Estudo in silico de derivados do G-CSF humano como antibacterianos

• Autor(a) principal: Saturnino, Christine Facco
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/1867
• topic: Antibacterial peptides; In silico analysis; Antimicrobial activity; Peptídeos antibacterianos; Análise in silico; Atividade antimicrobiana; Biotecnologia; Peptídios; Agentes antibacterianos; 61

In attempt to obtain new substances with antibacterial activity, the aim of this study was to evaluate the antibacterial potential of four synthesized peptides, where two of them have sequence derived from human G-CSF in silico fragmentation, while the other two were theoretically planned, allowing the verification of their interest as new therapeutic agents at human health. The evaluation was performed in two stages: in silico analysis, consisting of predictions of properties and parameters associated with antibacterial effect, through computational tools; and the in vitro experiment for determination of the minimum inhibitory concentration (MIC) of the peptides against Gram positive and negative bacteria. Most predictions was favorable for all four peptides, showed by determined results of hydrophobicity, amphipathicity, size, secondary structure, net charge, membrane binding potential, half-life and Boman Index, considered as desirable values for antibacterial potential. In the in silico analysis, only algorithmic prediction of antimicrobial activity revealed unfavorable results for peptides with sequences derived from G-CSF (peptides 1 and 2), nonetheless, the predictions were positive for the other two. The in vitro assay showed that up to the highest concentration used of the four peptides (500 μg/mL) was insufficient for determination of minimum inhibitory concentration, however it was possible to observe significant growing decrease of E. coli (58.7%) by peptide 4 and E. fecalis (86.1%) and E. coli (54.9%) by peptide 3, when compared with the viability control. These values indicate the presence of antibacterial activity in the theoretically planned peptides (peptides 3 and 4), confirming the computational predictions. Thus, it is possible to conclude that the in silico analysis was very important for the selection of the peptides to be synthesized, which showed results of in vitro assays in agreement with the computational prediction of antimicrobial activity.