Estrutura de carreadores de ácidos nucleicos baseados no peptídeo troiano penetratina

• Ano de defesa: 2019
• Autor(a) principal: Mello, Lucas Rodrigues De [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Peptídeos De Penetração Celular; Peptídeos; Penetratina; Biologia Estrutural; Biologia Molecular
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=7645710; https://repositorio.unifesp.br/handle/11600/59683

Elucidate the spatial organization of the Trojan peptide Penetratin, and a new heptamer with sequence KIWFQNR, conjugated with DNA at nanoscopic scale. To investigate the viability of the KIWFQNR sequence as a carrier for DNA in gene therapy-related applications. Methods: Structural organization, aggregation and cell imaging were determined by small angle X-ray scattering (SAXS), confocal microscopy, transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), infrared atomic force microscopy (AFM-IR), fluorimetry and circular dichroism (CD). Transfection assays were performed in different cell lines using the EGFP gene as a reporter. Conclusions: A model for the conjugation between Penetratin and DNA is proposed, where complexes aggregate into highly-condensed micrometric structures with “beads-on-a-string” morphology. The inner structure is ordered and nanospectroscopy data indicate that DNA is concentrated at the interfaces between complexes and surrounding medium. Complexes based on the KIWFQNR peptide self-assemble into thinner fibrillar structures, without the formation of condensates. The organization of both peptides follows a random-to-β-sheet transition at secondary structure, which is a key step for structuration according the proposed models. Cell assays show that complexes formed by the heptamer are able to interact with biological membranes.