In year 2024 and 2025 the Royal Swedish Navy is expected to launch two new submarines with new possibilities to dock underwater vehicles. The submarines are part of the new Blekinge Class (A26) and will aid the Swedish Armed Forces and the Swedish Defense Materiel Administration (FMV) in their aim to develop and use more autonomous systems, to increase staff efficiency and to face the technological challenges of tomorrow. This thesis was carried out at FMV, with the purpose of investigating the physical requirements put on the new submarines, when docking an autonomous underwater vehicle. These requirements were identified through an analysis of qualitative and quantitative research. The analysis resulted in ten key insights, which led to thirteen requirements. The requirements were combined with project specific data of the AUV62 system and A26 submarine, to develop three conceptual designs of hard docking systems. The concepts were verified through analysis of material, stress and deflection, and geometric constraints. The concepts were evaluated based on how well they were fulfilling each requirement. A hammock-alike concept was shown to have most potential in being the most reliable hard docking system. The thesis ended with concluding that its purpose had been fulfilled, followed with recommendations for continued work. / Under 2024 och 2025 förväntas Svenska Marinen sjösätta två nya ubåtar, med nya förmågor gällande dockning av undervattensfordon. Ubåtarna ingår i nya Blekingeklass (A26) och är en del av Försvarsmaktens och Försvarets Materielverks (FMV) målsättning om att utveckla och använda mer autonoma system, för att öka personaleffektivitet och för att kunna möta morgondagens tekniska utmaningar. Detta examensarbete utfördes på uppdrag av FMV, med syftet att undersöka vilka fysiska krav som ställs för att hårddocka ett autonomt undervattensfordon på de nya ubåtarna. Dessa krav identifierades genom analys av en kvalitativ och kvantitativ undersökning. Analysen uppdagade tio nyckelinsikter som gav upphov till tretton krav. Kraven kombinerades med projektspecifik data för AUV62-systemet och ubåt A26, för att utveckla tre konceptuella designförslag av hårddockningssystem. Koncepten verifierades genom analys gällande material, spänning och utböjning, samt geometriska begränsningar. Koncepten utvärderades baserat på hur väl de uppfyllde respektive krav. Ett hängmatteformat koncept visade sig ha störst potential för att bli ett pålitligt hårddockningssystem. Examensarbetet avslutades med att projektets syfte ansågs vara uppfyllt, följt av förslag på vidare arbete.

Docking maneuvers are a relevant part of the modern space mission, requiring precision and safety to ensure the success of the overall mission. This thesis proposes using a non-linear Model Predictive Control (MPC) as a controller with various constraints to ensure safe docking maneuvers for a satellite. This was done in MATLAB using as a model for the satellite the Sliders used by the Robotics Lab at Luleå University of Technology (LTU). The controller was tested first on the MATLAB model and then briefly on hardware.The main objective of this thesis is to develop and implement an MPC-based control strategy to achieve safe docking maneuvers between two satellites. Great attention has been paid to implementing constraints, such as collision avoidance, and hardware constraints, such as thrust limits, to ensure the safety and reliability of the process.Through the MATLAB simulations, it was possible to indicate that the introduced constraints contribute significantly to the safe execution of docking maneuvers, preventing collisions, andoptimizing fuel usage. The controller successfully adapts to unforeseen disturbances and uncertainties in real-time, showcasing its robustness and reliability in dynamic space environments.The hardware simulations have shown that the controller operates as expected but needs further tuning to adapt to the hardware uncertainties.In conclusion, this thesis comprehensively explores MPC-based control strategies with constraints for space docking maneuvers. The positive results underscore this approach’s potential to ensure the safety and reliability of future space missions, opening avenues for further research and application in autonomous space systems.

The city with its urban density, infrastructure, and cultural, social and educational opportunities can be a desirable place to live for all - regardless of age, income or background. The city of today has changed considerably from the city of the 19th century. Neither is it the city of the future. However, it has great potential to anticipate to the challenges we will face in the future. It is a place that constantly changes. It is a living organism! This constant change is a challenge for architects to develop concepts and design-solutions that can react to shifting uses, zoning requirements, and dweller habits. The constant alteration of lifestyle, residential and commercial use, as well as job-related needs demands a high flexibity and adaptability in architecture and urban planning. Today's life is fast and unpredictable. Other contemporary issues such as sustainabilty or climate change are becoming key issues of today's discussion - in society, in the media and in world policy. Architects - responsible for our built environment - have to find innovative solutions to such ever-changing problems within their profession - within architecture. How can a concept, project or building be designed or constructed to anticipate those future needs, and what are the limits? To explore these questions and many more that followed I chose a site in midtown Washington DC. My thesis project includes 23 townhouses with partial retail, incorporated along an alley in the interior of a city block. The new development is integrated into the existing structure. / Master of Architecture

This dissertation presents research in the development and use of a multi-modal visual and haptic virtual model in higher education. The model, named Chemical Force Feedback (CFF), represents molecular recognition through the example of protein-ligand docking, and enables students to simultaneously see and feel representations of the protein and ligand molecules and their force interactions. The research efforts have been divided between educational research aspects and development of haptic feedback techniques. The CFF model was evaluated in situ through multiple data-collections in a university course on molecular interactions. To isolate possible influences of haptics on learning, half of the students ran CFF with haptics, and the others used the equipment with force feedback disabled. Pre- and post-tests showed a significant learning gain for all students. A particular influence of haptics was found on students reasoning, discovered through an open-ended written probe where students' responses contained elaborate descriptions of the molecular recognition process. Students' interactions with the system were analyzed using customized information visualization tools. Analysis revealed differences between the groups, for example, in their use of visual representations on offer, and in how they moved the ligand molecule. Differences in representational and interactive behaviours showed relationships with aspects of the learning outcomes. The CFF model was improved in an iterative evaluation and development process. A focus was placed on force model design, where one significant challenge was in conveying information from data with large force differences, ranging from very weak interactions to extreme forces generated when atoms collide. Therefore, a History Dependent Transfer Function (HDTF) was designed which adapts the translation of forces derived from the data to output forces according to the properties of the recently derived forces. Evaluation revealed that the HDTF improves the ability to haptically detect features in volumetric data with large force ranges. To further enable force models with high fidelity, an investigation was conducted to determine the perceptual Just Noticeable Difference (JND) in force for detection of interfaces between features in volumetric data. Results showed that JNDs vary depending on the magnitude of the forces in the volume and depending on where in the workspace the data is presented.

L'enjeu des travaux effectués au cours de cette thèse est l'extraction in silico de molécules potentiellement intéressantes dans le processus d'inhibition du récepteur tyrosine kinase c-Met. La faculté de cette protéine à interagir dans les phénomènes d'embryogenèse et de réparation tissulaires rendent son inhibition cruciale dans les traitements contre les développements tumoraux où c-Met se trouve impliquée. Pour cela, la stratégie employée implique l'utilisation de méthodes in silico de conception rationnelle de médicaments. Nous avons utilisé comme support les multiples structures cristallographiques publiées sur la ProteinData Base. Un travail de modélisation par homologie fut tout d'abord nécessaire pour combler les lacunes des structures cristallographiques collectées. Afin d'échantillonner au mieux l'espace conformationnel de la kinase c-Met et de caractériser sa flexibilité, une longue campagne de simulation de Dynamique Moléculaire fut menée. Pour compléter ces simulations, nous avons également utilisé la méthode des modes normaux de vibration. De ces 2 approches, nous avons extrait un ensemble de 10 conformères considérés comme les plus représentatifs de l'espace conformationnel simulé pour la kinase c-Met et avons proposé un mode de fonctionnement de ce récepteur. Utilisant les conformations représentatives, nous avons ensuite mené une importante campagne de criblage virtuel sur plusieurs chimiothèques constituant environ 70.000 composés. L'analyse des résultats de l'arrimage moléculaire nous a conduits à la sélection de composés intéressants possédant théoriquement une bonne affinité pour la kinase c-Met. Ces molécules ont été soumises aux tests expérimentaux. / The challenge of this PhD work is the in silico identification of potentially interesting molecules concerning the inhibitory process of tyrosine kinase receptor c-Met. The faculty of this protein to interact in embryogenesis and tissue repair phenomena makes its inhibition crucial for treatments against tumor development in which c-Met is involved. For that purpose, the employed strategy involves the use of several in silico methods for rational drug design. As the basement of this work, we used the multiple crystal structures published in the ProteinData Base (PDB). A preliminary homology modeling work was needed to fill gaps in the crystal structures. To sample at best the c-Met kinase conformational space and to characterize its flexibility, a long Molecular Dynamics (MD) simulation campaign was carried out both on apo and holo forms of available crystal structures. To complete these simulations, part of this work consisted to use normal modes of vibration (NM) method. From these two approaches (DM and NM), we extracted a set of 10 conformers considered as the most representative of the kinase simulated conformational space and we suggested a mode of operation of this kinase. Using extracted conformations from the conformational sampling has enabled us to conduct an extensive campaign on several virtual screening libraries constituting a total of approximately 70,000 compounds. Analysis of the molecular docking results has led us to the selection of several theoretically interesting molecules with good potential affinity for c-Met kinase. These molecules were submitted to experimental tests performed by the biologist team associated to our work.

L'étude structurale de l'interactome cellulaire peut conduire à des découvertes intéressantes sur les bases moléculaires de certaines pathologies. La modélisation par homologie et l'amarrage de protéines ("protein docking") sont deux approches informatiques pour modéliser la structure tri-dimensionnelle (3D) d'une interaction protéine-protéine (PPI). Des études précédentes ont montré que ces deux approches donnent de meilleurs résultats quand des données expérimentales sur les PPIs sont prises en compte. Cependant, les données PPI ne sont souvent pas disponibles sous une forme facilement accessible, et donc ne peuvent pas être re-utilisées par les algorithmes de prédiction. Cette thèse présente une approche systématique fondée sur l'extraction de connaissances pour représenter et manipuler les données PPI disponibles afin de faciliter l'analyse structurale de l'interactome et d'améliorer les algorithmes de prédiction par la prise en compte des données PPI. Les contributions majeures de cette thèse sont de : (1) décrire la conception et la mise en oeuvre d'une base de données intégrée KBDOCK qui regroupe toutes les interactions structurales domaine-domaine (DDI); (2) présenter une nouvelle méthode de classification des DDIs par rapport à leur site de liaison dans l'espace 3D et introduit la notion de site de liaison de famille de domaines protéiques ("domain family binding sites" ou DFBS); (3) proposer une classification structurale (inspirée du système CATH) des DFBSs et présenter une étude étendue sur les régularités d'appariement entre DFBSs en terme de structure secondaire; (4) introduire une approche systématique basée sur le raisonnement à partir de cas pour modéliser les structures 3D des complexes protéiques à partir des DDIs connus. Une interface web (http://kbdock.loria.fr) a été développée pour rendre accessible le système KBDOCK / Understanding how the protein interactome works at a structural level could provide useful insights into the mechanisms of diseases. Comparative homology modelling and ab initio protein docking are two computational methods for modelling the three-dimensional (3D) structures of protein-protein interactions (PPIs). Previous studies have shown that both methods give significantly better predictions when they incorporate experimental PPI information. However, in general, PPI information is often not available in an easily accessible way, and cannot be re-used by 3D PPI modelling algorithms. Hence, there is currently a need to develop a reliable framework to facilitate the reuse of PPI data. This thesis presents a systematic knowledge-based approach for representing, describing and manipulating 3D interactions to study PPIs on a large scale and to facilitate knowledge-based modelling of protein-protein complexes. The main contributions of this thesis are: (1) it describes an integrated database of non-redundant 3D hetero domain interactions; (2) it presents a novel method of describing and clustering DDIs according to the spatial orientations of the binding partners, thus introducing the notion of "domain family-level binding sites" (DFBS); (3) it proposes a structural classification of DFBSs similar to the CATH classification of protein folds, and it presents a study of secondary structure propensities of DFBSs and interaction preferences; (4) it introduces a systematic case-base reasoning approach to model on a large scale the 3D structures of protein complexes from existing structural DDIs. All these contributions have been made publicly available through a web server (http://kbdock.loria.fr)

Com o objetivo de buscar e identificar novo(s) inibidor(es) da cruzaína uma cisteíno-protease do Trypanosoma cruzi, o agente etiológico da doença de Chagas foram propostos, validados e, a seguir, aplicados sobre a biblioteca de compostos ZINC (3.294.714 compostos), dois modelos de virtual screening (Modelos I e II). Os modelos de virtual screening propostos, contendo seqüências de filtros físicoquímicos, farmacofóricos, de docking e de seleção por inspeção visual, foram construídos a partir de informações de 13 complexos da cruzaína e de 20 complexos de outras cisteínoprotease, cujas estruturas estão disponíveis no PDB. Numa primeira etapa, o reconhecimento detalhado das características estruturais da cruzaína foi realizado por inspeção visual; pelos campos de interação molecular, gerados pelo programa GRID; pela identificação das propriedades de interação molecular na superfície da cavidade, geradas pelo programa CA VBASE e; por simulações de dinâmica molecular. O Modelo I de virtual screeníng - obtido a partir do reconhecimento das estruturas dos 13 complexos da cruzaína depositadas no PDB - foi aplicado sobre o ZINC, selecionando 10 compostos, dos quais 6 compostos foram adquiridos e submetidos ao teste de inibição enzimática da cruzaína, para a validação experimental do modelo. Observou-se que 3 destes compostos (ZINC02470662, ZINC02682879 e ZINC03192044, respectivamente) não mostraram inibição significativa da cruzaína, nas condições experimentais utilizadas, até a concentração de 7 mM, enquanto que os 3 restantes (ZINC02663001, ZINC01936854 e ZINC03326243, respectivamente) apresentaram inibição enzimática inespecífica, sugerindo que estes últimos agem pelo mecanismo promíscuo. O mecanismo promíscuo de inibição enzimática, foi verificado pela adição de 0,1% Triton X-100 no ensaio enzimático, observando-se a correspondente perda de inibição da cruzaína. Para estes compostos, a confirmação do mecanismo promíscuo foi feita observando-se a perda de inibição da enzima, após o aumento em dez vezes da concentração da cruzaína no ensaio enzimático. O Modelo II - obtido a partir do reconhecimento das estruturas dos 13 complexos da cruzaína e dos 20 complexos de outras cisteíno-proteases, identificadas na busca por cavidades similares à cruzaína - foi aplicado sobre o banco de dados ZINC,selecionando 55 compostos dos quais 19 foram adquiridos e submetidos ao teste de inibição enzimática da cruzaína, para validação experimental do modelo. Observou-se que o composto ZINC01794422 apresentou inibição específica da enzima com constante de inibição no valor de Ki = 21 µM, enquanto que os demais 18 compostos não mostraram inibição significativa, nas condições experimentais utilizadas, até a concentração de 592 µM. O mecanismo promíscuo de inibição enzimática não foi observado, uma vez que todos os testes foram realizados com 0,1% de Triton X-100. O Modelo II identificou, ainda, mais dois inibidores da cruzaína (ZINC04899534 e ZINC01547017) que, por serem estruturalmente semelhantes aos utilizados na construção do modelo e já terem sido descritos na literatura, não foram adquiridos ou testados nos ensaios enzimáticos. Considerando apenas o novo inibidor identificado, o Modelo II apresentou uma taxa de acerto de 5,3%. Este valor esta de acordo com as taxas de acerto encontradas na literatura que variam entre 1 a 50% . / In order to search and identify new cruzain inhibitor(s) - a cysteine-protease of Trypanosoma cruzi, the etiologic agent of Chagas disease - two virtual screening schemes(Models I and II) were proposed, validated- and applied to the ZINC database (3.294.714 compounds). The proposed virtual screening models, bearing a sequence of different physicalchemical, pharmacophore and docking filters, as well as a visual inspection filter, were built from information taken from 13 cruzain complexes and from 20 complexes of other cysteine proteases, having their structures available in PDB. In a first step, a detailed recognition of the cruzain structural features and characteristics was performed through visual inspection of the enzyme environment; followed by the analysis of GRID generated molecular interaction fields; through the identification of molecular interaction properties exposed at the enzyme cavity surface, generated by the CAVBASE program; and by molecular dynamics simulations. The virtual screening Model I, - generated from the structural characteristics recognized from 13 PDB cruzain complexes - when applied to the ZINC database selected 10 compounds. For the experimental validation ofthe model, six ofthese compounds have been acquired and were tested as cruzain inhibitors. It was observed that three of the tested compounds (ZINC02470662, ZINC02682879 and ZINC03192044, respectively) did not show any significant cruzain inhibition, up to 7 mM. Meanwhile the other three tested compounds (ZINC02663001, ZINC01936854 and ZINC03326243, respectively) showed an unspecific cruzain inhibition, suggesting that an enzyme inhibition by promiscuous mechanism occurred. This mechanism was verified by the addition of 0.1% Triton X-100 on the enzymatic assay with a concomitant loss of cruzain inhibition activity. For these compounds, the confirmation of the promiscuous mechanism was also done, observing the loss of enzyme inhibition, after a ten times increase in the cruzain concentration on the enzymatic assay. The virtual screenmg Model II - generated from the structural characteristics recognized from 13 cruzain complexes and 20 complexes of other cysteine proteases, that have been identified on a search for cavities similar to cruzain - selected 55 compounds, when applied to the ZINC database. In order to experimentally validate the model, nineteen compounds have been acquired and were tested as cruzain inhibitors. It has been observed that one compound, ZINC01794422, showed a specific cruzain inhibition (Ki = 21 µM), while the other eighteen showed no significant inhibition, up to 592 µM concentration. The promiscuous mechanism of enzymatic inhibition was not observed, since 0.1% of Triton X-100 was added in ali assays. Additionally, Model II identified two other cruzain inhibitors (ZINC04899534 and ZINC01547017). However, these compounds have not been acquired or tested, since they are known cruzain inhibitors - already described in the literature and are structurally similar to the inhibitors used in the construction of the mode!. Referring to new inhibitors found, Model II showed a hit rate of 5,3%. This value is in agreement with those found in the literature, which ranges from 1 to 50%.

The Tumor Necrosis Factor derived-TIP peptide is a small 17 amino acids cyclic peptide with lectin-like activity, that possesses several therapeutically relevant biological activities, among which is activation of alveolar liquid clearance in both healthy and injured lungs in vivo. Accumulation of fluid in the lungs? alveoli and interstitial spaces is a life-threatening condition called pulmonary edema. The mortality rate due permeability pulmonary edema, accompanied by a dysfunction of the alveolar/capillary barrier, is high because no effective treatment lacking side effects exists nowadays. It is known that the TIP peptide is able to activate vectorial Na+ transport ? which mediates lung liquid clearance. However, the mechanism of action of remains elusive. The aim of this thesis was to investigate the initial steps of interaction between the TIP peptide and airway epithelial cells. Numerous novel methods and single-molecule techniques were used to unravel: (i) how the TIP peptide interacts with the molecules on the apical side of the lung epithelial cells; (ii) whether the TIP peptide need to be internalized inside of the cells to trigger its effects; (iii) the nature of the interaction between the TIP peptide and its putative receptor(s); (iv) the putative receptor(s) for the TIP peptide on the apical surface of the lung epithelial cells.

Made available in DSpace on 2016-06-02T19:19:55Z (GMT). No. of bitstreams: 1 AMARANTE_Adriano_2013.pdf: 11925080 bytes, checksum: 6de5e4ba7ae233d30b78c7f1d927740a (MD5) Previous issue date: 2013-03-19 / Universidade Federal de Sao Carlos / In this work was developed a prototype of a new nanobiosensor with molecular specificity through a study of theoretical models of Chemical Force Microscope. For the sensing were used molecular modeling techniques as well as experimental models of the functionalized Atomic Force Microscope tip with the Acetil co-A Carboxylase (ACC) attached. Specific and non-specific inhibitors were used to evaluate substrate-enzyme interactions. The nanobiosensor investigates specific enzymatic inhibition characteristics of the ACC enzyme through the herbicide Diclofop by reversing this process applying a force in a determined direction. The force is theoretically calculated by using molecular dynamic techniques associated to the adhesion force experimentally obtained. Theoretical and experimental questions involving nanobiosensors of AFM tips still obscure until now, such as, the number of functional enzymes attached on the AFM tip, the number of the active sites available to interact after immobilization process, the consequences of the enzyme immobilization as well as the substrate and theoretical adhesion between AFM tip and substrate were analyzed here. / Este trabalho teve como objetivo principal desenvolver o protótipo de um novo nanobiossensor de alta especificidade por intermédio do estudo e desenvolvimento de modelos teóricos específicos para a Microscopia de Força Química (MFQ). Para o sensoriamento foram utilizadas técnicas de Modelagem Molecular Computacional (MMC) e resultados experimentais de MFQ, do qual a ponta do Microscópio de Força Atômica (AFM, do inglês Atomic Force Microscopy) foi funcionalizada com enzimas Acetil-coA Carboxilase (ACC). O nanobiossensor foi utilizado para detectar especificamente substratos de herbicidas específicos e não-específicos. O nanobiossensor explora as características de inibição enzimática específica da enzima ACC pelo herbicida Diclofop revertendo esse processo aplicando-se uma força numa determinada direção. Essa força foi calculada teoricamente por intermédio de cálculos de técnicas de Dinâmica Molecular e associada à força de adesão experimental. Os resultados experimentais validaram os modelos teóricos de forma inequívoca. Questões teóricas e experimentais envolvendo nanobiossensores de ponta de AFM não respondidas até o momento (número de enzimas úteis na ponta do AFM que podem interagir com o substrato, o número de sítios ativos disponíveis, consequências da imobilização das enzimas e do substrato, força de adesão teórica entre a ponta do AFM e o substrato de herbicidas, etc.) foram solucionadas neste trabalho.

Com o objetivo de buscar e identificar novo(s) inibidor(es) da cruzaína uma cisteíno-protease do Trypanosoma cruzi, o agente etiológico da doença de Chagas foram propostos, validados e, a seguir, aplicados sobre a biblioteca de compostos ZINC (3.294.714 compostos), dois modelos de virtual screening (Modelos I e II). Os modelos de virtual screening propostos, contendo seqüências de filtros físicoquímicos, farmacofóricos, de docking e de seleção por inspeção visual, foram construídos a partir de informações de 13 complexos da cruzaína e de 20 complexos de outras cisteínoprotease, cujas estruturas estão disponíveis no PDB. Numa primeira etapa, o reconhecimento detalhado das características estruturais da cruzaína foi realizado por inspeção visual; pelos campos de interação molecular, gerados pelo programa GRID; pela identificação das propriedades de interação molecular na superfície da cavidade, geradas pelo programa CA VBASE e; por simulações de dinâmica molecular. O Modelo I de virtual screeníng - obtido a partir do reconhecimento das estruturas dos 13 complexos da cruzaína depositadas no PDB - foi aplicado sobre o ZINC, selecionando 10 compostos, dos quais 6 compostos foram adquiridos e submetidos ao teste de inibição enzimática da cruzaína, para a validação experimental do modelo. Observou-se que 3 destes compostos (ZINC02470662, ZINC02682879 e ZINC03192044, respectivamente) não mostraram inibição significativa da cruzaína, nas condições experimentais utilizadas, até a concentração de 7 mM, enquanto que os 3 restantes (ZINC02663001, ZINC01936854 e ZINC03326243, respectivamente) apresentaram inibição enzimática inespecífica, sugerindo que estes últimos agem pelo mecanismo promíscuo. O mecanismo promíscuo de inibição enzimática, foi verificado pela adição de 0,1% Triton X-100 no ensaio enzimático, observando-se a correspondente perda de inibição da cruzaína. Para estes compostos, a confirmação do mecanismo promíscuo foi feita observando-se a perda de inibição da enzima, após o aumento em dez vezes da concentração da cruzaína no ensaio enzimático. O Modelo II - obtido a partir do reconhecimento das estruturas dos 13 complexos da cruzaína e dos 20 complexos de outras cisteíno-proteases, identificadas na busca por cavidades similares à cruzaína - foi aplicado sobre o banco de dados ZINC,selecionando 55 compostos dos quais 19 foram adquiridos e submetidos ao teste de inibição enzimática da cruzaína, para validação experimental do modelo. Observou-se que o composto ZINC01794422 apresentou inibição específica da enzima com constante de inibição no valor de Ki = 21 µM, enquanto que os demais 18 compostos não mostraram inibição significativa, nas condições experimentais utilizadas, até a concentração de 592 µM. O mecanismo promíscuo de inibição enzimática não foi observado, uma vez que todos os testes foram realizados com 0,1% de Triton X-100. O Modelo II identificou, ainda, mais dois inibidores da cruzaína (ZINC04899534 e ZINC01547017) que, por serem estruturalmente semelhantes aos utilizados na construção do modelo e já terem sido descritos na literatura, não foram adquiridos ou testados nos ensaios enzimáticos. Considerando apenas o novo inibidor identificado, o Modelo II apresentou uma taxa de acerto de 5,3%. Este valor esta de acordo com as taxas de acerto encontradas na literatura que variam entre 1 a 50% . / In order to search and identify new cruzain inhibitor(s) - a cysteine-protease of Trypanosoma cruzi, the etiologic agent of Chagas disease - two virtual screening schemes(Models I and II) were proposed, validated- and applied to the ZINC database (3.294.714 compounds). The proposed virtual screening models, bearing a sequence of different physicalchemical, pharmacophore and docking filters, as well as a visual inspection filter, were built from information taken from 13 cruzain complexes and from 20 complexes of other cysteine proteases, having their structures available in PDB. In a first step, a detailed recognition of the cruzain structural features and characteristics was performed through visual inspection of the enzyme environment; followed by the analysis of GRID generated molecular interaction fields; through the identification of molecular interaction properties exposed at the enzyme cavity surface, generated by the CAVBASE program; and by molecular dynamics simulations. The virtual screening Model I, - generated from the structural characteristics recognized from 13 PDB cruzain complexes - when applied to the ZINC database selected 10 compounds. For the experimental validation ofthe model, six ofthese compounds have been acquired and were tested as cruzain inhibitors. It was observed that three of the tested compounds (ZINC02470662, ZINC02682879 and ZINC03192044, respectively) did not show any significant cruzain inhibition, up to 7 mM. Meanwhile the other three tested compounds (ZINC02663001, ZINC01936854 and ZINC03326243, respectively) showed an unspecific cruzain inhibition, suggesting that an enzyme inhibition by promiscuous mechanism occurred. This mechanism was verified by the addition of 0.1% Triton X-100 on the enzymatic assay with a concomitant loss of cruzain inhibition activity. For these compounds, the confirmation of the promiscuous mechanism was also done, observing the loss of enzyme inhibition, after a ten times increase in the cruzain concentration on the enzymatic assay. The virtual screenmg Model II - generated from the structural characteristics recognized from 13 cruzain complexes and 20 complexes of other cysteine proteases, that have been identified on a search for cavities similar to cruzain - selected 55 compounds, when applied to the ZINC database. In order to experimentally validate the model, nineteen compounds have been acquired and were tested as cruzain inhibitors. It has been observed that one compound, ZINC01794422, showed a specific cruzain inhibition (Ki = 21 µM), while the other eighteen showed no significant inhibition, up to 592 µM concentration. The promiscuous mechanism of enzymatic inhibition was not observed, since 0.1% of Triton X-100 was added in ali assays. Additionally, Model II identified two other cruzain inhibitors (ZINC04899534 and ZINC01547017). However, these compounds have not been acquired or tested, since they are known cruzain inhibitors - already described in the literature and are structurally similar to the inhibitors used in the construction of the mode!. Referring to new inhibitors found, Model II showed a hit rate of 5,3%. This value is in agreement with those found in the literature, which ranges from 1 to 50%.