|
|
A Quantitative Model for the All-or-None Permeabilization of Phospholipid Vesicles by the Antimicrobial Peptide Cecropin A
- Article from:
-
Biophysical Journal
- Article date:
-
March 1, 2008
- Author:
- Gregory, Sonia M; Cavenaugh, Allison; Journigan, Velvet; Pokorny, Antje; Almeida, Paulo F F
|
Copyright informationCopyright Biophysical Society Mar 1, 2008. Provided by ProQuest LLC. (Hide copyright information)
|
ABSTRACT
The mechanism of the all-or-none release of the contents of phospholipid vesicles induced by the antimicrobial peptide cecropin A was investigated. A detailed experimental study of the kinetics of dye release showed that the rate of release increases with the ratio of peptide bound per vesicle and, at constant concentration, with the fraction of the anionic lipid phosphatidylglycerol in neutral, phosphatidylcholine membranes. Direct measurement of the kinetics of peptide binding and dissociation from vesicles revealed that the on-rate is almost independent of vesicle composition, whereas the off-rate decreases by orders of magnitude with increasing content of anionic lipid. A ...