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Previous issue date: 2017-11-03 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A obesidade ? uma das Doen?as Cr?nicas N?o Transmiss?veis de maior impacto na sa?de p?blica. A semente de tamarindo (Tamarindus indica L.) vem sendo estudada por possuir inibidor de tripsina, e, entre os atributos relacionados a esse inibidor parcialmente purificado (ITT), tem-se a sua rela??o com a saciedade, por aumentar colecistocinina (CCK) plasm?tica em animais eutr?ficos e seu efeito na redu??o da concentra??o circulante de leptina em animais com obesidade, entretanto sem aumento plasm?tico de CCK. Neste estudo, o ITT foi purificado, caracterizado e avaliado quanto ?s suas propriedades frente aos horm?nios CCK e leptina em ratos Wistar com obesidade. Para purifica??o e caracteriza??o desse inibidor, foram realizados: fracionamento do extrato bruto proteico com sulfato de am?nio; cromatografia de afinidade Tripsina-Sepharose; Cromatografia L?quida de Alta Efici?ncia (HPLC); determina??o da massa molecular por MS-ESI; sequenciamento parcial por MALDI-TOF com ISD; ensaio de estabilidade de temperatura e pH; estimativa dos par?metros de especificidade; eletroforese bidimensional (2-DE) e dosagens de CCK e leptina plasm?tica, por ELISA, em ratos com obesidade, submetidos ? gavagem oral (730 ?g/kg) do inibidor de tripsina purificado (ITTp) comparando-os a ratos com obesidade sem tratamento. Desse modo, o ITT purificado por HPLC foi denominado ITTp. Com o refinamento do m?todo, obtiveram-se, com base no ITTp, dois picos proteicos, as fra??es: Fr 1 e Fr 2. As massas moleculares m?dias dessas fra??es proteicas foram de [M+H]+ = 19594,690 Da e de [M+H]+ = 19578,266 Da, respectivamente. Ap?s redu??o e alquila??o, estimou-se a presen?a de 4 ciste?nas para Fr 1 e Fr 2. As sequ?ncias parciais obtidas para Fr 1 e Fr 2 foram de 54 e 53 res?duos de amino?cidos identificados e exatamente com a mesma sequ?ncia para ambas, sugerindo-se tratar da mesma mol?cula. O ITTp se mostrou resistente ? varia??o de temperatura at? 80?C, reduzindo cerca de 30% de sua atividade antitr?ptica quando em 100 ?C, e resistente aos extremos de pH. Para o ITTp estimou-se a IC50 de 2,7 x 10-10 mol.L-1 e a Ki de 2,9 x 10-11 mol.L-1. Na eletroforese bidimensional com ITTp foram revelados pontos isoel?tricos entre pH 5 e 6, al?m de um spot pr?ximo ao pH 8. Dessa forma, foi constatado que se trata de um inibidor de tripsina da fam?lia Kunitz. No experimento in vivo foi confirmada a a??o de ITTp sobre a redu??o de leptina plasm?tica, mas sem efeito sobre CCK em animais com obesidade, como j? atestado em estudos pr?vios com o ITT. A caracteriza??o bioqu?mica desse inibidor e os seus efeitos sobre CCK e leptina, observados em experimentos in vivo, constituem relatos in?ditos e promissores para uma prov?vel aplica??o biotecnol?gica. / Obesity is one of the non-communicable chronic diseases with a great impact on public health. The tamarind (Tamarindus indica L.) seed has been studied for its trypsin inhibitor and one of the attributes of this partially purified inhibitor (TTI) is its relationship with satiety, increasing cholecystokinin (CCK) in eutrophic and reducing leptin in obese animals. In this study the ITT was purified, characterized and evaluated for its properties against CCK and leptin in obese Wistar rats. For the purification and characterization of this inhibitor, the crude protein extract was fractionated with ammonium sulfate followed by trypsin-Sepharose affinity chromatography, two-dimensional electrophoresis (2-DE) and High Efficiency Liquid Chromatography (HPLC). TTIp molecular mass was determined by MS-ESI. Partial sequencing of TTIp was established by MALDI-ISD. Inhibitory specificity, stability to temperature and pH was characterized for TTIp. Plasma CCK and leptin was evaluated in rats submitted to oral gavage with TTIp (730 ?g / kg) comparing them to untreated obese rats. TTI was purified by HPLC with a single protein peak (ITTp). After refinement of the methods, two protein fractions were observed: Fr 1 and Fr 2, with average mass of [M+H]+ = 19594.690 Da and [M+H]+ = 19578.266 Da, respectively. The presence of 4 cysteines was estimated after reduction and alkylation of Fr 1 e Fr 2. The protein fractions showed 54 and 53 amino acid residues with exactly the same sequence. TTIp presented resistance to temperature variations, reducing about 30% of its anti-tryptic activity at 100 ?C, and resistance to pH extremes. TTIp IC50 was 2.7 x 10-10 mol.L-1 and Ki was 2.9 x 10-11 mol.L-1. The 2-DE revealed spots with isoelectric points between pH 5 and 6, and a spot near pH 8. TTIp characteristics are compatible with trypsin inhibitors from the Kunitz family. In the in vivo experiment, ITTp action on leptin reduction was confirmed, but no effect on CCK was observed in animals with obesity, corroborating previous studies using unpurified TTI. Biochemical knowledge of this molecule and the in vivo experiments shown here are novel and provide essential information for a biomolecule of possible biotechnological application.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/24460 |
| Date | 03 November 2017 |
| Creators | Medeiros, Amanda Fernandes de |
| Contributors | 02587306418, Arag?o, Cicero Fl?vio Soares, 62001728468, Lima, Liziane Maria de, 73747211453, Santos, Elizeu Antunes dos, Morais, Ana Heloneida de Ara?jo |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM BIOQU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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