Abordagem físico-química da interação da piperlongumina com alvos farmacológicos
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Data
2022-01-28
Autores
Povinelli, Ana Paula Ribeiro
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A busca por metabólitos com potencial farmacológico oriundos de plantas e de micro-organismos sempre foi uma área bastante explorada pela comunidade científica. Foi reportado que a piperlongumina (PPL), molécula extraída de espécies de pimenta, apresenta ação anti-inflamatória e por isso, o objetivo deste trabalho foi a descrição da interação da PPL com alguns alvos farmacológicos envolvidos no processo de transporte e de inflamação. A primeira etapa deste trabalho foi dedicada ao estudo da interação da PPL com a albumina de camundongo (RSA), pois entender a interação de pequenas moléculas com esta proteína contribui para compreensão da distribuição dos fármacos no organismo. Os resultados de supressão de fluorescência mostraram que a PPL se liga na RSA espontaneamente e que o processo é entropicamente dirigido. Também foi mostrado que a PPL acessa dois sítios cooperativos da RSA com constantes de ligação de (2.3±0.1)•105 e (1.3±0.1)•105 M-1. Com as ferramentas de docagem e dinâmica molecular verificou-se os sítios de interação como sendo ricos em resíduos apolares. Além disso, com a análise dos dados de supressão de fluorescência do sistema RSA-PPL, nós mostramos a necessidade da correção do efeito de filtro interno antes de associar os desvios no máximo de intensidade de fluorescência à mudanças de polaridade no ambiente da sonda fluorescente. Também mostramos a possibilidade de utilizar as áreas do espectro de emissão do Trp, em vez de um único comprimento de onda. A segunda etapa deste trabalho foi dedicada ao estudo da interação da PPL com o domínio NBD da HSP70. A análise dos dados de supressão de fluorescência mostrou o equilíbrio das componentes entrópicas e entálpica na interação da PPL com o NBD. Além disso, foi mostrado que a PPL acessa dois sítios do NBD com constantes de ligação equivalentes a (6.3 ± 0.2)•104 M-1 ,de modo cooperativo. Os ambientes de interação foram descritos com o uso do docagem molecular. Com a dinâmica molecular associada ao método de MMPBSA (Molecular Mechanics Poisson-Boltzmann Surface Area), a energia livre de interação foi estimada como sendo (-58 ± 3) e (-49 ± 3) kJ•mol-1 para os sítios 1 e 2. A terceira etapa deste trabalho foi dedicada à modificação de alguns grupos químicos da estrutura da PPL. As estruturas inspiradas na PPL foram submetidas aos cálculos de docagem molecular para a verificação na mudança de afinidade pela proteína NF-kB.
The search for metabolites with pharmacological potential from plants and microorganisms has always been an area widely explored by the scientific community. It was reported that piperlongumine (PPL), a molecule extracted from pepper species, exhibits anti-inflammatory property and therefore the aim of this work, was the description of the interaction of PPL with some pharmacological targets involved in the transport and inflammation process. The first step of this work was dedicated to the study of the interaction of PPL with rat serum albumin (RSA), once understanding the interaction of small molecules with albumin contributes to the understanding of the distribution of the drug in the body. Fluorescence quenching results showed that PPL binds to RSA spontaneously and that the process is entropically driven. It was also shown that PPL accesses two cooperative sites in RSA structure with binding constants of (2.3 ± 0.1)•105 e (1.3 ± 0.1)•105 M-1. With the docking and dynamic analyses, the interaction sites were found to be rich in non-polar residues. Furthermore, by analyzing the fluorescence quenching data from the RSA-PPL system, we showed the importance of applying inner filter correction over the entire fluorescence spectrum prior to any conclusion regarding changes in the polarity of the fluorophore microenvironment. We also demonstrated the convergence of the results obtained from the treatment of fluorescence data using the area below the spectrum curve and the intensity in a single wavelength. The second stage of this work was dedicated to the study of the interaction of PPL with the NBD domain of HSP70. Analysis of the fluorescence quenching data showed the balance of entropic and enthalpic components in the interaction of PPL with NBD. Furthermore, it was shown that PPL has a cooperatively mode of binding, accessing two NBD sites with a binding constant of (6.3 ± 0.2)•104 M-1. The interaction environments were described using molecular docking. With molecular dynamics associated with the MMPBSA method (molecular mechanics Poisson-Boltzmann surface area), the free energies of interaction were estimated to be (-58 ± 3) e (-49 ± 3) kJ•mol-1 for sites 1 and 2. The third step of this work was dedicated to the modification of some chemical groups of the PPL structure. PPL inspired molecules were submitted to molecular docking calculations in order to verify the changes in affinity for NF-kB protein.
The search for metabolites with pharmacological potential from plants and microorganisms has always been an area widely explored by the scientific community. It was reported that piperlongumine (PPL), a molecule extracted from pepper species, exhibits anti-inflammatory property and therefore the aim of this work, was the description of the interaction of PPL with some pharmacological targets involved in the transport and inflammation process. The first step of this work was dedicated to the study of the interaction of PPL with rat serum albumin (RSA), once understanding the interaction of small molecules with albumin contributes to the understanding of the distribution of the drug in the body. Fluorescence quenching results showed that PPL binds to RSA spontaneously and that the process is entropically driven. It was also shown that PPL accesses two cooperative sites in RSA structure with binding constants of (2.3 ± 0.1)•105 e (1.3 ± 0.1)•105 M-1. With the docking and dynamic analyses, the interaction sites were found to be rich in non-polar residues. Furthermore, by analyzing the fluorescence quenching data from the RSA-PPL system, we showed the importance of applying inner filter correction over the entire fluorescence spectrum prior to any conclusion regarding changes in the polarity of the fluorophore microenvironment. We also demonstrated the convergence of the results obtained from the treatment of fluorescence data using the area below the spectrum curve and the intensity in a single wavelength. The second stage of this work was dedicated to the study of the interaction of PPL with the NBD domain of HSP70. Analysis of the fluorescence quenching data showed the balance of entropic and enthalpic components in the interaction of PPL with NBD. Furthermore, it was shown that PPL has a cooperatively mode of binding, accessing two NBD sites with a binding constant of (6.3 ± 0.2)•104 M-1. The interaction environments were described using molecular docking. With molecular dynamics associated with the MMPBSA method (molecular mechanics Poisson-Boltzmann surface area), the free energies of interaction were estimated to be (-58 ± 3) e (-49 ± 3) kJ•mol-1 for sites 1 and 2. The third step of this work was dedicated to the modification of some chemical groups of the PPL structure. PPL inspired molecules were submitted to molecular docking calculations in order to verify the changes in affinity for NF-kB protein.
Descrição
Palavras-chave
Piperlongumina, RSA, HSP70, Espectroscopia de fluorescência, Dicroísmo circular, , Dinâmica molecular, MMPBSA, Fluorescence spectroscopy, Circular dichroism, Molecular docking, Molecular dynamics