Molecular dynamics simulation of dipalmitoylphosphatidylcholine membrane with cholesterol sulfate.
Using the molecular dynamics simulation technique, we studied the changes occurring in a dipalmitoylphosphatidylcholine (DPPC):cholesterol (CH) membrane at 50 mol% sterol when cholesterol is replaced with cholesterol sulfate (CS). Our simulations were performed at constant pressure and temperature on a nanosecond time scale. We found that 1) the area per DPPC:CS heterodimer is greater than the area of the DPPC:CH heterodimer; 2) CS increases ordering of DPPC acyl chains, but to a lesser extent than CH; 3) the number of hydrogen bonds between DPPC and water is decreased in a CS-containing membrane, but CS forms more water hydrogen bonds than CH; and 4) the membrane dipole potential reverses its sign for a DPPC-CS membrane compared to a DPPC-CH bilayer. We also studied the changes occurring in lipid headgroup conformations and determined the location of CS molecules in the membrane. Our results are in good agreement with the data available from experiments.
Smondyrev
A M
AM
Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina 27599, USA.
Berkowitz
M L
ML
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D055592:Biophysical Phenomena; D001703:Biophysics; D002784:Cholesterol / Q000737:chemistry; D002788:Cholesterol Esters / Q000737:chemistry*; D019281:Dimerization; D006860:Hydrogen Bonding; D008051:Lipid Bilayers / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D013816:Thermodynamics
D002788:Cholesterol Esters; D008051:Lipid Bilayers; D015060:1,2-Dipalmitoylphosphatidylcholine; D002784:Cholesterol; C007045:cholesteryl sulfate