Effect of N-terminal acetylation on lytic activity and lipid-packing perturbation induced in model membranes by a mastoparan-like peptide

ALVARES, DAYANE S.; WILKE, NATALIA; RUGGIERO NETO, JOÃO

BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES

ELSEVIER SCIENCE BV

Año: 2018 vol. 1860 p. 737 - 737

0005-2736

1A (IDGLKAIWKKVADLLKNT-NH2) is a peptide that displays aselective antibacterial activity to Gram-negative bacteria without beinghemolytic. Its lytic activity in anionic lipid vesicles was stronglyenhanced when its N-terminus was acetylated (ac-L1A). This modificationseems to favor the perturbation of the lipid core of the bilayer by thepeptide, resulting in higher membrane lysis. In the present study, weused lipid monolayers and bilayers as membrane model systems to explorethe impact of acetylation on the L1A lytic activity and its correlationwith lipid-packing perturbation. The lytic activity investigated in giantunilamellar vesicles (GUVs) revealed that the acetylated peptidepermeated the membrane at higher rates compared with L1A, and modifiedthe membrane´s mechanical properties, promoting shape changes. Thepeptide secondary structure and the changes in the environment of thetryptophan upon adsorption to