Author(s): Santos-Filho, Norival Alves [UNESP] ; de Freitas, Laura Marise [UNESP] ; Santos, Claudia Tavares dos [UNESP] ; Piccoli, Julia Pinto [UNESP] ; Fontana, Carla Raquel [UNESP] ; Fusco-Almeida, Ana Marisa [UNESP] ; Cilli, Eduardo Maffud [UNESP]
Date: 2021
Persistent ID: http://hdl.handle.net/11449/207575
Origin: Oasisbr
Subject(s): Antimicrobial peptides; BthTX-I; Carboxyfluorescein labeled-peptide; Flow cytometry; Phospholypase A2; Scanning electron microscopy
Made available in DSpace on 2021-06-25T10:57:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Based on the antimicrobial activity of bothropstoxin-I (BthTX-I) and on the premise that a C-terminal peptide of Lys49 myotoxin can reproduce the antimicrobial activity of the parent protein, we aimed to study the mechanism of action of a peptide derived from the C-terminal region of the myotoxin BthTX-I [(p-BthTX-I)2, sequence: KKYRYHLKPFCKK, disulfide-linked dimer] against Gram-positive and Gram-negative bacteria. Fluorescence quenching technique showed that the carboxyfluorescein labeled-peptide [CF-(p-BthTX-I)2] when incubated with E. coli displayed a superior penetration activity than when incubated with S. aureus. Cell death induced by the peptide (p-BthTX-I)2 showed a loss of membrane integrity in E. coli and S. aureus; however, the mechanisms of cell death were different, characterized by the presence of necrosis-like and apoptosis-like deaths, respectively. Scanning electron microscopy studies in E. coli and S. aureus showed morphological changes in the cells, with superficial deformities, appearance of wrinkles and bubbles, and formation of vesicles. Our results demonstrate that the mechanism of action of the peptide (p-BthTX-I)2 is different in Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. Knowledge of the mechanism of action of these peptides is important, since they are promising prototypes for new antimicrobial drugs.
Instituto de Química Universidade Estadual Paulista (UNESP)
Campus Experimental de Registro Universidade Estadual Paulista (UNESP)
Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista (UNESP)
Instituto de Química Depto de Bioquímica Universidade de São Paulo (USP), São Paulo
Instituto de Química Universidade Estadual Paulista (UNESP)
Campus Experimental de Registro Universidade Estadual Paulista (UNESP)
Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista (UNESP)
FAPESP: #2013/07600-3
FAPESP: #2014/05538-1
FAPESP: #2014/24581-5
