Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2016-11-22T16:54:28Z No. of bitstreams: 2 Dissertação - Raisa Melo Lima - 2016.pdf: 5394977 bytes, checksum: 7066675bd31ee0e72d9ecd420ea0d1e7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-11-30T15:46:54Z (GMT) No. of bitstreams: 2 Dissertação - Raisa Melo Lima - 2016.pdf: 5394977 bytes, checksum: 7066675bd31ee0e72d9ecd420ea0d1e7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-11-30T15:46:54Z (GMT). No. of bitstreams: 2 Dissertação - Raisa Melo Lima - 2016.pdf: 5394977 bytes, checksum: 7066675bd31ee0e72d9ecd420ea0d1e7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-10-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Paracoccidioidomycosis (PCM) is a systemic mycosis endemic in Brazil, where are recorded about 80% of cases worldwide, and has Paracoccidioides sp. as the etiologic agent. Malate synthase (MLS) is an important enzyme related to the fungal metabolism, once it is essential in the glyoxylate cycle, a secondary metabolic pathway of the citric acid cycle exclusive to microorganisms and plants. Its absence in humans makes this enzyme an interesting subject to study, mainly in rational drug design. From recent in vitro studies, several interacting proteins of MLS (receiver) were classified, but the modes of interaction and key regions involved in protein-protein interfaces (PPIs) have not yet been described. In this work, six (6) binding proteins (BPs) were selected to describe the IP's of MLS. Their tridimensonal structures, as well as MLS, were predicted by homology modeling using I-TASSER server, and subsequent molecular dynamics simulations (MD). The most common conformational modes of each protein were obtained by cluster analysis of the trajectories generated by MD. Molecular docking simulations using Gramm-X were then performed for the conformational modes of MLS against the BP's, resulting in a total of 36 complexes. Based on the higher frequency of some small fragments of proteins observed in the IPP's, 57 peptides with sizes between 5 and 20 residues, were initially selected from 5 regions of MLS which are considered more frequent in protein-protein interaction. FlexPepDock simulations were performed to optimize the atomic coordinates of the peptide complexed with MLS, and concomitantly, PepFOLD simulations were performed to evaluate the stability of each peptide in solution. Based on the lower energy score of peptides linked to MLS, and the stability of their structures in solution (MLS-free), 6 peptides were selected as promising ligands to MLS mode 1. The stability and patterns of interactions of these peptides were evaluated in detail. / A paracoccidioidomicose (PCM) é uma micose sistêmica endêmica no Brasil, onde são registrados cerca de 80% dos casos mundiais, e possui como agente etiológico o fungo Paracoccidioides spp. A Malato sintase (MLS) é uma importante enzima relacionada ao metabolismo fúngico, uma vez que é essencial no ciclo do glioxilato, uma via metabólica importante de produção de glicose para parede celular, sendo exclusiva de micro-organismos e plantas. Sua ausência em humanos a torna um alvo interessante de estudo, principalmente, no desenho racional de fármacos. A partir de recentes estudos in vitro, várias proteínas que interagem com a PbMLS (receptor) foram classificadas, porém os modos de interação e as regiões chaves envolvidas nas interfaces proteína-proteína (IPP’s), não foram ainda descritas. Neste trabalho, 6 (seis) proteínas ligantes (PL) foram selecionadas para verificar suas interações com PbMLS. As estruturas tridimensionais dessas proteínas, bem como de PbMLS, foram preditas por homologia, usando o servidor I-TASSER. Simulações de dinâmica molecular (DM) foram realizadas pelo programa GROMACS, e os modos das conformações mais representativas de cada proteína foram determinados baseando-se nas análises de agrupamentos a partir das trajetórias geradas por DM. Simulações de ancoragem molecular com GRAMM-X foram então realizadas entre os modos conformacionais de PbMLS contra os obtidos de PL’s, resultando num total de 36 complexos. Baseado na frequência maior de alguns pequenos fragmentos de proteínas, observados nas IPP’s, 57 peptídeos de tamanhos entre 5 e 20 resíduos de aminoácidos, foram inicialmente selecionados a partir de 5 regiões da PbMLS consideradas mais frequentes na interação proteína-proteína. Simulações com FlexPepDock foram realizadas para otimizar as coordenadas atômicas dos peptídeos complexados com MLS e, concomitantemente, simulações com PepFOLD foram realizadas para avaliar a estabilidade de cada peptídeo em solução. Com base nos mais baixos scores de energia dos peptídeos ligados a MLS bem como na estabilidade de suas estruturas não ligadas em solução , 5 peptídeos foram selecionados como promissores ligantes ao modo 1 de MLS. A estabilidade e os padrões de interações destes peptídeos são avaliados em detalhes.

Magister Scientiae (Biodiversity and Conservation Biology) / Fog and dew interception and utilization by plant canopies remains one of the least considered aspects of vegetation studies at any scale yet the few studies that have been conducted point to their considerable influence on ecological processes and a critical role in modulating climate in southern African arid ecosystems. Their relevance to succulent plant hydrology was investigated in this study.The first study measured stable 18O and 2H isotope ratios in samples of rain, fog and dew water and compared these with those assayed monthly in stem xylem water of six succulent shrub species over a one year period. Negative 18O and 2H ratios were observed in the stem xylem water of all six species signifying a predominance of water derived from fog and dew precipitation which was most conspicuous during the wet winter. This implied that fog and dew are even more important sources of water than rain and corroborated by significant correspondence found between fog and dew frequencies, succulent foliar water contents and quantum yields of photochemistry.The second study monitored variations in stem diameter at 2-hourly intervals in 8 succulent shrub species of diverse growth form over a 9-month period. Two groups of species were distinguished based on whether their daily amplitudes in stem diameter were consistently positively correlated with daily fluxes in vapour pressure deficit, which were indicative of a persistent CAM photosynthetic mode, or intermittently correlated with daily fluxes in vapour pressure deficit, which were indicative of mixed CAM and C3 photosynthetic modes. Among species displaying a persistent CAM photosynthetic mode, high nocturnal fog and dew precipitation amounts corresponded with low daily amplitudes in stem diameter, and vice versa, which pointed to reduced nocturnal stomatal water loss. These patterns, which were indistinct among species displaying mixed CAM and C3 photosynthetic modes, were corroborated by small daily amplitudes in stem diameter also consistently observed in one species displaying a CAM photosynthetic mode in ambient than artificially fog and dew excluded environments.The third study monitored changes in water mass at hourly intervals of quartz gravel substrates with different dwarf succulent species assemblages over an 8-month period.Consistently greater net amounts of water were intercepted daily by quartz gravel substrates containing Agyroderma pearsonii than Cephalophylum spissum plants as well as those without plants. These attributed to a high water repellence of A. pearsonii leaves and less radiation absorbed by the paler silvery to grey-green leaves of A. pearsonii leaves than the dark green leaves of C. spissum resulting in lower leaf temperatures and less water loss by transpiration. Quartz gravel soils devoid of plants intercepted nearly 5-times greater amounts of precipitation contributed by fog and dew than that contributed by rain. These precipitation amounts exceeding the high percentages of total hydrological input contributed by fog and dew reported in other ecosystems.The study concludes that fog and dew are a vital source of water for succulent shrubs in arid South African ecosystems and imply that diminished fog and dew frequencies associated with elevated night time temperatures accompanying global warming could exacerbate plant drought stress.

Delivery of biologically relevant ions such as drugs, neurotransmitters and hormones have been recognized as powerful a tool to control physiology of animals and plants for research purposes and practical applications. In the plant research community, ions are most commonly delivered as part of a solvent by soaking, spraying, pipetting or by adding to the soil. These methods have low control of the delivery dynamics and quantity of ion uptake. These issues motivated the development of the Organic Electronic Ion Pump (OEIP), which delivers only ions of interest by applying an external electric field through a polyelectrolyte membrane of high fixed charge concentration. A miniaturized, implantable version of the OEIP based on capillary fibres (c-OEIP), where the polyelectrolyte is enclosed in a capillary, enabled even higher precision of the delivery. In this master thesis, c-OEIP has been applied in the tropical plant Kalanchoe Blossfeldiana, chosen due to its characteristic skill to gradually learn to save water: while maturing it shifts to night time photosynthesis and transpiration, called Constitutive Crassulacean Acid Metabolism. A better understanding of this metabolism and water saving ability could guide engineering of enhanced drought tolerance in crop plants, which is motivated by the increasing global warming. One of the biologically relevant ions that is potentially involved in this water-saving learning process is the malate ions. The aim of this thesis is to test the hypothesis that c-OEIP is able to deliver malate ions to cause a reduction in stomatal conductance and transpiration of intact leaves of Kalanchoe Blossfeldiana. To test this hypothesis, firstly, the capillary-based OEIP were fabricated using polyimide coated glass capillaries filled with AETMAC polyelectrolyte. The ability of these devices to deliver malic acid (MA) was verified by using current-voltage characterisation during loading and delivery of MA. Secondly, the setup for MA delivery with c-OEIP to intact kalanchoe leaf was developed, optimising the insertion method to minimize the wounding of the plant and increase assay reproducibility. Finally, the MA was delivered to intact kalanchoe leaves via c-OEIP, where the plant transpiration response was evaluated using standard gas exchange porometer and also novel infrared camera, as plant temperature can be correlated with plant transpiration status. The results indicate that c-OEIP can deliver MA and trigger reduction of transpiration of young kalanchoe leaves, supporting the hypothesis that malate ions act to reduce stomatal conductance, potentially conveying a feedback message from the mesophyll to the guard cells. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

Stomata are small pores that are located on the surface of epidermal leaves, and they can regulate the uptake of CO2 and prevent water lose by opening and closing the pores. Stomata of plants can be regulated by external condition such as CO2, biotic and abiotic stresses and internal factors. CAM (crassulacean acid metabolism) plants adapt to hot and dry environments by closing stomata during the day and opening stomata during the cool night. However, it is still unclear how CAM plants open their stomata during the night and close them during the day. In this study, a number of factors were evaluated for their potential roles in promoting stomatal opening in the model CAM plant Kalanchoe laxiflora. Citrate is an important organic acid and it accumulates during the night in CAM plants. It is shown in this study that citrate promoted stomatal opening in detached leaf epidermis of Kalanchoe laxiflora. Further, the cytokinin zeatin is also shown to stimulate stomatal opening in detached leave of Kalanchoe laxiflora. Melatonin is an important regulator of circadian rhythms in mammals and has been implicated in regulation of plant abiotic stress responses. Melatonin was detected in the leaves of Kalanchoe laxiflora. It promoted stomatal opening in detached epidermis of Kalanchoe laxiflora. Together, these results suggest that stomata of Kalanchoe laxiflora respond to citrate and malate which are the main organic acids accumulate during nighttime and also to some signaling molecules (zeatin, melatonin, and serotonin) by opening stomata during dark period.

Les triacylglycérols d'algues (TAG) représentent une source prometteuse de biocarburants. Les principales étapes de la synthèse des acides gras et du métabolisme du TAG des algues ont été déduites de celles des plantes terrestres, mais on en sait peu sur les sources de carbones et d’énergie intervenant dans la synthèse de lipides de réserve. Nous avons donc étudié la synthèse des acides gras chez l’algue modèle Chlamydomonas reinhardtii en utilisant une combinaison d'approches génétiques, biochimiques et microscopiques. Plus précisément, j'ai d'abord examiné la localisation subcellulaire de gouttelettes de lipides dans des cellules d'algues exposées à une forte lumière, conditions où une plus grande quantité de pouvoir réducteur est produite. J'ai ensuite contribué à mettre en évidence que la bêta-oxydation des acides gras est un processus peroxysomal, et que pendant une carence en azote réalisée en conditions photoautotrophe, des mutants dépourvus de la malate déshydrogénase 2 peroxysomale (mdh2) accumulent 50% plus TAG que les souches parentales. Ces résultats nous ont permis de mettre en évidence l'importance du contexte redox cellulaire sur la synthèse lipidique. Cette étude a également permis de révéler l’existence d'un échange d’énergie entre le peroxysome et le chloroplaste. Enfin, en caractérisant des mutants déficients dans la dégradation des acides aminés à chaîne ramifiée (BCAA), j'ai montré que le catabolisme des BCAAs joue un double rôle dans la synthèse de TAG en fournissant des précurseurs carbonés et de l'ATP. L'ensemble de ces travaux ouvert de nouvelles pistes pour l'amélioration génétique future de souches d'algues pour la production de biocarburants. / Algal triacylglycerols (TAG) represent a promising source for biofuel. The major steps for fatty acid synthesis and TAG metabolism have been deduced based on that of land plants, but little is known about carbon and energy sources. To address this question, we investigated fatty acid synthesis in algal cells using a combination of genetic, biochemical and microscopic approaches in the model microalga Chlamydomonas reinhardtii. Specifically, I first examined subcellular localization of lipid droplets in algal cells exposed to high light, a condition favoring production of reducing power. Secondly, I contributed to put on evidence that the beta-oxidation of fatty acids is a peroxisomal process, and that during photoautotrophic nitrogen starvation, knock-out mutants of the peroxisomal malate dehydrogenase 2 (mdh2) made 50% more TAG than parental strains, highlighting the importance of cellular redox context on lipid synthesis. This study also revealed for the first time the occurrence of an energy trafficking pathway from peroxisome to chloroplast. And finally, by characterizing mutants defected in degradation of branched-chain amino acids (BCAAs), I showed that BCAA catabolism plays a dual role in TAG synthesis via providing carbon precursors and ATP. Taken together, this work highlighted the complex interplay between carbon and energy metabolism in green photosynthetic cells, and pointed future directions for genetic improvement of algal strains for biofuel productions.

NLO materials have been researched for nearly five decades from the point of view of understanding the basic mechanisms and also in the pursuit of new materials possessing improved properties. Materials satisfying a set of physico-chemical properties such as wide transmission range, good mechanical hardness, high po-larizablity, noncentric crystal structure, good chemical stability, etc are the ones which are sought after. Several organic and inorganic molecules have been synthe-sized with the hope of finding materials that possess the desired NLO properties. Most of the organic materials are known to possess high figure of merit. However, their poor mechanical strength and needle like growth habit are hindrances to practical applications. Inorganic NLO materials have better mechanical properties but many of them possess small deff and laser induced damage threshold. Semi-organic NLO materials are intended to have the merits of both organic and inorganic counterparts. In this investigation, three important NLO crystals, viz cesium hydrogen L-malate monohydrate (CsLM, CsH[C4H4O5]H2O), cesium lithium borate(CLBO,CsLiB6O10)and near stoichiometric lithium niobate codoped with Nd and Zn (Nd:Zn:LiNbO3)are chosen for detailed study. The thesis is organized into 6 chapters. First chapter contains the theoretical background of the physical and chemical phenomena including a review of nonlin-ear optics, second harmonic generation, multiphoton absorption & refraction con-cepts, single crystal growth, principles of ferroelectricity and the scope of the work involved. For better connectivity, a brief review of the earlier work carried out on the chosen materials is given in the beginning of each chapter. The second chapter discusses the methodology of work and experimental details used in the present study. The third chapter deals with studies on CsLM, the new organometallic NLO crystal. Its structure, electro-optical properties and dielectric properties in FIR region are reported very recently. This material is also reported to show a phase transition at 50 0C though not much is understood about its nature. Further details of crystal growth conditions, nonlinear optical properties and laser damage thresholds are little known on this newly discovered NLO material. In this chapter detailed crystal growth studies and investigations of physical properties are presented. During growth, CsLM crystals manifest in platy and prismatic morphologies depending on level of super saturation invoked. The maximum dimensions of the grown crystal are 20 x15 x35 mm3. It has very good transmission in the range, 250-1300 nm and dislocation density of ≈104/cm2 . The dc conductivity measurements place this crystal between an ionic conductor and a dielectric. Dielectric properties show considerable frequency dispersion and axial anisotropy with є′ being the highest along the polar b axis. Maker fringes experiment reveals that CsLM possesses good second harmonic generation efficiency, an order of magnitude higher than KDP. It also has high laser damage threshold for fundamental and second harmonic wavelengths of Nd:YAG pulsed laser. TGA/DTA experiments are performed on the crystals grown below and above the reported transition temperature(labelled as CsLM and Anhydrous-CsLM respectively). The present investigations on Anhydrous-CsLM show that it crystallizes in a structure different from that of CsLM and the nature of the reported ′phase transition ′is driven by sluggish hydration and dehydration processes. Recently UV transparent nonlinear optical materials were evaluated for the fab-rication of all solid state UVlasers and CLBO is one such NLO material. It crystal-lizes in non-centrosymmetric tetragonal space group, I42d. It is highly transparent in the wide range of wavelengths from 180 to 2500 nm and has good deff. It pos-sesses very good angular and spectral bandwidth tolerances compared to its contemporaries such as lithium triborate(LBO) and beta barium borate(β-BBO). There is, however, a problem associated with this material that it cracks when exposed to atmosphere due to its hygroscopic nature. This chapter details the fabrication of the required instrumentation to grow single crystals of this material and the study of possible solutions to avoid cracking problem besides its new nonlinear properties. Since the melts of borate materials are known to be highly viscous, the crystal growth apparatus should have the options for tuning the parameters like seed and crucible rotation rates, temperature isotherms, slow pulling rate, etc. Keeping the above in mind, a high temperature top seeded solution growth unit was designed and fabricated inhouse. Highly transparent single crystals of CLBO were grown using the above unit which were characterized for the defects/dislocations using X-ray topography. The average dislocation density estimated is ≈103/cm2. The nonlinear optical absorption(NLA) and refraction(NLR) properties are studied. Z-scan experiments reveal that five photon absorption(5PA )is responsible for nonlinear absorption when the wavelength and pulse width are 800 nm and 110 fs respectively. For 532 nm and 6 ns pulses, dielectric breakdown occurs before NLA could occur due to high pulse influence. CLBO is found to show negative nonlinear refraction under high intensities. Hygroscopicity of CLBO is attributed to the entry of water through the channels that are present along a and b axes, which in turn, cause cracking. Doping, is expected to modify the size of the channels. Since certain dopants are found to improve the stability of CLBO, substitution of Cs site with Zn and Gd is carried out to reduce the size of channels. As there was no significant improvement with doping experiments, an alternate approach is attempted by coating with SiO2 thin films on the optical elements to prevent the water molecules from entering lattice through the channels. The results and discussion of the above studies are presented in the chapter 4. Lithium niobate is the most widely used single crystal for fabricating optical modulators, waveguides, SAW devices and optical parametric oscillators. Although single crystals of this ferroelectric material were grown way back in 1965 by Ball-man and Fedulov independently, most of the work till the beginning of 90’s was concentrated on crystals with congruent composition(CLN) because there were no suitable methods available for growing homogeneous single crystals of stoichiomet-ric lithium niobate(SLN). Recently, Double Crucible Czochralski method with au-tomatic powder feeding technique and top seeded solution growth technique with Li2O and K2O fluxes are shown to produce SLN crystals. In this work, top seeded solution growth technique with58.6 mol% Li2O composition(self flux) is adopted to grow SLN crystals and the details of the growth and investigations are presented in chapter 5. Initially, crystal growth of SLN, and Zn & Nd codoped SLN are de-scribed. The maximum dimesions of the SLN crystals are 20 mm diameter and 35 mm length. CLN crystals(30mm diameter and 70 mm length) are also grown for comparison. The growth rate for SLN crystals is approximately 25 times lower than that for CLN. The maximum amount of Zn added to the melt is 2.5 mol%. For Nd codoping, four concentrations (0.2, 0.5, 0.9, 1.5 mol%) have been chosen with Zn concentration in the melt fixed at 2.5 mol%. Addition of Zn is to enhance the pho-torefractive damage threshold and Nd to use SLN as laser host. Structural studies on the grown crystals using powder X-ray diffraction show no additional phases. The domain structure analysis by chemical etching studies reveal that it is sensitive to doping and temperature gradient above the melt surface. The grown crystals possess good transmission in the UV-Vis-NIR region. Apparent increase in the dielectric constant found in doped crystals is attributed to space charge effect. In Nd:Zn codoped SLN, the parameters corresponding to lasing (Judd-Ofelt parameters, radiative transition probabilities, branching ratios) have been evaluated and found to be better than those obtained for codoped CLN. Surface laser damage and photorefractive damage thresholds are enhanced by 2 and 4 orders of magnitude respectively for the crystals grown with 2.5 mol% Zn in the melt. Nonlinear absorption and refraction studies using femtosecond Z-scan experiments reveal a correlation between the nonstoichiometric defects and nonlinear absorption & refraction coefficients. Polarization switching studies carried out on pure and Zn doped samples indicate an enhancement in switching rate at elevated temperatures. In the sixth and final chapter, a comprehensive summary of the present work and the scope for further investigations related to this work are given.

Made available in DSpace on 2014-12-17T14:03:41Z (GMT). No. of bitstreams: 1 TaffarelMT_DISSERT.pdf: 2213102 bytes, checksum: 779f70cd3a9747e4f3a386630bd3d1cc (MD5) Previous issue date: 2013-04-09 / Funda??o de Apoio ? Pesquisa do Estado do Rio Grande do Norte / Oilseeds are a high-value natural resource, due to its use as a substitute for petroleum. However, the storage time can reduce seed viability and oil quality. Therefore, scientific efforts have been made to provide a increment of storage time, germination rates and plant establishment of high-value oilseeds. The seedling establishment depends of the plant pass over the functional transition stage, characterized by a metabolic change from heterotrophic condition to autotrophic one. The storage oil mobilization is performed by &#946;-oxidation process and the glyoxylate cycle. Also, the functional transition involves acclimation to photosynthetic condition, which generally includes the participation of antioxidant system and the reactive oxygen species, the latter are produced in various reactions of primary and secondary metabolism. In the present study, Catalase was inhibited during the functional transition of sunflower and safflower, after were performed many analyzes to elucidate the effects caused on the SOD and APX antioxidant systems. Also, were checked the changes in expression pattern of the glyoxylate cycle enzymes markers, ICL and MLS. It was observed that after CAT inhibition, the SOD and APX antioxidant systems allow the seedling establishment. Besides, was verified that both oilseeds can be accelerate the reverse mobilization and the photosynthetic establishment when Catalase activity has dramatically decreased / As sementes oleaginosas armazenam ?leos, um recurso natural de alto valor econ?mico devido a sua aplicabilidade como substituto aos derivados do petr?leo. Por?m, o tempo de armazenamento pode inviabilizar a semente provocando a redu??o da qualidade do ?leo e perda da viabilidade da semente. Por este motivo, esfor?os cient?ficos t?m sido realizados para proporcionar um maior tempo de armazenamento e incrementar taxas de germina??o e estabelecimento destas plantas com alto valor econ?mico. O estabelecimento da pl?ntula depende da capacidade do vegetal transpassar a etapa de transi??o funcional, caracterizada pela mudan?a do estado heterotr?fico para o autotr?fico. O consumo das reservas de ?leo depende das vias de &#946;-oxida??o e do ciclo do glioxilato. No entanto, o processo de transi??o envolve a aclimata??o do vegetal ? condi??o de organismo fotossintetizante, que em geral conta com a participa??o fundamental do sistema antioxidante do vegetal devido ? produ??o de esp?cies reativas de oxig?nio em v?rias rea??es do metabolismo prim?rio e secund?rio. Neste estudo, a Catalase foi inibida durante a transi??o funcional de girassol e c?rtamo para analisar os efeitos provocados nos sistemas antioxidantes de APX e da SOD e verificar as modifica??es no padr?o de express?o das enzimas marcadoras do ciclo do glioxilato, ICL e MLS. Constatou-se que diante da inibi??o da Catalase o sistema antioxidante da APX e da SOD permitem o estabelecimento da pl?ntula. Verificou-se tamb?m que as duas oleaginoasas parecem acelerar a mobiliza??o de reservas e o estabelecimento fotossint?tico quando a Catalase tem a atividade drasticamente reduzida

A resposta metabólica do bagre Genidens genidens de três estuários (rios Grande, Indaiá e Escuro) do município de Ubatuba SP foi estudada comparativamente em relação ao impacto da atividade humana na região. Encéfalo, fígado e músculo epaxial foram utilizados para determinar a atividade específica das enzimas lactato desidrogenase (LDH), malato desidrogenase (MDH) e arginase, como prováveis marcadoras desse impacto. As diferenças entre os níveis teciduais de LDH dos bagres coletados nos três estuários não foram significativamente diferentes, provavelmente devido a sua capacidade adaptativa, associada à sazonalidade das concentrações de oxigênio nas águas estuarinas. Os níveis de arginase hepática e muscular dos bagres coletados nos estuários dos rios Escuro e Indaiá, respectivamente, foram diferentes em relação aos dois outros estuários. Comportamento semelhante a esse foi constatado em relação aos níveis da enzima MDH, marcadora do potencial gerador de ATP desses tecidos. Nesse sentido, os níveis de arginase e MDH do fígado e músculo epaxial podem estar refletindo o esforço adaptativo metabólico desse bagre às condições ambientais dessas regiões estuarinas. / The metabolic response of catfish Genidens genidens of the three estuaries (Grande, Indaia and Escuro rivers) in the municipality of Ubatuba - SP was studied in comparison to the impact of human activity in the region. Brain, liver and epaxial muscle were used to determine the specific activity of the enzymes lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and arginase, as probable markers of that impact. The differences between the tissues levels of LDH of the catfishes collected in the three estuaries were not significantly different, probably due to its adaptive capacity, associated with the seasonality of the oxygen concentrations in estuarine waters. Arginase levels of liver and muscle of the catfishes collected in estuaries of rivers Escuro and Indaia, respectively, were different in the relation to the other two estuaries. Behavior was similar to that observed in the levels of the enzyme MDH, marker of the potential generator of ATP of those tissues. Accordingly, the levels of arginase and MDH of the liver and epaxial muscle might reflect the effort of that adaptive metabolic catfish to environmental conditions such estuarine areas.

Made available in DSpace on 2014-07-29T15:16:38Z (GMT). No. of bitstreams: 1 Dissert part 1 Benedito.pdf: 5001631 bytes, checksum: 7d51091e361c98586e384be80ebe9178 (MD5) Previous issue date: 2009-05-11 / The pathogenic fungus Paracoccidioides brasiliensis causative of Paracoccidioidomycosis (PCM), a pulmonary mycose acquired by inhalation of fungal airborne propagules, which may disseminate to several organs and tissues leading to a severe form of the disease. Adhesion and invasion to host cells are essential steps involved in the internalization and dissemination of pathogens. Inside host, P. brasiliensis use the glyoxylate cycle for intracellular survival. Here, we provide evidence that malate synthase of P. brasiliensis (PbMLS) is localized on the cell wall, and is secreted. PbMLS was overexpressed in Escherichia coli, and polyclonal antibody against this protein was obtained. By using Confocal Laser Scanning Microscopy and Western blot analysis, PbMLS was detected in the cytoplasm and the cell wall of the yeast phase of P. brasiliensis of mother and bud yeast cells. PbMLSr and the respective polyclonal antibody produced against this protein inhibited the interaction of P. brasiliensis to in vitro cultured epithelial cells A549. These observations indicated that cell wall-associated MLS of P. brasiliensis could be mediating the binding of fungal cells, thus contributing to the adhesion of fungus to host tissues and to the dissemination of infection. / O fungo de patogênico Paracoccidioides brasiliensis agente causador da Paracoccidioidomicose (PCM), uma micose pulmonar adquirida pela inalação de propágulos aéreos do fungo que pode se disseminar a vários órgãos e tecidos levando a uma forma severa da doença. Dentro do hospedeiro, P. brasiliensis usa o ciclo do glioxalato (CG) para sobrevivência intracelular. Adesão e invasão das células do hospedeiro são passos essenciais envolvidos na internalização e disseminação do patógeno. Aqui, nós evidênciamos que malato sintase de P. brasiliensis (PbMLS) é secretada, e é localizada na parede da célula. PbMLS foi superexpressa em Escherichia coli, e o anticorpo policlonal contra esta proteína foi obtido. Usando Microscopia Laser Confocal (CLSM) e análise de Western blot, PbMLS foi encontrada no citoplasma e na parede da célula na fase leveduriforme de P. brasiliensis nas células mãe e broto. PbMLSr e o respectivo anticorpo policlonal produzido contra esta proteína inibiram a interação de P. brasiliensis com células epiteliais A549 cultivads in vitro. Estas observações indicariam que MLS associada à parede da célula de P. brasiliensis pode estar mediando a ligação do fungo às células, contribuindo assim com a adesão do fungo aos tecidos hospedeiros e para a disseminação da infecção.

No description available.