Photocopy of typescript. / Digitized by Kansas Correctional Industries

Os citros são as plantas economicamente mais importantes da fruticultura mundial. O Brasil responde por cerca de 30% da produção do planeta, e o Estado de São Paulo produz cerca de 80% dos citros do país. A pior ameaça atual a esse mercado é a doença bacteriana conhecida como greening ou huanglongbing (HLB), pela severidade dos sintomas, por afetar todas as variedades de citros e pela rapidez com que se espalha pelos pomares, transmitida pelo inseto psilídeo Diaphorina citri. O greening torna os frutos inúteis para consumo e leva à morte da planta. Não existe cura para a doença, de modo que o principal método de controle de infestação é a combinação das pulverizações, para reduzir a população do inseto vetor, com a erradicação das plantas doentes. Este último procedimento é efetuado porque a planta doente funciona como foco de propagação para o restante do pomar. Por isso, é importante identificar e erradicar a planta doente o mais cedo possível. Hoje, a identificação das plantas doentes é feita por inspeção visual. Esse método é muito pouco eficaz, pois, na ausência de frutos, os sintomas nas folhas não se manifestam de maneira uniforme em toda a planta e podem ser bastante sutis, sendo até confundidos com outras doenças. Além disso, as plantas inoculadas permanecem cerca de um ano sem manifestar sintoma algum. Por isso, a inspeção visual tipicamente identifica apenas cerca de 27% das plantas infectadas. O método de diagnóstico mais preciso disponível atualmente é a reação em cadeia de polimerase em tempo real (RT- PCR). Entretanto, essa técnica é trabalhosa e dispendiosa, o que torna impossível seu uso para o diagnóstico de grandes quantidades de plantas. Este trabalho propõe uma metodologia de diagnóstico baseada na obtenção de espectros de fluorescência induzida por laser (LIFS) das folhas e na aplicação de redes neurais artificiais para distinguir plantas sadias e doentes. Um experimento realizado no campo com pés de laranjeira Pêra-rio enxertada em limoeiro Cravo demonstrou que plantas sintomáticas podem ser diagnosticadas com eficiência de 87%. Um experimento controlado usando mudas de laranjeira Valência em citrumeleiro Swingle atestou que a técnica proposta também é capaz de diagnosticar plantas assintomáticas, obtendo taxas de acerto de até 63%. Da comparação dos resultados com os obtidos por RT-PCR constatou-se que a técnica aqui proposta apresenta taxa de acerto até duas vezes maior nos estágios iniciais do desenvolvimento da doença, até dois meses antes do aparecimento dos sintomas. Foram feitos também estudos preliminares da viabilidade do uso das técnicas de imagens de fluorescência induzida por laser (LIFI) e espectroscopia de emissão óptica com plasma induzido por laser (LIBS) para o diagnóstico precoce do greening. Os resultados foram bons em ambos os casos: na fase assintomática da doença, LIFI obteve sempre mais de 68% de acerto, e LIBS obteve mais de 62% em todos os casos. Todas as técnicas forneceram, portanto, resultados muito melhores que os da inspeção visual, e todas são mais viáveis que o RT-PCR, tanto pela rapidez quanto pelo custo envolvido. / Citrus plants are the most economically important fruit worldwide. Brazil accounts for about 30% of the planet\'s production, and the State of São Paulo produces 80% of citrus in the country. Nowadays, the worst threat to this market is the bacterial disease known as greening or huanglongbing (HLB), because it causes severe symptoms, affects all citrus varieties, and spreads very quickly through the orchards, being transmitted by the insect Diaphorina citri. The greening-affected fruits are useless and the plant dies. There is no healing for this disease, so the main method for infestation control is pulverization, to reduce the population of the vector insect, combined with eradication of diseased plants. The last procedure is done because the diseased plant acts as a focus, spreading HLB to the healthy trees around. Therefore, it is important to identify and eradicate the diseased plant as soon as possible. The identification of diseased plants is done currently by visual inspection. This method is very inefficient, because, in the absence of fruits, the leaf\'s symptoms do not appear uniformly throughout the plant and when appear they can be quite subtle, and even they can be mistaken for other diseases. Moreover, inoculated plants do not show any symptoms for about a year. This is why visual inspection typically identifies only about 27% of infected plants. At present, the most accurate method of diagnosis available is real-time polymerase chain reaction (RT-PCR). However, this technique is laborious and costly, making impossible to use it for large scale diagnosis. This study proposes a new diagnostic methodology carried out in the leaves, without any preparation, based on laser-induced fluorescence spectroscopy (LIFS) and artificial neural networks to distinguish diseased plants from healthy ones. A field experiment using Pêra-rio orange grafted on Cravo lemon plants has shown that symptomatic trees can be diagnosed with an efficiency of 87%. A controlled experiment using Valência orange on Swingle citrumelo trees testified that the proposed technique is also able to diagnose asymptomatic plants, achieving accuracy rates up to 63%. Comparison with results obtained by RT-PCR revealed that the technique proposed here achieves accuracy rates up to twice as high in the early stages of disease development, until two months before the onset of symptoms. Preliminary studies about the feasibility of laser-induced fluorescence imaging (LIFI) and laser-induced breakdown spectroscopy (LIBS) for greening early diagnosis were also performed. Results were good in both cases: in the symptomatic stage of the disease, LIFI always got more than 68% accuracy, and LIBS obtained more than 62% in all cases. All the techniques have provided thus far better results than those from visual inspection, and they all are more applicable than RT-PCR, because of quickness and low cost of analysis.

This thesis focuses on an important aspect of protein functionality – protein-protein interactions (PPI). Three physical chemistry techniques for or derived from protein-protein interaction investigation are discussed. First, in Chapter 2, we demonstrate a new fluorescent imaging technique that creates high-order nonlinear signals by harnessing the frustrated fluorescence resonance energy transfer (FRET) – energy transfer between certain proteins close in proximity which is commonly used in PPI studies. In Chapter 3, we combine fluorescence resonance energy transfer (FRET) and bioluminescence resonance energy transfer (BRET), two most commonly used approaches to monitor protein-protein interactions in vivo, to create a novel hybrid strategy, bioluminescence assisted switching and fluorescence imaging (BASFI), which integrates the advantages of FRET and BRET. We demonstrate BASFI with Dronpa-RLuc8 fusion constructs and drug-inducible intermolecular FKBP-FRB protein-protein interactions in live cells with high sensitivity, resolution, and specificity. Finally, in Chapter 4, we propose a systematic free energy perturbation (FEP) protocol to computationally calculate the binding affinities between proteins. We demonstrate our protocol with the gp120 envelope glycoprotein of HIV-1 and three broadly neutralizing antibodies (bNAbs) of the VRC01 class and analyze antibody residues’ contributions to the binding which further provides insights for antibody design.

Ce travail présente une étude, par microscopie optique et de fluorescence, de matériaux hybrides, basés sur des monolithes de silice contenant des dérivés du cyano-anthracène : 9,10-dicyano-anthracène (DCA) ou 9,14-dicyano-benzo(b)triphénylène (DBTP), qui sont des photo-sensibilisateurs de l'oxygène singulet. Alors que ces matériaux sont bien caractérisés du point de vue de la photo-oxydation des sulfures sous des conditions hétérogènes par des études macroscopiques, certaines propriétés concernant l'association du photosensibilisateur avec l'absorbant peuvent être masquées, dominées ou encore mal interprétées par uniquement des mesures d'ensemble. Ici, nous combinons la spectroscopie d'ensemble et la microscopie optique et de fluorescence, et développons des protocôles expérimentaux concernant des échantillons solides épais, dans le but d'étudier la distribution spatiale et la mobilité des photosensiblisateurs dans la matrice hôte ainsi que d'analyser les interactions entre ces deux entités. La microscopie optique montre dans tous les cas des inhomogénéités localisées à l'interface du monolithe et attribuées à la formation de bulles pendant la synthèse et une accumulation locale du DBTP. A partir de simulations Monte-Carlo de lancer de rayons, nous développons un protocôle pour corriger les artéfacts de réfraction dans les profils d'intensité de fluorescence en fonction de la profondeur, obtenus par des mesures confocales, pour déterminer la distribution axiale du photosensibilisateur ce qui permet de mettre en évidence une nette augmentation de la concentration en photosensibilisateurs dans les premiers 50—100 m dessous la surface. L'analyse FRAP montre la très lente mobilité de tous les photosensibilisateurs et un retour partiel de l'intensité ce qui signifie que les photosensibilisateurs se trouvent dans des régions compartimentées, probablement dues à des contraintes aléatoires du réseau de pores. De plus, l'analyse FLIM montrent des propriétés photo physiques semblables pour le DBTP inclus et greffé ce qui permet d'envisager l'inefficacité de la fonctionnalisation. Ces observations soulignent que les monolithes à base de silice sont des systèmes hors d'équilibre et correspondent à un instantané des inhomogénéités gelées pendant les derniers instants du processus de condensation-hydrolyse des monomères de silice. Enfin, corréler la spectroscopie classique avec nos observations confocales sur différentes formes de DBTP, nous permet d'établir que la bande d'émission de fluorescence non-structurée et fortement déplacée vers le rouge est probablement due à la formation d'excimères. / This work presents an optical and fluorescence microscopy study of hybrid materials based on porous silica monoliths containing derivatives of cyano-anthracene: 9,10-dicyano-anthracene (DCA) or 9,14-dicyano-benzo(b)triphenylene (DBTP), photo-sensitizers of singlet oxygen. While these materials are well known from bulk studies for the efficient photo-oxidation of sulphides under heterogeneous conditions, some characteristics of the association of the photo-sensitizer and the absorbent may be masked, overlooked or otherwise misinterpreted by bulk investigations alone. Here, we combine classical bulk spectroscopy with optical and fluorescence microscopy, and develop experimental protocols for thick solid state samples, to study the spatial distribution and the mobility of the guest in the host matrix, and analyse guest-host interactions. Optical microscopy shows in all cases localised inhomogeneities at monolith interface, ascribed to bubble formation during synthesis; wide-field fluorescence microscopy shows that these features are associated with local accumulation of the larger, more hydrophobic of the two photo-sensitizers, DBTP. Photo-sensitizer lateral distribution at the monolith interface is otherwise homogeneous. Based on Monte Carlo ray-tracing simulations, we develop a protocol for correcting refraction artefacts in measured confocal fluorescence depth profiles, to obtain the photo-sensitizer axial distribution. While it in general exhibits a sharp increase in concentration in the first 50—100 m below the surface compared to the bulk, this layer contributes negligibly to the total content of the monoliths. FRAP analysis shows mobility of the photo-sensitizers in all cases, but with diffusion constants implying months or years to equilibrate the centimetre-sized monoliths. Classical bulk and confocal spectroscopy with FLIM analysis show similar photo-physical properties of DBTP included and grafted. The main effects of funcionalization in this photo-sensitizer are to slow down diffusion and to counter its aggregation. Incomplete FRAP recovery implies photo-sensitizer mobility is compartmented, probably due to random constrictions in the pore network. These observations underline that silica-based monoliths are non-equilibrium systems encapsulating a snapshot of any homogeneities frozen in during the later stages of hydrolysis-condensation of silicate units. Correlating classical bulk spectroscopy with our confocal observations on the different DBTP forms, conclude that its unusual structureless, red-shifted emission is probably due to excimer emission.

All animals harbor microorganisms that interact with each other and with their hosts. These microorganisms play important roles in health, disease, and defense against pathogens. The microbial communities in the intestine are particularly important in preventing colonization by pathogens; however, this defense mechanism and the means by which pathogens overcome it remain largely unknown. Moreover, while the composition of animal-associated microbial communities has been studied in great depth, the spatial and temporal dynamics of these communities has only recently begun to be explored. Here, we use a transparent model organism, larval zebrafish, to study how a human pathogen, Vibrio cholerae, invades intestinal communities. We pay particular attention to a bacterial competition mechanism, the type VI secrection system (T6SS), in this process. In vivo 3D fluorescence imaging and differential contrast imaging of transparent host tissue allow us to establish that V. cholerae can use the T6SS to modulate the intestinal mechanics of its host to displace established bacterial communities, and we demonstrate that one part of the T6SS apparatus, the actin crosslinking domain, is responsible for this function. Next, we develop an automated high-throughput light sheet fluorescence microscope to allow rapid imaging of bacterial communities and host cells in live larval zebrafish. Light sheet fluorescence microscopy (LSFM) has been limited in the past by low throughput and tedious sample preparation, and our new microscope features an integrated fluidic circuit and automated positioning and imaging to address these issues and allow faster collection of larger datasets, which will considerably expand the use of LSFM in the life sciences. This microscope could also be used for future experiments related to bacterial communities and the immune system. The overarching theme of the work in this dissertation is the use and development of advanced imaging techniques to make new biological discoveries, and the conclusions of this work point the way toward understanding pathogenic invasion, maximizing the use of LSFM in the life sciences, and gaining a better grasp of host-associated bacterial community dynamics. This dissertation includes previously published and unpublished co-authored material.

Understanding the local conformations of DNA at the level of individual nucleic acid bases is important for the study of the mechanism of DNA sequence-dependent behavior. Here we apply linear absorption, circular dichroism (CD), and fluorescence spectroscopy to study the DNA local base conformation using 6-methyl Isoxanthopterin (6-MI) labeled DNA. We interpret excitation–emission peak shift (EES) measurements of the 6-MI, both as a ribonucleotide monophosphate in solution and as a site-specific substituent for guanine in various DNA constructs, by implementing a simple two-state model. We show that the spectroscopic properties of the 6-MI probe in DNA can be used to obtain detailed information about local base conformations and conformational heterogeneity and fluctuations. Based on these findings, we apply a simple theoretical model to calculate CD of 6-MI substituted DNA constructs. We find that our model can be used to extract basesequence- dependent information about the local conformation of the 6-MI probe as modulated by the local base or base-pair environment. We next apply 6-MI to probe the ligand insertion of small molecules to duplex DNA, further extending the potential of 6- MI as a useful reporter of local nucleic acid base conformation. These studies served to establish a new level of sophistication in qualitatively analyzing 6-MI structural behavior in terms of local base stacking and unstacking conformations. v This dissertation contains previously published and unpublished co-authored material.

Amostras de vidros aluminoboratos de bário contendo impureza de cromo, apresentando proporções de íons Cr POT. 3+, Cr POT 5+ e Cr POT. 6+, determinadas pelas condições oxidantes ou redutoras de fusão, foram preparadas e caracterizadas pelas técnicas de absorção óptica (AO), fluorescência e de ressonância paramagnética eletrônica (RPE). As condições redutoras necessárias para favorecer a obtenção de vidros contendo majoritariamente íons de Cr POT. 3+ foram satisfeitas com a adição de 0,6% em peso de Sb IND. 2 O IND. 3. Nos vidros contendo antimônio, a banda 4 ANTIPOT. T IND. 2 do Cr POT. 3+ aparece ligeiramente deslocada para comprimentos de onda maiores e mais alargada, em relação ao vidro contendo apenas cromo como impureza adicional. O parâmetro de Racah B e a intensidade de campo ligante Ll foram determinados, obtendo-se os valores B = 759 cm-1 e = 15800 cm-1 para o vidro com cromo e antimônio e B = 736 cm-1 e = 16150 cm-1 para o vidro contendo apenas a adição de cromo. Foram observadas antirressonâncias de Fano nos espectros de AO, mais definidas nas amostras sem antimônio. Os espectros de RPE indicam que os íons Cr POT. 3+ isolados estão preferencialmente localizados em sítios distorcidos de simetria octaédrica, apresentando uma linha de absorção em g = 5,15, notando-se também a presença de pares de Cr POT 3+ caracterizados por uma componente da linha em g = 2,0. Com a adição de neodímio, os espectros de AO e de RPE do Cr POT. 3- não sofreram alterações, mas o espectro de fluorescência, com o máximo localizado em 776 nm, foi bastante modificado, mostrando uma diminuição da intensidade em regiões do espectro características da absorção do Nd POT. 3+, indicando a ocorrência de um processo de transferência de energia dos íons Cr POT. 3+ para os íons Nd POT. 3+ nos vidros aluminoboratos de bário, à temperatura ambiente. Os espectros de fluorescência e excitação dos vidros duplamente dopados com cromo e neodímio mostraram o efeito de antiressonâncias de Fano, com o deslocamento de Lamb dos vales associados ao neodímio sobre do Cr POT. 3+. / Barium aluminoborate glass samples containing chromium impurities, presenting Cr3- , Cr5- e Cr6+ íon amounts determined by the oxidizing or reducing melting conditions, have been prepared and characterized by Optical Absorption (OA), fluorescence and Electron Paramagnetic Resonance (EPR) techniques. The reducing conditions necessary to obtain glasses having mainly Cr3+ íons were satisfied with the addition of 0.6 wt% of Sb2 O3 to the batch. In glasses containing antimony, the 4T2 band is wider and shifted towards the higher wavelengths in relation to glass containing only chromium as additional impurity. The Racah parameter B and the ligand field intensity L1 were determined, yielding B = 759 cm-1 and L1 = 15800 cm-1 for the chromium- and antimony-doped glass, and B = 736 cm-1 and L1 = 16150 cm-1 for glass containing only chromium impurity. Fano antiresonances were observed in the OA spectra, better defined in the samples without antimony. The RPE spectra show that the Cr3- ions are preferentially located at distorted octahedral sites. An absorption line was observed at g = 5. 15 and it has been noted also the presence of Cr3+ pairs characterized by a line component at g = 2.0. With the addition of neodymium, the OA and EPR spectra of Cr3+ did not change, but the fluorescence spectrum observed at 776 nm was considerably modified, indicating the occurrence of an energy transfer process from Cr3+ to Nd3- íons in barium aluminoborate glasses at room temperature. The fluorescence and excitation spectra of glasses doped with chromium and neodymium have shown the Fano antiresonance effect, with the Lamb shift of the valleys associated to neodymium over the emission bands ofCr3+.

Submitted by (edna.saturno@ufrpe.br) on 2016-12-19T15:34:38Z No. of bitstreams: 1 Orlando de Oliveira dos Santos.pdf: 1008703 bytes, checksum: 47b747aa1eaa483ff683caadd85cd715 (MD5) / Made available in DSpace on 2016-12-19T15:34:38Z (GMT). No. of bitstreams: 1 Orlando de Oliveira dos Santos.pdf: 1008703 bytes, checksum: 47b747aa1eaa483ff683caadd85cd715 (MD5) Previous issue date: 2013-07-30 / This study aimed to evaluate the ecophysiological characteristics of the species Zea mays, Sorghum bicolor and Brachiaria decumbens under water stress conditions in a greenhouse. The experiment was conducted in a completely randomized design, using three species, Zea mays, Sorghum bicolor and Brachiaria decumbens, with 10 plants of each species under two water regimes (control and stress). The parameters evaluated were: soil moisture (Smoisture) vapor pressure deficit (VPD), leaf water potential (Ψleaf); gas exchange (net CO2 assimilation (A), stomatal conductance (gs), transpiration (E) and intrinsic water use efficiency (WUEi)), chlorophyll a fluorescence (photochemical quenching (qP), non-photochemical quenching (NPQ), electron transport rate (ETR) and maximum quantum efficiency in Photosystem II (Fv / Fm)); and biochemical analysis (total soluble carbohydrate (TSC), total free aminoacids (TFA), total soluble protein (TSP), chlorophyll a (Chla), chlorophyll b (Chlb) and carotenoids (car). The data of leaf water potential and soil moisture were submitted to Student's T test with a significance level of 5%. When subjected to 21 days of water deficit, the species Z. mays declined 248% in Ψleaf, 87% in stomatal conductance, 53% in net CO2 assimilation, 84% in transpiration, 156% in intrinsic water use efficiency, 54% in photochemical quenching, 67% in electron transport rate, 10% in Fv / Fm and 17% in chlorophyll a; S. bicolor showed a decrease in Ψleaf about 212%, 42% in stomatal conductance, 26% in net CO2 assimilation, 31% in transpiration, and 40% in electron transport rate; and in the species B. decumbens was observed a decrease in Ψleaf about 105%, 36% in stomatal conductance, 31% in net CO2 assimilation, 24% in transpiration, 34% in intrinsic water use efficiency, 53% in photochemical quenching, 56% in electron transport rate, 54% in total free amino acid content. The species which presented the smallest decrease related to the evaluated parameters was S. bicolor. From 14 analyzed parameters, S. bicolor showed decrease in 5 of them, while the other two species reduced their rates in 9 at least. / Este trabalho teve como objetivo avaliar as características ecofisiológicas das espécies Zea mays, Sorghum bicolor e Brachiaria decumbens sob condição de déficit hídrico em casa de vegetação. O experimento foi conduzido em delineamento inteiramente casualizado, utilizando três espécies forrageiras- Zea mays, Sorghum bicolor e Brachiaria decumbens- com 10 plantas de cada espécie sob dois regimes hídricos (controle e estresse). Os parâmetros avaliados foram: umidade do solo (Usolo), deficit de pressão de vapor (DPV), potencial hídrico foliar (Ψfoliar); trocas gasosas (assimilação líquida de CO2 (A), condutância estomática (gs), transpiração (E) e eficiência intrínseca do uso da água (EUA)); fluorescência de clorofila a (quenching fotoquímico (qP), quenching não fotoquímico (NPQ), taxa de transporte de elétrons (ETR) e eficiência quântica máxima no fotossistema II (Fv / Fm)); e análises bioquímicas (carboidratos solúveis totais (CST), aminoácidos livres totais (ALT), proteínas solúveis totais (PST), clorofila a (Chla), clorofila b (Chlb) e carotenóides (car)). Os dados de potencial hídrico foliar e umidade do solo foram submetidos ao teste T, com nível de significância de 5%. Os demais parâmetros foram submetidos à ANOVA fatorial (Regime hídrico x Turno diário) e quando necessário às médias foram comparadas pelo teste de Student Newman Keul’s com nível de significância de 5%. Quando submetida à 21 dias de déficit hídrico, a espécie Z. mays apresentou uma queda no Ψ foliar de 248%, na condutância estomática de 87 %, na assimilação líquida de CO2 de 53%, na transpiração de 84%, na eficiência do uso da água de 156%, no quenching fotoquímico de 54%, na taxa de transporte de elétrons de 67%, na Fv / Fm de 10% e na Clorofila a de 17%; já o S. bicolor apresentou queda no foliar de 212%, na condutância estomática de 42%, na assimilação líquida de CO2 de 26%, na transpiração de 31% e na taxa de transporte de elétrons de 40%; E na espécie B. decumbens foi observado queda no Ψ foliar de 105%, na condutância estomática de 36%, na assimilação líquida de CO2 de 31%, na transpiração de 24%, na eficiência do uso da água de 34%, no quenching fotoquímico de 53%, na taxa de transporte de elétrons de 56% e no teor de aminoácidos livres totais de 54%. A espécie que apresentou a menor queda relacionada aos parâmetros avaliados foi o S. bicolor. De 14 parâmetros analisados S. bicolor apresentou queda em 5, enquanto que as outras duas espécies avaliadas suas taxas reduziram pelo menos em 9 parâmetros.

Os antipsicóticos são drogas utilizadas no tratamento de muitos transtornos psiquiátricos, sendo classificados em dois grupos: típicos e atípicos. Os típicos formam o grupo de drogas que bloqueiam especialmente os receptores de dopamina e, por isto, causam efeitos colaterais característicos, que se manifestam através de sintomas extrapiramidais e podem terminar em discinesia tardia. Os atípicos apresentam eficácia antipsicótica similar à dos antipsicóticos típicos, mas produzem menos efeitos colaterais extrapiramidais e não causam discinesia tardia. Os antipsicóticos se ligam às proteínas plasmáticas, principalmente a albumina, a qual representa cerca de 60% do total das proteínas no soro humano. Neste trabalho estudamos os processos de interação de duas drogas antipsicóticas atípicas, risperidona e sulpirida, com as albuminas séricas humana (HSA) e bovina (BSA), através da técnica de supressão da fluorescência intrínseca do triptofano. A partir dos espectros de fluorescência, a análise dos dados foi feita obtendo-se os gráficos e as constantes de Stern-Volmer. A análise da supressão da fluorescência foi feita a partir da média aritmética dos dados oriundos dos experimentos realizados em cada condição adotada. Como a molécula da sulpirida é fluorescente desenvolvemos uma modelagem matemática do processo de interação, que nos permitiu então obter os dados referentes à supressão da fluorescência da proteína. Os resultados mostraram que a risperidona e a sulpirida suprimem a fluorescência de ambas albuminas por um processo de quenching estático, formando complexos droga-albumina. A risperidona tem uma afinidade com a HSA cerca de 6,5 vezes maior do que a sulpirida, a 37 oC. As constantes de associação calculadas para a interação risperidona-HSA, através da Teoria de Stern-Volmer, foram 1,43 ( 0,05) x 105 M-1, a 37 C, e 2,56 ( 0,09) x 105 M-1, a 25 C1; e para a sulpirida, 2,20 ( 0,08) x 104 M-1, a 37 C, e 5,46 ( 0,20) x 104 M-1, a 25 C. Como a taxa de quenching da BSA foi maior do que a da HSA, sugerimos que o sítio primário para a risperidona nas albuminas esteja localizado mais próximo ao domínio do triptofano 134 da BSA do que do domínio do triptofano 212 da HSA. O mesmo sugerimos com relação ao sítio para a sulpirida a 37 C. / Antipsychotics are drugs used to treat many psychiatric disorders. They are classified into two groups: typical and atypical. The typical group act blocking dopamine receptors in particular and it causes characteristic side effects with extrapyramidal symptoms, and can lead to tardive dyskinesia. The atypical group presents similar efficacy to typical group, but they produce less extrapyramidal side effects and does not cause tardive dyskinesia. Antipsychotics bind to plasmatic proteins, mainly to albumin, which represents about 60% of total human serum proteins. In this study we studied the interactions of two atypical antipsychotic drugs, risperidone and sulpiride, with human serum albumin (HSA) and bovine (BSA) through the technique of intrinsic tryptophan fluorescence quenching. From the fluorescence spectra, a data analysis was made to obtain Stern-Volmer plots and constants. Quenching analysis was performed used from using arithmetic means of data from experiments for each adopted condition. As sulpiride molecule is fluorescent, a mathematical modeling for interaction process was made. It allows us then to obtain the data referents to fluorescence quenching of protein. Results showed that risperidone and sulpiride quench the fluorescence for both albumins by static quenching process, forming complexes drug-albumin. The risperidone affinity to HSA is about 6.5 higher than supiride, at 37 oC. Stern-Volmer constants for interaction risperidone-HSA were 1.43 ( 0.05) x 105 M-1, at 37oC, and 2.56 ( 0.09) x 105 M-1, at 25 oC; and for sulpiride were 2.20 ( 0.08) x 104 M-1, at 37 oC, and 5.46 ( 0.20) x 104 M-1, at 25 oC. As the quenching ratio for BSA was higher than HAS, we suggested that the primary site for risperidone on albumin is closer of the domain of trypthophan 134 of BSA than the domain of trypthophan 212 of HAS. The same is suggested for the primary site of supiride at 37oC.

No description available.