Estudos de transferência de energia peptídeos-lantanídeos com aplicações em biossensores
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Data
2018-05-15
Autores
Lima, Lais Roncalho de [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Neste trabalho, o peptídeo antimicrobiano hylina - a1 foi sintetizado e modificado estrategicamente com a adição de um resíduo de triptofano (W), visando o estudo da interação e a transferência de energia deste aminoácido aromático com nanopartículas luminescentes de YVO4:Ln3+. As análises foram realizadas em solução e no estado sólido por meio de filmes automontados via técnica Layer-by-Layer (LbL), utilizando a fibroína da seda (SF) como matriz de imobilização para as nanopartículas (NPs). Os resultados mostraram que o mecanismo de transferência de energia ocorre somente nos filmes contendo o peptídeo Hyl-K0-W6 em contato com as NPs de YVO4:Eu3+. Devido este peptídeo possuir atividade contra cepas de bactérias Staphylococcus aureus Resistentes à Meticilina (MRSA), estudos espectroscópicos foram realizados utilizando a proteína PBP2a, presente na membrana citoplasmática da bactéria e responsável pela resistência contra os antibióticos β-lactâmicos. Os resultados confirmaram a interação da proteína somente com o peptídeo Hyl-K0-W6 em junção das NPs de YVO4:Eu3+. Visando a aplicação deste filme como biossensor, foram realizadas medidas eletroquímicas, na qual os resultados apresentaram nitidamente maior interação quando a PBP2a foi adsorvida sobre os filmes de SF/Hyl-K0-W6+NPs. A partir desses dados, o sistema foi aplicado como protótipo biossensor contra MRSA, através da detecção de um extrato antigênico contendo a bactéria real.
In this work the antimicrobial peptide hylina - a1 was synthetized and strategically modified with add one tryptophan residue (W) in position 6 of the chain, aiming the interaction study and energy transfer that aromatic amino acid with YVO4:Ln3+ luminescent nanoparticles. The analyses were realized in solution and in solid state from self-assembled films by Layer-by-Layer (LbL) technique, using silk fibroin (SF) as immobilization matrix for the nanoparticles (NPs). Results show the energy transfer mechanism occurs only in the films containing the Hyl-K0-W6 peptide in touch with the YVO4:Eu3+ NPs. Because this peptide has activity against strains of Methicillin Resistant Staphylococcus aureus (MRSA), spectroscopic studies were realized using the PBP2a protein, it is present at cytoplasmic membrane of the bacterium and it is responsible for resistance against β-lactam antibiotics. Results confirmed interaction of PBP2a protein only with the Hyl-K0-W6 peptide in conjunction of the YVO4:Eu3+ NPs. Aiming application that film as a biosensor, electrochemistry measurements were realized, which the results showed clearly greater interaction when PBP2a was adsorbed on SF/Hyl-K0-W6+NPs films. From these dates, the system was applied as MRSA biosensor prototype, through detection a antigenic extract containing the real bacterium.
In this work the antimicrobial peptide hylina - a1 was synthetized and strategically modified with add one tryptophan residue (W) in position 6 of the chain, aiming the interaction study and energy transfer that aromatic amino acid with YVO4:Ln3+ luminescent nanoparticles. The analyses were realized in solution and in solid state from self-assembled films by Layer-by-Layer (LbL) technique, using silk fibroin (SF) as immobilization matrix for the nanoparticles (NPs). Results show the energy transfer mechanism occurs only in the films containing the Hyl-K0-W6 peptide in touch with the YVO4:Eu3+ NPs. Because this peptide has activity against strains of Methicillin Resistant Staphylococcus aureus (MRSA), spectroscopic studies were realized using the PBP2a protein, it is present at cytoplasmic membrane of the bacterium and it is responsible for resistance against β-lactam antibiotics. Results confirmed interaction of PBP2a protein only with the Hyl-K0-W6 peptide in conjunction of the YVO4:Eu3+ NPs. Aiming application that film as a biosensor, electrochemistry measurements were realized, which the results showed clearly greater interaction when PBP2a was adsorbed on SF/Hyl-K0-W6+NPs films. From these dates, the system was applied as MRSA biosensor prototype, through detection a antigenic extract containing the real bacterium.
Descrição
Palavras-chave
Peptídeos, Transferência de energia, Nanopartículas, Fibroína da seda, Aminoácido aromático, Detecção eletroquímica, Staphylococcus aureus, Peptides, Energy transfer, Nanoparticles, Silk fibroin, Aromatic amino acid, Electrochemistry detection, Staphylococcus aureus