Dissertations / Theses on the topic 'Proteins'
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Gill, Katrina Louise. "Protein-protein interactions in membrane proteins." Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400016.
Stylianou, Julianna. "Protein-protein interaction of HSV-1 tegument proteins." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/24663.
Pateman, Cassandra Sophie Catherine. "RGS proteins and G protein signalling." Thesis, University of Warwick, 2002. http://wrap.warwick.ac.uk/2367/.
Nauli, Sehat. "Folding kinetics and redesign of Peptostreptococcal protein L and G /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/9237.
Wadahama, Hiroyuki. "Identification and Characterization of Soybean Protein Disulfide Isomerase Family Proteins as Functional Proteins for Folding of Seed-storage Proteins." Kyoto University, 2010. http://hdl.handle.net/2433/120458.
0048
新制・課程博士
博士(農学)
甲第15414号
農博第1799号
新制||農||978(附属図書館)
学位論文||H22||N4513(農学部図書室)
27892
京都大学大学院農学研究科食品生物科学専攻
(主査)教授 河田 照雄, 教授 村田 幸作, 教授 井上 國世
学位規則第4条第1項該当
Sakhawalkar, Neha. "Hub Proteins, Paralogs, and Unknown Proteins in Bacterial Interaction Networks." VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4730.
Nguyen, Giang Huong. "A functional analysis of the human LPA₁G protein coupled receptor." Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131304/unrestricted/nguyen%5Fgiang%5Fh%5F200405%5Fms.pdf.
Ndabambi, Nonkululeko. "Recombinant expression of the pRb- and p53-interacting domains from the human RBBP6 protein for in vitro binding studies." Thesis, University of the Western Cape, 2004. http://etd.uwc.ac.za/index.php?module=etd&.
Baisden, Joseph M. "AFAP-110 is a cSrc activator." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=2766.
Title from document title page. Document formatted into pages; contains v, 149 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
Filipponi, Luisa. "New micropatterning techniques for the spatial addressable immobilization of proteins." Australian Digital Thesis Program, 2006. http://adt.lib.swin.edu.au/public/adt-VSWT20060905.113858/index.html.
A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy, Industrial Research Institute Swinburne, Swinburne University of Technology - 2006. Typescript. Includes bibliographical references (p. 184-197).
Louie, Brenton E. "Modeling uncertainty in data integration for improving protein function assignment /." Thesis, Connect to this title online; UW restricted, 2008. http://hdl.handle.net/1773/7154.
Gilker, Eva Adeline Gilker. "INTERACTIONS AND LOCALIZATION OF PROTEIN PHOSPHATASES, YWHA PROTEINS AND CELL CYCLE CONTROL PROTEINS IN MEIOSIS." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1532699317257539.
Li, Wei. "Protein-protein interaction specificity of immunity proteins for DNase colicins." Thesis, University of East Anglia, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302033.
Tse, Muk-hei. "Investigations on recombinant Arabidopsis acyl-coenzyme A binding protein 1." View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B36427664.
Hedin, Linnea E., Kristoffer Illergård, and Arne Elofsson. "An Introduction to Membrane Proteins." Stockholms universitet, Institutionen för biokemi och biofysik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-69241.
authorCount :3
Arbuckle, Janeen Lynnae. "Identification and characterization of domains in non-core RAG1." Oklahoma City : [s.n.], 2007.
Kazlauskas, Arunas. "Regulation of dioxin receptor function by the Hsp90 chaperone complex /." Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-176-4.
Schmiele, Marcio 1979. "Interações físicas e químicas entre isolado protéico de soja e glúten vital durante a extrusão termoplástica a alta e baixa umidade para a obtenção de análogo de carne = Physical and chemical interactions between isolated soy protein and vital gluten during thermoplastic extrusion at high and low moisture content to obtain meat analogue." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255892.
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Os análogos de carne obtidos por extrusão termoplástica de proteínas vegetais são caracterizados pelo seu elevado teor proteico e estrutura semelhante às fibras da carne, envolvendo diversos tipos de ligações e/ou interações químicas entre as proteínas. O objetivo deste trabalho foi avaliar as características tecnológicas e físico-químicas de análogos de carne, à base de isolado proteico de soja, obtidos por processo de extrusão termoplástica a alta umidade (AU) e baixa umidade (BU). Para cada condição de umidade foi utilizado um Delineamento Composto Central Rotacional de três variáveis independentes (glúten vital, umidade de condicionamento e temperatura de extrusão). As variáveis dependentes avaliadas foram a textura instrumental, cor instrumental, capacidade de absorção de água, índice de solubilidade em água, capacidade de absorção de óleo, índice de dispersibilidade de proteína, energia mecânica específica e o tipo de interações proteicas. Estas interações foram avaliadas através de sete tipos de solventes específicos: (i) tampão fosfato para as proteínas no estado nativo; (ii) dodecil sulfato de sódio para as interações hidrofóbicas e iônicas; (iii) Triton 100X para as interações hidrofóbicas; (iv) ureia para as interações hidrofóbicas e pontes de hidrogênio; (v) ß-mercaptoetanol para as ligações dissulfeto; e (vi) ß-mercaptoetanol e ureia e (vii) dodecil sulfato de sódio e ureia, para avaliar o efeito sinérgico entre os sistemas. O ponto otimizado (caracterizado principalmente por promover maiores valores de L* e de capacidade de absorção de água, menores valores de índice de solubilidade em água, de capacidade de absorção de óleo, de desnaturação proteica e valores intermediários de textura instrumental e de energia mecânica específica) foi processado juntamente com uma amostra controle para ambos os processos com o intuito de validar os modelos matemáticos e avaliar as possíveis alterações na morfologia dos análogos de carne, na massa molecular das proteínas, na composição de aminoácidos totais e na desnaturação proteica. As melhores condições de processamento foram obtidos para os análogos de carne contendo de 12 e 5 % de glúten vital, 58 e 18 % de umidade de condicionamento e 135 e 100 °C para a temperatura de extrusão, para o processo AU e BU, respectivamente. As principais interações proteína-proteína encontradas nos análogos de carne foram as ligações dissulfeto e ligações de hidrogênio para o processo AU e as ligações dissulfeto e interações iônicas para o processo BU. A adição de glúten vital promoveu uma aparência mais lisa e melhor orientação na estrutura das fibras. Verificou-se que ocorreu aumento nas proteínas de baixa massa molecular e diminuição nas proteínas de alta massa molecular. No perfil de aminoácidos totais houve maior variação negativa para os aminoácidos essenciais (triptofano e treonina), semi essenciais (cisteína) e não essenciais (serina), indicando que houve redução no valor nutricional. As estruturas secundárias (a-hélice, ß-folha, ß-volta e a estrutura desordenada) mostraram alteração na sua conformação devido à desnaturação proteica e formação de novos agregados
Abstract: Meat analogue obtained by termoplastic extrusion of vegetable proteins are characterized by its high protein levels and structure similar to meat fibers, which comprises many types of chemical bonds and/or interactions between proteins. The aim of this work was to evaluate the technological and physico-chemical characteristics of meat analogue based on isolated soy protein obtained by thermoplastic extrusion process at high moisture (HM) and low moisture (LM) content. For each moisture condition was used a Central Rotational Composite Design with three independent variables (vital gluten, moisture content and extrusion temperature). The dependent variables evaluated were instrumental texture, instrumental color, water absorption capacity, water solubility index, oil absorption capacity, protein dispersibility index, specific mechanical energy, and the type of protein interactions. These interactions were evaluated using seven specific solvents types: (i) phosphate buffer for proteins in native state; (ii) sodium dodecil sulphate for hydrophobic and ionic interactions; (iii) Triton 100X for hydrophobic interactions; (iv) urea for hydrophobic interactions and hydrogen bonds; (v) ß-mercaptoethanol for dissulfide bonds; and (vi) ß-mercaptoethanol and urea and (vii) sodium dodecil sulphate and urea, for the synergistic effect between the systems. The optimized point (characterized mainly by promoting higher values for L* and water absorption capacity, lower values for water solubility index, oil absoption capacity and protein denaturation and intermediate values for instrumental texture and specific mechanical energy) was processed, together with a control sample for each processes, in order to validate the mathematical models and to evaluate possibles changes in the meat analogues morphology, in the protein molecular weight, in the total amino acid composition, and in the protein denaturation. The best processing conditions were obtained for the meat analogue containing 12 and 5 % of vital gluten, 58 and 18 % of moisture content and 135 and 100 °C of extrusion temperature, for the HM and LM processes, respectively. The main protein-protein interactions found in meat analogues were the dissulfide bonds and hydrogen bonds for the LM process and the dissulfide bonds and ionic interactions for the HM process. The addition of vital gluten promoted a smoother appearance and better orientation in the fiber structure. It was found that occured an increase in the protein with low molecular weight and a reduction in the protein with high molecular weight. There were a greater negative variation for the essential (tryptophan and threonine), semi-essential (cysteine) and nonessential (serine) amino acids in the total amino acid profile, indicating a reduction of the nutritional value. The secondary structure (a-helix, ß-sheet, ß-turn and disordered structure) showed alteration in its conformation due to the protein denaturation and formation of new aggregates
Doutorado
Tecnologia de Alimentos
Doutor em Tecnologia de Alimentos
Long, Jiafu. "Supramodular nature of neuronal scaffolding proteins /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?BICH%202004%20LONG.
Includes bibliographical references (leaves 167-184). Also available in electronic version. Access restricted to campus users.
Shu, Xiaokun. "Photophysics of emission color in flourescent proteins /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1400969251&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 176-185). Also available for download via the World Wide Web; free to University of Oregon users.
Bateman, Libei. "Studies of heme proteins using protein film voltammetry." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289588.
Schymkowitz, Joost Wilhelm Hendrik. "Protein engineering studies on cell-cycle regulatory proteins." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621312.
Nelson, Heather M. "Protein rich extruded snack foods using hydrolyzed proteins." Online version, 2003. http://www.uwstout.edu/lib/thesis/2003/2003nelsonh.pdf.
Joachimiak, Lukasz A. "In silico evolution of protein-protein interactions : from altered specificities to de novo complexes /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/9211.
Henderson, Julius Nathan. "Crystallographic and spectroscopic studies of photoswitching in fluorescent proteins /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1417810431&sid=5&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 143-151). Also available for download via the World Wide Web; free to University of Oregon users.
Song, Hongman. "The roles of the phosducin family proteins in the regulation of heterotrimeric G proteins in vertebrate photoreceptors." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10413.
Title from document title page. Document formatted into pages; contains vi, 96 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
Baas, Tracey Lynn. "The design, synthesis, and characterization of template assembled synthetic proteins /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/11561.
Koscky, Paier Carlos Roberto 1983. "Padronização da expressão heterologa e de modelo de ensaio de atividade para a proteina quinase humana S6K." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314787.
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A quinase de 70 kDa da proteína ribossomal S6, isoforma 1 (S6K1), é uma fosfoproteína implicada na regulação de genes relacionados ao controle da tradução em mamíferos e possui uma forma nuclear (a1) e uma citoplasmática (a2). A fosforilação do seu principal alvo, a proteína RPS6, tem sido comumente associada ao recrutamento seletivo dos 5'-TOP (5' tract of oligopyrimidine) mRNAs pela maquinaria de tradução, embora haja estudos contrariando esta hipótese. Devido às funções de seus demais alvos, S6K1 tem sido implicada na sobrevivência celular e em diversos outros processos, como crescimento, câncer e resistência à insulina. S6K1 é ativada por um mecanismo que envolve fosforilação seqüencial através da ativação das vias mTORC1 (complexo 1 do alvo da rapamicina em mamíferos) e PI3K (fosfoinositol-3 quinase). Como uma quinase da família AGC, S6K1 deve ser fosforilada por mTORC1 no resíduo Thr389 do domínio hidrofóbico e, em seguida, por PDPK1 (proteína quinase 1 dependente de fosfoinositol) no resíduo Thr229 da alça T do domínio catalítico. Estes eventos ocorrem somente após a fosforilação em diversos sítios do domínio auto-inibitório carboxiterminal, por mTORC1. O objetivo deste trabalho foi desenvolver um ensaio modelo para análise da função da S6K1 in vitro e utilizá-lo como ferramenta na elucidação do papel de proteínas adaptadoras da via de mTOR em interações com a S6K1. Para isso foi necessário produzir as proteínas recombinantes para ensaios de interação e para realização de um ensaio de atividade para a S6K1. Foram testados vários sistemas de expressão para Escherichia coli para produção das construções GST-S6K1a1-His6, GST-S6K1a2-His6 e GST-S6K1a2T389E?CT (forma a2 de S6K1 com a substituição T389E e o carboxiterminal truncado), GST-PDPK1 e GST-CDPDPK1 (domínio catalítico de PDPK1 fusionado a GST). A expressão das formas truncadas de S6K1 e PDPK1 foi mais eficiente em E. coli. Embora o rendimento tenha ficado muito aquém do esperado, foi suficiente para os ensaios de interação in vitro. Também foi feita a expressão em E. coli da região C-terminal da proteína RPS6, que é o substrato da S6K1, em fusão com a proteína D do fago ?. Posteriormente, foram montados sistemas de expressão das construções His6-S6K1a2T389E?CT e His6-CDPDPK1 em células de inseto, a partir de vetor de baculovírus. Constatou-se que essas construções são expressas na forma de fosfoproteínas em células de inseto. Ensaios de GST pull-down com GST-S6K1a2-His6 e GST-S6K1a2T389E?CT contra as duas isoformas da subunidade catalítica da PP2AC, His6-PP2ACa(maior) e His6-PP2ACa(menor), revelaram que His6-PP2ACa(maior) não interage com GST-S6K1a2-His6, embora interaja fortemente com GST-S6K1a2T389E?CT. Já a construção His6-PP2ACa(menor) interage fracamente com as construções GST-S6K1a2-His6 e GST-S6K1a2T389E?CT. Tomados em conjunto, os resultados sugerem que a presença do C-terminal não fosforilado de S6K1a2 impede a interação com PP2ACa(maior). PP2ACa(menor) comporta-se de forma completamente diferente da isoforma maior, pois a interação entre PP2ACa(menor) e S6K1a2 parece ser independente do carboxiterminal da quinase, visto que as quantidades de S6K1a2T389E?CT e de S6K1a2 inteira que interagem com PP2ACa(menor) são semelhantes. Esses resultados necessitam ainda serem confirmados in vivo. Outros experimentos de GST pull-down confirmaram que as construções de S6K1 não interagem com a4, embora interajam com TIPRL1. Se confirmado in vivo, esse resultado compõe um novo quadro na regulação coordenada entre mTOR1 e PP2A, do qual TIPRL1 parece participar. As construções genéticas e os sistemas de expressão gerados neste trabalho possibilitaram a obtenção dos reagentes necessários para analisar o mecanismo de regulação da quinase S6K1, mediado por proteínas regulatórias. Permitem também desenvolver uma série de experimentos, como busca de inibidores específicos para a S6K1, que dependem da reconstituição de ensaios de atividade in vitro com a S6K1 ativada. Contudo, o ensaio de atividade realizado não apresentou resultados satisfatórios e precisa ser desenvolvido.
Abstract: The 70kDa ribosomal S6 protein kinase 1 (S6K1) is a phosphoprotein involved in the regulation of genes related to translational control in mammals. S6K1 shows distinct nuclear (a1) and cytoplasmic (a2) forms. Phosphorylation of the S6K1 best characterized target, the protein of the small ribosomal subunit (RPS6), has been generally associated to the selective recruitment of the 5'-TOP mRNAs (5' tract of oligopyrimidine) by the translational machinery, although there is still some controversy on this issue. Due to the function of its targets, S6K1 has been implicated in several cellular processes including cell growth, cancer and insulin resistance. S6K1 is activated by a mechanism of sequential phosphorylation following activation of the mTORC1 (mammalian target of rapamycin complex 1) and PI3K (phosphoinositide-3-kinase) pathways. As a kinase of the AGC family, S6K1 activation requires mTORC1 phosphorylation of residue Thr389 of the hydrophobic domain followed by PDPK1 (phosphoinositide dependent protein kinase 1) phosphorylation of residue Thr229 at the T loop of the catalytic domain. These take place only after phosphorylation by mTORC1 of several residues of the autoinhibitory C-terminal domain. The objective of this work was to develop an assay to analyze the function of S6K1 in vitro and use it as a tool in the discovering of the functions of regulators proteins of the mTOR cascade in interactions with S6K1. For these purposes, expression systems were constructed to produce the various recombinant proteins to be used in the interaction and activity assays. Several genetic constructions were tested in Escherichia coli for the production of GST-S6K1a1-His6, GST-S6K1a2-His6 and GST-S6K1a2T389E?CT (a2 form of S6K1 with the T389E substitution and truncated carboxiterminus), GST-PDPK1 and GST-CDPDPK1 (GST fusion protein of the catalytic domain of PDPK1). The truncated forms were expressed more efficiently in E. coli. Although the yield in E. coli was lower than expected, it was sufficient to perform interaction assays. The C-terminal domain of RPS6, a substrate for S6K1, was successfully expressed in E. coli as a fusion protein with the phage ? protein D. Subsequently, expression systems for production of His6-S6K1a2T389E?CT and His6-CDPDPK1 in insect cells were constructed using baculovirus vectors. It was found that these constructs are expressed in the form of phosphoproteins in insect cells. GST pull-down assays using GST-S6K1a2-His6 e GST-S6K1a2T389E?CT to test interaction with the PP2AC isoforms His6-PP2ACa(major) and His6-PP2ACa(minor) revealed that His6-PP2ACa(major) does not interact with GST-S6K1a2-His6, although it interacts strongly with GST-S6K1a2T389E?CT. On the other hand, His6-PP2ACa(minor) interacts weakly with both GST- S6K1a2-His6 and GST-S6K1a2T389E?CT. This finding suggests that the unphosphorylated C-terminal of S6K1a2 inhibits interaction with PP2ACa(major). His6-PP2ACa(minor) behaves differently form His6-PP2ACa(major). Its interaction with S6K1a2 seems to be independent of the C-terminal since the amounts of S6K1a2T389E?CT and S6K1a2 that interact with His6-PP2ACa(minor) are similar. Future work in vivo is required to confirm these results. GST pull-down assays confirmed that a4 does not interact with the constructions of S6K1, while TIPRL1 interacts with them. If confirmed in vivo, these results provides a new perspective for the coordinated regulation between mTOR1 and PP2A, which apparently involves also TIPRL1. The genetic constructions and expression systems established in this work allow the production of the reagents required to study the mechanism of S6K1 regulation mediated by adaptor proteins. They will also allow the development of experiments such as screening for specific S6K1 inhibitors, which depend on reconstitution of S6K1 activity assays using activated S6K1. Nevertheless, the activity assay performed did not yield satisfactory outcomes and must be improved.
Mestrado
Bioquimica
Mestre em Biologia Funcional e Molecular
Cepeda, Ana Oliva Tiroli. "Caracterização da relação entre estabilidade, estrutura e função de duas sHsps de cana-de-açucar e da Hsp40 da subfamilia A humana, chaperones envolvidos com o reconhecimento e apresentação de proteinas parcialmente enoveladas." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314021.
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: As proteínas estão envolvidas com as mais diversas funções biológicas. No entanto, para realizar sua função adequadamente, uma proteína deve estar enovelada, ou seja, em sua conformação nativa. Para garantir isso, existe nas células, um elaborado sistema que envolve chaperones moleculares, capaz de auxiliar na prevenção do enovelamento incorreto e da agregação de proteínas Chaperones, de uma maneira geral, são proteínas que ligam e estabilizam polipeptídeos, facilitando seu enovelamento correto sem contribuir com informações conformacionais. O aumento no número de doenças provocadas pelo enovelamento incorreto de proteínas que se depositam nos tecidos na forma de amilóides (também chamadas de doenças conformacionais), tem chamado a atenção para estudos de agregados protéicos, que outrora foram considerados artefatos quando se trabalhava com esse tipo de macromolécula. Nesse sentido, o estudo de chaperones tem ganhado um interesse particular, já que são fortes candidatos ao combate de doenças amiloloidogênicas. Neste trabalho, são apresentados estudos sobre duas famílias de chaperones, a Hsp40 da subfamília A humana e duas sHsps de classe I de cana-de-açúcar, as quais estão envolvidas com o reconhecimento e a apresentação de substratos (proteínas parcialmente desenoveladas) para outras famílias de chaperones responsáveis pelo processo de reenovelamento. Essas duas famílias de chaperones em particular são também conhecidas como 'holdases¿, e são muito diversas, característica necessária para interagir com a grande diversidade de substratos em potencial que existe na célula. As duas sHsps estudadas aqui, as mais expressas em cana-de-açúcar, e a caracterização de suas estruturas e suas eficiências como chaperones, tornou possível a elaboração de uma hipótese sobre o mecanismo de ação dessas proteínas em função do aumento de temperatura. Nesse sentido, é mostrado neste trabalho que sHsps, respondem ao aumento de temperatura passando por expansão conformacional, provavelmente para aumentar a superfície hidrofóbica para a interação com os substratos. O efeito do calor sobre a Hsp40 também foi estudado e os resultados mostraram que essa proteína forma agregados com propriedades amiloidogênicas. Esta é a primeira vez que tais características são descritas para um chaperone de eucarioto. De maneira geral, as implicações dos resultados apresentados aqui podem aumentar o conhecimento geral sobre chaperones e sobre a pesquisa de tratamentos para as doenças conformacionais
Abstract: Proteins are involved with a large variety of biological functions. However, to function properly, proteins must be folded, i.e., they must reach their native conformation. According to that, an elaborated system involving molecular chaperones exists in the cell that helps to prevent the incorrect folding of proteins and also their aggregation. Chaperones, in a general way, are proteins that bind and stabilize polypeptides, facilitating its correct folding without contributing with conformational information. The increasing number of diseases caused by the incorrect folding of proteins that deposit in the form of amyloids (also called conformational diseases) has raised the interest in the study of protein aggregates, which, not long ago, where considered just purification artifacts. In this way, the study of chaperones has gained particular interest because they are potential candidates against amyloidogenic diseases. In this work, we present studies on two families of chaperones, a human Hsp40 from subfamily A and two sugar cane sHsps from class I, which are involved in substrate (partially unfolded proteins) recognition and presentation to other chaperone families that are more active in the protein refolding process. These particular chaperones are also know as 'holdases¿ and they are usually diverse, a characteristic necessary to interact with a large variety of substrate in the cell. The two sHsps studied here are the most expressed in sugar cane and their structure and chaperone efficiency characterization made possible to elaborate a hypothesis on the mechanism of action of these proteins when temperature increases. In that matter, we were able to show that sHsps respond to an increase in temperature by undergoing conformational expansion, likely to increase the hydrophobic area for substrate interaction. The effect of heat on Hsp40 has also been studied and our results showed that this protein form aggregates with amyloidogenic properties. To our knowledge, this is the first time that such characteristics are described for an eukaryotic chaperone. To sum up, we believe that the implications of the results shown here may add to the general knowledge on chaperones and to the search of a treatment for conformational diseases
Doutorado
Bioquimica
Doutor em Biologia Funcional e Molecular
Fladvad, Malin. "Structure and function in c-Myc and Grx4 : two key proteins involved in transcriptional activation and oxidative stress /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7357-007-9/.
Wei, Heng. "Split PH domain identification & redundancy analyses in the classification of PDZ domains /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?BICH%202006%20WEI.
Flöck, Dagmar. "Protein-protein docking and Brownian dynamics simulation of electron transfer proteins." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969418736.
Marri, Lucia <1977>. "CP12: Intrinsically Unstructured Proteins regulating photosynthetic enzymes through protein-protein interactions." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/423/1/LMarri-BiolFunzSistCellMol-XIX.pdf.
Marri, Lucia <1977>. "CP12: Intrinsically Unstructured Proteins regulating photosynthetic enzymes through protein-protein interactions." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/423/.
Hennessy, Fritha. "Characterisation of the J domain aminoacid residues important for the interaction of DNAJ-like proteins with HSP70 chaperones." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1003996.
Mostafa, Kamel Abdelfatah Ali. "Interactions of food proteins with plant phenolics – modulation of structural, techno- and bio-functional properties of proteins." Phd thesis, Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2013/6903/.
Für die Verbesserung von Nahrungsmitteleigenschaften können Modifikationen an verschiedenen Inhaltsstoffen vorgenommen werden. Beispielsweise werden bereits Proteine miteinander verknüpft und bilden sogenannte „Crosslinks“ oder vernetzte Biomoleküle. Diese werden für die Herstellung fester, viskoelastischer Produkte, die zum Verdicken als auch zum Stabilisieren von Emulsionen oder Schäumen eingesetzt werden, genutzt. Da die Verbraucher sich Zunehmens mit gesundheitsfördernden Lebensmitteln befassen, ist das Einbringen von gesundheitsfördernden Inhaltsstoffen wie z.B. phenolische Verbindungen, immer mehr in den Fokus der Forschung gerückt. Demnach ist das wissenschaftliche Bestreben phenolische Verbindungen in die Vernetzung von Proteinen mit einzubeziehen und deren positive Wirkungen (antioxidativ) auszunutzen, vorteilhaft. Als Phenole werden Verbindungen bezeichnet, die eine oder mehrere Hydroxygruppen am Benzolring aufweisen. Phenole liegen in der Enolform vor, da diese, bedingt durch den Erhalt des aromatischen Benzolringes, energetisch begünstigt ist. Kaffeesäure ist eine Hydroxyzimtsäure und in Kaffeebohnen zu finden. Der am häufigsten anzutreffende Ester besteht aus Kaffee- und Chinasäure. Der einfachste Vertreter ist die Chlorogensäure (5-Caffeoylchinasäure, 5-CQA), die in vielen Pflanzenteilen enthalten ist. Chlorogensäure und ihre Derivate besitzen ebenfalls antioxidative Eigenschaften. Zusätzlich wirken sie auf Enzyme, die an entzündlichen- oder allergischen Reaktion teilnehmen, inhibierend. Während Verarbeitungs- und Lagerungsprozessen können phenolische Komponenten pflanzlicher Lebensmittel mit den Aminosäuren der Proteine in Lebensmitteln reagieren. Solche Reaktionen können die physikalisch-chemischen Eigenschaften von Proteinen verändern und deren ernährungsphysiologische Wertigkeit vermindern. Proteine weisen verschiedene reaktive Seitengruppen (Sulfhydryl-, Hydroxyl-, Aminogruppen) auf, mit denen sie über kovalente und nicht-kovalente Wechselwirkungen mit Phenolen Verbindungen eingehen können. Zu den nicht-kovalenten Verbindungen gehören u. a. Wasserstoffbrückenbindungen, hydrophobe Wechselwirkungen und Ionenbindungen. Phenole (z.B. Chlorogensäuren) können bei Anwesenheit von Sauerstoff enzymatisch bzw. nichtenzymatisch oxidiert werden. Die Reaktionsprodukte (Chinone) bilden anschließend mit reaktiven Thiol- bzw. Aminogruppen von Proteinen Addukte. Die Erfassung dieser verschiedenen Facetten von Interaktionen stellt somit die primäre Forschungsaufgabe im Rahmen dieser Arbeit. Die primäre Aufgabe der vorliegenden Arbeit besteht demzufolge in der Etablierung der Analysen- und der Charakterisierungsmöglichkeiten solcher Wechselwirkungen (Bindung) pflanzlicher Verbindungen bzw. deren Reaktionsprodukten mit Proteinen u.a. über massenspektrometrische Methoden. Da die Wechselwirkung mit Proteinen auch zu Veränderungen der Proteinstruktur führt, können deren funktionelle Eigenschaften auch verändert sein. Dies soll anhand der Messung von isolierten Proteinen die an der Wechselwirkung beteiligt sind, nachgewiesen werden. Anschließend sollen über Docking-Untersuchungen die entsprechenden Bindungsstellen näher charakterisiert werden. Durch die vorliegenden Ergebnisse wurden mögliche Reaktionen von phenolischen Verbindungen mit Proteinen, näher charakterisiert. Es wurde festgestellt, dass die Apfelsorte Braeburn über die höchste PPO- Enzymaktivität beim gleichzeitigen niedrigen CQA Gehalt im Vergleich zu den anderen untersuchten Sorten verfügt. Die PPO/Tyrosinase modulierte Reaktionen zwischen CQA und Lysine wurden in Abhängigkeit der vorherrschenden Bedingungen optimiert und die Reaktionsprodukte analysiert. In dem zweiten Teil wurden solche Reaktionsmöglichkeiten in den Grünen Kaffeebohnen lokalisierte und modelliert. Dazu wurden die sortenabhängige CQA-Zusammensetzung ermittelt und die möglichen Reaktionen mit den Hauptspeicherproteinen des Kaffees dargestellt. Im letzten Teil wurden dann diese Reaktionen mit Molkenproteinen simuliert und Einflüsse auf die Struktur und die funktionellen Eigenschaften erfasst. Die Ergebnisse belegen eine umfangreiche und sehr heterogene Adduktbildung mit den Aminoseitenketten des Lysins und Cysteins. Ein Katalog der unterschiedlichen Reaktionsprodukte wurde erstellt und am Protein modelliert. Die entsprechende Veränderung an die Proteinstruktur wurde experimentell belegt und der Einfluss wurde in den technofunktionelle Eigenschaften (wie die Löslichkeit, Emulgierbarkeit usw.) wiederspiegelt. Ein Anstieg des antioxidativen Potentials der Proteine wurde erreicht und diese so modifizierten Proteine wurden weiter zur Stabilisierung und Produktentwicklung getestet. Die ersten Ergebnisse eröffnen Nutzungsmöglichkeiten der modifizierten Proteine zur Verkapselung von bioaktiven Sekundären Pflanzenstoffen.
Hellborg, Fredrik. "Identification, cloning and characterization of the p53 induced gene human wig-1 /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7140-190-3/.
Morris, Amie Michelle. "Structure and function of the mammalian small heat shock protein Hsp25." Access electronically Access electronically, 2007. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20080605.104334/index.html.
Xu, Ping. "Sensing and analyzing unfolded protein response during heterologous protein production :." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 205 p, 2008. http://proquest.umi.com/pqdweb?did=1555621341&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Diaz, Manisha Regina. "Use of bionanotechnology to decipher the patterns of assemblage and interactions of multi-protein complexes." Bowling Green, Ohio : Bowling Green State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1250955267.
Legate, Kyle R. Andrews D. W. "Characterization of the beta-subunit of the mammalian SRP receptor and its role in assembly of the SRP receptor /." *McMaster only, 2003.
Prichard, Lisa. "The role of the IQ motif, a protein kinase C and calmodulin regulatory domain, in neuroplasticity, RNA processing, and RNA metabolism /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/6302.
Berger, Bryan William. "Protein-surfactant solution thermodynamics applications to integral membrane proteins /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 15.42 Mb., 304 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3200533.
Kovács-Bogdán, Erika. "Characterization of protein import channel-forming proteins in chloroplasts." Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-133198.
Stege, Gerardus Johannes Jozef. "Hyperthermia and protein aggregation role of heat shock proteins /." [S.l. : [Groningen] : s.n.] ; [University Library Groningen] [Host], 1995. http://irs.ub.rug.nl/ppn/138287325.
Singh, Prabhjot. "Antioxidant activity of food proteins and food protein hydrolysates." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104895.
Le but principal de cette recherche constituait l'analyse du potentiel antioxydant, à diverses concentrations, d'hydrolysats de protéine de soya (HPS) et d'hydrolysats de protéine de pois chiche (HPP). Les hydrolysats de protéine ont été isolés à l'aide de l'enzyme protéolytique trypsine. Les HPS et HPP démontraient respectivement un potentiel antioxydant de 16.5 à 32% et 3.4 à 26.8 % lorsque présents à des concentrations de 2.5 à 10 mg/mL. L'utilisation d'une colonne C18 a permis de séparer, par CLHP-PI, les HPS et HPP en quatre fractions (F I, F II, F III, et F IV) qui furent dosées avec du DPPH (1,1-diphényl-2-picrylhydrazyle) afin de comparer leur pouvoir de scavenging sur les radicaux. Pour les HPS, le potentiel antioxydant de F III (47.7 %) était supérieur à celui des autres échantillons alors que pour les HPP, 27.9 % (F II) était le seuil maximal. Dans les deux cas, les hydrolysats étaient concentrés à 1mg/mL. L'hydrolyse des échantillons de protéine a été confirmée par SDS-page. La deuxième partie de l'étude visait à mesurer l'impact de la pascalisation sur le degré d'hydrolyse et le potentiel antioxydant des protéines. Des isolats de protéine de soya (IPS) et de protéine de pois chiche (IPP) ont été traités à haute pression (400 MPa et 600 MPa) pendant 5 et 10 min. Le degré d'hydrolyse des IPS et IPP soumis à la pascalisation et à la trypsin ont démontré une augmentation constante allant de 12.4 à 24.9 % pour les isolats de protéine de soya et de 13.6 à 26.2 % pour les isolats de protéine de pois chiche. L'analyse au DPPH du pouvoir d'épuration des radicaux a montré que le potentiel antioxydant des hydrolysats a plus que doublé, passant de 32 à 67 % pour les HPS et de 26.8 à 56.6 % pour les HPP, lorsqu'ils étaient traités par hautes pressions. Cela démontre que la pascalisation améliore le degré d'hydrolyse et le potentiel antioxydant des hydrolysats de protéines.
Campbell, Colin James. "The electrochemical nitration of proteins and protein model systems." Thesis, Coventry University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361652.
Keegan, Neil. "From engineered membrane proteins to self-assembling protein monolayers." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419991.
Toker, I. Alex. "Purification and characterisation of protein kinase C inhibitor proteins." Thesis, University College London (University of London), 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277909.
Keen, Nicholas John. "Interaction of human papillomavirus E6 protein with cellular proteins." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321494.