Publication: Binding free energy and counterion release for adsorption of antimicrobial peptide lactoferricin B on POPG lipid bilayer
All || By Area || By Year| Title | Binding free energy and counterion release for adsorption of antimicrobial peptide lactoferricin B on POPG lipid bilayer | Authors/Editors* | V. Vivcharuk, B. Tomberli, I.S. Tolokh and C.G. Gray |
|---|---|
| Where published* | Phys. Rev. E |
| How published* | Journal |
| Year* | 2009 |
| Volume | 80 |
| Number | |
| Pages | 031911 |
| Publisher | |
| Keywords | |
| Link | |
| Abstract |
Molecular dynamics (MD) simulations are used to study the interaction of an anionic palmitoyl- oleoyl-phosphatidylglycerol (POPG) bilayer with the cationic antimicrobial peptide bovine lacto- ferricin (LFCinB) in a 100 mM NaCl solution at 310 K. The interaction of LFCinB with a POPG bilayer is employed as a model system for studying the details of membrane adsorption selectivity of cationic antimicrobial peptides. Seventy eight 4 ns MD production run trajectories of the equili- brated system, with six restrained orientations of LFCinB at thirteen different separations from the POPG membrane, are generated to determine the free energy profile for the peptide as a function of the distance between LFCinB and the membrane surface. To calculate the profile for this relatively large system, a variant of constrained MD and thermodynamic integration is used. A simplified method for relating the free energy profile to the LFCinB-POPG membrane binding constant is employed to predict a free energy of adsorption of -5.4 ± 1.3 kcal/mol and a corresponding max- imum adsorption binding force of about 58 pN.We analyze the results using Poisson-Boltzmann theory. We find the peptide-membrane attraction to be dominated by the entropy increase due to the release of counterions and polarized water from the region between the charged membrane and peptide, as the two approach each other. We contrast these results with those found earlier for adsorption of LFCinB on the mammalian-like palmitoyl-oleoyl-phosphatidylcholine (POPC) membrane. |
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