AMBROGGIO ERNESTO
Artículos
Título:
Direct visualization of membrane leakage induced by the antibiotic peptides: maculatin, citropin, and aurein.
Autor/es:
AMBROGGIO ERNESTO E.; SEPAROVIC FRANCES; BOWIE JOHN; FIDELIO GERARDO D.; BAGATOLLI LUIS A.
Revista:
BIOPHYSICAL JOURNAL
Referencias:
Año: 2005 vol. 89 p. 1874 - 1874
ISSN:
0006-3495
Resumen:
p class="abstract">Membrane lysis caused by antibiotic peptides is often rationalized by means of two different models: the so-called carpet model and the pore-forming model. We report here on the lytic activity of antibiotic peptides from Australian tree frogs, maculatin 1.1, citropin 1.1, and aurein 1.2, on POPC or POPC/POPG model membranes. Leakage experiments using fluorescence spectroscopy indicated that the peptide/lipid mol ratio necessary to induce 50% of probe leakage was smaller for maculatin compared with aurein or citropin, regardless of lipid membrane composition. To gain further insight into the lytic mechanism of these peptides we performed single vesicle experiments using confocal fluorescence microscopy. In these experiments, the time course of leakage for different molecular weight (water soluble) fluorescent markers incorporated inside of single giant unilamellar vesicles is observed after peptide exposure. We conclude that maculatin and its related peptides demonst