Avaliação computacional de mecanismos de quinases e proteínas relacionadas
Data
2018-04-26
Autores
Dias, Raphael Vinicius Rodrigues
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A proteína Carboxyl-terminal Src Kinase, Csk, é uma proteína tirosina quinase com função de reguladora essencial para as proteínas da família das Src quinases (SFKs). Seu mal funcionamento regulatório tem sido reportado como responsável por diversas moléstias como: deformações na fase de desenvolvimento embrionário, manifestação de cânceres de mama, próstata, pâncreas, leucemia, linfoma e cólon. A CSK apresenta uma alta homologia sequencial com as SFKs, mas com disposições distintas de seus domínios. Outro diferencial é a ausência de uma porção terminal contendo uma tirosina que possa ser fosforilada, elemento fundamental para os demais membros das SFKs que podem se autofosforilar. Curiosamente, sua estrutura cristalográfica apresenta conformações distintas classificadas como formas ativa e inativa sendo o objetivo principal desse trabalho, modelar as transições e avaliar os seus possíveis mecanismos fazendo um link de como mudanças conformacionais entre essas duas conformações estão relacionadas com a ação da proteína quinase Csk baseando-se em experimentos in vitro. Complementarmente, a proteína adaptadora Grb2 relacionada com regulações de proteínas pertencente ao universo das quinases como a FGFR2, também é alvo do estudo. O conjunto quinase mais proteína adaptadora desempenham um importante papel na transmissão de sinal em cascatas de sinalizações envolvidas em processos celulares fundamentais como proliferação celular, diferenciação e apoptose. Dessa maneira, Grb2 é um alvo em potencial para o estudo de interações com pequenas moléculas de interesse biológico por seus efeitos anticarcinogênicos como a Cumarina 1,2-Benzopirona e Morina (2’,3,4’,5,7-pentahidroxiflavona). Experimentos in vitro comprovam a interação entre a proteína adaptadora Grb2 e o ligante Cumarina e Morina, sendo neste trabalho avaliado a determinação espacial e o conjunto de interações entre os complexos formados.
The Carboxyl-terminal Src Kinase (Csk) is a protein that plays an essential role for the down-regulation of Src kinase family proteins (SFKs). When Csk presents malfunction on its regulation action, several diseases can occurs, like deformations during the fetal develop, mama, prostate, pancreas, colon cancers, as well leukemia and lymphomas. Csk presents a high sequence homology with other SFK members, but without a similar arrangement of domains. Yet, the Csk lacks a tyrosine tail, so it cannot auto-phosphorylate, but it can phosphorylate their family members. Surprisingly, the crystallography structure of Csk presents two distinct conformations classified as active and inactive. The main objective of this work is to construct a model to evaluate transitions and possible mechanisms involving Csk, making a link between conformational changes and its action. On the other hand, the adaptor protein Growth factor Receptor-Bound protein 2 (Grb2) is related to the universe of protein regulators linked to the proteins kinase as the Fibroblast Growth Factor Receptor 2 (FGFR2), being an important target for study. The set kinase and adaptor proteins is important for signaling processes involving cell proliferation, differentiation and apoptosis. Thus, Grb2 is an potential aim for the evaluation of interactions with small anticarcinogen molecules as 1,2-benzopyrone Coumarin and 2',3,4',5,7-pentahydroxyflavon Morin. In vitro essays verified the interaction between the Grb2-coumarin and Grb2-morin complexes. Thus, the second part of this work investigate the spatial location for the docking of the Coumarin and Morin into Grb2 and evaluate their interactions.
The Carboxyl-terminal Src Kinase (Csk) is a protein that plays an essential role for the down-regulation of Src kinase family proteins (SFKs). When Csk presents malfunction on its regulation action, several diseases can occurs, like deformations during the fetal develop, mama, prostate, pancreas, colon cancers, as well leukemia and lymphomas. Csk presents a high sequence homology with other SFK members, but without a similar arrangement of domains. Yet, the Csk lacks a tyrosine tail, so it cannot auto-phosphorylate, but it can phosphorylate their family members. Surprisingly, the crystallography structure of Csk presents two distinct conformations classified as active and inactive. The main objective of this work is to construct a model to evaluate transitions and possible mechanisms involving Csk, making a link between conformational changes and its action. On the other hand, the adaptor protein Growth factor Receptor-Bound protein 2 (Grb2) is related to the universe of protein regulators linked to the proteins kinase as the Fibroblast Growth Factor Receptor 2 (FGFR2), being an important target for study. The set kinase and adaptor proteins is important for signaling processes involving cell proliferation, differentiation and apoptosis. Thus, Grb2 is an potential aim for the evaluation of interactions with small anticarcinogen molecules as 1,2-benzopyrone Coumarin and 2',3,4',5,7-pentahydroxyflavon Morin. In vitro essays verified the interaction between the Grb2-coumarin and Grb2-morin complexes. Thus, the second part of this work investigate the spatial location for the docking of the Coumarin and Morin into Grb2 and evaluate their interactions.
Descrição
Palavras-chave
Quinases, C-terminal Src, Csk, Modelo baseado em estrutura, Mudanças conformacionais, Growth Factor Receptor Bound Two, Grb2, Cumarina, Morina, SFKs, Kinases, Structure Based Model, Conformational Changes, Growth Factor Receptor Bound Protein 2, Coumarin, Morin