Effect of ions on a dipalmitoyl phosphatidylcholine bilayer. a molecular dynamics simulation study.
The effect of physiological concentrations of different chlorides on the structure of a dipalmitoyl phosphatidylcholine (DPPC) bilayer has been investigated through atomistic molecular dynamics simulations. These calculations provide support to the concept that Li+, Na+, Ca2+, Mg2+, Sr2+, Ba2+, and Ac3+, but not K+, bind to the lipid-head oxygens. Ion binding exhibits an influence on lipid order, area per lipid, orientation of the lipid head dipole, the charge distribution in the system, and therefore the electrostatic potential across the head-group region of the bilayer. These structural effects are sensitive to the specific characteristics of each cation, i.e., radius, charge, and coordination properties. These results provide evidence aimed at shedding some light into the apparent contradictions among different studies reported recently regarding the ordering effect of ions on zwitterionic phosphatidylcholine lipid bilayers.
Cordomí
Arnau
A
Department of Chemical Engineering, Technical University of Catalonia (UPC), Av. Diagonal 647, 08028 Barcelona, Spain.
Edholm
Olle
O
Perez
Juan J
JJ
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry; D003198:Computer Simulation; D007477:Ions; D008051:Lipid Bilayers / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D012984:Software
D002712:Chlorides; D007477:Ions; D008051:Lipid Bilayers; D008670:Metals; D015060:1,2-Dipalmitoylphosphatidylcholine; D010100:Oxygen