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Ciambellotti S, Pratesi A, Tassone G, Turano P, Mangani S, Pozzi C. Iron Binding in the Ferroxidase Site of Human Mitochondrial Ferritin. Chemistry 2021; 27:14690-14701. [PMID: 34343376 DOI: 10.1002/chem.202102270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Indexed: 12/12/2022]
Abstract
Ferritins are nanocage proteins that store iron ions in their central cavity as hydrated ferric oxide biominerals. In mammals, further the L (light) and H (heavy) chains constituting cytoplasmic maxi-ferritins, an additional type of ferritin has been identified, the mitochondrial ferritin (MTF). Human MTF (hMTF) is a functional homopolymeric H-like ferritin performing the ferroxidase activity in its ferroxidase site (FS), in which Fe(II) is oxidized to Fe(III) in the presence of dioxygen. To better investigate its ferroxidase properties, here we performed time-lapse X-ray crystallography analysis of hMTF, providing structural evidence of how iron ions interact with hMTF and of their binding to the FS. Transient iron binding sites, populating the pathway along the cage from the iron entry channel to the catalytic center, were also identified. Furthermore, our kinetic data at variable iron loads indicate that the catalytic iron oxidation reaction occurs via a diferric peroxo intermediate followed by the formation of ferric-oxo species, with significant differences with respect to human H-type ferritin.
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Affiliation(s)
- Silvia Ciambellotti
- Department of Chemistry "Ugo Schiff" Department of Excellence 2018-2022, University of Florence, via della Lastruccia 2, 50019, Sesto Fiorentino, Italy.,Magnetic Resonance Center (CERM), University of Florence, Luigi Sacconi 6, 50019, Sesto Fiorentino (FI), Italy.,Consorzio Interuniversitario Risonanze Magnetiche di, Metallo Proteine (C.I.R.M.M.P.), via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
| | - Alessandro Pratesi
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via Giuseppe Moruzzi 13, 56124, Pisa, Italy
| | - Giusy Tassone
- Department of Biotechnology, Chemistry and Pharmacy Department of Excellence 2018-2020, University of Siena, via Aldo Moro, 2, 53110, Siena, Italy
| | - Paola Turano
- Department of Chemistry "Ugo Schiff" Department of Excellence 2018-2022, University of Florence, via della Lastruccia 2, 50019, Sesto Fiorentino, Italy.,Magnetic Resonance Center (CERM), University of Florence, Luigi Sacconi 6, 50019, Sesto Fiorentino (FI), Italy.,Consorzio Interuniversitario Risonanze Magnetiche di, Metallo Proteine (C.I.R.M.M.P.), via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
| | - Stefano Mangani
- Magnetic Resonance Center (CERM), University of Florence, Luigi Sacconi 6, 50019, Sesto Fiorentino (FI), Italy.,Consorzio Interuniversitario Risonanze Magnetiche di, Metallo Proteine (C.I.R.M.M.P.), via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy.,Department of Biotechnology, Chemistry and Pharmacy Department of Excellence 2018-2020, University of Siena, via Aldo Moro, 2, 53110, Siena, Italy
| | - Cecilia Pozzi
- Department of Biotechnology, Chemistry and Pharmacy Department of Excellence 2018-2020, University of Siena, via Aldo Moro, 2, 53110, Siena, Italy
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2
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Effect of the point mutation H54N on the ferroxidase process of Rana catesbeiana H′ ferritin. J Inorg Biochem 2019; 197:110697. [DOI: 10.1016/j.jinorgbio.2019.110697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 01/15/2023]
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3
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Chandramouli B, Del Galdo S, Mancini G, Barone V. Mechanistic insights into metal ions transit through threefold ferritin channel. Biochim Biophys Acta Gen Subj 2018; 1863:472-480. [PMID: 30496786 DOI: 10.1016/j.bbagen.2018.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/26/2018] [Accepted: 11/14/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND The mechanism of how the hydrophilic threefold channel (C3) of ferritin nanocages facilitates diffusion of diverse metal ions into the internal cavity remains poorly explored. METHODS Computational modeling and free energy estimations were carried out on R. catesbeiana H´ ferritin. Transit features and associated energetics for Fe2+, Mg2+, Zn2+ ions through the C3 channel have been examined. RESULTS We highlight that iron conduction requires the involvement of two Fe2+ ions in the channel. In such doubly occupied configuration, as observed in X-ray structures, Fe2+ is displaced from the internal site (stabilized by D127) at lower energetic cost. Moreover, comparison of Fe2+, Mg2+ and Zn2+ transit features shows that E130 geometric constriction provides not only an electrostatic anchor to the incoming ions but also differentially influence their diffusion kinetics. CONCLUSIONS Overall, the study provides insights into Fe2+ entry mechanism and characteristic features of metal-protein interactions that influence the metal ions passage. The dynamics data suggest that E130 may act as a metal selectivity gate. This implicates an ion-specific entry mechanism through the channel with the distinct diffusion kinetics being the discriminating factor. GENERAL SIGNIFICANCE Ferritin nanocages not only act as biological iron reservoirs but also have gained importance in material science as template scaffolds for synthesizing metal nanoparticles. This study provides mechanistic understanding on the conduction of different metal ions through the channel.
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Affiliation(s)
- Balasubramanian Chandramouli
- Compunet, Istituto Italiano di Tecnologia (IIT), Via Morego 30, I-16163 Genova, Italy; Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.
| | - Sara Del Galdo
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy; Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti OrganoMetallici (ICCOMCNR), UOS di Pisa, Area della Ricerca CNR, Via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Giordano Mancini
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy; Istituto Nazionale di Fisica Nucleare (INFN) sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127, Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy; Istituto Nazionale di Fisica Nucleare (INFN) sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127, Pisa, Italy
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4
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Ahn B, Lee SG, Yoon HR, Lee JM, Oh HJ, Kim HM, Jung Y. Four-fold Channel-Nicked Human Ferritin Nanocages for Active Drug Loading and pH-Responsive Drug Release. Angew Chem Int Ed Engl 2018; 57:2909-2913. [DOI: 10.1002/anie.201800516] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Indexed: 01/07/2023]
Affiliation(s)
- Byungjun Ahn
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Seong-Gyu Lee
- Department of Biological Sciences; Korea Advanced Institute of Science and Technology; Korea
| | - Hye Ryeon Yoon
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Jeong Min Lee
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Hyeok Jin Oh
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering; Korea Advanced Institute of Science and Technology; Korea
| | - Yongwon Jung
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
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5
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Ahn B, Lee SG, Yoon HR, Lee JM, Oh HJ, Kim HM, Jung Y. Four-fold Channel-Nicked Human Ferritin Nanocages for Active Drug Loading and pH-Responsive Drug Release. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800516] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Byungjun Ahn
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Seong-Gyu Lee
- Department of Biological Sciences; Korea Advanced Institute of Science and Technology; Korea
| | - Hye Ryeon Yoon
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Jeong Min Lee
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Hyeok Jin Oh
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering; Korea Advanced Institute of Science and Technology; Korea
| | - Yongwon Jung
- Department of Chemistry; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
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Ferraro G, Ciambellotti S, Messori L, Merlino A. Cisplatin Binding Sites in Human H-Chain Ferritin. Inorg Chem 2017; 56:9064-9070. [PMID: 28737381 DOI: 10.1021/acs.inorgchem.7b01072] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The aim of this work is to identify the cisplatin binding sites on human H-chain ferritin. High-resolution X-ray crystallography reveals that cisplatin binds four distinct protein sites, that is, the side chains of His136 and Lys68, the side chain of His105, the side chain of Cys90 and the side chain of Cys102. These Pt binding sites are compared with those observed for the adduct that cisplatin forms upon encapsulation within horse spleen L-chain ferritin (87% identity with human L-chain ferritin).
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Affiliation(s)
- Giarita Ferraro
- Department of Chemical Sciences, University of Naples Federico II , Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126 Naples, Italy
| | - Silvia Ciambellotti
- Dipartimento di Chimica, Università di Firenze , Via Della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
| | - Luigi Messori
- Dipartimento di Chimica, Università di Firenze , Via Della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
| | - Antonello Merlino
- Department of Chemical Sciences, University of Naples Federico II , Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126 Naples, Italy.,Institute of Biostructures and Bioimages , Naples, Italy
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7
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Ravera E, Martelli T, Geiger Y, Fragai M, Goobes G, Luchinat C. Biosilica and bioinspired silica studied by solid-state NMR. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.06.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Chandramouli B, Bernacchioni C, Di Maio D, Turano P, Brancato G. Electrostatic and Structural Bases of Fe2+ Translocation through Ferritin Channels. J Biol Chem 2016; 291:25617-25628. [PMID: 27756844 DOI: 10.1074/jbc.m116.748046] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/03/2016] [Indexed: 01/14/2023] Open
Abstract
Ferritin molecular cages are marvelous 24-mer supramolecular architectures that enable massive iron storage (>2000 iron atoms) within their inner cavity. This cavity is connected to the outer environment by two channels at C3 and C4 symmetry axes of the assembly. Ferritins can also be exploited as carriers for in vivo imaging and therapeutic applications, owing to their capability to effectively protect synthetic non-endogenous agents within the cage cavity and deliver them to targeted tissue cells without stimulating adverse immune responses. Recently, X-ray crystal structures of Fe2+-loaded ferritins provided important information on the pathways followed by iron ions toward the ferritin cavity and the catalytic centers within the protein. However, the specific mechanisms enabling Fe2+ uptake through wild-type and mutant ferritin channels is largely unknown. To shed light on this question, we report extensive molecular dynamics simulations, site-directed mutagenesis, and kinetic measurements that characterize the transport properties and translocation mechanism of Fe2+ through the two ferritin channels, using the wild-type bullfrog Rana catesbeiana H' protein and some of its variants as case studies. We describe the structural features that determine Fe2+ translocation with atomistic detail, and we propose a putative mechanism for Fe2+ transport through the channel at the C3 symmetry axis, which is the only iron-permeable channel in vertebrate ferritins. Our findings have important implications for understanding how ion permeation occurs, and further how it may be controlled via purposely engineered channels for novel biomedical applications based on ferritin.
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Affiliation(s)
- Balasubramanian Chandramouli
- From the Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, .,the Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, and
| | - Caterina Bernacchioni
- the Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Danilo Di Maio
- From the Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa.,the Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, and
| | - Paola Turano
- the Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Giuseppe Brancato
- From the Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, .,the Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, and
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9
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Bernacchioni C, Pozzi C, Di Pisa F, Mangani S, Turano P. Ferroxidase Activity in Eukaryotic Ferritin is Controlled by Accessory-Iron-Binding Sites in the Catalytic Cavity. Chemistry 2016; 22:16213-16219. [DOI: 10.1002/chem.201602842] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Caterina Bernacchioni
- CERM and Department of Chemistry; University of Florence; Via Sacconi 6 Sesto Fiorentino Firenze 50019 Italy
| | - Cecilia Pozzi
- Dipartimento di Biotecnologie; Chimica e Farmacia; University of Siena; Via Aldo Moro 2 Siena 53100 Italy
| | - Flavio Di Pisa
- Dipartimento di Biotecnologie; Chimica e Farmacia; University of Siena; Via Aldo Moro 2 Siena 53100 Italy
| | - Stefano Mangani
- Dipartimento di Biotecnologie; Chimica e Farmacia; University of Siena; Via Aldo Moro 2 Siena 53100 Italy
| | - Paola Turano
- CERM and Department of Chemistry; University of Florence; Via Sacconi 6 Sesto Fiorentino Firenze 50019 Italy
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10
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Theil EC, Tosha T, Behera RK. Solving Biology's Iron Chemistry Problem with Ferritin Protein Nanocages. Acc Chem Res 2016; 49:784-91. [PMID: 27136423 DOI: 10.1021/ar500469e] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ferritins reversibly synthesize iron-oxy(ferrihydrite) biominerals inside large, hollow protein nanocages (10-12 nm, ∼480 000 g/mol); the iron biominerals are metabolic iron concentrates for iron protein biosyntheses. Protein cages of 12- or 24-folded ferritin subunits (4-α-helix polypeptide bundles) self-assemble, experimentally. Ferritin biomineral structures differ among animals and plants or bacteria. The basic ferritin mineral structure is ferrihydrite (Fe2O3·H2O) with either low phosphate in the highly ordered animal ferritin biominerals, Fe/PO4 ∼ 8:1, or Fe/PO4 ∼ 1:1 in the more amorphous ferritin biominerals of plants and bacteria. While different ferritin environments, plant bacterial-like plastid organelles and animal cytoplasm, might explain ferritin biomineral differences, investigation is required. Currently, the physiological significance of plant-specific and animal-specific ferritin iron minerals is unknown. The iron content of ferritin in living tissues ranges from zero in "apoferritin" to as high as ∼4500 iron atoms. Ferritin biomineralization begins with the reaction of Fe(2+) with O2 at ferritin enzyme (Fe(2+)/O oxidoreductase) sites. The product of ferritin enzyme activity, diferric oxy complexes, is also the precursor of ferritin biomineral. Concentrations of Fe(3+) equivalent to 2.0 × 10(-1) M are maintained in ferritin solutions, contrasting with the Fe(3+) Ks ∼ 10(-18) M. Iron ions move into, through, and out of ferritin protein cages in structural subdomains containing conserved amino acids. Cage subdomains include (1) ion channels for Fe(2+) entry/exit, (2) enzyme (oxidoreductase) site for coupling Fe(2+) and O yielding diferric oxy biomineral precursors, and (3) ferric oxy nucleation channels, where diferric oxy products from up to three enzyme sites interact while moving toward the central, biomineral growth cavity (12 nm diameter) where ferric oxy species, now 48-mers, grow in ferric oxy biomineral. High ferritin protein cage symmetry (3-fold and 4-fold axes) and amino acid conservation coincide with function, shown by amino acid substitution effects. 3-Fold symmetry axes control Fe(2+) entry (enzyme catalysis of Fe(2+)/O2 oxidoreduction) and Fe(2+) exit (reductive ferritin mineral dissolution); 3-fold symmetry axes influence Fe(2+)exit from dissolved mineral; bacterial ferritins diverge slightly in Fe/O2 reaction mechanisms and intracage paths of iron-oxy complexes. Biosynthesis rates of ferritin protein change with Fe(2+) and O2 concentrations, dependent on DNA-binding, and heme binding protein, Bach 1. Increased cellular O2 indirectly stabilizes ferritin DNA/Bach 1 interactions. Heme, Fe-protoporphyrin IX, decreases ferritin DNA-Bach 1 binding, causing increased ferritin mRNA biosynthesis (transcription). Direct Fe(2+) binding to ferritin mRNA decreases binding of an inhibitory protein, IRP, causing increased ferritin mRNA translation (protein biosynthesis). Newly synthesized ferritin protein consumes Fe(2+) in biomineral, decreasing Fe(2)(+) and creating a regulatory feedback loop. Ferritin without iron is "apoferritin". Iron removal from ferritin, experimentally, uses biological reductants, for example, NADH + FMN, or chemical reductants, for example, thioglycolic acid, with Fe(2+) chelators; physiological mechanism(s) are murky. Clear, however, is the necessity of ferritin for terrestrial life by conferring oxidant protection (plants, animals, and bacteria), virulence (bacteria), and embryonic survival (mammals). Future studies of ferritin structure/function and Fe(2+)/O2 chemistry will lead to new ferritin uses in medicine, nutrition, and nanochemistry.
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Affiliation(s)
- Elizabeth C. Theil
- Children’s Hospital Oakland Research Institute, Oakland, California 94609, United States
- Department of Structural
and Molecular Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7313, United States
| | - Takehiko Tosha
- Children’s Hospital Oakland Research Institute, Oakland, California 94609, United States
- Department of Structural
and Molecular Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7313, United States
| | - Rabindra K. Behera
- Children’s Hospital Oakland Research Institute, Oakland, California 94609, United States
- Department of Structural
and Molecular Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7313, United States
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11
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Bernacchioni C, Ghini V, Theil EC, Turano P. Modulating the permeability of ferritin channels. RSC Adv 2016. [DOI: 10.1039/c5ra25056k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Electric field gradients across the C3 and C4 ferritin channels controls the directional Fe2+fluxes towards the catalytic ferroxidase center.
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Affiliation(s)
- C. Bernacchioni
- CERM
- University of Florence
- 50019 Sesto Fiorentino
- Italy
- Department of Chemistry
| | - V. Ghini
- CERM
- University of Florence
- 50019 Sesto Fiorentino
- Italy
- Department of Chemistry
| | - E. C. Theil
- Children's Hospital Oakland Research Institute
- Oakland
- USA
- Department of Molecular and Structural Biochemistry
- North Carolina State University
| | - P. Turano
- CERM
- University of Florence
- 50019 Sesto Fiorentino
- Italy
- Department of Chemistry
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12
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Pozzi C, Di Pisa F, Bernacchioni C, Ciambellotti S, Turano P, Mangani S. Iron binding to human heavy-chain ferritin. ACTA ACUST UNITED AC 2015; 71:1909-20. [PMID: 26327381 DOI: 10.1107/s1399004715013073] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/07/2015] [Indexed: 11/10/2022]
Abstract
Maxi-ferritins are ubiquitous iron-storage proteins with a common cage architecture made up of 24 identical subunits of five α-helices that drive iron biomineralization through catalytic iron(II) oxidation occurring at oxidoreductase sites (OS). Structures of iron-bound human H ferritin were solved at high resolution by freezing ferritin crystals at different time intervals after exposure to a ferrous salt. Multiple binding sites were identified that define the iron path from the entry ion channels to the oxidoreductase sites. Similar data are available for another vertebrate ferritin: the M protein from Rana catesbeiana. A comparative analysis of the iron sites in the two proteins identifies new reaction intermediates and underlines clear differences in the pattern of ligands that define the additional iron sites that precede the oxidoreductase binding sites along this path. Stopped-flow kinetics assays revealed that human H ferritin has different levels of activity compared with its R. catesbeiana counterpart. The role of the different pattern of transient iron-binding sites in the OS is discussed with respect to the observed differences in activity across the species.
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Affiliation(s)
- Cecilia Pozzi
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Flavio Di Pisa
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Caterina Bernacchioni
- Dipartimento di Chimica, Università di Firenze, Via Della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
| | - Silvia Ciambellotti
- Dipartimento di Chimica, Università di Firenze, Via Della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
| | - Paola Turano
- Dipartimento di Chimica, Università di Firenze, Via Della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
| | - Stefano Mangani
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, Via Aldo Moro 2, 53100 Siena, Italy
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Xu Z, Zhang L, Li D, Liu X, Wang Y, Lin J. Binding of a Dy(III) complex to apoferritin inhibits iron mineralization. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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14
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Pozzi C, Di Pisa F, Lalli D, Rosa C, Theil E, Turano P, Mangani S. Time-lapse anomalous X-ray diffraction shows how Fe(2+) substrate ions move through ferritin protein nanocages to oxidoreductase sites. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:941-53. [PMID: 25849404 PMCID: PMC4388269 DOI: 10.1107/s1399004715002333] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Accepted: 02/03/2015] [Indexed: 11/10/2022]
Abstract
Ferritin superfamily protein cages reversibly synthesize internal biominerals, Fe2O3·H2O. Fe(2+) and O2 (or H2O2) substrates bind at oxidoreductase sites in the cage, initiating biomineral synthesis to concentrate iron and prevent potentially toxic reactions products from Fe(2+)and O2 or H2O2 chemistry. By freezing ferritin crystals of Rana catesbeiana ferritin M (RcMf) at different time intervals after exposure to a ferrous salt, a series of high-resolution anomalous X-ray diffraction data sets were obtained that led to crystal structures that allowed the direct observation of ferrous ions entering, moving along and binding at enzyme sites in the protein cages. The ensemble of crystal structures from both aerobic and anaerobic conditions provides snapshots of the iron substrate bound at different cage locations that vary with time. The observed differential occupation of the two iron sites in the enzyme oxidoreductase centre (with Glu23 and Glu58, and with Glu58, His61 and Glu103 as ligands, respectively) and other iron-binding sites (with Glu53, His54, Glu57, Glu136 and Asp140 as ligands) reflects the approach of the Fe(2+) substrate and its progression before the enzymatic cycle 2Fe(2+) + O2 → Fe(3+)-O-O-Fe(3+) → Fe(3+)-O(H)-Fe(3+) and turnover. The crystal structures also revealed different Fe(2+) coordination compounds bound to the ion channels located at the threefold and fourfold symmetry axes of the cage.
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Affiliation(s)
- Cecilia Pozzi
- Dipartimento di Biotecnologie, Chimica e Farmacia, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Flavio Di Pisa
- Dipartimento di Biotecnologie, Chimica e Farmacia, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Daniela Lalli
- Dipartimento di Chimica and CERM, University of Florence, Via Della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
| | - Camilla Rosa
- Dipartimento di Chimica and CERM, University of Florence, Via Della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
| | - Elizabeth Theil
- Children’s Hospital, Oakland Research Institute, 5700 Martin Luther King Jr Way, Oakland, CA 94609, USA
| | - Paola Turano
- Dipartimento di Chimica and CERM, University of Florence, Via Della Lastruccia 3, Sesto Fiorentino, 50019 Firenze, Italy
| | - Stefano Mangani
- Dipartimento di Biotecnologie, Chimica e Farmacia, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
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Bernacchioni C, Ciambellotti S, Theil EC, Turano P. Is His54 a gating residue for the ferritin ferroxidase site? BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1118-22. [PMID: 25727028 DOI: 10.1016/j.bbapap.2015.02.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 10/23/2022]
Abstract
Ferritin is a ubiquitous iron concentrating nanocage protein that functions through the enzymatic oxidation of ferrous iron and the reversible synthesis of a caged ferric-oxo biomineral. Among vertebrate ferritins, the bullfrog M homopolymer ferritin is a frequent model for analyzing the role of specific amino acids in the enzymatic reaction and translocation of iron species within the protein cage. X-ray crystal structures of ferritin in the presence of metal ions have revealed His54 binding to iron(II) and other divalent cations, with its imidazole ring proposed as "gate" that influences iron movement to/from the active site. To investigate its role, His54 was mutated to Ala. The H54A ferritin variant was expressed and its reactivity studied via UV-vis stopped-flow kinetics. The H54A variant exhibited a 20% increase in the initial reaction rate of formation of ferric products with 2 or 4 Fe²⁺/subunit and higher than 200% with 20 Fe²⁺/subunit. The possible meaning of the increased efficiency of the ferritin reaction induced by this mutation is proposed taking advantage of the comparative sequence analysis of other ferritins. The data here reported are consistent with a role for His54 as a metal ion trap that maintains the correct levels of access of iron to the active site. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
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Affiliation(s)
- Caterina Bernacchioni
- Magnetic Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy; Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy
| | - Silvia Ciambellotti
- Magnetic Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy; Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy
| | - Elizabeth C Theil
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King, Jr. Way, Oakland, CA 94609, USA; Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 29695-7622, USA
| | - Paola Turano
- Magnetic Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy; Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy.
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16
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Piccioli M, Turano P. Transient iron coordination sites in proteins: Exploiting the dual nature of paramagnetic NMR. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Bernacchioni C, Ghini V, Pozzi C, Di Pisa F, Theil EC, Turano P. Loop electrostatics modulates the intersubunit interactions in ferritin. ACS Chem Biol 2014; 9:2517-25. [PMID: 25148224 DOI: 10.1021/cb500431r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Functional ferritins are 24-mer nanocages that self-assemble with extended contacts between pairs of 4-helix bundle subunits coupled in an antiparallel fashion along the C2 axes. The largest intersubunit interaction surface in the ferritin nanocage involves helices, but contacts also occur between groups of three residues midway in the long, solvent-exposed L-loops of facing subunits. The anchor points between intersubunit L-loop pairs are the salt bridges between the symmetry-related, conserved residues Asp80 and Lys82. The resulting quaternary structure of the cage is highly soluble and thermostable. Substitution of negatively charged Asp80 with a positively charged Lys in homopolymeric M ferritin introduces electrostatic repulsions that inhibit the oligomerization of the ferritin subunits. D80K ferritin was present in inclusion bodies under standard overexpressing conditions in E. coli, contrasting with the wild type protein. Small amounts of fully functional D80K nanocages formed when expression was slowed. The more positively charged surface results in a different solubility profile and D80K crystallized in a crystal form with a low density packing. The 3D structure of D80K variant is the same as wild type except for the side chain orientations of Lys80 and facing Lys82. When three contiguous Lys groups are introduced in D80KI81K ferritin variant the nanocage assembly is further inhibited leading to lower solubility and reduced thermal stability. Here, we demonstrate that the electrostatic pairing at the center of the L-loops has a specific kinetic role in the self-assembly of ferritin nanocages.
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Affiliation(s)
- Caterina Bernacchioni
- Magnetic
Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Veronica Ghini
- Magnetic
Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Cecilia Pozzi
- Department
of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Flavio Di Pisa
- Department
of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Elizabeth C. Theil
- CHORI (Children’s
Hospital Oakland Research Institute), 5700 Martin Luther King, Jr. Way, Oakland, California 94609, United States
- Department
of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 29695-7622, United States
| | - Paola Turano
- Magnetic
Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
- Department
of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy
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