Academic literature on the topic 'Hemeprotein'
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Journal articles on the topic "Hemeprotein"
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Ascenzi, Paolo, and Maurizio Brunori. "A molecule for all seasons: The heme." Journal of Porphyrins and Phthalocyanines 20, no. 01n04 (January 2016): 134–49. http://dx.doi.org/10.1142/s1088424616300081.
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If life without heme-Fe were at all possible, it would definitely be different. Indeed this complex and versatile iron-porphyrin macrocycle upon binding to different “globins” yields hemeproteins crucial to sustain a variety of vital functions, generally classified, for convenience, in a limited number of functional families. Over-and-above the array of functions briefly outlined below, the spectacular progress in molecular genetics seen over the last 30 years led to the discovery of many hitherto unknown novel hemeproteins in prokaryotes and eukaryotes. Here, we highlight a few basic aspects of the chemistry of the hemeprotein universe, in particular those that are relevant to the control of heme-Fe reactivity and specialization, as sculpted by a variety of interactions with the protein moiety.
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Frauenfelder, H., and P. Wolynes. "Rate theories and puzzles of hemeprotein kinetics." Science 229, no. 4711 (July 26, 1985): 337–45. http://dx.doi.org/10.1126/science.4012322.
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Madhavi Sastry, G., and V. Sabareesh. "The Lie-algebraic approach to hemeprotein-ligand dynamics." Chemical Physics Letters 369, no. 5-6 (February 2003): 691–97. http://dx.doi.org/10.1016/s0009-2614(03)00041-1.
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Díaz-Quintana, Antonio, Gonzalo Pérez-Mejías, Alejandra Guerra-Castellano, Miguel A. De la Rosa, and Irene Díaz-Moreno. "Wheel and Deal in the Mitochondrial Inner Membranes: The Tale of Cytochrome c and Cardiolipin." Oxidative Medicine and Cellular Longevity 2020 (April 22, 2020): 1–20. http://dx.doi.org/10.1155/2020/6813405.
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Cardiolipin oxidation and degradation by different factors under severe cell stress serve as a trigger for genetically encoded cell death programs. In this context, the interplay between cardiolipin and another mitochondrial factor—cytochrome c—is a key process in the early stages of apoptosis, and it is a matter of intense research. Cytochrome c interacts with lipid membranes by electrostatic interactions, hydrogen bonds, and hydrophobic effects. Experimental conditions (including pH, lipid composition, and post-translational modifications) determine which specific amino acid residues are involved in the interaction and influence the heme iron coordination state. In fact, up to four binding sites (A, C, N, and L), driven by different interactions, have been reported. Nevertheless, key aspects of the mechanism for cardiolipin oxidation by the hemeprotein are well established. First, cytochrome c acts as a pseudoperoxidase, a process orchestrated by tyrosine residues which are crucial for peroxygenase activity and sensitivity towards oxidation caused by protein self-degradation. Second, flexibility of two weakest folding units of the hemeprotein correlates with its peroxidase activity and the stability of the iron coordination sphere. Third, the diversity of the mode of interaction parallels a broad diversity in the specific reaction pathway. Thus, current knowledge has already enabled the design of novel drugs designed to successfully inhibit cardiolipin oxidation.
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IZUMIMOTO, Masatoshi, and Yongning ZHU. "Influence of Saccharides on the Stabilization of Frozen Hemeprotein." NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI 45, no. 9 (1998): 539–44. http://dx.doi.org/10.3136/nskkk.45.539.
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Sasaki, Tomikazu, and Emil T. Kaiser. "Helichrome: synthesis and enzymic activity of a designed hemeprotein." Journal of the American Chemical Society 111, no. 1 (January 1989): 380–81. http://dx.doi.org/10.1021/ja00183a065.
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Young, Lawrence J., and Lewis M. Siegel. "Alkaline low spin form of sulfite reductase hemeprotein subunit." Biochemical and Biophysical Research Communications 169, no. 1 (May 1990): 39–45. http://dx.doi.org/10.1016/0006-291x(90)91429-v.
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Ikeda-Saito, M., H. C. Lee, K. Adachi, H. S. Eck, R. C. Prince, K. S. Booth, W. S. Caughey, and S. Kimura. "Demonstration that spleen green hemeprotein is identical to granulocyte myeloperoxidase." Journal of Biological Chemistry 264, no. 8 (March 1989): 4559–63. http://dx.doi.org/10.1016/s0021-9258(18)83779-6.
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Dal Farra, Maria Giulia, Sabine Richert, Caterina Martin, Charles Larminie, Marina Gobbo, Elisabetta Bergantino, Christiane R. Timmel, Alice M. Bowen, and Marilena Di Valentin. "Light‐Induced Pulsed EPR Dipolar Spectroscopy on a Paradigmatic Hemeprotein." ChemPhysChem 20, no. 7 (March 21, 2019): 931–35. http://dx.doi.org/10.1002/cphc.201900139.
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Morishima, Yoshihiro, Haoming Zhang, Miranda Lau, and Yoichi Osawa. "Improved method for assembly of hemeprotein neuronal NO-synthase heterodimers." Analytical Biochemistry 511 (October 2016): 24–26. http://dx.doi.org/10.1016/j.ab.2016.07.031.
Full textDissertations / Theses on the topic "Hemeprotein"
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Neto, Ladislau Martin. "O papel da água de hidratação na estrutura e conformação de hemoproteínas visto pelas mudanças na simetria e estado de spin do centro ativo: um estudo por RPE." Universidade de São Paulo, 1988. http://www.teses.usp.br/teses/disponiveis/54/54132/tde-10032014-103509/.
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Neste trabalho foi estudado a influência da água na estabilização da estrutura e conformação da mioglobina (Mb) e hemoglobina (Hb) através de mudanças no centro ativo (grupo heme), detectadas por Ressonância Paramagnética Eletrônica (RPE). Utilizou-se os derivados meta Mb e nitrosil-Mb de baleia, meta Mb eqüina, meta Hb humana e meta Hb bovina. Amostras com diferentes graus de hidratação (0 a 0,50g H2/g proteína) foram submetidas as medidas de RPE, a T= -160°C, acompanhando o sinal do íon ferro (III) nas metas Mb (e Hb) e do grupo NO na nitrosil-Mb. A fração populacional dos complexos formados foram obtidos a partir da integral dupla do espectro de RPE. Na desidratação da meta Mb 65% das moléculas perderam a água da sexta coordenação do ferro (III) dando origem a outros complexos. Um desses complexos foi o hemicromo H (bi-histidina) onde um átomo de nitrogênio da histidina distal E7 se coordena ao ferro, com a hélice E se movimentando em direção ao heme. Adicionalmente a formação do hemicromo observou-se uma diminuição de 40% de moléculas detectáveis por RPE, na desidratação, e sugeriu-se a formação de moléculas com ferro reduzido [Fe (II)] como explicação para essa redução. Foi observado também um alargamento da linha com g ≈ 6 para as amostras com graus de hidratação menores que 0,20g H2O/g Mb devido a desvios da simetria axial em torno do íon ferro (III). Esses desvios de simetria foi proposto originar-se de distorções conformacionais nas amostras com baixa hidratação. Em níveis de hidratação acima de 0,20g H2O/g Mb observou-se um aumento considerável de centros detectáveis por RPE com a recuperação de moléculas com a forma meta. Na meta Hb somente 5% das moléculas permaneceram com a água da sexta coordenação do ferro após a desidratação. As outras 95% das moléculas deram origem a dois tipos de hemicromos (55%) e moléculas de Fe2+ (40%). Foram formados o hemicromo H e principalmente o hemicromo P (o 5° ligante do ferro deve ser o átomo de enxofre da cisteína da cadeia β posição 93 (𗇥), vizinho da histidina proximal 𗇤 que é deslocada, e o 6° ligante é proposto ser o nitrogênio da histidina distal E7). Em um nível de hidratação em torno de 0,40g H2O/g Hb há um aumento considerável de moléculas que voltam a ter a água na 6° coordenação do ferro com o concomitante decréscimo da quantidade de hemicromos e de moléculas com ferro (II). Na adição do gás NO nas amostras de meta Mb de baleia com diferentes graus de hidratação houve a formação significante do complexo Fe2+ - NO somente abaixo de 0,25g H2O/g Mb. Em valores superiores de hidratação (até 0,50g H2O/g Mb) as amostras tornaram-se praticamente diamagnética, após a adição do NO, com a formação do complexo Fe2+ - NO+. Os resultados foram interpretados supondo que o NO reage diretamente com íons Fe2+ disponíveis abaixo de 0,25g H2O/g Hb formando o complexo Fe2+ - NO paramagnético. Em hidratações superiores como praticamente não há mais íons Fe2+ disponíveis o NO reduz o Fe3+ parando no intermediário Fe2+ - NO+ - diamagnético. O espectro tripleto observado para o NO em baixa hidratação na Mb é associado a um complexo onde o ferro (II) está pentacoordenado. Isso indica que a histidina proximal F8 se afastou do heme tornando possível a entrada de um novo grupo em seu lugarIn this work the role of water was studied in the stabilization of structure and conformation of myoglobin (Mb) and hemoglobin ( Hb) by changes in the active center (heme group), detected by Electron Paramagnetic Resonance (EPR). Whale met Mb and nitrosyl-Mb, equine met Mb, human and bovine met Hb were used. Samples with differents hydration degrees (0 to 0,50 g H2O/g protein) were measured by EPR, T= -160°C, analysing the iron (III) signal in the met Mb (and Hb) and NO signal in the nitrosyl-Mb. The populational fractions of complexes were obtained by double integration of EPR spectrum. In the dehydration of met Mb 65% of molecules lost the water molecule coordinated to the iron (II) giving origin to other complexes. One of these complexes was the hemichrome H (bishistidin) where the nitrogen atom of the E7 distal histidin binds to the iron (III). For this to occur the E helix must be close to the heme group. A percentual of 40% of the molecules were not detected by EPR in the dehydration and we suggest the reduction of iron (III) to iron (II) in these molecules. We also observed an increase of line width of g ∼ 6 signal in the samples with hydration degree below 0,20g H2O/g Mb, due to changes in the axial symmetry around at iron(III) ion. These symmetry changes were suggested to occur due to conformational distortions in the samples at low hydration. For hydrations levels above 0,20g H2O/g Mb a considerable increase was observed in the groups detectable EPR with recuperation of molecules in the met form. In met Hb only 5% of molecules remained with the water molecule coordinated to the iron after dehydration. The other 95% of molecules gave origin to two types of hemicromes (55%) and molecules with iron (II) (40%). The hemichromes observed were the bi-histidin and hemichrome P (the proximal histidin 92 was deslocated with the coordination of sulphur atom of cystein 93). For hydration levels around 0,40 g H2O/g Hb there is a considerable increase of molecules that return to met form. There is for the same hydration level a decrease of quantities of hemichromes and molecules with iron (II). In the NO gas addition to whale met Mb sample with differents hydration degrees we observed significant formation of Fe (II) - NO complex only below 0,25 g H2O/g Mb. For higher hydration levels (until 0,50 g H2O/g Mb) after the NO addition, the samples were pratically diamagnetic, with the formation of Fe (II) NO+ complex. The results were interpreted supposing that NO binds directly to Fe (II) ion that is present below 0,25 g H2O/g Hb with the formation of a paramagnetic complex Fe (II) - NO. For higher hydrations there is no iron (II) available and the NO reduces the iron (III) with the formation of intermediate diamagnetic complex Fe (II) NO+. The triplet spectrum displayed by NO at low hydration in Mb is associated with a complex where the iron (II) is pentacoordinated. This result indicates that F8 proximal histidin moves away from the heme group possibilitating the coordination of a new group in this place
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Shah, Kinjalkumar K. "Design, Synthesis and Characterization of Heme-proteins: Developing Potential Catalysts for Bio-remediation." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/31187.
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The next generation of toxic chemicals and hazardous wastes from sophisticated chemical industries will demand the environmental agencies to employ biological methods over the conventional physical and chemical remediation methods. Over the past decade, natural metallo-enzymes have been identified to degrade some of the major chemical contaminants through electron transfer pathways. However, these natural enzymes are less stable in organic solvents and they are not effective for the degradation of toxic compounds such as polychlorinated biphenyls or dioxins. This thesis explores the use of protein design approaches to produce chemically and molecularly modified enzymes, which are highly stable, possess little substrate specificity, and have higher activity than the natural enzymes. The experiments presented in this thesis make use of solid phase synthesis and site-directed mutagenesis for the synthesis and production of these enzymes and popular chromatographic techniques for their purification. The partial characterization of these proteins revealed the essential structural features of these proteins, and their catalytic activity was demonstrated by the use of peroxidase assays.Master of Science
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Balducci, Lodovico. "Dynamics of hemeproteins by femtosecond X-ray techniques." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S115.
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Récemment, la mise au point de techniques de radiographie à résolution temporelle a ajouté la dimension temporelle à la recherche dans le domaine de la biologie structurale et celles-ci se sont avérées être d'excellents outils pour suivre l'évolution structurale des protéines lors d'une réaction. En particulier, les sources de rayons X de 4ème génération (appelées lasers à électrons libres et à rayons X), avec des impulsions de l'ordre de la femtoseconde et des fluences extrêmement élevées, sont capables de sonder des ensembles de molécules essentiellement gelées dans le temps dans des conditions physiologiques. Après un aperçu des études publiées dans la littérature scientifiques, une introduction de base des techniques utilisées est présentée, accompagnée d'une description du dispositif expérimental et du flux de réduction des données. Les deux derniers chapitres sont consacrés à la présentation des résultats obtenus au cours de deux séries d'expériences réalisées au LCLS (SLAC, Menlo Park, CA, USA), pour étudier les changements structuraux des protéines dans la réaction de photodissociation prototypique du monoxyde de carbone chez des hemoprotéines. Au cours de la première expérience, la modification structurelle globale de trois hemoprotéines a été sondée par une technique de diffusion à résolution temporelle, afin d'observer d'éventuelles différences dans ce que l'on appelle le ''protein quake'' lié à la structure de la protéine. Dans la deuxième expérience, le site actif de la myoglobine a été sondé au cours de la même réaction par absorption de rayons X. Les spectres XANES à résolution temporelle ont été comparés à des calculs théoriques, dans le cadre de la théorie de la diffusion multiple, afin d'obtenir une image détaillée de la dynamique ultrarapide. Un bref projet secondaire portait à mesurer précisément des modèles de diffusion statique de la carboxyhémoglobine, afin de définir ses structures d'équilibre multiple par comparaison avec des combinaisons linéaires de structures cristallographiques connues. En conclusion, dans cette thèse de doctorat, nous avons essayé d'apporter quelques petits éléments dans la compréhension de la dynamique ultrarapide des protéines, en appliquant à la fois des méthodes d'analyse standard (Guinier), mais aussi des méthodes presque inexplorées (calculs de diffusion multiple sur des données à résolution temporelle). Selon le système et le niveau de détail requis, ces méthodes, appliquées ici aux à des systèmes modèles, peuvent être considérées d'excellents outils dans la recherche ultérieure sur des protéines plus complexesRecently, the development of time resolved X-ray techniques has added the time dimension to structural biology studies, and have proven to be great tools to track proteins during the course of a reaction, or a specific conformational change. In particular the 4th generation X-ray sources (so called X-ray Free-Electron Lasers), with femtosecond pulses and extremely high fluences, are capable of probing ensembles of molecules essentially frozen in time under physiological conditions. After an overview of the past studies in the field, a basic introduction of the used techniques, the description of the experimental set-up and the flow of data reduction are presented. The last two chapters are devoted to present the results obtained during two separate sets of experiments, conducted at the XPP beamline of the Linac Coherent Light Source (SLAC, Menlo Park, CA, USA), to study the protein's structural changes, upon prototypical photo-dissociation reaction of carbon monoxide from heme proteins. During the first experiment, the global structural modification of three heme proteins has been probed by means of time resolved scattering technique, in order to observe eventual differences in the so called “protein-quake” depending on the protein's structure. In the second experiment, the active site of myoglobin was probed, during the same reaction, by X-ray absorption. The time resolved XANES spectra have been compared with theoretical calculations, in the framework of the multiple scattering theory, in order to retrieve a detailed picture of the ultra-fast dynamics. A further small side-project dealt with the precise measurement of static scattering patterns of carboxy hemoglobin with the goal of defining its multiple equilibrium structures by comparison with linear combinations of known crystallographic structures. In conclusion, in this Ph.D. thesis we tried to add some small pieces in the understanding of ultra-fast proteins dynamics by applying both standard (Guinier) and almost unexplored (multiple scattering calculations on time resolved data) analysis methods: depending on the system and the level of details required, these methodologies, here applied on model systems, can be considered excellent tools for further research on more complicated proteins
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Lim, Anthony Richard. "Role of heme propionates in myoglobin electron transfer." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30591.
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Myoglobin (Mb) is a well characterized hemeprotein found in skeletal muscle. The dimethylester heme-substituted derivative of equine Mb (DME-Mb) was prepared to evaluate the involvement of the heme propionate groups in the electron transfer reactions of Mb. To achieve this goal, an efficient procedure to reconstitute and purify DME-Mb in high yield was developed. The near UV-visible absorption spectra of DME-Mb in various states of ligation and oxidation did not change significantly relative to those of native Mb. The ¹H NMR spectra obtained for native metMb (heme Fe(III) oxidation state) and metDME-Mb showed differences in the electromagnetic environment of their respective heme groups.
The reactivity of DME-Mb was different from that of native Mb. For example the water ligand of metDME-Mb (Fe-H₂O) has a lower pKa than that of native metMb as determined by spectroscopic pH titrations. The autoxidation rate of oxyDME-Mb (Fe(II)-O₂) is faster than that of native oxyMb. MetDME-Mb apparently has a binding affinity for ferricyanide not evident in native metMb. Compared to native Mb, DME-Mb has decreased susceptibility to the oxidant hydrogen peroxide.
The oxidation-reduction equilibrium of DME-Mb has been studied under a variety of solution conditions. At standard conditions (pH 7, I=0.1 M and 25°C) the midpoint reduction potential (Em) of DME-Mb is 100.0(2) mV vs. SHE, which is 39 mV higher than the Em of native Mb. Analysis of the pH dependence of Em showed differences in the identity or pKa between titratable groups found in native and DME-Mb. The ionic strength dependence of Em showed a higher net positive charge estimate for DME-Mb than native Mb consistent with the nature of the chemical modification involved. The temperature dependence of Em showed that DME-Mb has a greater difference in stability between oxidation states than native Mb.
The kinetics of metDME-Mb reduction by Fe(EDTA)²⁻were also studied under a variety of conditions. At standard conditions, metDME-Mb reacted with the reductant Fe(EDTA)²⁻ at a second order rate constant (k₁₂) two orders of magnitude greater than that of native metMb. After correcting for the differences in reduction potential between reactants, metDME-Mb still reacted at a significantly faster rate than native metMb, indicating differences in their reaction mechanisms. The pH, temperature and ionic strength dependences of k₁₂ for DME-Mb and Fe(EDTA)²⁻ showed that DME-Mb had electrostatic and thermodynamic properties significantly different from that of native Mb.
The functional differences between DME-Mb and native Mb can be attributed to the structural and electrostatics properties of the heme propionate groups. The interactions of these groups within the surrounding protein and the external environment are discussed with reference to the structure of Mb available from x-ray crystallographic studies. As a result, it is concluded that the heme propionate groups are involved in the structural stability, electron transfer specificity and reactivity of Mb.Medicine, Faculty of
Biochemistry and Molecular Biology, Department of
Graduate
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Tanaka, Tomoyoshi. "Resonance raman and surface enhanced raman studies of hemeproteins and model compounds." Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/27678.
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Novo, de Oliveira Ana Luísa. "Theoretical study of ligand migration in Hemeproteins: Truncated Hemoglobin N and Nitrophorin 7." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/307543.
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The diversity of functional roles played by heme proteins in all kingdoms of life is to a large extent regulated by the thermodynamic and kinetic properties of their interaction with small gaseous molecules.
The aim of this PhD thesis is to examine the structural and dynamical properties of two hemeproteins, the truncated hemoglobin N from M. Tuberculosis and nitrophorin 7 from R. Proxilus, and to examine their relationships with the biological role of these proteins. Particular attention has been paid to the diffusion of small ligands between the internal cavities in the two hemeproteins, and the entry/release pathways from the protein matrix to the solvent. Qualitative and semi-quantitative agreements between experiment and simulations are obtained for the identities of the cavities that physically trap the ligand and for the connections between them.
The truncated hemoglobin N (trHbN) is believed to constitute a defense mechanism of M. Tuberculosis against NO produced by the macrophages during the initial growth infection stage, which is converted to the harmless nitrate anion, through the chemical reaction NO+ FE(II)-O2 ->FE(III)+ [NO3]-. The dual path ligand-dependent mechanism proposed in previous studies of the group ensures the access of NO to the heme cavity in the oxygenated form of the protein, which should warrant survival of the microorganism under stress conditions and allowing the bacillus to stay in latency. As a consequence, the processes mediated by trHbN are worth for searching a therapeutical intervention, since the inactivation of the NO scavenging should reduce significantly the bacteria resistance.
In this work we have validated the importance of the PheE15 residue in the previous proposed dual path mechanism, as PheE15 was proposed to act as a gate that regulates the access of NO to the heme cavity in the oxygenated form of the protein. Thus, we have studied the impact of three residue mutations of the gate residue, PheE15Ala, PheE15Ile and PheE15Tyr, in the ligand migration mechanism and in the NO detoxification activity. The results support the gating role played by PheE15, because all the mutations are predicted to either block the long branch of the tunnel (PheE15Ile, PheE15Tyr) or to induce structural alterations that affect the passage of NO at the entrance of the tunnel (PheE15Ala).
After release of the NO3- anion, the protein, which rests in its ferric form, is assumed to be recycled by a putative reductase, rendering trHbN in the ferrous form suitable to bind a new O2 molecule, thus ensuring an efficient detoxification mechanism. In order to gain insight into the reduction process, we have examined the interaction between trHbN and a flavodocin reductase (FdR) from E. Coli, which has shown to be very efficient in restoring the ferrous form of the protein. Thus, our studies have yielded a 3D model of the complex between trHbN and FdR, which allows to identify the residues implicated in the binding of the two proteins. Moreover, the model predicts that the heme and flavin cofactors are close (between 6 and 9 Å) in the complex, which facilitates an efficient electron transfer, as reinforced by the calculated electron couplings.
Nitrophorin 7 is a hemeprotein implicated in the NO transport, which can be found in the saliva of blood feeding insects. One of the bugs, Rhodnius prolixus, is the causative agent of Chagas disease, and is responsible for a high number of deaths (approximately 15000 each year). Among the nitrophorin family, we have examined nitrophorin 7, which presents three extra residues in N-terminal sequence and the unique ability to bind membranes negatively charged. The results point out the existence of up to three inner cavities, which may define an internal pathway for migration of a gaseous ligand (NO) from the heme to the back of the protein. This topological feature is not present in other nitrphorins, such as NP4, and justifies a more complex kinetic rebinding scheme in NP7. In conjunction with the ability to interact with membranes, these findings might support a specific role in NO-controlled release.
Both projects are carried out in closed collaboration with experimental groups, and we believe that in the future such collaborations will allow the development of new strategies with therapeutically implications in these diseases.El proyecto a desarrollar se centrará en los aspectos dinámicos del transporte de ligandos en hemoproteínas, centrándose en dos tipos principales. Por un lado la hemoglobina truncada N de Mycobacterium tuberculosis, y por otro nitroforina. La hemoglobina truncada N desempeña un papel muy importante como mecanismo de defensa del microorganismo, pues transforma el óxido nítrico (NO) generado por los macrófagos durante las etapas iniciales de respuesta a la infección en anión nitrato. Ello, pues, permite la subsistencia del microorganismo, que permanece en estado de latencia, dificultando la recuperación del paciente de tuberculosis. En consecuencia, dicha proteína aparece como una diana de potencial valor terapéutico, puesto que su inactivación debería reducir significativamente la resistencia del microorganismo. Los estudios del Prof. Luque han perseguido dilucidar los aspectos moleculares que subyacen en la capacidad de la proteína de captar O2 y NO, y de llevar a cabo la reacción química de conversión a nitrato. En particular, se ha propuesto un mecanismo de transporte de ligandos, y el objetivo que se plantea es su validación mediante el examen de diversos mutantes obtenidos al modificar el residuo que controla la migración a través del canal. En cuanto a nitroforina, es una hemoproteína transportadora de NO que se halla en la saliva de insectos cuya alimentación se basa en sangre. Uno de ellos, Rhodnius prolixus, está implicado en la enfermedad de Chagas, que causa un número elevado de muertes (aproximadamente 15000 por año). De entre los diversos tipos de nitroforinas, nuestro interés se centra en nitroforina 7 (NP7), que difiere en el extremo N-terminal respecto a otras nitroforinas. El objetivo del trabajo se centra en determinar el efecto de dichas diferencias sobre la capacidad de captación y transporte de NO. En ambos casos, los proyectos se llevan a cabo en colaboración con grupos experimentales, y confiamos que dicha colaboración permita abrir estrategias de intervención terapéutica.
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Lai-Thi, Thanh-Lan. "Propriétés physico-chimiques et structurales de deux hémoprotéines de cyanobactérie thermophile." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112187/document.
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La photosynthèse permet de convertir l’énergie solaire en énergie chimique. Ce processus met en jeu un grand nombre de protéines et complexes protéiques. Le premier complexe de la chaîne photosynthétique est le photosystème II où a lieu l’oxydation de l’eau. Le PSII est composé des protéines D1 et D2. Chez la cyanobactérie thermophile Thermosynechococcus elongatus, il y a trois gènes qui codent trois protéines D1 différentes. La première partie de la thèse décrit le développement d’outils protéomiques basés sur les gels d’électrophorèse 2D pour étudier le protéome des trois différents variants, qui expriment chacun une seule protéine pour D1. Peu de différences ont été trouvées. Toutefois, un seul des variants exprime Tll0287. La deuxième partie de la thèse décrit la caractérisation de Tll0287 avec différents techniques : spectroscopies d’absorption UV-visible ou de résonance Raman et spectro-électrochimie. Tll0287 a été identifié comme un cytochrome de type c, mais il présente beaucoup de caractéristiques inattendues. Les spectres d’absorption UV-visible et de résonance Raman de Tll0287 réduit montrent une dépendance vis-à-vis du pH. Deux formes d’hèmes sont présents dans chacun des états oxydé et réduit. Un changement du ligand cystéine a été observé quand l’hème est réduit. Les titrages redox présentent de multiples potentiels à pH 10 et pH 5. Tll0287 peut fixer une molécule de CO à pH 7,6. Ces caractéristiques suggèrent que Tll0287 pourrait être une protéine senseur. De plus, la structure cristallographique montre que Tll0287 n’a pas un repliement classique d’un cytochrome de type c mais celui d’une protéine senseur. Les mutants de délétion du gène tll0287 ont été construits et aideront à comprendre la fonction de ce nouveau cytochrome. La troisième partie décrit l’étude de PsbV2 : un autre cytochrome de type c. Afin d’obtenir en quantité suffisante la protéine pour permettre sa caractérisation, elle a été surexprimée dans un système homologue en utilisant le promoteur de l’enzyme de la rubisco. Le potentiel redox de PsbV2 a été déterminé, comme étant très bas, inférieur à -460 mV (vs SHE, pH 5). Le spectre d’absorption UV-visible de la forme réduite a été caractérisé. La structure cristallographique de PsbV2 a été résolue et a révélé une cystéine comme ligand axial et un repliement proche de celui de cytochromes connus de T.elongatus. Bien que Tll0287 et PsbV2 présentent une cystéine comme ligand axial, leurs structures et leurs propriétés physico-chimiques suggèrent que leurs fonctions sont bien différentes. Une contribution majeure de cette thèse est la caractérisation d’un nouveau senseur à hème de type c chez les cyanobactéries et le développement d’outils nécessaires pour son étudePhotosynthesis converts solar energy into chemical energy. This process involves a large number of proteins and protein complexes. The first protein complex in the photosynthetic chain is Photosystem II within the oxidation of water takes place. PSII is composed of the D1 and D2 proteins. In the thermophile cyanobacterium Thermosynechococcus elongatus, three genes encoded three different D1 proteins. The first part of this thesis describes the development of proteomics tools based on 2D gel-electrophoresis to study the proteome of three different variants, each expressing a single different D1 protein. Very few differences were found. However, only one expressed the protein Tll0287. The second part of the thesis describes the characterization of Tll0287. It was characterized using different techniques: electronic absorption and Raman resonance spectroscopies and spectro-electrochemistry. Tll0287 has been previously identified as a c-type cytochrome, but it presents some unexpected characteristics. The UV-visible absorption and Raman resonance spectra of reduced Tll0287 show a pH dependence. The reduced and oxidized states each had two different forms of the heme. A switch of ligands from a cysteine to histidine was observed in the reduced state. Redox titration showed multiple midpoints at pH 10 and 5. Tll0287 was shown to fix a CO molecule at pH 7.6. These physical properties suggested that Tll0287 could be a sensor. The crystallographic studies reveal that Tll0287 does not have a classical c-type cytochrome fold and is similar to other known sensor proteins, strengthening the hypothesis that it is a sensor. Deletion mutants were constructed that will help to better understand the function of this new cytochrome. The third part describes a study of the PsbV2, another c-type cytochrome. In order to obtain sufficient quantities to carry out characterization of this protein, it was overexpressed in a homologous system using the promotor of the rubisco enzyme. The redox midpoint potential of PsbV2 was found to be very low, below -460 mV (vs SHE, pH 5). The UV-visible absorption spectrum of the reduced form was determined. The crystallographic structure of PsbV2 was solved and reveals an axial cysteine ligand. Although both Tll0287 and PsbV2 share this feature, their different structures and physico-chemical properties suggest that their functions are unlikely to be similar. A major contribution of this thesis is the characterization of a new c-type cytochrome sensor in cyanobacteria and the development of proteomic tools required to study it
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Moran, John Joseph. "Hemeproteins Bathed in Ionic Liquids: Examining the Role of Water and Protons in Redox Behavior and Catalytic Function." Cleveland, Ohio : Cleveland State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1249089802.
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Thesis (Ph.D.)--Cleveland State University, 2009.Abstract. Title from PDF t.p. (viewed on Sept.8, 2009). Includes bibliographical references (p. 101-104). Available online via the OhioLINK ETD Center and also available in print.
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Agyepong, Andoh-Baidoo Rosemarie. "SPECTROSCOPIC CHARACTERIZATIONS OF THE COMPOUND II INTERMEDIATE OF SOYBEAN PEROXIDASE FROM SOYBEAN SEED COATINGS." VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/20.
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Spectroscopic characterization of ferric soybean peroxidase with peroxides were studied to determine the ligand coordination and to characterize the structure of the heme active site and its intermediates (ferryl species). The lifetime, chemical reactivity and distinctive colors of the ferryl species (FeIV) formed during the oxidation of peroxidase (FeIII) by peroxides enabled structure, dynamics and reaction mechanisms to be studied. Resonance Raman spectroscopy was used as a means of characterizing the structure of the soybean peroxidase and its intermediates. Excitation in the Soret absorption band at 406.7nm with 2-5mW laser power was used for this study. Resonance Raman spectra in the 200 to 1700 cm-1 region were obtained for the soybean peroxidase. However, the focus of this study was on the vibrational region of the resonance Raman spectra from 900 to 500cm-1 where the FeIV=O stretching frequencies for heme compound II intermediates are expected. Several pH and pD (deuterium substitution) samples of the soybean peroxidase were analyzed using resonance Raman spectroscopy. The vibrational stretching frequencies of the ferryl peroxidases varied with varying pH/pD were observed within the 773–787cm-1 range. From the deuterium experiment, accompanied with changes in the vibrational frequencies of the iron-ligand, a 3cm-1 upshift and intense resonant enhancement of the peaks, we observed the ferryl nature of compound II intermediate for soybean peroxidase. Badger’s rule was used to estimate the bond distances that existed within Fe-O which offers additional insight into the structure of the ferryl species. The estimated bond distance for the soybean peroxidase was significantly less than Fe-O bond distances proposed by X-ray crystallographers for other peroxidases in the same family. Comparing the vibrational frequencies of the ferryl intermediates in soybean peroxidase to that in heme proteins portrayed the effect the protein environment has on the vibrational frequencies.
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Neto, Ladislau Martin. "Contribuição da técnica de RPE no estudo de três diferentes sistemas: complexos de Cu(II)- Aliina; Cu(II)-bdfpo e hemoproteínas com diferentes graus de hidratação." Universidade de São Paulo, 1985. http://www.teses.usp.br/teses/disponiveis/54/54132/tde-18082014-154354/.
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Neste trabalho são apresentados estudos em três diferentes sistemas utilizando-se as técnicas de Ressonância Paramagnética Eletrônica (RPE) e absorção eletrônica. No primeiro estudou-se a formação dos possíveis complexos entre o aminoácido aliina, extraído do alho, e o íon cobre (II). Os dados de RPE e absorção eletronica no visível (400-1100 nm) foram utilizados para caracterizar os diferentes complexos obtidos. No segundo utilizou-se o monocristal do complexo dicloro bis (benzil difenil fosfinóxido) Cobre (II) e efetuaram-se medidas de RPE variando-se a direção de aplicação do campo magnético no monocristal. Os auto-valores encontrados para as componentes do tensor g¯ foram: g1= 2,0891; g2= 2,4554 e g3= 2,0767. Com base nos dados de RPE e cristalográficos e usando a teoria de campo cristalino foi proposto dxy como estado fundamental para o íon cobre (II) neste complexo. Fez-se também um estudo preliminar observando-se as variações no centro ativo de hemoproteínas moduladas pelo grau de hidratação. Metahemoglobina bovina e metamioglobina eqüina liofilizadas foram usadas e o sinal de RPE do íon ferro (III) monitorado. Dos espectros de RPE das duas proteínas são observadas pelo menos duas simetrias para o íon ferro (III), uma axial caracterizada por um valor de g próximo de 6 e outra caracterizada por g= 4,3 correspondendo a simetria rômbica. A intensidade dos sinais mostrou-se muito sensíveis ao grau de hidratação. Metahemoglobina e metamioglobina apresentaram comportamentos distintos dos sinais de RPE e sugeriu-se serem eles devido as diferenças estruturais entre as duas proteínasIn this work studies in three different systems using Electron Paramagnetic Resonance (EPR) and eletronic absorption techniques are presented. The formation of possible complexes between the amino acid aliin, extracted of garlic, and the copper (II) íon was studied in the first work. EPR and visible eletronic absorption (400-1100 nm) data were utilized to characterize the different complexes obtained. In the second work a crystal of the complex dichloro bis (benzyl diphenyl phosphinoxide) copper (II) was used and the EPR measures were made for different directions of application of the magnetic field in the crystal. The eigenvalues obtained for the g¯ tensor components were: g1= 2,0891; g2= 2,4554 and g3= 2,0767. Using EPR and crystallographic data and crystal field theory dxy was proposed as the ground state of the copper (II) íon in this complex. A preliminary study was also made observing changes at the active Center of the hemeproteins modulated by the hydration degree. Lyophilized bovine methemoglobin ande quine metmyoglobin were used and the EPR signal of the iron (III) íon monitored. Or both proteins the EPR spectra corresponding to at least two iron symmetries were observed, one axial characterized by a g value near 6.0 and another characterized by g= 4,3 corresponding to rhombic symmetry. The intensity of these signals were very sensitive to the hydration degree. Metmyoglobin and methemoglobin showed distint behaviors of the EPR signals and it was suggested that they were due to structural differences between the two proteins
Books on the topic "Hemeprotein"
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Maines, Mahin D. Heme oxygenase: Clinical applications and functions. Boca Raton, Fla: CRC Press, 1992.
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Hiroyoshi, Fujita, ed. Regulation of heme protein synthesis. Dayton, Ohio: AlphaMed Press, 1994.
Find full textBook chapters on the topic "Hemeprotein"
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Alpert, Bernard. "Protein Fluctuations and Hemeprotein Affinity for Ligand." In Structure and Dynamics of Nucleic Acids, Proteins, and Membranes, 153–60. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4684-5308-9_12.
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Teraoka, J., N. Yamamoto, Y. Matsumoto, Y. Kyogoku, and H. Sugeta. "Vibrational Circular Dichroism of Ligand Vibrations in Hemeprotein." In Spectroscopy of Biological Molecules, 237–38. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0371-8_106.
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De la Cerda, B., F. P. Molina-Heredia, M. Hervás, J. A. Navarro, A. Díaz-Quintana, and M. A. De la Rosa. "Site-Directed Mutants of Cytochrome c6 Provide New Insights into the Interaction Between Psi and the Hemeprotein." In Photosynthesis: Mechanisms and Effects, 1601–4. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-3953-3_377.
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Mizutani, Yasuhisa, Naoki Fujii, Mitsuhiro Miyamoto, Misao Mizuno, and Haruto Ishikawa. "Vibrational Energy Flow in Hemeproteins." In Springer Proceedings in Physics, 532–34. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-13242-6_130.
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García-Rubio, Inés. "Pulsed EPR: Principles and Examples of Applications to Hemeproteins." In Encyclopedia of Biophysics, 2115–24. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-16712-6_654.
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Yoshimura, T. "Nitric oxide, a versatile biological ligand for hemeproteies." In Bioradicals Detected by ESR Spectroscopy, 217–35. Basel: Birkhäuser Basel, 1995. http://dx.doi.org/10.1007/978-3-0348-9059-5_16.
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Henry, E. R., W. A. Eaton, and R. M. Hochstrasser. "Molecular Dynamics Study of Vibrational Cooling in Optically Excited Hemeproteins." In Springer Series in Chemical Physics, 430–32. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82918-5_115.
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Marnett, Lawrence J., Paul Weller, and John R. Battista. "Comparison of the Peroxidase Activity of Hemeproteins and Cytochrome P-450." In Cytochrome P-450, 29–76. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4757-9939-2_2.
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Houde, D., J. W. Petrich, O. L. Rojas, C. Poyart, A. Antonetti, and J. L. Martin. "Reactivity and Dynamics of Hemeproteins in the Femtosecond and Picosecond Time Domains." In Springer Series in Chemical Physics, 419–22. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82918-5_112.
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Kanner, Joseph, Stella Harel, and Avior Menahem Salan. "The Generation of Ferryl or Hydroxyl Radicals During Interaction of Hemeproteins with Hydrogen Peroxide." In Oxygen Radicals in Biology and Medicine, 145–48. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4684-5568-7_20.
Full textConference papers on the topic "Hemeprotein"
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Mizutani, Yasuhisa, Naoki Fujii, Mitsuhiro Miyamoto, Misao Mizuno, and Haruto Ishikawa. "Vibrational Energy Flow in Hemeproteins." In International Conference on Ultrafast Phenomena. Washington, D.C.: OSA, 2014. http://dx.doi.org/10.1364/up.2014.07.mon.p1.13.
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Arcovito, Alessandro, Maurizio Benfatto, Paola D’Angelo, and Stefano Della Longa. "Hemeproteins: Recent Advances in Quantitative XANES Analysis." In X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference. AIP, 2007. http://dx.doi.org/10.1063/1.2644508.
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Sanfratello, Vincenzo. "Structural and dynamic properties of bulky ligand derivatives of hemeproteins." In Fifth scientific conference on nuclear and condensed matter physics. AIP, 2000. http://dx.doi.org/10.1063/1.1303367.
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