Comparison of reversible membrane destabilisation induced by antimicrobial peptides derived from Australian frogs.
Biochim Biophys Acta
; 1838(9): 2205-15, 2014 Sep.
Article
em En
| MEDLINE
| ID: mdl-24593995
ABSTRACT
The membrane destabilising properties of the antimicrobial peptides (AMP) aurein 1.2, citropin 1.1, maculatin 1.1 and caerin 1.1, have been studied by dual polarisation interferometry (DPI). The overall process of peptide induced membrane destabilisation was examined by the changes in bilayer order as a function of membrane-bound peptide mass per unit area and revealed three different modes of action. Aurein 1.2 was the only peptide that significantly destabilised the neutral membrane (DMPC), while all four peptides induced destabilisation of the negatively charged membrane (DMPC/DMPG). On DMPC, citropin 1.1, maculatin 1.1 and caerin 1.1 bound irreversibly at low concentrations but caused a reversible drop in the bilayer order. In contrast to DMPC/DMPG, these three peptides caused a mass drop at the higher concentrations, which may correspond to insertion and bilayer expansion. The critical level of bound peptide necessary to induce membrane destabilisation (peptidelipid ratio) was determined and correlated with peptide structure. As the most lytic peptide, aurein 1.2 adsorbed strongly prior to dissolution of the bilayer. In contrast, the binding of citropin 1.1, maculatin 1.1 and caerin 1.1 needed to reach a critical level prior to insertion into the membrane and incremental expansion and disruption. Our results demonstrate that sequential events can be monitored in real-time under fluidic conditions to elucidate the complex molecular mechanism of AMP action. In particular, the analysis of birefringence in real time allows the description of a detailed mechanistic model of the impact of peptides on the membrane bilayer order. This article is part of a Special Issue entitled Interfacially Active Peptides and Proteins. Guest Editors William C. Wimley and Kalina Hristova.
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Base de dados:
MEDLINE
Assunto principal:
Peptídeos Catiônicos Antimicrobianos
/
Proteínas de Anfíbios
Limite:
Animals
País como assunto:
Oceania
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article