Estudos in silico de análogos N-acilidrazônicos com potencial ação sobre as proteínas do tipo JAK2
Data
2019
Autores
Costa, Marcela Oliveira Legramanti da 
Orientadores
Rando, Daniela Gonçales Galasse
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Proteínas do tipo JAK2 estão envolvidas na transmissão de informações do meio
extracelular para o núcleo celular, por meio da fosforilação de peptídeos STAT, os quais
controlam os processos de crescimento e diferenciação celular. Assim, a ativação
exacerbada da via JAK-STAT está diretamente vinculada a processos patogênicos
como doenças autoimunes, neoplásicas, bem como doenças inflamatórias. Por esta
razão, as enzimas JAK se tornam um alvo interessante do ponto de vista terapêutico.
Nos últimos anos, derivados N-acilidrazônicos, como a nifuroxazida (NFZ), têm se
mostrado promissores inibidores da via JAK-STAT. A NFZ apresenta estrutura química
de fácil obtenção, a partir de reagentes de baixo custo e com altos graus de rendimento
e pureza, tornando-a um bom protótipo. Frente ao exposto, este trabalho tem por
finalidade o estudo de modelagem molecular de análogos N-acilidrazônicos diretos da
NFZ, bem como de compostos híbridos, os quais combinam características estruturais
tanto da NFZ quanto de cromonas, a fim de elucidar seus potenciais modos de
interação com as proteínas JAK2. Para tanto foram utilizadas técnicas de docking
molecular seguidas de dinâmica molecular. A estrutura da NFZ e de sete análogos da
mesma foram ancoradas na estrutura tridimensional da JAK2, tanto em sua forma ativa
(DFG-in) quanto na sua conformação inativa (DFG-out). Os resultados de docking
molecular demonstram, que tanto a NFZ quanto seus análogos N-acilidrazônicos diretos
e derivados de cromonas se comportam de forma similar e parecem ancorar de forma
mais satisfatória quando a JAK2 se encontra na sua conformação DFG-out.
Ancoramento no sítio do ATP da enzima ativa também poderia ser possível, muito
embora os valores de função de pontuação e a frequência observada para uma única
pose, no caso da NFZ e de seus análogos, não tenham sido tão bons quanto os
observados com os estudos com a forma inativa da enzima. Estudos de dinâmica
molecular com a NFZ demonstraram que ela poderia se ligar tanto ao sítio do ATP
quanto aos sítios expostos na forma DFG-out da enzima, embora pareça ter ligeira
preferência pelo modo de ligação com a enzima na conformação inativa.
JAK2 proteins are involved in information transmission from the extracellular media to the nucleus, through STAT peptide phosphorylation, which modulate growth cell and differentiation processes. Therefore, enhanced activation of the JAK-STAT pathway is related to several pathological processes such as autoimmune and neoplastic disorders, as well as inflammatory diseases. For this reason, JAK enzymes have been pointed out as important targets to be explored. In the last years, N-acylhydrazone derivatives, such as nifuroxazide (NFZ), have been studied as promising inhibitor of JAK-STAT system. NFZ presents simple chemical structure with easy synthesis, using reagents of low cost and with high degrees of yield and purity, making it a good prototype. This project presents as main goal the molecular modeling studies of new structures analogues from NFZ, to elucidate their ability in interacting with phosphorylating proteins of the JAK2 type, as well as new hybrids compounds that combine structural characteristics both from NFZ and chromone derivatives, to elucidate their ability in interacting with kinases from JAK2. For this, molecular docking analysis followed by molecular dynamics simulations were employed. The structure of the NFZ and seven analogues were docked in the three-dimensional structure of JAK2, both in its active conformation (DFGin) and in its inactive conformation (DFG-out). Molecular docking results demonstrate that both NFZ and its direct and chromone derivatives N-acylidrazonic analogues behave similarly and appear to dock more satisfactorily when JAK2 is in its DFG-out conformation. Docking at the ATP site of the active enzyme could also be possible, although the scoring function values and the observed frequency for a single pose, in the case of NFZ and its analogues, were not as good as those observed with studies with the inactive form of the enzyme. Molecular dynamics studies with NFZ demonstrated that it could bind to both the ATP site and the exposed sites in the DFGout form of the enzyme, although it appears to have slight preference for the bindingmode with the enzyme in the inactive conformation.
JAK2 proteins are involved in information transmission from the extracellular media to the nucleus, through STAT peptide phosphorylation, which modulate growth cell and differentiation processes. Therefore, enhanced activation of the JAK-STAT pathway is related to several pathological processes such as autoimmune and neoplastic disorders, as well as inflammatory diseases. For this reason, JAK enzymes have been pointed out as important targets to be explored. In the last years, N-acylhydrazone derivatives, such as nifuroxazide (NFZ), have been studied as promising inhibitor of JAK-STAT system. NFZ presents simple chemical structure with easy synthesis, using reagents of low cost and with high degrees of yield and purity, making it a good prototype. This project presents as main goal the molecular modeling studies of new structures analogues from NFZ, to elucidate their ability in interacting with phosphorylating proteins of the JAK2 type, as well as new hybrids compounds that combine structural characteristics both from NFZ and chromone derivatives, to elucidate their ability in interacting with kinases from JAK2. For this, molecular docking analysis followed by molecular dynamics simulations were employed. The structure of the NFZ and seven analogues were docked in the three-dimensional structure of JAK2, both in its active conformation (DFGin) and in its inactive conformation (DFG-out). Molecular docking results demonstrate that both NFZ and its direct and chromone derivatives N-acylidrazonic analogues behave similarly and appear to dock more satisfactorily when JAK2 is in its DFG-out conformation. Docking at the ATP site of the active enzyme could also be possible, although the scoring function values and the observed frequency for a single pose, in the case of NFZ and its analogues, were not as good as those observed with studies with the inactive form of the enzyme. Molecular dynamics studies with NFZ demonstrated that it could bind to both the ATP site and the exposed sites in the DFGout form of the enzyme, although it appears to have slight preference for the bindingmode with the enzyme in the inactive conformation.