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Sokolov AV, Vasilyev VB, Samygina VR. X-Ray Analysis of the Monoclinic Crystal Form of Human Ceruloplasmin. CRYSTALLOGR REP+ 2022. [DOI: 10.1134/s1063774522060232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Bonaccorsi di Patti MC, Cutone A, Nemčovič M, Pakanová Z, Baráth P, Musci G. Production of Recombinant Human Ceruloplasmin: Improvements and Perspectives. Int J Mol Sci 2021; 22:ijms22158228. [PMID: 34360993 PMCID: PMC8347646 DOI: 10.3390/ijms22158228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 01/25/2023] Open
Abstract
The ferroxidase ceruloplasmin (CP) plays a crucial role in iron homeostasis in vertebrates together with the iron exporter ferroportin. Mutations in the CP gene give rise to aceruloplasminemia, a rare neurodegenerative disease for which no cure is available. Many aspects of the (patho)physiology of CP are still unclear and would benefit from the availability of recombinant protein for structural and functional studies. Furthermore, recombinant CP could be evaluated for enzyme replacement therapy for the treatment of aceruloplasminemia. We report the production and preliminary characterization of high-quality recombinant human CP in glycoengineered Pichia pastoris SuperMan5. A modified yeast strain lacking the endogenous ferroxidase has been generated and employed as host for heterologous expression of the secreted isoform of human CP. Highly pure biologically active protein has been obtained by an improved two-step purification procedure. Glycan analysis indicates that predominant glycoforms HexNAc2Hex8 and HexNAc2Hex11 are found at Asn119, Asn378, and Asn743, three of the canonical four N-glycosylation sites of human CP. The availability of high-quality recombinant human CP represents a significant advancement in the field of CP biology. However, productivity needs to be increased and further careful glycoengineering of the SM5 strain is mandatory in order to evaluate the possible therapeutic use of the recombinant protein for enzyme replacement therapy of aceruloplasminemia patients.
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Affiliation(s)
- Maria Carmela Bonaccorsi di Patti
- Department of Biochemical Sciences ‘A. Rossi Fanelli’, Sapienza University of Rome, 00185 Rome, Italy
- Correspondence: (M.C.B.d.P.); (G.M.)
| | - Antimo Cutone
- Department Biosciences and Territory, University of Molise, 86090 Pesche, Italy;
| | - Marek Nemčovič
- Institute of Chemistry, Slovak Academy of Sciences, 84538 Bratislava, Slovakia; (M.N.); (Z.P.); (P.B.)
| | - Zuzana Pakanová
- Institute of Chemistry, Slovak Academy of Sciences, 84538 Bratislava, Slovakia; (M.N.); (Z.P.); (P.B.)
| | - Peter Baráth
- Institute of Chemistry, Slovak Academy of Sciences, 84538 Bratislava, Slovakia; (M.N.); (Z.P.); (P.B.)
| | - Giovanni Musci
- Department Biosciences and Territory, University of Molise, 86090 Pesche, Italy;
- Correspondence: (M.C.B.d.P.); (G.M.)
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Tanaka YK, Ogra Y. Evaluation of copper metabolism in neonatal rats by speciation analysis using liquid chromatography hyphenated to ICP mass spectrometry. Metallomics 2020; 11:1679-1686. [PMID: 31417989 DOI: 10.1039/c9mt00158a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is known that copper (Cu) is highly accumulated in several organs in the perinatal period, suggesting changes in Cu metabolism with development, although the precise mechanisms are still unclear. To elucidate the mechanisms underlying Cu accumulation in the organs of neonatal rats, we performed speciation analysis using high-performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry. In the neonatal rat liver immediately after birth, the Cu concentration was elevated 10-fold compared to that in the juvenile rat liver. Most of the accumulated Cu was bound to metallothionein, although Cu in Cu, zinc-superoxide dismutase (SOD) was reduced. Contrary to the hepatic Cu accumulation, the serum Cu concentrations in the neonatal rats were low due to the decreased amount of Cu bound to ceruloplasmin. The mRNA expression of antioxidant protein 1 (Atox1), a Cu chaperone that transports Cu to Atp7b, remained low up to two weeks after birth. These results suggest that Cu accumulation in the neonatal rat liver is caused by the low expression of Atox1, and the accumulation is useful to distribute Cu to Cu-containing anti-oxidative enzymes (e.g., SOD and Atox1) after respiration starts.
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Affiliation(s)
- Yu-Ki Tanaka
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo, Chiba 260-8675, Japan.
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Samygina VR, Sokolov AV, Bourenkov G, Schneider TR, Anashkin VA, Kozlov SO, Kolmakov NN, Vasilyev VB. Rat ceruloplasmin: a new labile copper binding site and zinc/copper mosaic. Metallomics 2017; 9:1828-1838. [PMID: 29177316 DOI: 10.1039/c7mt00157f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Ceruloplasmin (Cp) is a copper-containing multifunctional oxidase of plasma, an antioxidant, an acute-phase protein and a free radical scavenger. The structural organization of Cp causes its sensitivity to proteolysis and ROS (reactive oxygen species), which can alter some of the important Cp functions. Elucidation of the orthorhombic crystal structure of rat Cp at 2.3 Å resolution revealed the basis for stronger resistance of rat Cp to proteolysis and a new labile copper binding site. The presence of this site appears as a very rare and distinctive feature of rat Cp as was shown by sequence alignment of ceruloplasmin, hephaestin and zyklopen in the Deuterostomia taxonomic group. The trigonal crystal form of rat Cp at 3.2 Å demonstrates unexpected partial substitution of copper by zinc.
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Affiliation(s)
- V R Samygina
- Shubnikov Institute of Crystallography of FSRC "Crystallography and Photonics" RAS, Leninsky pr.59, Moscow 117333, Russia. and NRC Kurchatov Institute, Kurchatov pl. 1, Moscow 123098, Russia
| | - A V Sokolov
- Institute of Experimental Medicine, ul. Academica Pavlova, 12, Saint-Petersburg 197376, Russia and Saint-Petersburg State Universisty, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia and Centre of Preclinical Translational Research, Almazov National Medical Research Centre, ul. Dolgoozernaya, 43, Saint-Petersburg 197371, Russia
| | - G Bourenkov
- EMBL, Notkestrasse 85, 22607 Hamburg, Germany
| | | | - V A Anashkin
- Shubnikov Institute of Crystallography of FSRC "Crystallography and Photonics" RAS, Leninsky pr.59, Moscow 117333, Russia. and Belozersky Institute of Physico-Chemical Biology and Department of Chemistry, Lomonosov Moscow State University, Moscow 119899, Russia
| | - S O Kozlov
- Institute of Experimental Medicine, ul. Academica Pavlova, 12, Saint-Petersburg 197376, Russia
| | - N N Kolmakov
- Institute of Experimental Medicine, ul. Academica Pavlova, 12, Saint-Petersburg 197376, Russia
| | - V B Vasilyev
- Institute of Experimental Medicine, ul. Academica Pavlova, 12, Saint-Petersburg 197376, Russia and Saint-Petersburg State Universisty, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia
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5
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Moshkov KA, Zaitsev VN, Grishina TV, Stefanov VE. Multinuclear blue copper-proteins: the evolutionary design. J EVOL BIOCHEM PHYS+ 2014. [DOI: 10.1134/s0022093014030016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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6
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Musci G, Polticelli F, Bonaccorsi di Patti MC. Ceruloplasmin-ferroportin system of iron traffic in vertebrates. World J Biol Chem 2014; 5:204-215. [PMID: 24921009 PMCID: PMC4050113 DOI: 10.4331/wjbc.v5.i2.204] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 02/19/2014] [Indexed: 02/05/2023] Open
Abstract
Safe trafficking of iron across the cell membrane is a delicate process that requires specific protein carriers. While many proteins involved in iron uptake by cells are known, only one cellular iron export protein has been identified in mammals: ferroportin (SLC40A1). Ceruloplasmin is a multicopper enzyme endowed with ferroxidase activity that is found as a soluble isoform in plasma or as a membrane-associated isoform in specific cell types. According to the currently accepted view, ferrous iron transported out of the cell by ferroportin would be safely oxidized by ceruloplasmin to facilitate loading on transferrin. Therefore, the ceruloplasmin-ferroportin system represents the main pathway for cellular iron egress and it is responsible for physiological regulation of cellular iron levels. The most recent findings regarding the structural and functional features of ceruloplasmin and ferroportin and their relationship will be described in this review.
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Samygina VR, Sokolov AV, Bourenkov G, Petoukhov MV, Pulina MO, Zakharova ET, Vasilyev VB, Bartunik H, Svergun DI. Ceruloplasmin: macromolecular assemblies with iron-containing acute phase proteins. PLoS One 2013; 8:e67145. [PMID: 23843990 PMCID: PMC3700992 DOI: 10.1371/journal.pone.0067145] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 05/15/2013] [Indexed: 11/19/2022] Open
Abstract
Copper-containing ferroxidase ceruloplasmin (Cp) forms binary and ternary complexes with cationic proteins lactoferrin (Lf) and myeloperoxidase (Mpo) during inflammation. We present an X-ray crystal structure of a 2Cp-Mpo complex at 4.7 Å resolution. This structure allows one to identify major protein-protein interaction areas and provides an explanation for a competitive inhibition of Mpo by Cp and for the activation of p-phenylenediamine oxidation by Mpo. Small angle X-ray scattering was employed to construct low-resolution models of the Cp-Lf complex and, for the first time, of the ternary 2Cp-2Lf-Mpo complex in solution. The SAXS-based model of Cp-Lf supports the predicted 1:1 stoichiometry of the complex and demonstrates that both lobes of Lf contact domains 1 and 6 of Cp. The 2Cp-2Lf-Mpo SAXS model reveals the absence of interaction between Mpo and Lf in the ternary complex, so Cp can serve as a mediator of protein interactions in complex architecture. Mpo protects antioxidant properties of Cp by isolating its sensitive loop from proteases. The latter is important for incorporation of Fe(3+) into Lf, which activates ferroxidase activity of Cp and precludes oxidation of Cp substrates. Our models provide the structural basis for possible regulatory role of these complexes in preventing iron-induced oxidative damage.
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Affiliation(s)
- Valeriya R. Samygina
- Institute of Crystallography RAS, Moscow, Russia
- Structural Biology Unit, CICbioGUNE, Derio, Spain
| | | | | | | | - Maria O. Pulina
- Institute of Experimental Medicine NWB RAMS, St.Petersburg, Russia
| | | | | | - Hans Bartunik
- Research Unit for Structural Molecular Biology, Max-Planck Institute, Hamburg, Germany
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Gupta A, Nederlof I, Sottini S, Tepper AWJW, Groenen EJJ, Thomassen EAJ, Canters GW. Involvement of Tyr108 in the enzyme mechanism of the small laccase from Streptomyces coelicolor. J Am Chem Soc 2012; 134:18213-6. [PMID: 23094962 DOI: 10.1021/ja3088604] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The enzyme mechanism of the multicopper oxidase (MCO) SLAC from Streptomyces coelicolor was investigated by structural (XRD), spectroscopic (optical, EPR), and kinetics (stopped-flow) experiments on variants in which residue Tyr108 had been replaced by Phe or Ala through site-directed mutagenesis. Contrary to the more common three-domain MCOs, a tyrosine in the two-domain SLAC is found to participate in the enzyme mechanism by providing an electron during oxygen reduction, giving rise to the temporary appearance of a tyrosyl radical. The relatively low k(cat)/K(M) of SLAC and the involvement of Y108 in the enzyme mechanism may reflect an adaptation to a milieu in which there is an imbalance between the available reducing and oxidizing co-substrates. The purported evolutionary relationship between the two-domain MCOs and human ceruloplasmin appears to extend not only to the 3D structure and the mode of binding of the Cu's in the trinuclear center, as noted before, but also to the enzyme mechanism.
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Affiliation(s)
- Ankur Gupta
- Leiden Institute of Physics, Leiden University, Leiden, The Netherlands
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Vashchenko G, Bleackley MR, Griffiths TAM, MacGillivray RTA. Oxidation of organic and biogenic amines by recombinant human hephaestin expressed in Pichia pastoris. Arch Biochem Biophys 2011; 514:50-6. [PMID: 21802403 DOI: 10.1016/j.abb.2011.07.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 06/28/2011] [Accepted: 07/12/2011] [Indexed: 11/15/2022]
Abstract
Hephaestin is a multicopper ferroxidase involved in iron absorption in the small intestine. Expressed mainly on the basolateral surface of duodenal enterocytes, hephaestin facilitates the export of iron from the intestinal epithelium into blood by oxidizing Fe(2+) into Fe(3+), the only form of iron bound by the plasma protein transferrin. Structurally, the human hephaestin ectodomain is predicted to resemble ceruloplasmin, the major multicopper oxidase in blood. In addition to its ferroxidase activity, ceruloplasmin was reported to oxidize a wide range of organic compounds including a group of physiologically relevant substrates (biogenic amines). To study oxidation of organic substrates, the human hephaestin ectodomain was expressed in Pichia pastoris. The purified recombinant hephaestin has an average copper content of 4.2 copper atoms per molecule. The K(m) for Fe(2+) of hephaestin was determined to be 3.2μM which is consistent with the K(m) values for other multicopper ferroxidases. In addition, the K(m) values of hephaestin for such organic substrates as p-phenylenediamine and o-dianisidine are close to values determined for ceruloplasmin. However, in contrast to ceruloplasmin, hephaestin was incapable of direct oxidation of adrenaline and dopamine implying a difference in biological substrate specificities between these two homologous ferroxidases.
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Affiliation(s)
- Ganna Vashchenko
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Vancouver, BC, Canada
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Maio N, Polticelli F, De Francesco G, Rizzo G, Bonaccorsi di Patti MC, Musci G. Role of external loops of human ceruloplasmin in copper loading by ATP7B and Ccc2p. J Biol Chem 2010; 285:20507-13. [PMID: 20430895 DOI: 10.1074/jbc.m109.090027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Ceruloplasmin is a multicopper oxidase required for correct iron homeostasis.Previously, we have identified a ceruloplasmin mutant associated with the iron overload disease aceruloplasminemia, which was unable to acquire copper from the mammalian pump ATP7B but could be produced in an enzymatically active form in yeast. Here, we report the expression of recombinant ceruloplasmin in the yeast Pichia pastoris and the study of the role of five surface-exposed loops in copper incorporation by comparing the efficiencies of mammalian ATP7B and yeast Ccc2p. The possibility to "mix and match" mammalian and yeast multicopper oxidases and copper ATPases can provide clues on the molecular features underlying the process of copper loading in multicopper oxidases.
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Affiliation(s)
- Nunziata Maio
- Dipartimento di Biologia, Università ROMA TRE, 00146 Rome
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11
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Samygina VR, Sokolov AV, Pulina MO, Bartunik HD, Vasil’ev VB. X-ray diffraction study of highly purified human ceruloplasmin. CRYSTALLOGR REP+ 2008. [DOI: 10.1134/s1063774508040172] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Arredondo M, González M, Olivares M, Pizarro F, Araya M. Ceruloplasmin, an indicator of copper status. Biol Trace Elem Res 2008; 123:261-9. [PMID: 18270661 DOI: 10.1007/s12011-008-8110-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Accepted: 01/24/2008] [Indexed: 01/22/2023]
Abstract
For clinical purposes, the non-ceruloplasmin copper fraction is routinely derived on the basis that ceruloplasmin binds six Cu atoms. However, this approach is limited because the actual ceruloplasmin copper binding is unclear. We performed direct measurement of the total serum copper and ceruloplasmin in 790 healthy individuals. We used an immunoprecipitation technique to separate ceruloplasmin and determined Cu content. With these values, we calculated the Cu/ceruloplasmin (Cp) ratio and thus generated data to support or discard the theoretical calculation of the non-ceruloplasmin fraction. Average of serum Cu and Cp levels were 18.4 +/- 4.4 micromol/l and 390 +/- 100 mg/l, respectively. The immunoprecipitation procedure allowed us to calculate a Cu/Cp ratio of 5.8, respectively, which supports the methodology of calculation that assigns a mean of six copper atoms to each ceruloplasmin molecule. With these values, we calculated that, in apparently normal adults, the non-ceruloplasmin copper (NCPC) fraction is lower than 1.3 micromol/l of Cu. In this report, we examine the Cp/Cu ratio by using Cp immunoprecipitation procedure. Our in vitro and in vivo studies indicate that, as a mean, there are 5.8 atoms of Cu per Cp molecule and that <1.3 micromol/l of Cu would correspond to the NCPC.
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Affiliation(s)
- Miguel Arredondo
- Micronutrient Laboratory, Nutrition and Food Technology Institute (INTA), University of Chile, El Líbano, 5524, Macul, Santiago, Chile.
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Bento I, Peixoto C, Zaitsev VN, Lindley PF. Ceruloplasmin revisited: structural and functional roles of various metal cation-binding sites. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2007; 63:240-8. [PMID: 17242517 PMCID: PMC2483498 DOI: 10.1107/s090744490604947x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 11/18/2006] [Indexed: 11/10/2022]
Abstract
The three-dimensional molecular structure of human serum ceruloplasmin has been reinvestigated using X-ray synchrotron data collected at 100 K from a crystal frozen to liquid-nitrogen temperature. The resulting model, with an increase in resolution from 3.1 to 2.8 A, gives an overall improvement of the molecular structure, in particular the side chains. In addition, it enables the clear definition of previously unidentified Ca2+-binding and Na+-binding sites. The Ca2+ cation is located in domain 1 in a configuration very similar to that found in the activated bovine factor Va. The Na+ sites appear to play a structural role in providing rigidity to the three protuberances on the top surface of the molecule. These features probably help to steer substrates towards the mononuclear copper sites prior to their oxidation and to restrict the size of the approaching substrate. The trinuclear copper centre appears to differ from the room-temperature structure in that a dioxygen moiety is bound in a similar way to that found in the endospore coat protein CotA from Bacillus subtilis.
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Affiliation(s)
- Isabel Bento
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Cristina Peixoto
- Laboratory of Animal Cell Technology, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal
| | - Vjacheslav N. Zaitsev
- Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews KY16 9ST, Scotland
| | - Peter F. Lindley
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
- Department of Crystallography, Birkbeck College, University of London, Malet Street, London WC1E 7HX, England
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Griffiths TAM, Mauk AG, MacGillivray RTA. Recombinant Expression and Functional Characterization of Human Hephaestin: A Multicopper Oxidase with Ferroxidase Activity. Biochemistry 2005; 44:14725-31. [PMID: 16274220 DOI: 10.1021/bi051559k] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human hephaestin (Hp) is a transmembrane protein that has been implicated in duodenal iron export. Mutations in the murine hephaestin gene (sla) produce microcytic, hypochromic anemia that is refractory to oral iron therapy. Hp shares approximately 50% sequence identity with the plasma multicopper ferroxidase ceruloplasmin including conservation of residues involved in disulfide bond formation and metal coordination. On the basis of this similarity to ceruloplasmin, human hephaestin may also bind copper and possess ferroxidase activity. To test this hypothesis, human hephaestin cDNA has been cloned by reverse transcription of human duodenal mRNA. Following in vitro mutagenesis to make the encoded polypeptide suitable for expression and purification, the hephaestin cDNA was cloned into the expression vector pNUT and introduced into baby hamster kidney cells. After selection with methotrexate, the baby hamster kidney cells secreted the recombinant human hephaestin into the medium at a level of approximately 2 mg/L. Purification was achieved by a single immunoaffinity chromatography step. As judged by SDS-PAGE, N-terminal sequence analysis, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, the purified hephaestin was homogeneous with a mass of 129600 Da, suggesting a carbohydrate content of 7.7%. Inductively coupled plasma mass spectrometry revealed that recombinant hephaestin contained an average of 3.13 atoms of copper per protein molecule. A visible absorption maximum was observed at 607 nm, consistent with the presence of a Type 1 copper site. By using ferrous ammonium sulfate as a substrate, recombinant hephaestin was shown to have ferroxidase activity with a K(m) of 2.1 microM for Fe(II). Lastly, urea PAGE showed that hephaestin was able to catalyze formation of diferric transferrin from Fe(II) and apotransferrin.
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Affiliation(s)
- Tanya A M Griffiths
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Life Sciences Centre, 2350 Health Sciences Mall, Vancouver, British Columbia, Canada V6T 1Z3
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Kataoka K, Tanaka K, Sakai Y, Sakurai T. High-level expression of Myrothecium verrucaria bilirubin oxidase in Pichia pastoris, and its facile purification and characterization. Protein Expr Purif 2005; 41:77-83. [PMID: 15802224 DOI: 10.1016/j.pep.2005.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Revised: 01/27/2005] [Indexed: 10/25/2022]
Abstract
Bilirubin oxidase (BO) from Myrothecium verrucaria (authentic BO) catalyzing the oxidation of bilirubin to biliverdine was overexpressed in the methylotrophic yeast, Pichia pastoris. The cDNA encoding BO was cloned into the P. pastoris expression vector pPIC9K under the control of the alcohol oxidase 1 promoter and its protein product was secreted using the Saccharomyces cerevisiae alpha-mating factor signal sequence. The productivity of recombinant BO (rBO) in P. pastoris was approximately 5000 U/L of culture broth, being about 2.5- and 250-fold higher than rBO expressed in Aspergillus oryzae and S. cerevisiae, respectively. The calculated molecular mass of rBO consisting of 538 amino acids was 60,493 kDa, however, that of SDS-PAGE was 66 kDa because of non-native type N-linked sugar chains. The spectroscopic properties of rBO were typical of multicopper oxidase containing four Cu ions per protein molecule. The specific activity to oxidize bilirubin was 57 U/mg, having a value about twice that of authentic BO and rBO expressed in A. oryzae. Moreover, the thermostability of rBO expressed in P. pastoris was significantly high compared to the authentic BO previously reported. Accordingly, a heterologous expression system of rBO to meet clinical and industrial needs was constructed.
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Affiliation(s)
- Kunishige Kataoka
- Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan.
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Brown MA, Stenberg LM, Mauk AG. Identification of catalytically important amino acids in human ceruloplasmin by site-directed mutagenesis. FEBS Lett 2002; 520:8-12. [PMID: 12044861 DOI: 10.1016/s0014-5793(02)02652-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The involvement of amino acid residues previously proposed on the basis of structural data to have roles in the ferroxidase and diamine oxidase activities of human ceruloplasmin was investigated. Variants of human ceruloplasmin, in which residues proposed to be involved in electron transfer and/or iron-binding had been altered by site-directed mutagenesis, were expressed in HEK293 cells. E633A and E597A/H602A variants exhibited reduction in both activities by 50-60% compared to recombinant wild-type ceruloplasmin. The variant E935A/H940A had reduced ferroxidase activity (50%) but unaltered diamine oxidase activity, whereas the variant E971A exhibited enhanced diamine oxidase activity. For the L329M variant, both activities were identical to those of wild-type ceruloplasmin.
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Affiliation(s)
- Mark A Brown
- Department of Biochemistry and Molecular Biology, and the UBC Centre for Blood Research, Faculty of Medicine, University of British Columbia, 2146 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3.
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