), as observed using atomic force microscopy. Circular dichroism spectroscopy demonstrated that in the presence of LPC as opposed to cholesterol, N-ethylmaleimide-sensitive factor + adenosine triphosphate induces disassembly of beta-sheet structures but not the alpha-helical contents within the t-/v-SNARE complex.
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Affiliation(s)
- Leah Shin
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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