To see the other types of publications on this topic, follow the link: Iron proteins.
Dissertations / Theses on the topic 'Iron proteins'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Iron proteins.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Camba, Acosta Raul O. "Reaction mechanisms of iron-sulfur proteins studied by protein-film voltammetry." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365860.
Full text
2
Fawcett, Sarah E. J. "Reactions of iron-sulfur clusters in proteins." Thesis, University of Oxford, 1998. https://ora.ox.ac.uk/objects/uuid:87b10a8e-67a8-476b-ae20-49e6892051f5.
Full textAbstract:
This thesis describes the investigation of reactions of iron-sulfur clusters in proteins using direct electrochemistry. The influence of potential on metal uptake to generate the [M3Fe-4S] cluster from the [3Fe-4S] cluster of Desulfovibrio africanus Fd III is studied. The influence of potential was complex: rapid and reversible interconversions (M = Fe and Zn) occurred only between the states [M3Fe-4S]<sup>2+</sup> and [3Fe-4S]<sup>0</sup>, with [3Fe-4S]<sup>1+</sup> having little affinity for M. The [M3Fe-4S]<sup>1+</sup> cubanes and the hyper-reduced [3Fe-4S]<sup>2-</sup> were relatively unreactive. The reactivity of the transformed cluster, [M3Fe-4S] (M = Fe, Zn, Co), from the 7Fe Fd of Desulfovibrio africanus was studied and was found to react with a number of small thiol molecules, indicating that either ligand addition or exchange takes place at the transformed M site of the cluster. No reaction was observed with oxygenic ligands. In all cases, with the exception of imidazole, negative shifts in reduction potentials were observed. Reactions of the [2Fe-2S] cluster from the ferredoxin of Clostridium pasteurianum and a number of site-directed mutants of this ferredoxin are studied. The cysteine ligands of the cluster were identified and evidence was obtained for serinate ligation of the cluster in a number of mutants. The reduction potentials of these serinateligated clusters were found to have a notable dependence on pH. A mutant ferredoxin containing only three cysteine ligands was investigated, which was found to interact with an exogenous thiolate ligand and, in addition, displayed a second reduction couple, indicating the formation of the [2Fe-2S]<sup>0</sup> state. Reactions of the [3Fe-4S] cluster and various [M3Fe-4S] adducts, from the ferredoxin of the hyperthermophile Pyrococcus furiosus, are studied. The [3Fe-4S] cluster exhibited a complex pH dependence over a wide pH range. The formation of the hyper-reduced [3Fe-4S]<sup>2-</sup> state was observed, which required 3H<sup>+</sup> for the overall 3e⧠reduction from [3Fe-4S]<sup>1+</sup>. Metal uptake reactions for M = Fe, Zn, Cd, were found to be slower than for its mesophilic counterpart, the 7Fe Fd III from Desulfovibrio africanus. Conversely, Tl uptake was found to be rapid, suggesting that co-ordination of Tl does not require reorganisation of the protein structure.
3
Morris, Patricia Ann. "EXAFS of non-heme iron containing proteins." Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/27402.
Full text
4
St, Pierre T. G. "Moessbauer spectroscopic studies of iron-storage proteins." Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380097.
Full text
5
Valer, Luca. "Histidine ligated Iron-Sulfur Proteins and Peptides." Doctoral thesis, Università degli studi di Trento, 2022. https://hdl.handle.net/11572/355641.
Full textAbstract:
Iron-sulfur clusters play a fundamental role in biology and are believed to be ancient cofactors that could have played a role in early protometabolic systems. Thus far, redox active, prebiotically plausible iron-sulfur clusters have always been obtained through cysteine coordination to the iron ions. However, extant iron-sulfur proteins can be found to exploit other modes of binding, including ligation by histidine residues, as seen with [2Fe-2S] Rieske and MitoNEET proteins. In this thesis, we investigated the ability of cysteine- and histidine-containing proteins and peptides to coordinate mononuclear [1Fe-0S] centers and a [2Fe-2S] clusters. The iron-sulfur peptides were characterized by UV-vis, circular dichroism, and paramagnetic NMR spectroscopies and cyclic voltammetry. Small (≤ 6 amino acids) peptides can coordinate [2Fe-2S] clusters through a combination of cysteine and histidine residues with similar reduction potentials as their corresponding proteins. Such complexes may have been important for early cell-like systems.
6
Maddocks, Sarah Elizabeth. "Iron metabolism in bacteria : examination of the Feo system (Ferrous iron transporter) and Dps-iron storage proteins." Thesis, University of Reading, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434313.
Full text
7
Le, Brun Nicolas Edward. "Studies of iron centres in bacterioferritin." Thesis, University of East Anglia, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.482780.
Full text
8
Yoon, Taejin. "Functional and structural studies of human frataxin an iron chaperone protein for mitochondrial iron-sulfur cluster and heme biosyntheses /." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124287807.
Full text
9
Dzikaitė, Vijolė. "Studies of proteins in heme and iron metabolism /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-762-2/.
Full text
10
Tilley, Gareth John. "Electrochemical investigations into iron-sulfur cluster containing proteins." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365300.
Full text
11
George, S. J. "Magnetic circular dichroism studies of iron-sulphur proteins." Thesis, University of East Anglia, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376059.
Full text
12
Folgosa, Filipe dos Santos. "Structural and mechanistic studies of iron containing proteins." Doctoral thesis, FCT - UNL, 2008. http://hdl.handle.net/10362/1774.
Full textAbstract:
Dissertação apresentada para obtenção do Grau de Doutor em Bioquímica, ramo de Bioquímica-Física, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia<br>Over the last few decades a large effort has been done in the structural biochemistry
field. This effort is based on the study of some proteins, namely metalloproteins, that
contain cofactors and/or active sites with metal ions in their constitution.
This thesis will focus on different studies performed in metalloproteins that contain
non-heme iron centers. An important point is their relation to oxygen and reactive oxygen species.
To perform these studies, fast kinetic techniques were used coupled to spectroscopic
techniques, such as Electronic Paramagnetic Resonance (EPR), Mössbauer and UVVisible.<br>Fundação para a Ciência e Tecnologia (SFRH/BD/18905/2004)
13
Dizin, Eric Michel. "Insights On Iron-Sulfur Cluster Assembly Donor Proteins." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1208532379.
Full text
14
Ding, Shu. "Thermodynamic studies on iron-sulfur cluster assembly proteins." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316472363.
Full text
15
Wang, Jian 1966. "Molecular control of iron metabolism in mammalian cells : new insights into iron regulatory proteins." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86063.
Full textAbstract:
Iron is an essential but potentially harmful metal element. Iron regulatory protein 1 and IRP2 posttranscriptionally control cellular iron homeostasis by binding to iron-responsive elements (IREs). Binding of IRPs to single IRE within 5'-untranslated region (5'-UTR) of ferritin mRNA attenuates biosynthesis of the iron-storage protein by translational repression, while their binding to multiple IREs within 3'-UTR of transferrin receptor 1 (TfR1) mRNA stimulates that of the iron-acquisition protein through mRNA stabilization. IRP1 and IRP2 share extensive homology, but respond to levels of cellular iron by distinct mechanisms. According to cellular iron status, IRP1 is switched between the states of RNA-binding and cytosolic (c-)aconitase by reversible assembly of a cubane [4Fe-4S] cluster. In contrast, IRP2 is mainly regulated through iron-dependent proteasomal degradation. Previous studies have identified constitutive IRP mutants. Substitution of any IRP1 cluster-coordinating cysteine residue with serine rendered the mutant (such as IRP1C437S) constitutively active for IRE-binding. In the case of IRP2, replacement of cysteines at positions of 168, 174 and 178 within an IRP2-specific, 73-amino-acid fragment (73 aa) was reported to yield an apparently stable mutant (IRP23CS). This project was initially designed to study the functional characteristics of IRPs in vivo by stably expressing constitutive IRP mutants in human cells. To this end, we first established clones of human lung (H1299) and breast (MCF7) cancer cells that express epitope-tagged IRP1C437S in a tetracycline-dependent manner and characterized the biological effects associated with IRP1C437S expression (Chapter II). In agreement with the commonly accepted regulatory model of IRE/IRP regulatory system, we demonstrated that IRP1C437S stimulates TfR1 by stabilizing its mRNA, resulting in increased uptake of cellular iron from 59Fe-transferrin. However, we observed a more complex
16
Stys, Agnieska. "Role of iron regulatory proteins in the regulation of iron metabolism by nitric oxide." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA11T056.
Full textAbstract:
Les Iron Regulatory Proteins 1 (IRP1/2) sont des protéines cytosoliques qui contrôlent l’homéostasie du fer chez les mammifères. Elles régulent la concentration de fer intracellulaire au niveau post-transcriptionnel, en interagissant spécifiquement avec des motifs appelés iron responsive élément (IREs). Ces motifs sont localisés dans les régions non traduites des ARNm codant notamment pour la ferritine (Ft), la ferroportine (Fpn) et le récepteur de la transferrine (TfR1). L’IRP1 est une protéine bifonctionnelle, majoritairement exprimée sous une forme contenant un centre [4Fe-4S] qui présente une activité aconitase. Les deux activités de l’IRP1 (aconitase/trans-régulateur) s’excluent mutuellement par la présence ou non du centre Fe-S. L’IRP2 est exprimée constitutivement sous une forme liant les IREs. Le monoxyde d’azote (NO), une importante molécule de signalisation impliquée dans les défenses immunitaires, cible le centre Fe-S de l’IRP1 et permet la conversion de l’IRP1 de sa forme aconitase vers sa forme liant les séquences IREs. Il a également été rapporté que l’IRP2 détecterait NO, cependant la fonction intrinsèque de l’IRP1 et de l’IRP2 dans le contrôle du métabolisme du fer intracellulaire en réponse à NO reste à ce jour non élucidée. Dans cette étude, nous avons identifié le régulateur principal du métabolisme du fer intracellulaire en réponse à NO, en utilisant des modèles de souris déficients pour les gènes IRP1 et/ou IRP2 et testé la contribution de la tension en oxygène dans cette régulation. Ainsi, nous avons exposé des macrophages primaires issus de la moelle osseuse de souris Irp1-/-, Irp2-/- et de souris Irp1-/- Irp2-/- de la lignée macrophagique à une source de NO, sous différentes tensions en oxygène. Les activités IRPs, l’expression des gènes Ft, Fpn et TfR1 ainsi que l’activité d’une protéine à centre Fe-S (l’aconitase mitochondriale) ont été mesurées après fractionnement cellulaire. Nous avons montré qu’en normoxie, la conversion de l’aconitase cytosolique en apo-IRP1 par NO est entièrement responsable de la régulation post-transcriptionnelle des ferritines (L-Ft et H-Ft), de la Fpn et du TfR1. En augmentant le transport du fer intracellulaire et en diminuant le stockage et l’export, l’activation de l’IRP1 par NO servirait à maintenir des taux de fer intracellulaire suffisants pour alimenter la biogenèse des centres Fe-S après l’arrêt des flux de NO. En effet, nous observons une restauration efficace de l’activité de l’aconitase mitochondriale dans les macrophages de souris sauvage alors qu’elle est bloquée dans les macrophages de souris Irp1-/-. De plus, l’IRP1 activée par NO, permet également de diminuer les taux de L- et H-Ft, anormalement élevée dans les macrophages de souris Irp2-/-. Nous montrons que le NO endogène active l’IRP1 sous sa forme trans-régulatrice alors qu’il tend à diminuer l’activité de l’IRP2. Néanmoins, l’IRP1 reste le régulateur principal des ferritines en conditions de normoxie. En condition hypoxique, les deux IRPs semble coopérer pour inhiber la traduction des ferritines car dans les macrophages Irp1-/-exposés à NO, l’IRP2 stabilisée est suffisante pour inhiber la traduction de la L- et H-Ft et ceci malgré l’activation transcriptionnelle des gènes de la L- et H-Ft. Concernant la régulation du TfR1 par NO et en hypoxie, TfR1 est principalement régulé par une voie transcriptionnelle dominant largement la voie post-transcriptionnelle impliquant l’IRP1. Le facteur de transcription HIF-1 alpha pourrait être le régulateur critique dans cette régulation. En conclusion, nous montrons dans cette étude, comment le regulon IRP participe à la régulation du métabolisme du fer intracellulaire en réponse à NO et son étroite connexion avec la concentration en oxygène. Nos résultats soulignent l’importance d’explorer davantage le rôle de l’IRP1 dans des situations inflammatoires in vivo, où les tissus peuvent être exposé à un microenvironnement non hypoxique<br>Iron Regulatory Protein 1 (IRP1) and 2 (IRP2) are two cytosolic regulators of mammalian cellular iron homeostasis. IRPs post-transcriptionally modulate expression of iron-related genes by binding to specific sequences, called Iron Regulatory Elements (IREs), located in the untranslated regions (UTR) of mRNAs. Either of the two IRPs inhibits translation when bound to the single 5’UTR IRE in the mRNA encoding proteins of iron export (ferroportin - Fpn) and storage (ferritin - Ft) or prevents mRNA degradationwhen bound to the multiple IREs within the 3’UTR of the mRNA encoding the transferrinreceptor 1 (TfR1) - iron uptake molecule. The IRE-binding activity of both IRPs respondsto cellular iron levels, albeit via distinct mechanisms. IRP1 is a bifunctional protein, whichmostly exists in its non IRE-binding, [4Fe-4S] aconitase form and can be regulated by apost-translational incorporation or removal of the Fe-S cluster. In contrast to IRP1, IRP2 isnot able to ligate an Fe-S cluster, and its IRE-binding activity is determined by the rate ofits proteasomal degradation. Although both IRP1 and IRP2 can regulate cellular ironhomeostasis, only mice lacking IRP2 were shown to display iron mismanagement in mosttissues. This could be explained by the fact that IRP1 exists mostly in its non IRE−binding,aconitase form under physiological oxygen conditions (3-6%). Interestingly, nitric oxide(NO), an important signalling molecule involved in immune defence, targets the Fe-Scluster of IRP1 in both normoxia and hypoxia, and converts IRP1 from aconitase to anIRE-binding form. It has also been reported that IRP2 could sense NO, but the intrinsicfunction of IRP1 and IRP2 in NO−mediated regulation of cellular iron metabolism hasremained a matter of controversy. In this study, we took advantage of mouse models ofIRP deficiency to define the respective role of IRP1 and IRP2 in the regulation of cellulariron metabolism by NO and assess the contribution of oxygen tension on the regulation.Therefore, we exposed bone marrow-derived macrophages (BMMs) from Irp1-/-, Irp2-/- andmacrophage specific double knockout mosaic mice (Irp1/2-/-) to exogenous andendogenous NO under different oxygen conditions (21% O2 for normoxia and 3-5% forhypoxia experiments) and measured IRPs activities, iron-related genes expression andactivity of Fe-S cluster protein – mitochondrial aconitase. We showed that in normoxia, thegenerated apo-form of IRP1 by NO was entirely responsible for the post-transcriptionalregulation of TfR1, H-Ft, L-Ft and Fpn. Moreover, by increasing iron uptake and reducingiron sequestration and export, NO−dependent IRP1 activation served to maintainadequate levels of intracellular iron in order to fuel the Fe−S biosynthetic pathway, asdemonstrated by the efficient restoration of the mitochondrial Fe−S aconitase, which wasprevented under IRP1 deficiency. Furthermore, activated IRP1 was potent enough todown-regulate the abnormally increased L-Ft and H-Ft protein levels in Irp2-/-macrophages. Endogenous NO activated IRP1 IRE-binding activity and tended todecrease IRP2 IRE-binding activity. Nevertheless, IRP1 was the predominant regulator offerritin in those conditions. In hypoxia, in Irp1+/+ and Irp2+/+ macrophages exposed to NO,both stabilized IRP2 and NO-activated IRP1 seemed to cooperate to inhibit ferritinsynthesis. However, in Irp1-/- cells, IRP2 stabilized in hypoxia was sufficient to inhibit LandH-Ft synthesis despite the concomitant increase of corresponding mRNAs.Interestingly, TfR1 was shown to be predominantly regulated at the transcriptional level byNO in hypoxia, in which HIF-1 alpha may be the critical regulator. In conclusion, we revealin this study how the IRP regulon participates in the regulation of cellular iron metabolismin response to NO and its intimate interplay with the oxygen pathway. The findingsunderlie the importance to further explore the role of IRP1 in inflammation in vivo, in nonhypoxictissue microenvironments
17
Dunford, Adrian J. "Kinetic studies on synthetic and biological iron-sulfur based clusters." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270825.
Full text
18
Adedeji, Dolapo A. Duin Evert C. "Isoprenoid synthesis new roles for iron sulfur clusters /." Auburn, Ala., 2007. http://repo.lib.auburn.edu/Send%2002-04-08/ADEDEJI_DOLAPO_4.pdf.
Full text
19
Wilks, Paula Elizabeth. "Iron-sulphur proteins from bovine heart NADH-ubiquinone oxidoreductase." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339592.
Full text
20
Baptista, Joana Morais. "The role of Di-iron proteins in pathogen resistance." Doctoral thesis, Universidade Nova de Lisboa. Instituto de Tecnologia Química e Biológica, 2012. http://hdl.handle.net/10362/8583.
Full textAbstract:
Dissertation presented to obtain the Ph.D. degree in Biochemistry<br>Reactive oxygen and nitrogen species (ROS and RNS) are produced
by phagocytic cells of the human immune system to attack invading
pathogens due to their ability to damage DNA and the metal centres of
proteins. In order to survive inside the host, bacteria activate genes that
encode detoxifier enzymes, like the Escherichia coli nitric oxide-reductase
flavodiiron protein, also known as flavorubredoxin (FlRd), and repairing
proteins, such as the E. coli YtfE di-iron protein involved in the recovery of
damaged Fe-S centres. Using E. coli and Staphylococcus aureus, the work
presented in this thesis aimed at unravelling: i) the role of E. coli FlRd in
bacteria exposed to a combination of oxidative and nitrosative stresses, ii)
the identification and characterisation of S. aureus YtfE homologue, iii) the
study of E. coli YtfE mechanisms that allow the repair of damaged Fe-S
clusters, and iv) the identification of proteins that interact with E. coli YtfE.
To analyse the role of E. coli FlRd in cells submitted to both
hydrogen peroxide and nitric oxide, the transcription and expression of
norV was explored by means of β-galactosidase and immunoblotting
assays, respectively. Under these conditions, it was observed that the norV
transcription and expression were hindered. To identify if the lack of norV
expression was related to its regulator, the NorR transcription factor, the
gene was cloned and expressed, and the protein was purified and the
binding of nitric oxide to NorR in the presence of hydrogen peroxide was
studied. EPR experiments revealed that upon incubation of NorR with nitric
oxide and hydrogen peroxide the oxidation promoted by H2O2 of the monoiron
centre of NorR impairs the ligation of nitric oxide.(...)
21
Dill, Brian D. "Identification of Chlamydial Iron-Responsive Proteins during Intracellular Growth." Digital Commons @ East Tennessee State University, 2008. https://dc.etsu.edu/etd/1955.
Full textAbstract:
Chlamydia trachomatis is an obligate intracellular bacterium and the most prevalent cause of bacterial sexually transmitted disease. Genital chlamydial infections, marked by chronic, intense inflammation, can lead to genital tissue scarring and infertility and is a contributing factor to development of pelvic inflammatory disease and ectopic pregnancy. Iron is required as a cofactor for numerous highly conserved pathways, and nearly all studied organisms rely on iron for growth. In response to iron restriction, the chlamydial developmental cycle arrests at the intracellular reticulate body stage, resulting in a phenomenon termed persistence. Persistence likely plays a role in chlamydial pathogenesis through the expression of virulence factors and antigens in addition to sustaining chronic infection; however, little is known concerning how chlamydiae respond to iron limitation at the molecular level, and no systems for iron acquisition have been identified in Chlamydia. This dissertation presents an investigation into the chlamydial response to iron restriction. Chlamydial heat shock protein 60 (cHsp60) has been implicated in development of the more severe disease sequelae and has been found to increase in expression following iron restriction; however, three cHsp60 homologues were identified following the sequencing of the chlamydial genome. Here, iron restriction is shown to increase expression of cHsp60-2 but not the two other homologs, cHsp60-1 or -3. Next, in order to investigate an alternate model for restricting iron availability to chlamydiae, a cell line with inducible expression of recombinant ferroportin, a eukaryotic iron efflux protein, was examined. Lastly, 10 chlamydial proteins differentially expressed during growth in iron-restricted host cells were identified by proteomic analysis of radiolabeled proteins followed by mass spectrometry analysis; transcripts encoding 5 iron responsive proteins were examined across a timecourse of infection and revealed increased transcript levels at 18 and/or 24 hours post infection. Together, these studies have examined the molecular response of chlamydiae to reduced iron availability and have underlined the importance for pathways involved in protection against oxidative damage and adaptation to stress.
22
Wu, Shu-Pao. "Iron-sulfur cluster biosynthesis. Iron-sulfur cluster transfer from holo ISU and ISA to apo ferredoxin." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1078866123.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2004.<br>Title from first page of PDF file. Document formatted into pages; contains xx, 161 p.; also includes graphics Includes bibliographical references (p. 153-161). Available online via OhioLINK's ETD Center
23
Mansy, Sheref S. "Structure and function of iron-sulfur cluster biosynthesis proteins and the influence of oxygen ligation." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1059664189.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2003.<br>Title from first page of PDF file. Document formatted into pages; contains xxi, 250 p.; also includes graphics (some col.) Includes bibliographical references (p. 226-250). Available online via OhioLINK's ETD Center
24
Houldershaw, David. "The electrostatics of iron binding to transferrin." Thesis, Birkbeck (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244463.
Full text
25
Bond, Jennifer M. "Investigations on antioxidant defence proteins and peptides." Thesis, Cranfield University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278723.
Full text
26
Ravindranath, Velaga M. "Elucidating the role of mitoferrin (Mfrn), iron regulatory proteins (IRP1 and IRP2) and hephaestin (Heph) in iron metabolism by tagSNP and protein-protein interaction (PPI) analysis." Thesis, London Metropolitan University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.639414.
Full textAbstract:
Precisely how Hephaestin (Heph) facilitate iron release from cells is poorly understood. The work in this thesis tried to establish the role of different iron metabolic proteins, Mitoferrin (Mfrn), IRPs and Heph in iron homeostasis. Analysis of 18 tagSNPs in the Mfrn gene was carried out in an AsianCaucasian population to establish any correlation between the Mfrn tagSNPs, haemoglobin levels and birth weight in the presence of covariates such as sex of the fetus, gestational age and mother's booking weight. Two-way ANCOVA analysis was carried out to check if the covariates have any influence on the dependent variable in the presence of fixed factors. From the ANCOVA analysis of Mfrn tagSN Ps it can be concluded that neither the haemoglobin levels nor the birth weight are dependent on the genotype, fetal sex, nor on their interaction. Owing to the significance in identifying the interacting partners of IRPs and Heph to understand more about their role in iron metabolism, protein-protein interaction studies were also carried out. IRPs and Heph genes were successfully cloned with One-Strep tag. Full length clones were sequence confirmed for any variation after PCR. Before carrying out immunoprecipitation to identify the interacting partners, transfection efficiency, viability and the role of magnetic particles on K562 cells was performed by using IRPs and Heph cloned with One-Strep tag. Lipofectamine-L TX plus transfection had more viable cells and higher efficiency compared with magnetic-assisted transfection . Also, this study confirms that magnetic nanoparticles do not have any adverse or significant effect on IRPs during the transfection. An unsuccessful attempt was made to identify the interacting partners of IRPs and Heph by immunoprecipitation. The current thesis work also involved identification of a potential ferroxidase . Ceruloplasmin (Cp) was used as a postive control. Non-denaturing gel eletrophoresis of the K562, MDA-MB-231 and PNT2-C2 cell fractions confirmed the presence of the extra band establishing the ubiquitous nature of the band. Mass spectrometry analysis identified the excised band as Calreticulin (CALR). This is the first report of calreticulin having ferroxidase activity.
27
Ricard, Michelle. "Iron acquisition from porcine proteins by Actinobacillus pleuropneumoniae biotype 1." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0034/MQ64438.pdf.
Full text
28
Chen, Guohua 1966. "A potential role of iron-regulatory proteins in tumor growth /." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97925.
Full textAbstract:
Iron is indispensable for cell proliferation and growth, but it is potentially toxic when present in excess. Two homologous iron regulatory proteins (IRP1 and IRP2) control cellular iron homeostasis by binding to iron-responsive elements (IREs) and post-transcriptionally coordinating the expression of transferrin receptor 1 (TfR1) and ferritin. We have previously reported that overexpression of IRP1C437S, a constitutive IRP1 mutant, inhibits H1299 human lung cancer cell growth in vitro. In current study, we investigated the potential role of IRPs in tumor growth in vivo by the injection of H1299 cells expressing IRP1C437S or wild type IRP1 or IRP2 into the flanks of nude mice. We observed that overexpression of IRP1C437S or wild type IRP1 suppressed tumor growth in nude mice. In contrast, surprisingly, overexpression of wild type IRP2 promoted tumor growth. Our results suggest that IRP1 may exhibit tumor suppressor activity, while IRP2 may have oncogenic activity.
29
Dycke, Camille. "Modulation de l'activité des Iron regulatory proteins par divers mécanismes." Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10145.
Full textAbstract:
L'homéostasie du fer est assurée chez les métazoaires au niveau post-transcriptionnel par le système IRE (Iron Responsive Elemenf)/IRP (Iron Responsive Proteins). Les IRP sont des protéines cytosoliques interagissant avec des motifs IRE de l'ARN messager de certaines protéines. En présence de fer, IRP1 intègre un centre [4Fe-4S] et acquiert une activité aconitase, alors qu'IRP2 est rapidement dégradée par le protéasome. IRP1 humaine produite dans la levure Saccharomyces cerevisiae interagit avec les thiorédoxines, suggérant un nouveau mécanisme de régulation de son activité. Un peptide de 73 acides aminés présent dans IRP2 a été décrit comme le senseur de fer intracellulaire responsable de l'adressage de la protéine au protéasome en présence de fer. Ce fragment a été produit, purifié, et son interaction potentielle avec le fer a été analysée. Les résultats obtenus remettent en cause le mécanisme moléculaire de régulation d'IRP2 par le fer. IRP2 et IRP2 dépourvue du fragment spécifique de 73 acides aminés ont été sur-produites dans des cellules mammifères pour en étudier la dégradation. Sans excès de fer dans le milieu de culture, l'implication des lysosomes dans la dégradation de ces deux protéines a été mise en évidence. Enfin, l'effet de certaines situations de stress sur l'activité des IRP a été analysé. Les différents résultats obtenus illustrent la variété des mécanismes observés suivant les types de stress appliqués. L'analyse de la modulation de l'activité des IRP dans divers contextes a permis de mettre en évidence des mécanismes spécifiques d'IRP1 ou IRP2 apportant de nouveaux éléments pour la compréhension du mode de régulation de l'homéostasie du fer<br>Ln metazoans, iron homeostasis is regulated post-transcriptionally by the IRE (Iron Responsive Element )/IRP (Iron Responsive Proteins) system. IRP are two cytosolic proteins that binds specifie sequences, noted IRE, on untranslated regions of mRNA of certain proteins involved in iron homeostasis. When iron is abundant, IRP1 assembles a [4Fe-4S] cluster and becomes an aconitase, whereas IRP2 is rapidly degraded by the proteasome. Human IRP1 produced in the yeast Saccharomyces cerevisiae interacts with thioredoxins, suggesting a new nechanism of regulation for IRP1 activity. A 73 amino acids peptide of IRP2 is said to be an iron sensor responsible for IRP2 proteasomal degradation in iron-Ioaded cells. This peptide was produced, purified and its interaction wih iron was analysed. Results suggest that this peptide may not always be an efficient iron sensor. IRP2 and IRP2 in which this specifie peptide has been deleted were overproduced in mammalian cells to study their degradation. Without iron excess in the culture medium, the lysosomes were found to be involved in the degradation of these two proteins. The effects of different stress conditions on IRP activity were analysed, demonstrating various mechanisms depending on the stress types applied. Analysis of IRP activity and its regulation pointed out specifie mechanisms for IRP1 and IRP2, partly explaining the complexity of iron homeostasis regulation
30
Zhang, Dianzheng. "Cloning, overexpression and characterization of iron regulatory proteins from insects." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/279922.
Full textAbstract:
Iron is essential for life and iron homeostasis is important for all species. Compared to the understanding of iron metabolisms in vertebrates, we know much less about insect intracellular iron homeostasis. The iron regulatory proteins (IRPs) play central roles in this process by interaction with iron responsive elements (IREs). Here, I report the cloning, sequencing, overexpression, purification and characterization of IRP1s from two insect species, Manduca sexta and Aedes aegypti. Electrophoretic mobility shift assays demonstrated that both IRP1s specifically bind IREs s not only from the same species, but also from human ferritin IRE. Another ferritin subunit also was cloned from Manduca sexta and an IRE was identified in the 5'-untranslated region of the mRNA, and the IRE reacted with Manduca IRP1 specifically. Transcription/translation assays demonstrated that both IRP1s repress ferritin synthesis in vitro, and the repression is IRE dependent. Iron administration to Manduca sexta increased hemolymph ferritin levels and decreased fat body IRP1/IRE binding activities without affecting either the IRP1 mRNA or protein levels. These data indicates that translational control of ferritin synthesis by IRP1/IRE interaction could occur in insects in a manner similar to that of mammals. To our knowledge this is the first report of the control of insect ferritin synthesis by IRP1/IRE interaction. The different responses to reducing agent of Manduca sexta and mammalian IRP1s could provide a potential future strategy for designing pesticides in insect control.
31
Torres, Alfredo Gabriel. "Characterization of the heme transport system in Escherichia coli O157:H7, and importance of iron uptake systems in virulence /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
Full text
32
Im, Sang-Choul. "Redox studies on rubredoxin and [2Fe-2S] proteins." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295479.
Full text
33
Thomas, Carla. "The validation and use of the rat intestinal epithelial cell line 6 (IEC-6) to study the role of ferroportin1 and divalent metal transporter 1 in the uptake of iron from Fe(II) and Fe(III)." University of Western Australia. Physiology Discipline Group, 2003. http://theses.library.uwa.edu.au/adt-WU2004.0019.
Full textAbstract:
[Formulae and special characters can only be approximated here. Please see the pdf version of the abstract for an accurate reproduction.] Iron is vital for almost all living organisms by participating in a wide variety of metabolic processes, including oxygen transport, DNA synthesis, and electron transport. However, iron concentrations in body tissues must be tightly regulated because excessive iron leads to tissue damage, as a result of formation of free radicals. In mammals since no controlled means of eliminating unwanted iron has evolved, body iron balance is maintained by alterations in dietary iron intake. This occurs in the duodenum where most dietary iron is absorbed. Absorption involves at least two steps, uptake of iron from the intestinal lumen and then its transport into the body, processes that occur at the apical and basal membranes of enterocytes, respectively. In chapter one of this thesis the background information relevant to iron absorption is described. Despite numerous studies, the role of these proteins in iron absorption remains unclear, partly because many studies have reported them in non-enterocyte cell lines where the expression of the proteins involved in iron absorption is unlikely and therefore the physiological significance of the findings uncertain. Therefore, the study of iron absorption would value from additional cell lines of intestinal origin being used, preferably derived from a species used to comprehensively study this process in vivo, namely the rat. Validation of such a model would enable comparisons to be made from a molecular level to its relevance in the whole organism. In chapter 3 of this thesis, the rat intestinal cell line 6 (IEC-6) was examined as a model of intestinal iron transport. IEC-6 cells expressed many of the proteins involved in iron absorption, but not the ferrireductase Dcytb, sucrase or αvβ3 integrin. In addition, in IEC-6 cells the expression of the apical transporter divalent metal transporter 1 (DMT1), the iron storage protein ferritin, the uptake of Fe(II) and Fe(III) were regulated by cellular iron stores as is seen in vivo. This suggests that IEC-6 cells are of a lower villus enterocyte phenotype. Presented in chapter 4 is the study of the uptake of iron from Fe(II):ascorbate and Fe(III):citrate by IEC-6 cells in the presence of a blocking antibody to the putative basolateral transporter ferroportin1 and of colchicine and vinblastine, different pHs, and over-expression of DMT1. It was shown that optimal Fe(II) uptake required a low extracellular pH and was dependent on DMT1. Uptake of Fe(III) functioned optimally at a neutral pH, did not require surface ferrireduction, and was increased during over-expression of DMT1. These observations suggest that intravesicular ferrireduction takes place before transport of Fe(II) to the cytoplasm by DMT1. This pathway was not blocked by a functional antibody against αvβ3 integrin but was inhibited by competition with unlabeled iron citrate or citrate alone. Surprisingly, a functional antibody against ferroportin1 had no effect on efflux but significantly reduced (p<0.05) uptake of Fe(II) by 40-50% and Fe(III) by 90%, indicating two separate pathways for the uptake of iron from Fe(II)-ascorbate and from Fe(III)-citrate in IEC-6 cells. Presented in chapter 5 is the development and validation of a technique for the removal of freshly isolated enterocytes from the rat duodenum and their use to study iron transport processes that enabled comparisons to be made between these cells, IEC-6 cells and the human enterocyte cell line Caco-2 cells. In chapter 6 a blocking antibody to ferroportin1 was shown to inhibit uptake of Fe(II) but not release of iron in freshly isolated duodenal enterocytes from rats and Caco-2 cells supporting the findings obtained with IEC-6 cells described in chapter 4. Fe(II) uptake was reduced only when the antibody was in contact with the apical membrane indicating its expression at the microvillus membrane. Confirming this, ferroportin1 was shown along the microvillus membrane of Caco-2 cells, in enriched microvillus membrane preparations and in enterocytes of duodenum tissue of rats where it co-localised with lactase. The significant findings to emerge from this thesis are that the IEC-6 cell is a valid model to study iron absorption producing results consistent with those found in freshly isolated enterocytes and in human enterocyte-like cells. In particular, ferroportin1 functions in the uptake of iron at the apical membrane possibly by modulating surface binding of Fe(II) to DMT1 or the activity of DMT1. In addition to this in Fe(II) uptake from Fe(III) ferroportin1 may also affect the number of Fe(III): citrate binding sites. Preliminary studies further characterizing the function of ferroportin1 at the apical membrane and at intracellular sites of IEC-6 cells along with integration of these data are discussed in chapter 7.
34
Zuccola, Harmon Jay. "The crystal structure of monoferric human serum transferrin." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/26304.
Full text
35
Kwan, Miu-fan, and 關妙芬. "Characterization of TM4 of NRAMP1: implication for FEII transport." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29275143.
Full text
36
Al-Massad, Fareeda Khalid Nasser. "Comparative physicochemical & biochemical studies of ferritin & bacterioferritin." Thesis, University of East Anglia, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358458.
Full text
37
Busch, J. L. H. C. "Structural and spectroscopic studies of Desulfovibrio africanus ferrodoxin III." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267262.
Full text
38
Hunt, Colette. "Magnetic studies of fine particle biological systems." Thesis, University of Liverpool, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359198.
Full text
39
Wisedchaisri, Goragot. "Structural basis for transcription regulations in Mycobacterium tuberculosis by iron-dependent regulator and dormancy survival regulator /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/9269.
Full text
40
He, Didi. "Structural basis for iron (II) metabolism in encapsulated ferritin-like proteins." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/23466.
Full textAbstract:
Ferritins are ubiquitous proteins that serve the dual-function of iron reservoir and sequestering the Fe(II) toxicity. The function of ferritins totally depends on the characteristic spherical structure with a di-iron centre performing the iron oxidation and a hallow cavity enclosing the iron minerals in a bioavailable form. I have characterised the structure, assembly and function of a new member of ferritin superfamily that is natively enclosed within an encapsulin shell. Encapsulin proteins are structurally-related to a virus capsid and form 60-meric or 180-meric icosahedrons. I show that this encapsulin associated ferritin-like protein (EncFtn) possesses two main alpha helices, which assemble in a metal-dependent manner to form a ferroxidase centre at a dimer interface. EncFtn adopts an annular decamer structure in contrast to the 24-meric classical ferritins or 12-meric mini-ferritin (DPS). The resemblance of the dimeric EncFtn and monomeric classical ferritins suggests that it is likely that classical ferritin evolves from EncFtn because of the gene duplication. EncFtn is a catalytically active ferroxidase but with only a limited iron binding ability due to its open structure. The encapsulin itself is not able to oxidise Fe(II), but is able to store about 2200 iron ions. I have demonstrated that the EncFtn must be housed in the encapsulin to achieve a maximum loading of approximately 4200 iron ions. The encapsulin nanocompartments are widely-distributed in both eubacteria and archaeon with distinct life styles and represent a distinct class of iron storage system, where iron oxidation and mineralisation are distributed between two proteins.
41
Wardrop, Stacey Leanne. "Regulation of molecules involved in cellular iron homeostasis and transport /." [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16265.pdf.
Full text
42
Ebert, C. Edward. "Effects of mutations of the iron-sulfur protein on the function and structure of the cytochrome bc₁ complex of yeast mitochondria." Morgantown, W. Va. : [West Virginia University Libraries], 2003. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3.
Full textAbstract:
Thesis (Ph. D.)--West Virginia University, 2003.<br>Title from document title page. Document formatted into pages; contains viii, 144 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 129-144).
43
Gelling, Cristy Lee Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Tetrahydrofolate and iron-sulfur metabolism in Saccharomyces cerevisiae." Publisher:University of New South Wales. Biotechnology & Biomolecular Sciences, 2008. http://handle.unsw.edu.au/1959.4/43270.
Full textAbstract:
Tetrahydrofolate-mediated one-carbon metabolism is required for the biosynthesis of many central metabolites, including some amino acids, nucleobases, and nucleotides, and hence dysfunction of one-carbon metabolism is associated with many human diseases and disorders. The mitochondrial glycine decarboxylase complex (GDC) is an important component of one-carbon metabolism, generating 5,10-methylene-tetrahydrofolate (5,10-CH2-H??4folate) from glycine. Previous work has shown that the genes encoding the unique sub-units of the Saccharomyces cerevisiae GDC (GCV1, GCV2 and GCV3) are regulated in response to changes in the levels of cytosolic 5,10-CH2-H??4folate (Piper et al., 2000). Given the centrality of 5,10-CH2-H??4folate to many aspects of metabolism, it was hypothesised that other genes may be regulated by the same mechanism. Using microarray analysis of S. cerevisiae under a number of conditions that affect 5,10-CH2-H??4folate levels, the ??one-carbon regulon??, a group of genes that were co-regulated with the GCV genes was identified. The one-carbon regulon corresponds closely to genes whose promoters are bound by the purine biosynthesis regulator Bas1p, but not all one-carbon regulon members are significantly purine regulated. Genetic approaches demonstrated that the one-carbon unit response and the purine response are distinct, though both depend on the presence of Bas1p. This demonstrated that the close metabolic connections of one-carbon and purine metabolism are reflected in over-lapping, but separable regulatory mechanisms. The identity of the sensor of one-carbon unit depletion remains unknown, but in the course of investigation of the candidate regulator Caf17p, it was demonstrated that Caf17p is in fact involved in Fe/S cluster protein maturation. Examination of the effects of Caf17p depletion revealed that Caf17p is required for the function and maturation of the related mitochondrial Fe/S proteins aconitase and homoaconitase, as well as the function of, but not de novo iron incorporation into, the mitochondrial radical-SAM Fe/S protein biotin synthase. Because other Fe/S proteins were unaffected, Caf17p appears to be a specialised Fe/S maturation factor. The presence of a putative H4folate binding site indicates that Caf17p may constitute a metabolic link between one-carbon and iron metabolism.
44
Faraldo-GoÌmez, JoseÌ D. "Computational studies of bacterial iron transport proteins : methodological aspects and application." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249243.
Full text
45
Foster, Matthew W. "Biosynthetic assembly and nitric oxide mediated degradation of iron-sulfur proteins /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488199501404912.
Full text
46
Xu, Xiangcong. "THE MOLECULAR MECHANISMS OF IRON AND FERRITIN METABOLISM IN." University of Sydney, 2008. http://hdl.handle.net/2123/3535.
Full textAbstract:
Doctor of Philosophy(PhD)<br>Iron (Fe) is essential for cell growth and replication as many Fe-containing proteins catalyse key reactions involved in energy metabolism (cytochromes, mitochondrial aconitase and Fe-S proteins of the electron transport chain), respiration (hemoglobin and myoglobin) and DNA synthesis (ribonucleotide reductase). If not appropriately shielded, Fe could participate in one-electron transfer reactions that lead to the production of extremely toxic free radicals. The Fe storage protein, ferritin, is essential to protect cells against Fe-mediated oxidative stress by accommodating excess Fe into its protein shell (Xu et al., 2005). However, despite intensive research over the last few decades, many questions relating to intracellular Fe metabolism, e.g. Fe release from ferritin remain unanswered. Therefore, it is important to elucidate the molecular mechanisms of Fe trafficking in cells. At the beginning of my candidature, little was understood regarding the effect of anti-cancer agents, anthracyclines on the Fe-regulated genes, including transferrin receptor-1 (TfR1), N-myc downstream-regulated gene-1 (Ndrg1) and ferritin. Furthermore, the mechanisms of ferritin-Fe release and anthracycline-mediated ferritin-Fe accumulation are unclear. The work presented in Chapters 3 and 4 has addressed these issues. Apart from the studies examining the molecular interactions of anthracyclines with Fe, a mouse model with perturbed Fe metabolism was used and the marked alterations of protein expression in the heart of this knockout mouse model was discussed in Chapter 5. Chapter 3 Anthracyclines are effective anti-cancer agents. However, their use is limited by cardiotoxicity, an effect linked to their ability to chelate iron (Fe) and perturb Fe metabolism (Xu et al., 2005). These effects on Fe-trafficking remain poorly understood, but are important to decipher as treatment for anthracycline cardiotoxicity utilises the chelator, dexrazoxane. Incubation of cells with doxorubicin (DOX) up-regulated mRNA levels of the Fe-regulated genes, transferrin receptor-1 (TfR1) and N-myc downstream-regulated gene-1 (Ndrg1). This effect was mediated by Fe-depletion, as it was reversed by adding Fe and was prevented by saturating the anthracycline metal-binding site with Fe. However, DOX did not act like a typical chelator, as it did not induce cellular Fe mobilisation. In the presence of DOX and 59Fe-transferrin, Fe-trafficking studies demonstrated ferritin-59Fe accumulation and decreased cytosolic-59Fe incorporation. This could induce cytosolic Fe-deficiency and increase TfR1 and Ndrg1 mRNA. Up-regulation of TfR1 and Ndrg1 by DOX was independent of anthracycline-mediated radical generation and occurred via HIF-1α-independent mechanisms. Despite increased TfR1 and Ndrg1 mRNA after DOX treatment, this agent decreased TfR1 and Ndrg1 protein expression. Hence, the effects of DOX on Fe metabolism were complex due to its multiple effector mechanisms. Chapter 4 The Fe storage protein, ferritin, can accommodate up to 4500 atoms of Fe in its protein shell (Harrison and Arosio, 1996). However, the underlying mechanism of ferritin-Fe release remains unknown. Previous studies demonstrated that anti-cancer agents, anthracyclines, led to ferritin-59Fe accumulation (Kwok and Richardson, 2003). The increase in ferritin-59Fe was shown to be due to a decrease in the release of Fe from this protein. It could be speculated that DOX may impair the Fe release pathway by preventing the synthesis of essential ferritin partner proteins that induce Fe release. In this study, a native protein purification technique has been utilised to isolate ferritin-associated partners by combining ultra-centrifugation, anion-exchange chromatography, size exclusion chromatography and native gel electrophoresis. In addition to cells in culture (namely, SK-Mel-28 melanoma cells), liver taken from the mouse was used as a physiological in vivo model, as this organ is a major source of ferritin. Four potential partner proteins were identified along with ferritin, e.g. aldehyde dehydrogenase 1 family, member L1 (ALDH1L1). Future studies are required to clarify the relationship of these proteins with cellular Fe metabolism and ferritin-Fe release. Chapter 5 A frequent cause of death in Friedreich’s ataxia patients is cardiomyopathy, but the molecular alterations underlying this condition are unknown. We performed two dimensional electrophoresis to characterise the changes in protein expression of hearts using the muscle creatine kinase frataxin conditional knockout (KO) mouse. Pronounced changes in the protein expression profile were observed in 9-week-old KO mice with severe cardiomyopathy. In contrast, only a few proteins showed altered expression in asymptomatic 4-week-old KO mice. In hearts from frataxin KO mice, components of the iron-dependent complex-I and -II of the mitochondrial electron transport chain and enzymes involved in ATP homeostasis (creatine kinase, adenylate kinase) displayed decreased expression. Interestingly, the KO hearts exhibited increased expression of enzymes involved in the citric acid cycle, catabolism of branched-chain amino acids, ketone body utilisation and pyruvate decarboxylation. This constitutes evidence of metabolic compensation due to decreased expression of electron transport proteins. There was also pronounced up-regulation of proteins involved in stress protection, such as a variety of chaperones, as well as altered expression of proteins involved in cellular structure, motility and general metabolism. This is the first report of the molecular changes at the protein level which could be involved in the cardiomyopathy of the frataxin KO mouse.
47
Bae, Dong-Hun. "The Effects of Iron Levels on the Interaction between Polyamine Metabolism and Iron Metabolism in Neoplastic Cells." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18081.
Full textAbstract:
Iron is a crucial element that is associated with many metabolic pathways important for life sustaining processes. Polyamines are small positively charged polycations involved in various physiological functions. Both iron and polyamines levels are known to be high in cancer cells which suggests a possible unexplored link between the two metabolic pathways. For the first time, we demonstrate that iron-depletion robustly regulates the expression of 13 polyamine pathway proteins. Iron-depletion also decreased polyamine and S-adenosylmethionine levels (required for spermidine/spermine biosynthesis) and decreased 3H-spermidine uptake in accordance with expression of the polyamine importer, SLC22A16. The “reprogramming” of polyamine metabolism by iron-depletion showed dependence on the proto-oncogene, c-Myc, and tumour suppressor, p53 expression. Furthermore, the ability of iron chelators to inhibit proliferation can be rescued by polyamine supplementation. Collectively, these data demonstrate that iron and polyamine metabolism are closely linked at multiple levels. Moreover, we have identified that the mRNA and protein expression of the iron-containing enzyme, aci-reductone dioxygenase 1 (ADI1), was regulated by iron levels. Cellular iron depletion or deficient ADI1 metalation by the iron chaperone, PCBP1, promotes the proteasomal degradation of ADI1. Collectively, this demonstrates that cellular iron regulates ADI1 stability, a key enzyme involved in methionine salvage, polyamine biosynthesis and proliferation. In addition to regulating ADI1, poly(rC)-binding proteins (PCBPs) have been reported to function as iron-binding chaperones that deliver iron to ferritin. We observed that PCBP2 enhances, while PCBP1 inhibits ferritin 59Fe-loading and ferritin protein expression. Our results suggest that the regulation of ferritin iron-loading by PCBPs may involve a combination of translational regulation and/or iron chaperone activity. Overall this study has demonstrated for the first time the direct interaction between iron metabolism and polyamine metabolism, which is important in understanding how cancer cells can survive adverse environments.
48
Lugo-Mas, Priscilla. "Synthetic analogues of cysteinate-ligated non-heme iron enzymes : understanding the structure-function relationship of nitrile hydratase (NHase) and superoxide reductase (SOR) /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8635.
Full text
49
Beard, Collen Alana. "Rubredoxin cobalt substitution and crystallization attempts." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/29863.
Full text
50
Lee, David Andrew. "Computer simulation of a conformational change in lactoferrin." Thesis, Birkbeck (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368084.
Full text