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    Title: NMR studies of tetrahaem cytochomes from D. desulfuricans and S. frigidimarina Authors: Paixão, Vítor Bordona Abstract: Tetrahaem cytochromes are small soluble proteins with four non-planar haems with bis-histidinyl axial coordination that were first isolated from Desulfovibrio vulgaris in the 1950s and subsequently in several other bacteria. Even though the sequence homology, the amino acid composition and the thermodynamic properties of the several tetrahaem cytochromes may be different; the overall haem core architecture and the general fold of the protein established by X-ray crystallography and nuclear magnetic resonance (NMR) are highly conserved.(...) Description: Dissertation Presented to obtain the Ph.D. in Biochemistry

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    Title: Heat stress adaptation in hyperthermophiles: bosynthesis of inositol-containing compatible solutes Authors: Rodrigues, Marta Viseu Abstract: The accumulation of low-molecular mass organic compounds, named compatible solutes, is an efficient, widespread strategy to counterbalance increases in the external osmolarity, thereby preserving cell viability. The intracellular accumulation of compatible solutes also occurs in response to supra-optimal temperatures, and this observation led to the assumption that they play a role in the thermoadaptation process. Hyperthermophiles, organisms with optimal growth temperatures above 80ºC, have been isolated from a variety of hot habitats. Many hyperthermophiles thrive in marine geothermal areas and are slightly halophilic. As a result, they have to cope with fluctuations in the salinity of the external medium and generally accumulate compatible solutes as a defense strategy. Interestingly, these hyperthermophilic organisms show a clear preference for negatively charged solutes, such as diglycerol phosphate, di-myo-inositol 1,3’-phosphate and mannosylglycerate, over neutral or zwitterionic solutes typically found in mesophiles (glycerol, trehalose, myo-inositol, and ectoines). The question then arises whether those charged solutes were selected by organisms adapted to grow at high temperatures because they are more suitable to protect proteins and other cell components against thermal denaturation.(...) Description: Dissertation presented to obtain the Ph.D. degree in Biochemistry

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    Title: Metabolism of primary astrocytes studied by NMR: metabolic trafficking and neuroprotection Authors: Fonseca, Luís Lopes Abstract: The human brain is the product of 600 million years of evolution and it is by far the most complex structure in the known universe. The vertebrates’ brain is composed of several different cell types, which perform the different functions required. The two most abundant cell types are neurons, which are the brain function unit, and glial cells, which are responsible for a myriad of housekeeping, homeostatic and structural functions. Glial metabolism is so far interconnected with the neuronal metabolism, that it is difficult to state where one finishes and the other starts. Trafficking between the two compartments include metabolites of almost all metabolic pathways (glycolysis, TCA, amino acids, ketone bodies, etc) and also ions.(...) Description: Dissertation presented to obtain a Ph. D. degree in Biochemistry by Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica.

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    Title: Insights into the molecular mechanisms of protein stabilization by osmolytes of hyperthermophiles Authors: Pais, Tiago Vasconcelos Duarte Moreira Description: Dissertation presented to obtain the Ph.D degree in Biochemistry

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    Title: Osmo- and thermo-adaptation in hyperthermophilic Archaea: identification of compatible solutes accumulation profiles, and biosynthetic routes in Archaeoglobus spp. Authors: Gonçalves, Luís Pedro Gafeira Abstract: Hyperthermophilic organisms have optimum growth temperatures above 80°C and belong to genera that are placed near the root of the Tree of Life, in short phylogenetic branches within the domains Bacteria or Archaea. Although hyperthermophiles have been isolated from a variety of hot environments, most species originate from marine geothermal areas, hence they are slightly halophilic. The accumulation of low-molecular mass organic solutes, i. e., compatible solutes, is one of the most common strategies developed by cells to cope with fluctuations of the salinity of the medium. Interestingly, in marine hyperthermophiles, compatible solute accumulation occurs not only in response to an increase in the external salt concentration, but also in response to supraoptimal growth temperatures. Moreover, microorganisms adapted to grow optimally at elevated temperatures tend to use negatively charged solutes that are not present or rarely encountered in mesophilic organisms.(...) Description: Dissertation presented to obtain the Ph.D degree in Biochemistry

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    Título: Electron Transfer and Ligand Binding Properties of Cytochromes Autor: Quintas, Pedro Oliveira Resumo: Haem proteins are one of the most versatile groups of proteins in nature. They are able to perform several functions, such as transport and storage of oxygen, electron transfer, sensing of small molecules, and catalysis. The nature of the haem, the presence or absence and the nature of the axial ligands to the iron atom, and the effect of the polypeptide chain of the protein on the environment of the haem all contribute to this versatility. The work presented in this thesis focuses on the mechanisms of electron transfer and the discrimination of small ligands by cytochromes containing haem c with axial histidines.(...) Descrição: Dissertation presented to obtain the Ph.D degree in Biochemistry

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    Título: Insights into the biochemical strategies of adaptation to heat stress in the hyperthermophilic archaeon Pyrococcus furiosus Autor: Esteves, Ana Maria Resumo: Organisms that thrive optimally at temperatures above 80°C are called hyperthermophiles. These prokaryotes have been isolated from a variety of hot environments, such as marine geothermal areas, hence they are usually slightly halophilic. Like other halophiles, marine hyperthermophiles have to cope with fluctuations in the salinity of the external medium and generally use low-molecular mass organic compounds to adjust cell turgor pressure. These compounds can accumulate to high levels without interfering with cell metabolism, thereby deserving the designation of compatible solutes. Curiously, the accumulation of compatible solutes also occurs in response to supraoptimal temperatures.(...)

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    Título: Metabolic engineering of Corynebacterium glutamicum for the production of succinate and 2,3-butanediol Autor: Rados, Dusica Resumo: The depletion of fossil raw materials and the environmental pollution associated with their processing motivated the development of alternative methods for production of fuels and bulk chemicals. The solution offered by White Biotechnology is to produce these chemicals from biomass, a renewable resource rich in carbohydrates, using microorganisms as biocatalysts. Corynebacterium glutamicum is a well-known industrial bacterium employed for decades in the large scale production of L-amino acids. In this work, the potential of C. glutamicum as a bio-platform for the production of succinate and 2,3-butanediol was explored.(...)