Abstract
The electrostatics of solvent and lipid bilayer interfaces are investigated with the aim of understanding the interaction of ions and charged peptides with biological membranes. We overcome the lacking dielectric response of hydrocarbon by carrying out atomistic molecular dynamics simulations using a polarizable model. For air-solvent or solvent-solvent interfaces, the effect of polarizability itself is small, yet changes in the fixed atomic charge distribution are responsible for substantial changes in the potential. However, when electrostatics is probed by finite solutes, a cancellation of dominant quadrupolar terms from the macroscopic and microscopic (solute-solvent) interfaces eliminates this dependence and leads to small net contributions to partitioning thermodynamics. In contrast, the membrane dipole potential exhibits considerable dependence on lipid electronic polarizability, due to its dominant dipolar contribution. We report the dipole potential for a polarizable lipid hydrocarbon membrane model of 480-610 mV, in better accord with experimental measurements.
| Original language | English (US) |
|---|---|
| Article number | 185101 |
| Journal | Journal of Chemical Physics |
| Volume | 132 |
| Issue number | 18 |
| DOIs | |
| State | Published - May 31 2010 |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry
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The electrostatics of solvent and membrane interfaces and the role of electronic polarizability. / Vorobyov, Igor; Allen, Toby W.
In: Journal of Chemical Physics, Vol. 132, No. 18, 185101, 31.05.2010.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The electrostatics of solvent and membrane interfaces and the role of electronic polarizability
AU - Vorobyov, Igor
AU - Allen, Toby W.
PY - 2010/5/31
Y1 - 2010/5/31
N2 - The electrostatics of solvent and lipid bilayer interfaces are investigated with the aim of understanding the interaction of ions and charged peptides with biological membranes. We overcome the lacking dielectric response of hydrocarbon by carrying out atomistic molecular dynamics simulations using a polarizable model. For air-solvent or solvent-solvent interfaces, the effect of polarizability itself is small, yet changes in the fixed atomic charge distribution are responsible for substantial changes in the potential. However, when electrostatics is probed by finite solutes, a cancellation of dominant quadrupolar terms from the macroscopic and microscopic (solute-solvent) interfaces eliminates this dependence and leads to small net contributions to partitioning thermodynamics. In contrast, the membrane dipole potential exhibits considerable dependence on lipid electronic polarizability, due to its dominant dipolar contribution. We report the dipole potential for a polarizable lipid hydrocarbon membrane model of 480-610 mV, in better accord with experimental measurements.
AB - The electrostatics of solvent and lipid bilayer interfaces are investigated with the aim of understanding the interaction of ions and charged peptides with biological membranes. We overcome the lacking dielectric response of hydrocarbon by carrying out atomistic molecular dynamics simulations using a polarizable model. For air-solvent or solvent-solvent interfaces, the effect of polarizability itself is small, yet changes in the fixed atomic charge distribution are responsible for substantial changes in the potential. However, when electrostatics is probed by finite solutes, a cancellation of dominant quadrupolar terms from the macroscopic and microscopic (solute-solvent) interfaces eliminates this dependence and leads to small net contributions to partitioning thermodynamics. In contrast, the membrane dipole potential exhibits considerable dependence on lipid electronic polarizability, due to its dominant dipolar contribution. We report the dipole potential for a polarizable lipid hydrocarbon membrane model of 480-610 mV, in better accord with experimental measurements.
UR - http://www.scopus.com/inward/record.url?scp=77952680504&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77952680504&partnerID=8YFLogxK
U2 - 10.1063/1.3402125
DO - 10.1063/1.3402125
M3 - Article
AN - SCOPUS:77952680504
VL - 132
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 18
M1 - 185101
ER -