Diss. (sammanfattning) Göteborg : Univ. , 2009. / Härtill 2 uppsatser.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1964. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 129-136).

Thesis (M. Med. Sc.)--University of Hong Kong, 2005.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 117-138).

Submitted by DEBORA MARIA ALVES VIEGAS null (de-viegas@hotmail.com) on 2016-05-19T20:21:13Z No. of bitstreams: 1 Dissertação - Debora Viegas 2016.pdf: 4214783 bytes, checksum: 5434f9b5c2bdcbea1bd5b8d7bbaa7527 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-23T18:52:19Z (GMT) No. of bitstreams: 1 viegas_dma_me_araiq.pdf: 4214783 bytes, checksum: 5434f9b5c2bdcbea1bd5b8d7bbaa7527 (MD5) / Made available in DSpace on 2016-05-23T18:52:19Z (GMT). No. of bitstreams: 1 viegas_dma_me_araiq.pdf: 4214783 bytes, checksum: 5434f9b5c2bdcbea1bd5b8d7bbaa7527 (MD5) Previous issue date: 2016-05-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O desenvolvimento tecnológico dos setores industriais associados à mineração e metalurgia vem crescendo nas últimas décadas devido à busca incessante por melhorias na qualidade de vida. Se por um lado a demanda por metais é crescente, por outro, a indústria de mineração está diante da problemática em relação ao esgotamento das reservas. Isso impõe a necessidade de se extrair metais a partir de minérios de baixos teores e também de rejeitos industriais. Para tanto são necessários processos que exijam baixos custos de investimento e de operação para que a extração se torne viável economicamente, e a biolixiviação é a tecnologia que aparece como a principal alternativa diante dos processos convencionais. O cobre tem sido um dos metais mais importantes por mais de cinco mil anos, devido a suas propriedades e formação de ligas metálicas. O cobre é um dos metais de maior interesse econômico. Cerca de 70% deste metal é encontrado na natureza na forma de calcopirita (CuFeS2). É o mineral mais abundante entre todos os tipos de minérios de sulfeto de cobre. A biolixiviação de cobre a partir de calcopirita é considerada mais econômica e ambientalmente sustentável que o processo convencional pirometalúrgico, especialmente quando os minérios de sulfeto de cobre estão presentes em baixo teor. No entanto, a taxa de oxidação lenta bacteriana continua a ser um grande problema para ser resolvido na biolixiviação. Sendo assim, estratégias para melhorar a atividade bacteriana na superfície do sulfeto mineral têm sido amplamente exploradas por muitos autores. Recentemente a adição de substâncias de origem biológica como os aminoácidos também tem sido um fator testado em ensaios com o objetivo de melhorar o desempenho do processo, como a L-cisteína, um aminoácido importante sulfuroso que despertou grande interesse devido a sua capacidade de acelerar o processo de biolixiviação. O principal microrganismo envolvido neste processo é a Acidithiobacillus ferrooxidans, bactéria mesófila capaz de obter energia a partir da oxidação de íons ferrosos e de compostos de enxofre reduzidos. Além dessa, a Leptospirillum ferrooxidans, também mesófila e capaz de obter energia apenas a partir de oxidação de íons ferrosos. Neste contexto, o presente trabalho teve como objetivo avaliar estas diferentes espécies bacterianas isoladas e em consórcio quanto a capacidade de solubilizarem cobre a partir da calcopirita e avaliar a melhora da eficiência do processo com a adição de cisteína no meio. Foi realizado um ensaio prévio de oxidação de íons ferrosos na presença de cisteína para determinar a concentração inibitória do aminoácido para o crescimento das linhagens. Posteriormente realizou-se o ensaio de biolixiviação em frascos agitados a 150 rpm, 30 oC, na presença de 2,5% (m/m) de calcopirita em meio T&K, 5% (v/v) do inóculo e 10-3 mmol.L-1 de cisteína. Avaliando a influência dos consórcios e das espécies isoladas no processo, determinou-se que os frascos que continham a bactéria At. ferrooxidans – LR adaptada apresentaram as maiores porcentagens de recuperação (23,2%), após 35 dias de ensaio. Os sistemas abióticos apresentaram uma recuperação ínfima de cobre, chegando a apenas 6%, em um potencial médio de 350 mV (Ag/AgCl). A adição de cisteína promoveu aumentos na recuperação de cobre, comparado à mesma condição na ausência de cisteína. Foram detectadas diferenças na extração de cobre nas diferentes condições inoculadas estabelecendo-se a seguinte ordem decrescente: At. ferrooxidans – LR + cisteína (25,3%) > At. ferrooxidans – LR > mutante + cisteína > L. ferrooxidans + cisteína > mutante > L. ferrooxidans (18,0%). Por fim uma análise estatística foi realizada para determinar a correlação entre os parâmetros estudados, pH, Eh e [Fe2+]/[Fe3+] e a solubilização de cobre para cada microrganismo. Os resultados indicaram uma alta correlação (>75%) em 85% dos casos, onde para a bactéria At. ferrooxidans a maior correlação encontrada foi ao parâmetro [Fe3+]/[Fe2+] e diferentemente para a bactéria L. ferrooxidans que a maior correlação foi a que relacionou a solubilização com o pH. / Technological development of mining and metallurgical industries has increased in recent decades due to constant search for improving life quality. Mining industries are now facing an issue related to the depletion of reserves since the demand for metals is growing progressively year after year. Therefore, he need of extracting metals from low grade ores and industrial wastes become an important key to this sector. For this purpose, processes that require low investment and low operating costs for metal extraction are preferentially used for being economically feasible compared to conventional processes. Bioleaching is one of the main alternative technologies for extracting metals, such as copper one of the most important metals for over five thousand years, due to its properties and formation of metal alloys. Copper is one of the largest economic interest metals. About 70% of this metal is found in nature as chalcopyrite (CuFeS2). This is the most abundant mineral among all types of copper sulfide ores. Copper bioleaching from chalcopyrite is considered more economically and environmentally sustainable than conventional pyrometallurgical processes. The main microorganisms involved in this process are the well-known Acidithiobacillus ferrooxidans, mesophilic bacteria capable of using ferrous ions and reduced sulfur compounds as energy source through oxidative reactions Leptospirillum ferrooxidans also mesophilic and able to oxidize ferrous ions as energy source. The addition of carbohydrates, proteins and other substances of biological origin has also been a factor tested in assays aiming to improve the performance of the process. In this context, this study aimed to evaluate the ability to solubilize copper from chalcopyrite mediated by both At. ferrooxidans and L. ferrooxidans separately and combined, as a consortium. Besides, to evaluate the efficiency of the process adding cysteine in the growth medium. A previous study of oxidation of ferrous ions in the presence of cysteine was performed to determine the inhibitory concentrations for the growth of the strains. In general, bioleaching tests were performed in shake flasks at 150 rpm, 30 °C, in the presence of 2.5% (w/v) of chalcopyrite in T&K medium, 5% (v/v) inoculum and 10-3 mmol.L-1 of cysteine. Evaluating the influence of the consortia and species isolated in the process, it was determined that the vials containing the At. ferrooxidans - LR adapted showed the highest recovery percentages (23.2%) after 35 days. Abiotic systems showed a negligible recovery of copper, reaching only 6% in an average potential of 350 mV (Ag / AgCl). The addition of cysteine promotes an increase in copper recovery compared to the same condition in the absence of cysteine. Differences were detected in the copper extraction in different conditions inoculated by establishing the following descending order: At. ferrooxidans - LR + cysteine (25.3%) > At. ferrooxidans - LR (23.5%) > mutant + cysteine (23.0%)> L. ferrooxidans + cysteine (20.3%)> mutant (20.0%)> L. ferrooxidans (18.0%). Finally a statistical analysis was performed to determine the correlation between the parameters studied, pH, Eh and [Fe3+]/[Fe2+] and copper solubilization for each microorganism. The results showed a high correlation (>75%) in 85% of cases, where for bacteria At. ferrooxidans the highest correlation was found to the parameter [Fe3+]/[Fe2+] and differently for the bacteria L. ferrooxidans the highest correlation it was related to the solubilization pH.

Orientador: Wilter Ricardo Russiano Vicente / Banca: Maria Denise Lopes / Banca: Camila Infantosi Vannucchi / Resumo: O objetivo desta pesquisa foi avaliar os efeitos da suplementação de cisteína e cisteamina no desenvolvimento meiótico de oócitos caninos durante o processo de maturação ín vítro. Os oócitos foram coletados de sete cadelas hígidas em fase pré-ovulatória imediata, submetidas à ovario-histerectomia. Os COC's selecionados foram cultivados por um período de 72 horas em quatro meios diferentes: A (controle) - TCM199 suplementado com BSA (3 mg/mL) + FSH (5 J.Lg/mL) + LH (10 f.Lg/mL) + progesterona (2 f.Lg/mL) + estradiol (2 f.Lglml); 8 - controle + 0,1mM de cisteína; C - controle + 100J.1M de cisteamina; D - controle + 0,1 mM de cisteína + 100J.1M de cisteamina. Os resultados demonstraram que não houve diferença significativa entre os tratamentos (p<0,05), ou seja, a suplementação de compostos antioxidantes no meio de maturação não favoreceu a competência meiótica. Além disso, neste estudo pode-se inferir que para cada fase do ciclo estral, talvez seja necessário um período de maturação diferenciado. / Abstract: The aim of this research was to evaluate the effects of the cysteine and cysteamine supplementation on meiotic deveropment of canine oocytes dunng the process of in vitro maturation. The oocytes were collected atter ovanohysterectomy from seven healthy bitches in immediate preovulatory stage. The selected COC's were cultured by a period of 72 hours in four different media: A (control) - TCM199 supplemented with BSA (3 mg/mL) + FSH (5 J-Lg/mL) + LH (10 J-Lg/mL) + progesterone (2 f.Lg/mL) + estradiol (2 f.LglmL); 8 - control + 0,1mM of cysteine; C - control + 100JlM of cysteamine; O - control + 0,1 mM of cysteine + 100J,lM of cysteamine. The present study demonstrated that there was not significant difference among the treatments (p<0,05), in other words, the supplementation of antioxidant in the medium of maturation didn't favor the meiotic competence. Besides, in this study it can be inferred that for each stage of the oestrus cycle, perhaps it is necessary a different maturation penod. / Mestre

No description available.

A rapid, two-step procedure is described for the isolation of both "high molecular weight" (H-) and "low molecular weight" (L-) plasma kininogens from a single sample of plasma. Affinity chromatography on carboxymethyl-papain-Sepharose is used, together with high-resolution anion exchange chromatography.

Thesis advisor: Jianmin . Gao / Cysteine residues perform many essential cellular functions, including nucleophilic and redox catalysis, metal coordination, structural stabilization and cellular protection. Cysteine-related mutations are oftentimes related to diseases due to the amino acid’s functional importance. This has led cysteine to become a focus of small molecule drug discovery. A comparison of the cysteine proteome of diseased cells versus healthy cells can elucidate novel cysteine residues that play an important role in progressing the disease state. Two disease models were chosen to be the focus of this proteomic study; breast cancer through the human epithelial MCF10 progression series and immunoactivation through the Raw 246.7 mouse macrophage cell line. Comparative proteomics with mass spectrometry revealed several changes within the cysteine proteome when the cells were diseased. Some cysteines had changes in reactivity, most likely indicating a loss or gain of a modification or disulfide bond. Other cysteines showed increased labeling due to an increase in the overall expression of the protein encompassing the cysteine residue. Further follow-up of an interesting hit from the Raw cell comparison, immune responsive gene 1 (IRG1), was conducted. IRG1 produces itaconate from cis-aconitate under inflammatory conditions, disrupting the citric acid cycle. IRG1 was confirmed to have increased expression following activation of the macrophage cells by lipopolysaccharides. It was also successfully recombinantly expressed in and purified from Escherichia coli for use in an activity assay to determine if the cysteine labeled in the mass spectrometry experiment is essential for the protein function. With additional knowledge of cysteines that help progress disease states, new small molecule inhibitors can be developed to target these cysteines and impede the function that is beneficial for the disease. / Thesis (MS) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Protein arginine methylation is an abundant post-translational modification catalyzed by protein arginine methyltransferases (PRMTs). Arginine methylation plays important roles in a variety of cellular pathways and human diseases. PRMT1, the predominant PRMT, catalyzes approximately 85% of all protein arginine methylation in vivo. While many details of how PRMT1 functions have been uncovered through the past two decades, there are many details which remain unclear, including how arginine methylation is regulated, how PRMT1 binds substrates, and what role PRMTs play in RNA surveillance. Our recent data presented in this thesis showed that reduction of the PRMT1 enzyme, following recombinant expression and purification, changes both enzymatic activity and oligomeric state. A cysteine residue(s) was found to be responsible for the observed redox chemistry in PRMT1 and at least one parameter in the kinetic mechanism, S-adenosylmethionine (AdoMet) binding, was faster with a reduced enzyme. This work suggests exciting potential for the regulation of PRMTs in vivo by oxidative stress. In addition to studying the effects of reduction/oxidation on PRMT1, a foundation for future experiments was laid. These experiments investigate substrate recognition by PRMTs and what the role arginine methylation may play in RNA processing and surveillance. To better understand how PRMTs selectively bind a wide variety of substrates, I have designed and preliminarily characterized several Hmt1 (the S. cerevisiae homologue of PRMT1) variants. These variants will be used for crystallization trials of a homogeneous complex, containing Hmt1, AdoMet, and a peptide substrate, capable of revealing specific chemical interactions between Hmt1 and the peptide substrate. To further our understanding of Hmt1's role in RNA processing and surveillance, particularly in RNA degradation pathways, I extracted yeast RNA from both wild type and Hmt1-null cells. The RNA was probed using a S. cerevisiae whole-genome microarray. This analysis revealed that Hmt1 exhibits statistically significant effects in several broad areas including molecular function, biological processes, cellular components, and some KEGG pathways. The presented studies have revealed the exciting potential for an in vivo regulatory mechanism of PRMT1 and each study is primed for further investigation both in vivo and in vitro.