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dc.date.accessioned2013-03-12T08:39:40Z
dc.date.available2013-03-12T08:39:40Z
dc.date.issued2011en_US
dc.date.submitted2012-01-24en_US
dc.identifier.citationHarbitz, Espen. Studies on c-type cytochromes exhibiting "large g-max"/HALS EPR behaviour. Doktoravhandling, University of Oslo, 2011en_US
dc.identifier.urihttp://hdl.handle.net/10852/11471
dc.description.abstractSmå vannløselige c cytokrommer finnes i elektrontransportkjeder i alle livets domener, og har essensielle roller i metabolismen. De inneholder jernatomer bundet i den plane kofaktoren hem. Disse jernatomene er koordinert av én eller to aksielle aminosyreligander fra proteinkjeden. Det finnes flere aminosyrer med mulighet for å koordinere til hemjernet. Elektron paramagnetisk resonans (EPR) har vært et viktig verktøy for bestemmelse av aminosyreligeringen av jernet, og har vært viktig i studiene av mange proteiner når strukturinformasjon ikke har vært tilgjengelig. Observasjonen av at histidin-histidin og histidin-metionin ligerte hemgrupper kunne utvise flere typer EPR spektre vanskeliggjorde bestemmelsen av aksielle ligander, og komplementære metoder (som nærinfrarød magnetisk sirkulærdikroisme (NIR-MCD) spektroskopi)) må benyttes. I histidin-histidin ligerte hemgrupper, er de strukturelle faktorene som bestemmer type EPR spekter kjent, og det er histidinenes relative orientering som bestemmer EPR oppførselen. En tilsvarende sammenheng har ikke blitt observert for histidin-metionin ligerte hemgrupper. I denne avhandlingen har forskjellige aspekter ved histidin-metionin ligeringen blitt studert. Karakteriseringen av et c cytokrom fra den metanspisende bakterien Methylosinus trichosporium OB3b, som har typisk ”stor gmaks” / HALS (Høyanisotropisk eller Høyaksielt Lav Spinn) EPR oppførsel er presentert. Videre viser mutasjons og spektroskopiske studier av c cytokrommer fra flere forskjellige bakterier at selv små forandringer er nok til å endre type EPR oppførsel. Det virker nå klart at konformasjonen til de aksielle ligandene ikke er en avgjørende faktor for ligandfeltet rundt hemjernet i histidin-metionin ligerte hemgrupper.nor
dc.description.abstractSmall soluble c-type cytochromes are found in electron transport chains in all domains of life, and have key roles in metabolism. They contain iron atoms bound in the planar haem cofactor. These iron atoms are axially coordinated by one or two amino acid ligands from the protein backbone. There are several amino acids that can serve as axial ligands to the haem iron. Electron paramagnetic resonance (EPR) has been an important tool in determining the amino acid ligation, and has been important for the study of many proteins in the absence of structural information. The observation that bis-histidine and histidine-methionine ligated haems could exhibit more EPR spectral types complicated the assignment of the axial ligands, and complimentary methods (near infrared magnetic circular dichroism (NIR-MCD)) must be used. In bis-histidine ligated haems, the structural factors governing the EPR spectral types has been elucidated, and the ligands relative orientation is determining of the EPR behaviour. A similar relationship has not been found for histidine-methionine ligated haems. In this thesis, different aspects of the histidine-methionine ligation have been investigated. The characterisation of c-type cytochrome from the methylotroph Methylosinus trichosporium OB3b, which shows a typical “large gmax” / HALS (Highly Anisotropic or Highly Axial Low Spin) EPR behaviour, is presented. Furthermore, mutational and spectroscopic studies of c-type cytochromes from several different bacteria indicate that subtle changes can trigger a change in the EPR spectral type. At present, it seems evident that the conformation of the axial ligands is not a dominant factor in determining the ligand field around the haem iron in histidine-methionine ligated haems.eng
dc.language.isoengen_US
dc.relation.haspartPaper I Cytochrome c-554 from Methylosinus trichosporium OB3b; a protein that belongs to the cytochrome c2 family and exhibit a HALS-type EPR signal Espen Harbitz, K. Kristoffer Andersson PLoS One, 2011, Vol. 6 (7), Article Number: e22014 Published under a Creative Commons Attribution License http://dx.doi.org/10.1371/journal.pone.0022014
dc.relation.haspartPaper II Low-Temperature EPR and Mössbauer Spectroscopy of Two Cytochromes with His-Met Axial Coordination Exhibiting HALS Signals Giorgio Zoppellaro, Thomas Teschner, Espen Harbitz, Volker Schünemann, Solveig Karlsen, David M. Arciero, Stefano Ciurli, Alfred X. Trautwein, Alan B. Hooper, K. Kristoffer Andersson CHEMPHYSCHEM, 2006, Vol. 7 (6), 1258-1267 The paper is removed from the thesis in DUO due to publisher restrictions. The published version is available at:http://dx.doi.org/10.1002/cphc.200500693
dc.relation.haspartPaper III Modulation of the Ligand-Field Anisotropy in a Series of Ferric Low-Spin Cytochrome c Mutants derived from Pseudomonas aeruginosa Cytochrome c-551 and Nitrosomonas europaea Cytochrome c-552: A Nuclear Magnetic Resonance and Electron Paramagnetic Resonance Study Giorgio Zoppellaro, Espen Harbitz, Ravinder Kaur, Amy A. Ensign, Kara L. Bren, K. Kristoffer Andersson Journal of the American Chemical Society, 2008, 130 (46), 15348-15360 The paper is removed from the thesis in DUO due to publisher restrictions. The published version is available at: http://dx.doi.org/10.1021/ja8033312
dc.relation.haspartPaper IV Studies of Ferric Heme Proteins with Highly Anisotropic/Highly Axial Low Spin(S=1/2) Electron Paramagnetic Resonance Signals with bis-Histidine and Histidine-Methionine Axial Iron Coordination Giorgio Zoppellaro, Kara L. Bren, Amy A. Ensign, Espen Harbitz, Ravinder Kaur, Hans-Petter Hersleth, Ulf Ryde, Lars Hederstedt, K. Kristoffer Andersson Biopolymers, 2009, 91 (12), 1064-1082 The paper is removed from the thesis in DUO due to publisher restrictions. The published version is available at: http://dx.doi.org/10.1002/bip.21267
dc.relation.urihttp://dx.doi.org/10.1371/journal.pone.0022014
dc.relation.urihttp://dx.doi.org/10.1002/cphc.200500693
dc.relation.urihttp://dx.doi.org/10.1021/ja8033312
dc.relation.urihttp://dx.doi.org/10.1002/bip.21267
dc.titleStudies on c-type cytochromes exhibiting "large g-max"/HALS EPR behaviouren_US
dc.typeDoctoral thesisen_US
dc.date.updated2012-09-17en_US
dc.creator.authorHarbitz, Espenen_US
dc.subject.nsiVDP::473en_US
cristin.unitcodenullen_US
cristin.unitnameMolekylærbiologien_US
dc.identifier.bibliographiccitationinfo:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft.au=Harbitz, Espen&rft.title=Studies on c-type cytochromes exhibiting "large g-max"/HALS EPR behaviour&rft.inst=University of Oslo&rft.date=2011&rft.degree=Doktoravhandlingen_US
dc.identifier.urnURN:NBN:no-30553en_US
dc.type.documentDoktoravhandlingen_US
dc.identifier.duo149756en_US
dc.contributor.supervisorK. Kristoffer Andersson, Giorgio Zoppellaroen_US
dc.identifier.bibsys121212718en_US
dc.identifier.fulltextFulltext https://www.duo.uio.no/bitstream/handle/10852/11471/3/dravhandling-harbitz.pdf


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