Avaliação do Uso de Técnicas de MMGBSA na Triagem Virtual de Bibliotecas de Ligantes para o Desenvolvimento de Fármacos contra Leishmania amazonensis e Leishmania chagasi.

• Ano de defesa: 2011
• Autor(a) principal: Carvalho, Gabriel Aires Urquiza de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraí­ba; BR; Química; Programa de Pós-Graduação em Química; UFPB
• Palavras-chave em Português: Química; Leishmania; Dinâmica molecular; Triagem virtual; CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/7046

Leishmaniases are a group of diseases caused by protozoans of the Leishmania sp. genus. whose vector are the sandflies. These diseases are characterized by lesions in the skin and mucous tissues which can severely impair and deform the patient, without killing them. Leishmaniases, however, can evolve to more severe forms and attack internal organs, particularly the spleen and liver. In their final stages of progression, leishmaniases can be fatal. The treatment of leishmanioses is carried out mainly with the pentavalent antimonials (remarkably sodium stibogluconate and meglumine antimoniate) as first choice drugs, assisted by other antibiotics (anfothericin B, paromomycin and pentamidine) as second line therapeutic agents. These therapeutical options, however, suffer with a number of problems with severe side effects, high costs, the appearance of parasite resistent strains or any combination of these factors. Because of these facts, we have evaluated methods to estimate the free energy variation of interaction between ligands and medically interesting enzymes (Trypanothione Reductase, Pharnesyl Pyrophosphate Synthase and Dihydro Orotate Dehydrogenase) for which there are no theoretical works in this sense. We have also suggested, based on the method that performed better in the tests, those ligands which seem promising. We have evaluated the possibility of replacing the conventional molecular docking, in studies of virtual screening, with free energy estimation calculations done with the MMGBSA (Molecular Dynamics, Generalized Born, Solvent Accessibility) methodology applied to a single minimzed geometry of the solvated ligand-enzyme complex. The role of computation in graphics boards processors, time economy, accuracy of afinity values and the overall capacity of the methods to point out the good ligands were analysed and discussed.