The cyclic peptide labaditin does not alter the outer membrane integrity of Salmonella enterica serovar Typhimurium

Autor(es)

Barbosa, Simone C. ^[1] ; Nobre, Thatyane M. ^[1] ; Volpati, Diogo ^[2] ; Cilli, Eduardo M. ^[3] ; Correa, Daniel S. ^[4] ; Oliveira, Jr., Osvaldo N. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Phys, CP 369, BR-13560970 Sao Carlos, SP - Brazil

^[2] Sol Volta AB, S-22363 Lund - Sweden

^[3] Univ Estadual Paulista, UNESP, Inst Chem, BR-14800060 Araraquara, SP - Brazil

^[4] Nanotechnol Natl Lab Agr LNNA, Embrapa Instrumentacao, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SCIENTIFIC REPORTS; v. 9, FEB 13 2019.
• Citações Web of Science: 1

Resumo

Antimicrobial peptides are a promising class of new antibiotics with the ability to kill bacteria by disrupting their cell membrane, which is especially difficult for Gram-negative bacteria whose cell wall contains an outer layer of lipopolysaccharides (LPS). Here we show that the cyclic decapeptide Labaditin (Lo), with proven activity against the Gram-positive Staphylococcus aureus and Streptococcus mutans, is not able to kill the Gram-negative Salmonella enterica serovar Typhimurium (S.e.s. Typhimurium). We found that Lo induced significant changes in the surface pressure isotherms of Langmuir monolayers representing the Salmonella enterica serovar Typhimurium inner membrane (S.e.s. Typhimurium IM), and caused leakage in large unilamellar vesicles made with this IM lipid composition. On the basis of these results one should expect bactericidal activity against S.e.s. Typhimurium. However, Lo could not interact with a monolayer of LPS, causing no significant changes in either the surface pressure isotherms or in the polarization-modulated infrared reflection absorption spectra (PM-IRRAS). Therefore, the failure of Lo to kill S.e.s. Typhimurium is associated with the lack of interaction with LPS from the outer bacteria membrane. Our approach with distinct monolayer compositions and combined techniques to investigate molecular-level interactions is useful for drug design to fight antibiotic-resistant bacteria. (AU)

• Processo FAPESP: 14/03748-9 - Peptídeos antimicrobianos cíclicos: importância da estrutura cíclica no mecanismo de ação de duas diferentes estruturas.
• Beneficiário: Simone Cristina Barbosa
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/14262-7 - Filmes nanoestruturados de materiais de interesse biológico
• Beneficiário: Osvaldo Novais de Oliveira Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/12174-4 - Desenvolvimento de nanofibras poliméricas híbridas para aplicação na agricultura
• Beneficiário: Daniel Souza Corrêa
• Modalidade de apoio: Auxílio à Pesquisa - Regular