Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-03-13T18:50:12Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Duarte, Letícia de Souza Guimarães [Dissertação, 2016].pdf: 2499210 bytes, checksum: 961dab593ba2ea593fadba0a224c15cc (MD5) / Made available in DSpace on 2017-03-13T18:50:12Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Duarte, Letícia de Souza Guimarães [Dissertação, 2016].pdf: 2499210 bytes, checksum: 961dab593ba2ea593fadba0a224c15cc (MD5) / A papaína, que corresponde a um complexo de enzimas extraídas do vegetal Carica papaya L., tem sido utilizada pela sua propriedade proteolítica em desbridamento enzimático de feridas. Diversos estudos descrevem o uso da papaína na forma de pó, solução, gel e creme sobre feridas, porém a baixa estabilidade da enzima nesses meios limita sua utilização em larga escala. O objetivo principal do trabalho consiste em desenvolver e avaliar formulações de papaína 10%(p/p) em gel carbômero, contendo antioxidantes como acetato de alfa-tocoferol e metabissulfito de sódio, associados a outros adjuvantes que permitam melhor estabilidade da enzima. As formulações iniciais para o estudo foram planejadas segundo desenho experimental fatorial 23, sendo as variáveis independentes representadas pelas concentrações de cisteína, de polissorbato 80 e de antioxidante (acetato de alfa-tocoferol ou metabissulfito de sódio). As amostras, mantidas sob refrigeração (5°C ± 3) por 7 dias, foram submetidas a ensaios de espectrofluorimetria para avaliação da atividade enzimática. Os resultados iniciais revelaram que as amostras que continham metabissulfito de sódio associado às maiores concentrações de polissorbato 80, apresentaram as melhores condições para manutenção da atividade proteolítica, enquanto que as amostras contendo alfa-tocoferol não foram capazes de manter a atividade. Sendo assim, realizou-se estudo de estabilidade com preparações contendo concentrações fixas de papaína 10% (p/p), polissorbato 80 2,0% (p/p), com variações nas concentrações de cisteína de 0,10, 0,13 e 0,16% (p/p) e metabissulfito de sódio de 0,50, 0,75 e 1,00% (p/p). Durante o período estudado, as amostras apresentaram aspecto homogêneo, sem mudanças na coloração e no odor. Na avaliação de pH não houve variação significativa dos valores (p>0,05). A variação de potencial Zeta foi menor que ǀ10ǀmV, não havendo diferença estatisticamente significativa em função do tempo (p>0,05). A partir dos resultados obtidos, novo desenho fatorial 23 foi traçado considerando como variáveis independentes: o tempo, as concentrações de metabissulfito e de cisteína. A presença de metabissulfito 0,5% ou 1,0% (p/p) associado a cisteína 0,16%(p/p) e polissorbato 80 2,0% (p/p), proporcionaram os menores valores de decaimento na concentração de papaína ativa nas formulações testadas por 28 dias. / Papain, which corresponds to a complex of enzymes from the plant Carica papaya L., has been used for its proteolytic property in enzymatic wound debridement. Several studies describe the use of papain as powder, solution, gel and cream forms over wounds; however, the low stability of the enzyme in the media limits its use in large scale. The main objective of this work is to develop and evaluate formulations with papain 10% (w/w) at carbomer gel, containing antioxidants as alpha-tocopherol acetate and sodium metabisulphite, associated with other adjuvants that enable better stability of the enzymes. The early formulations for the study were planned in a factorial experimental design 23, with the independent variables represented by cysteine, polysorbate 80 and antioxidant (alpha-tocopherol or sodium metabisulphite) concentrations. The samples, kept under refrigeration (5°C ± 3) for 7 days, were submitted to spectrofluorimetry essays for enzyme activity evaluation. Initial findings showed that the samples containing sodium metabisulphite associated with higher concentrations of polysorbate 80, presented the best conditions for proteolytic activity maintenance, whereas the samples containing alpha-tocopherol were not able to maintain activity. Thus, stability study was carried out with preparations with fixed concentrations of papain 10% (w/w), polysorbate 80 2.0% (w/w), with variations in the concentrations of cystein 0.10, 0.13 and 0.16% (w/w) and sodium metabisulphite 0.50, 0.75 and 1.00% (w/w). During the studied period, the samples showed a homogeneous appearance, without color or odor changes. At pH evaluation there was no significant change in values (p> 0.05). Zeta potential have varied less than |10|mV, with no statistically significant difference over time (p> 0.05). From the results, a new factorial design 23 was traced, considering as independent variables: time, metabisulphite and cystein concentrations. The presence of metabisulphite 0.5 % or 1.0 % (w/w) associated with cysteine 0.16 % (w/w), and polysorbate 80 2.0% (w/w), showed the lowest decay values of active papain concentration in the formulations tested for 28 days.

The search for more effective treatment strategies in melanoma led to many new innovative approaches aiming at different molecular targets. Chemotherapy still remains the most effective treatment and many efforts are put in order to improve targeting and delivery of the chemotherapeutic agents. Among these, peptide conjugates of anticancer drugs were designed to increase stability, cell penetration, specificity and accumulation in cancer cells. We as well as others evaluated such a conjugate, termed PSF (L-prolyl-m-L-sarcolysyl-L-p-fluorophenylalanine-ethylester) in terms of its cytotoxicity in vitro and in vivo using a human melanoma tumor as a model, its stability, transport, and metabolisation. <p>By comparing the cytotoxicity of PSF and melphalan towards different cancer primary melanoma cell cultures, we noticed some interesting observations: PSF displayed the same toxicity pattern both in short (2h) and long term (24h) cell exposures whereas melphalan and m-sarcolysin needed long term exposure to reach the same toxicity. This could indicate that PSF very quickly penetrates the cells in accordance with what has been shown with red blood cells (RBCs). PSF has shown a much better and quicker penetration into the cells in vitro as compared to melphalan. <p>In this present work, the cytotoxic effect of PSF was further evaluated in vivo using a standardized nude mice tumor model bearing a human melanoma. First, the acute toxicity in rats and mice and the maximum tolerated dose were determined. After a dose-escalation study one dose was singled out and tested as a single dose and as a fractionated dose. PSF was able to reach the tumor site and a dose-response relationship was observed. The IP administration of fractionated doses of PSF had significantly better effect on tumor growth inhibition, regression and regrowth than single dose administration and this without any evidence for general toxicity monitored by animal weight loss. We also compared the efficacy of PSF to its parent drug m-sarcolysin, melphalan and cyclophosphamide and observed that PSF was much more active than both melphalan and m-sarcolysin at the same molar doses.<p>Body distribution of the 14C-labelled PSF revealed ratios of 2.4 and 1.5 compared to muscle tissue for the two melanoma tumors evaluated with no significant and stable accumulation in any vital organ. The amount of tracer was still high in the blood after 24 hours explaining the high radioactivity in the kidney and partly in the liver. Interestingly, the spleen had an unusual high radioactivity uptake reflecting the exceptional binding of the tracer to blood cells (BC), while the pancreas very high load was an indicator of protease-mediated specific delivery and strongly support our hypothesis elaborated on the basis of in vitro results. <p><p>Our in vitro data point to a particular mechanism of action of PSF based on the transport of PSF through the body by the rapid binding to blood cells and the delivery at the tumor site by the subsequent release of its active metabolites due to cleavage by tumor-associated proteases.<p>Concerning the binding of PSF to membranes and its transport the following observations were made: while PSF was stable in human plasma, it disappeared very quickly in whole blood along with the generation of a main metabolite: m-sarcolysin. The presence of BC membranes was required for both binding and generating the metabolites. Binding to natural or artificial membranes was achieved and only competition with melanoma cells or proteolytic enzymes such as dispase, led to the generation of active metabolites. The different metabolites were isolated using preparative LC and were then identified using Electrospray Ionisation Mass Spectrometry (ESI). Three metabolites, of which m-sarcolysin was the main one, were identified all bearing the chloroethyl alkylating group. <p>Enzymatic catalysis was further supported by a set of experiments where the enzymatic activity was non-specifically and specifically inhibited. In order to look at the effect of extracellular matrix proteases on PSF, three representatives of ECM proteases were incubated with PSF: collagenase A had no effect, but both dispase and trypsine were able to process PSF. <p>The following data indicate the higher processing of PSF in the presence of cells with a higher proteolytic activity and thus the delivery of the blood cell-bound PSF. When comparing BC with melanoma cells (MC), the latter showed a higher ability to bind and process PSF both by membrane-associated and most interestingly soluble proteases. A lot of families of enzymes are reported to be overexpressed by melanoma cells including: metalloproteases, cysteine cathepsins, serine proteases and aminopeptidases. All the melanoma cells and cell lines evaluated were able to generate PSF active metabolites. <p>To identify the families of enzymes expressed on the membrane of melanoma cells that might be involved in the mechanism of action of PSF, we performed 2D-gel electrophoresis on their membrane extracts. The 2D-gels experiments revealed the presence of proteins compatible with enzymes known to be important in melanoma and further work is needed to identify the individual enzymes involved by using mass spectrometry and Western blotting. <p><p>Both our in vitro and in vivo findings strongly suggest that not only melanoma tumor cells and tumor sites but other types of tumors as well may be targets for the toxic activity of PSF owing to their much higher load in proteolytic enzymes that are closely related to their invasive potential. The transport of PSF by the blood cells and the release of its metabolites at the tumor site result in a low amount of drug in its free soluble form within the blood and this may explain the relatively lower side-effects observed. PSF is thus expected to have a much better therapeutic index than conventional alkylating agents. This original mechanism of drug delivery may well be extended to other cancer and non-cancer drugs than alkylating agents.<p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

L’objectif de cette thèse était de développer et d’optimiser de nouvelles méthodologies et approches analytiques afin d’améliorer le potentiel de l’analyse protéomique pour les études biologiques.La première partie de ce travail est consacrée à la détermination massive et exacte de la position N-Terminale des protéines (N-Terminome). Pour cela, nous avons utilisé et développé une approche basée sur une dérivation N-Terminale au TMPP. Cette méthodologie de marquage de la position N-Terminale a permis d’aborder l’étude des clivages protéolytiques des protéines exportées par le parasite P. falciparum (pathogène de la malaria) dans le globule rouge.Afin de permettre une exploitation automatique à haut débit des données de MS/MS, nous avons élaboré une nouvelle méthodologie (dénommée dN-TOP). Celle-Ci repose sur l’utilisation de TMPP portant des isotopes stables et permet ainsi d’accéder à la détermination des positions N-Terminales pour des études de N-Terminome à large échelle.La seconde partie est dédiée aux développements de différentes stratégies analytiques de quantification, aussi bien au niveau peptidique qu’au niveau protéique, appliquées à une série de problématiques biologiques. Ces optimisations ont été réalisées dans le contexte de l’étude des complexes protéiques, du dosage de prion par SRM, de quantification des glycations d’anticorps monoclonaux thérapeutiques et de l’hémoglobine HbA2 pour la standardisation des méthodes de référence. / The objective of this Ph.D. thesis was to develop and optimize new methodologies and analytical approaches to improve the potential of the mass spectrometry based proteomics.The first part of this work focused on the development of the N-Termini proteomics. This topic was addressed with a specific N-Termini chemical derivatization based on TMPP. We have shown that our method allowed both specific N-Terminomics and classical proteomics studies in the same experiment.This N-Terminus methodology was applied to study the proteolytic cleavages of the exported proteins in P. falciparum, a parasite responsible for the malaria.In order to automatize the complex and tedious informatics processsing of the MS/SM data of ourTMPP based N-Terminomics method, we have introduced a new approach (named dN-TOP), based on the use of a stable isotope labeled TMPP which made now N-Terminome proteomics compatible with high throughput studies.The second part addresses quantitative aspects of proteomics. It describes the optimization of quantitative methods at the peptide level or at the protein level for five different proteomic studies in the context of protein complex subunits, targeted SRM based prion, quantification of monoclonal antibodies glycation and hemoglobin HbA2 for reference measurement methods standardization.

This study has involved the design, synthesis and evaluation of novel HIV-1 enzyme inhibitors accessed by synthetic elaboration of Baylis-Hillman adducts. Several series of complex coumarin-AZT and cinnamate ester-AZT conjugates have been prepared, in high yields, by exploiting the click reaction between appropriate Baylis-Hillman derived precursors and azidothymidine (AZT), all of which have been fully characterised using spectroscopic techniques. These conjugates, designed as potential dual-action HIV-1 inhibitors, were tested against the appropriate HIV-1 enzymes, i.e. HIV-1 reverse transcriptase and protease or HIV-1 reverse transcriptase and integrase. A number of the ligands have exhibited % inhibition levels and IC50 values comparable to drugs in clinical use, permitting their identification as lead compounds for the development of novel dual-action inhibitors. In silico docking of selected ligands into the active sites of the respective enzymes has provided useful insight into binding conformations and potential hydrogen-bonding interactions with active-site amino acid residues. A series of furocoumarin carboxamide derivatives have been synthesised in four steps starting from resorcinol and these compounds have also been tested for HIV-1 integrase inhibition activity. The structures of unexpected products isolated from Aza-Baylis-Hillman reactions of N-tosylaldimines have been elucidated by spectroscopic analysis, and confirmed by single crystal X-ray analysis. A mechanism for what appears to be an unprecedented transformation has been proposed. Microwave-assisted SeO₂ oxidation of Baylis-Hillman-derived 3-methylcoumarins has provided convenient and efficient access to coumarin-3-carbaldehydes, and a pilot study has revealed the potential of these coumarin-3-carbaldehydes as scaffolds for the construction of tricyclic compounds. The HCl-catalysed reaction of tert-butyl acrylate derived Baylis-Hillman adducts has been shown to afford 3-(chloromethyl)coumarins and α-(chloromethyl)cinnamic acids, the Zstereochemistry of the latter being established by X-ray crystallography. ¹H NMR-based experimental kinetic and DFT-level theoretical studies have been undertaken to establish the reaction sequence and other mechanistic details. Base-catalysed cyclisation on the other hand, has been shown to afford 2H-chromene rather than coumarin derivatives.

A series of chromone-3-carbaldehydes have been prepared using Vilsmeier-Haack methodology while a corresponding series of chromone-2-carbaldeydes have been synthesized via the Kostanecki-Robinson reaction. Baylis-Hillman reactions have been conducted on both series of chromone carbaldehydes using three different catalysts, viz., 1,4-diazabicyclo(2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]undec- 7-ene (DBU) and 3-hydroxyquinuclidine (3HQ), and acrylonitrile, methyl acrylate and methyl vinyl ketone as the activated alkenes. These reactions have typically (but not always!) afforded both normal Baylis-Hillman and dimeric products. Attention has also been given to the use of 1-methyl-2-pyrrolidine (1-NMP), an ionic liquid, to replace normal organic solvents, and it has been found that, in the presence of DABCO, chromone-3-carbaldehydes afford the dimeric products alone. Reactions of chromone-3-carbaldehydes with methyl vinyl ketone have yielded unexpected, novel adducts, which appear to arise from preferential attack at C(2) in the chromone nucleus. Research on chromone-2-carbaldeydes under Baylis-Hillman conditions has also resulted in the formation of some interesting products instead of the expected Baylis-Hillman adducts. The Baylis-Hillman products have been explored as substrates for aza-Michael reactions using various amino derivatives including protected amino acids in the presence of the tetrabutylammonium bromide (TBAB) and the ionic liquid, 3-butyl-1- methylimidazoleboranetetrafluoride (BmimBF₄), as catalysts. The aza-Michael products have been targeted as truncated ritonavir analogues for investigation as potential HIV -1 protease inhibitors, and representative compounds have been subjected to enzyme inhibition assays to explore the extent and type of inhibition. Lineweaver-Burk and Dixon plots have indicated competitive inhibition in one case as well as non-competitive inhibition in another, and the inhibition constants (Ki) have been compared with that of the ritonavir. Computer modelling studies have also been conducted on selected chromonecontaining derivatives, using the ACCELRYS Cerius² platform. Interactive docking of the chromone-containing ligands into the HIV -1 protease receptor site, using the Ligandfit module, has indicated the importance of hydrogen-bonding interactions mediated by bridging water molecules situated in the receptor cavity. NMR spectroscopy has been used to elucidate complex and competing mechanistic pathways involved in the Baylis-Hillman reactions of selected 2-nitrobenzaldehydes with MVK in the presence of DABCO - reactions which afford the normal BaylisHillman product, the MVK dimer and syn- and anti-Baylis-Hillman type diadducts. The kinetic data confirm the concomitant operation of two pathways and reveal that, in the initial stage of the reaction, the product distribution is kinetically controlled, whereas in the latter stage, thermodynamic control results in the consumption of the normal Baylis-Hillman product and predominance of the anti-diadduct.

Made available in DSpace on 2017-06-01T18:20:40Z (GMT). No. of bitstreams: 1 elisangela_teixeira_silva.pdf: 805083 bytes, checksum: 4f700b752106d3810c1baa4954dc2462 (MD5) Previous issue date: 2013-05-26 / Enzymes are specific biocatalysts that work in wide field of applications as food industry as detergent formulation. The proteases represents an important commercial bioproduct used in industry, managing billion of dollars year by year, producing tons of detergents for different applications. Enzymatic reactions are processed under mild temperature and pressure with great commercial interest, being these catalysts biodegradable. The proteases demand in the brazilian market promoves the researches, as the entrepreneurship in this area althought more investments from government agencies must be necessary. The potenciality in renewable raw material and the increase of development of enzyme technologies are the bases that can promove the enzymes exportation. Hydrogen and disulfide bonds, van der Waals and ionic powers, as well as hydrophobic interactions need to be keeped among these amino acids to manage the spacial conformation of the enzymes, avoiding the inactivation or the protein desnaturation. The formulation process need of physical and chemical managements to promove the stability of the protein chains to try to protect the catalytic site and the spacial structure, adding elements like preservatives, salts, polymers, surfactantes, solvents, detergents and others elements to manage the structure of the enzyme in this process of formulation is necessary. In this work was analyzed the chemical composition of three bioprocts sold in the brazilian market used for domestic laundry, the presence of the main active agents among them like: enzymes, tensioactives and others, and the interaction these additives during the formulation process that could promove the respective differences and characteristics that make these products competitive. / Enzimas são biocatalisadores específicos que são utilizadas em vários campos de atuação, desde a indústria de alimentos, até na formulação de detergentes. As proteases são biocatalisadores de grande interesse comercial na indústria, movimentando bilhões de dólares com produção de toneladas de detergentes para diferentes aplicações. A demana de proteases no mercado brasileiro promove pesquisas como também o empreendorismo nesse segmento embora mais investimentos por parte das agências do governo devem ser necessárias. A potencialidade da matéria prima renovável e o aumento do desenvolviemnto de tecnologias para enzimas, como o conhecimento sobre a conformação protéica e estabilidade com atividades catalítica são as bases que podem promover a exportação de enzimas. Ligações de hidrogênio, forças iônicas e de van der Walls, como também as interações hodrofóbicas precisam ser matindas entre os amimoácidos para gerenciar a conformação espacial das enzimas, evitando desnaturação protéica. No processo de formulação, é necessário investigar a interrrelação de parâmetros físicos e aditivos químicos cujas variáveis são importantes para manter a estabilidade da conformação espacial, adicionando elementos como conservantes, sais, polímeros, surfactantes, solventes, detergentes e outros elementos para manter a estrutura da enzima. Nesse trabalho foram analizadas as composições de três bioprodutos dispostos no mercado brasileiro para lavagem de roupa. A presença de agentes ativos entre eles: enzimas e tensioativos e, a interação entre esses aditivos durante o armazenamento e as condições operacionais promovem as respectivas diferenças e características que impulsionam a competitividade desses produtos.

Made available in DSpace on 2017-06-01T18:20:42Z (GMT). No. of bitstreams: 1 fernanda_cristina_padilha_rocha_silva.pdf: 2431932 bytes, checksum: f7140668c1558241152571bad405e7c7 (MD5) Previous issue date: 2014-02-12 / Oil refineries, as well as other large-scale industrial processes, are potential sources of environmental pollution. Accidents involving spills of oil and oil products in Brazil, in the period 1975-2012, add infective million liters of soil, rivers and sea. In this sense, the process of dissolved air flotation (DAF) is still widely used in industry, both for water supply and for wastewater. The physico-chemical processes such as centrifugation, ultrafiltration and dissolved air flotation (DAF), can be effective when used to separate emulsified oils. The effluent from the oily water type cause many environmental problems, particularly in thermal power plants (TPP s). Thus the aim of the study was to propose the separation water/oil by FAD in pilot scale and to compare the efficiency of the pilot prototype of FAD with and without addition of biosurfactant separation of oily waste waters. According the results, the biosurfactant produced by Candida sphaerica was selected, this being cultivated in using low cost industrial waste. Use of this bioproduct increased the efficiency of the flotation 80.0% to 98.0 %, to provide better determination of the operating conditions. Thus, it is suggested that the use of biosurfactants as auxiliary flotation is a promising alternative for the mitigation of pollution caused by the accumulation of synthetic surfactants in the environment. / As refinarias de petróleo, assim como outros processos industriais em grande escala, são fontes potenciais de poluição ambiental. Os acidentes ocorridos com derramamento de petróleo e seus derivados no Brasil, no período de 1975 a 2012, somam milhões de litros de poluentes que promoveram a contaminação de solos, rios e mar. Os processos fisíco-químicos tais como, a centrifugação, ultrafiltração e flotação por ar dissolvido (FAD), podem ser eficazes quando usados para separar óleos emulsionados. Nesse sentido, o processo de FAD continua sendo amplamente utilizado nas indústrias, tanto para águas de abastecimento como para águas residuárias. A FAD pode ser considerada como uma tecnologia limpa, uma vez que utiliza pequenas quantidades de coagulantes e ar para promover a separação. A utilização de coletores/coagulantes é essencial para melhorar a eficiência do processo, tendo em vista suas características específicas que facilitam a adesão das partículas e, consequentemente, a separação dos poluentes. Por outro lado, esses coletores químicos são tóxicos, fator que representa um agravante no sentido da geração de outros poluentes ambientais. Assim, os surfactantes microbianos ou biossurfactantes, biomoléculas anfipáticas produzidas por bactérias e leveduras, em detrimento dos coagulantes sintéticos, apresentam-se como uma tecnologia sustentável e promissora no aumento de eficiência da flotação. Essas biomoéculas, além de serem muito eficientes, são biodegradáveis e atóxicas, motivando as pesquisas no sentido de produzir e utilizar cada vez mais esses agentes tensoativos. Dessa forma, o presente trabalho foi desenvolvido na busca de uma estratégia para comparar as eficiências de separação água/derivado de petróleo por FAD, em escala piloto, com e sem a adição de um biossurfactante. De acordo com os resultados obtidos, o biossurfactante produzido por Candida sphaerica cultivada em residuos industriais foi considerado adequado como coletor do processo de separação. A utilização da biomolécula elevou a eficiência do processo de FAD de 80,0% para 98,0%, proporcionando a determinação das melhores condições operacionais. Dessa forma, concluiu-se que o uso de biossurfactantes como auxiliares na flotação constitui uma alternativa promissora na mitigação da poluição provocada pelo derramamento de petróleo e derivados em ambientes marinhos.

A PEGlação é uma bem sucedida estratégia nano-biotecnológica que envolve a ligação covalente do polietilenoglicol (PEG) a uma droga para melhorar sua farmacocinética, farmacodinâmica e perfil imunológico, e portanto, aumentar seu efeito terapêutico. Atualmente, a PEGlação é usada para modificar proteínas, peptídeos, oligonucleotídeos e fragmentos de anticorpos. A Uricase (EC 1.7.3.3, UC) é uma enzima pertencente à classe das oxidorredutases, responsável pela oxidação do ácido úrico, produzindo alantoína. Essa enzima é encontrada em muitos organismos vivos como: bactérias, leveduras, fungos, vegetais e animais. Entretanto, durante a evolução das espécies o gene da UC tornou-se inativo, por isso, em humanos a UC é inativa. Nesse sentido, a UC adquiriu destaque como um potencial fármaco uricolítico, devido à necessidade do desenvolvimento de novos agentes terapêuticos no tratamento de hiperuricemia e gota. Neste estudo, a uricase recombinante purificada de Candida sp (UC-r) e a de rim bovino (UC-b) foram modificadas por PEGlação com mPEG-p-nitrofenil carbonato (mPEG-pNP) e 2-O-mPEG-4,6-dicloro-s-triazina (mPEG-CN), produzindo conjugados com considerável atividade enzimática residual UC-r-mPEG-pNP (87%), UC-r-mPEG-CN (75%) e UC-b-mPEG-pNP (75%), UC-b-mPEG-CN (50%).Além disso, os conjugados obtidos com a UC-r e UC-b apresentaram valores de KM menores do que as enzimas nativas, indicando que a PEGlação conferiu uma interessante propriedade aos conjugados, que permitiu um aumento da afinidade da UC-r e UC-b pelo ácido úrico. O efeito do pH e da temperatura sobre a UC-r e UC-b modificadas indicou que os conjugados obtidos foram mais ativos em pH próximo ao fisiológico e mais estáveis do que a respectiva enzima nativa. As formas PEGladas da UC-r e UC-b foram mais resistentes à ação de diferentes proteases e mantiveram-se estáveis em soro humano, indicando que a PEGlação favoreceu a resistência a degradação proteolítica. Análises espectroscópicas de dicroísmo circular (CD) e infravermelho (FTIR) não apresentaram nenhuma diferença relevante entre a estrutura protéica da UC-r nativa e PEGlada. Estudos in vivo com coelho e camundongos Balb/c mostraram que a UC-r nativa induziu uma intensa resposta imune sendo altamente imunogênica. Por outro lado, a UC-r PEGlada quando injetada cronicamente em camundongos não induziu qualquer resposta detectável de anticorpos. Esses resultados indicam uma suficiente redução da imunogenicidade dessa enzima, devido à conjugação do mPEG-pNP ou mPEG-CN, tornando-a adequada para um possível uso terapêutico. Portanto, nesse trabalho, os resultados obtidos com a UC-r de Candida sp, mostram que dois conjugados apresentaram interessantes propriedades físico-química, biológicas e imunológicas, que permitiram um significativo avanço na transformação de uma enzima de origem fúngica em uma droga, com uma possível aplicação terapêutica no tratamento de hiperuricemia e gota. / PEGylation is a successful nanobiotechnology strategy that involves the covalent attachment of polyethylene glycol (PEG) to a drug to improve its pharmacokinetic, pharmacodynamic, and immunological profiles, and thus, enhance its therapeutic effect. Currently, PEGylation is used to modify proteins, peptides, oligonucleotides, antibody fragments, and small organic molecules. Uricase (EC 1.7.3.3, UC) is an enzyme belonging to the class of oxidorreductases responsible for the oxidation of uric acid, producing allantoin. This enzyme is found in many living organisms such as bacteria, yeasts, fungi, plants and animals. However, during the evolution of the species gene became inactive UC, therefore, in humans UC is inactive. Accordingly, UC has acquired prominence as a potential drug uricolytic due to the need of developing new therapeutic agents for the treatment of hyperuricemia and gout. In this study, purified recombinant uricase from Candida sp (UC-r) and ox kidney (UC-b) were modified by PEGylation with mPEG-p-nitrophenyl-carbonate (mPEG-pNP) and 2-O-mPEG-4,6-dichloro-s-triazine (mPEG-CN), producing conjugates with considerable residual enzyme activity UC-r-mPEG-pNP (87%), UC-r-mPEG-CN (75%) and UC-b-mPEG-pNP (75%),UC-b-mPEG-CN (50%). In addition, conjugates obtained with the UC-r and UC-b had lower KM values than native enzymes, indicating that the PEGylation gave an interesting property the conjugate that increased the affinity of UC-r and UC-b by uric acid. The effect of pH and temperature on the modified UC-r and UC-b indicated that the conjugates were more active at pH close to the physiological and more stable than its native enzyme. PEGylated forms of UC-r and UC-b were more resistant to the action of different proteases and remained stable in human serum, indicating that the PEGylation favored resistance to proteolytic degradation. Spectroscopic analysis of circular dichroism (CD) and infrared (FTIR) did not show any relevant difference in protein structure between native and PEGylated UC-r. In vivo studies with rabbit and Balb/c mice showed that UC-r native elicited an intense immune response being highly immunogenic. On the other hand, the PEGlated UC-r when chronically injected into mice did not induce any detectable response to antibodies. These results indicate a sufficient reduction of immunogenicity of this enzyme, due to conjugation of mPEG-pNP or mPEG-CN, making it suitable for possible therapeutic use. Therefore, the results obtained with the UC-r of Candida sp, showed that two conjugates have interesting physical-chemical, biological and immunological, which allowed a significant advance in the transformation of an enzyme of fungal origin in a drug with a possible application therapeutic in the treatment of hyperuricemia and gout.

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Gabriela Kocurová Supervisor: Prof. MUDr. Jaroslav Dršata, CSc. Title of diploma thesis: Investigation of proteolytic enzymes expression in different tissues at the transgenic animal model of Huntington's disease by means of biochemical and immunohistochemical methods Background: Huntington's disease (HD) is a neurodegenerative disorder that is caused by an expansion of a polyglutamine (polyQ) domain in the huntingtin (Htt) protein. Because it is known that mutant Htt and especially its small proteolytic fragments are toxic to neurons (particularly those in the striatum and cortex), it has been suggested that proteolysis of mutant huntingtin (mHtt) might play an important role in HD pathogenesis. Therefore, the aim of the present study was to examine the expression of endogenous and mtHtt and possible participation of the proteolytic enzymes from the group of caspases, matrix metalloproteinases (MMPs), kallikreins (KLKs) and calpains in HD pathology of brain tissue. Methods: In this study we used WT and TgHD minipigs for N-terminal part of the human mtHtt (548aaHTT-145Q, both F2 generation, age 36 months; F3 generation, age 48 months in additional experiment), R6/2 mice were used as...

Indiana University-Purdue University Indianapolis (IUPUI) / Periodontal disease is the leading cause of tooth loss in adults. Bacterial biofilm on tooth surfaces is the primary initiator of periodontal disease. Various factors contribute to the severity of periodontal disease including the different virulence factors of the bacteria within the biofilm. In the progression of periodontal disease, the microflora evolves from a predominantly Gram positive microbial population to a mainly Gram negative population. Specific gram negative bacteria with pronounced virulence factors have been implicated in the etiology and pathogenesis of periodontal disease, namely Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola which form the red complex of bacteria. The orange complex bacteria become more dominant in the maturation process of dental plaque and act to bridge the early colonizers of plaque with the later more dominant red complex bacterial and consists of such bacteria as Campylobacter showae, Campylobacter rectus, Fusobacterium nucleatum and Prevotella intermedia. Perhaps the most investigated contributing factor is the relationship between smoking and periodontal disease. When examining the association between cigarette smoking and interproximal bone loss, greater bone loss is associated with higher cigarette consumption, longer duration (i.e., pack year history) and higher lifetime exposure. The presence of various virulence factors such as the production of a capsular material, as well as the proteolytic activity of the various periopathodontic bacteria has been associated with the pathogenesis of periodontitis. Even though many different enzymes are produced in large quantities by these periodontal bacteria, trypsin-like enzymes, chymotrypsin-like enzymes and elastase-like enzymes, as well as dipeptidyl peptidase-like enzymes, have been thought to increase the destructive potential of the bacterium and mediate destruction of the periodontal apparatus. More specifically, it is hypothesized that the proteolytic activity of other clinically important periodontal pathogens, such as Fusobacterium nucleatum, Prevotella intermedia and Porphyromonas assacharolyticus, is increased in the presence of nicotine. The purpose of this study was to determine the effects of nicotine on F. nucleatum, P. intermedia and P. assacharolyticus proteolytic activity. Cultures were maintained on anaerobic blood agar plates containing 3% sheep blood. Bacterial cells were harvested from the plates and washed. Washed F. nucleatum, P. intermedia and P. assacharolyticus cells were incubated with 1 mg/ml of nicotine. Bacterial cells not incubated with nicotine were used as positive controls. Secreted enzymatic activity was measured using the synthetic chromogenic substrates glycyl-L-proline-p-nitroanilide (GPPNA), N-succinyl-L-alanyl-L-alanyl-L-alanyl-p-nitroanilide (SAAAPNA), N-succinyl-alanine-alanine-proline-phenylalanine-p-nitroanilide (SAAPPPNA) and N-α-benzoyl-L-arginine-p-nitroanilide (L-BAPNA) (Sigma-Aldrich Products, St. Louis, MO, USA). Appropriate means and standard deviations were determined for each of the enzymatic activities measured and analysis of variance (ANOVA) was used to compare the groups utilizing a 5% significance level for all comparisons. Results demonstrated that after 60 minutes of incubation of F. nucleatum, P. intermedia and P. assacharolyticus cells with 1 mg/ml of nicotine and the various synthetic substrates, had the following proteolytic activity for GPPNA: 0.83 ± 0.14, 0.72 ± 0.03 and 0.67 ± 0.10, respectively; SAAAPNA: 0.82 ± 0.06, 0.76 ± 0.05 and 0.68 ± 0.08, respectively; SAAPPPNA: 0.90 ± 0.13, 0.85 ± 0.17 and 0.72 ± 0.03, respectively; and BAPNA: 0.81 ± 0.15, 0.74 ± 0.13 and 0.74 ± 0.16, respectively. In conclusion, the results indicate that in the presence of 1 mg/ml of nicotine, the proteolytic activity of F. nucleatum and P. assacharolyticus was increased with all of the synthetic substrates (with statistical significance seen only in the increases with F. nucleatum and GPPNA, SAAAPNA and BAPNA). The proteolytic activity exhibited an increasing trend in activity for P. intermedia with SAAPPPNA and BAPNA but a decreasing trend in activity with GPPNA and SAAAPNA when incubated with 1 mg/ml of nicotine, once again demonstrating no statistical significance for any of the substrates. Therefore, it could be concluded that based on these results nicotine at a concentration of 1 mg/ml may increase the proteolytic activity of periodontal pathogens and thus may increase periodontal disease activity and subsequent periodontal breakdown. Further studies are needed to validate these results utilizing different concentrations of nicotine.