@article {364, title = {Calculating the Bulk Modulus for a Lipid Bilayer with Nonequilibrium Molecular Dynamics Simulation}, journal = {Biophys J}, volume = {82}, number = {3}, year = {2002}, note = {Ayton, Gary Smondyrev, Alexander M Bardenhagen, Scott G McMurtry, Patrick Voth, Gregory A R01 GM63796/GM/NIGMS NIH HHS/United States Research Support, U.S. Gov{\textquoteright}t, P.H.S. United States Biophysical journal Biophys J. 2002 Mar;82(3):1226-38.}, pages = {1226-38}, abstract = {

Nonequilibrium molecular dynamics (NEMD) computer simulations are used to calculated the bulk modulus for a dimyristoylphosphatidylcholine bilayer. A methodology is developed whereby NEMD can be effectively used to calculate material properties for complex systems that undergo long time-scale conformational changes. It is found that the bulk modulus upon expansion from a zero stress state agrees well with experimental estimates. However, it is also found that the modulus upon contraction from a zero stress state is larger. From a molecular perspective, it is possible to explain this phenomena by examining the molecular origins of the pressure response. The finding that the two moduli are not equal upon compression and expansion is in apparent contradiction to osmotic stress experiments where the area modulus was found to be the same upon expansion and contraction. This issue is addressed.

}, keywords = {Algorithms Computer Simulation Lipid Bilayers/*chemistry Osmosis Protein Conformation Temperature Time Factors Water/chemistry}, doi = {10.1016/S0006-3495(02)75479-9}, author = {G. Ayton and Smondyrev, A. M. and Bardenhagen, S. G. and P. McMurtry and G. A. Voth} }